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Definitive Technology StudioMonitor 45

Bookshelf speaker

54 Reviews | 1 question - 5 answers

Item # 735SM45

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Was: $199.99

Special Purchase: -$100.00

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Our take on the Definitive Technology StudioMonitor 45

Definitive Technology's StudioMonitor 45 packs an astonishingly big punch into a surprisingly small package. It should — it's the result of more than 20 years of research and development by Definitive in their quest to create speakers with a perfect balance of style, utility, and performance.

Precise, potent sound for tight spaces

Definitive Technology's StudioMonitor 45 packs an astonishingly big punch into a surprisingly small package. It should — it's the result of more than 20 years of research and development by Definitive in their quest to create speakers with a perfect balance of style, utility, and performance.

Each rock-solid cabinet features an advanced 5-1/4" mid/bass driver that delivers plenty of impact and detail, plus a 1" pure aluminum dome tweeter for crisp, extended highs that shimmer. If you're a music enthusiast short on living space, these compact gems should be high on your list of speakers to consider.

" In spite of its almost laughably low price, the SM45 is a speaker that demands to be taken seriously…they were unexpectedly full-bodied and offered an astonishing amount of bass reach (down into the upper 30Hz region)—reach few other small monitors can match. …it provides giant helpings of musical richness, relaxation, and enjoyment at a ridiculously modest price. For these reasons and many more, Definitive's SM45s are a no-brainer recommendation for music lovers whose sights are set high, but whose budgets are limited."

— From Chris Martens' review in The Absolute Sound, April, 2013

Definitive Technology StudioMonitor 45

Definitive's second-generation patented BDSS driver with Linear Response Waveguide™ technology gives this speaker exceptional sound quality.

High-tech driver design for impressive performance

The StudioMonitor 45s are chock full of technology that's also found in Definitive's top-of-the-line speaker models. Its 5-1/4" mid/bass driver uses their latest Balanced Dual Surround System (BDSS) driver design, which places a surround on both the outer and inner edge of the speaker cone. This helps the cone remain more stable as it moves, resulting in clearer, more accurate sound — even at high volume levels. The '45's mid/bass driver also gets Definitive's second-generation Linear Response Waveguide™. This mushroom-shaped post in the center of the cone smooths off-axis frequency response for broad, even sound dispersion and a more realistic sonic "image." That means every listener in the room gets to hear balanced, open sound with lifelike vocals and instruments.

Crisp, sparkling highs

Definitive also equipped the StudioMonitor 45 with their latest 1" pure aluminum dome tweeter. This advanced driver is first heat-treated to relax the crystal structure of the metal, then coated with a ceramic that helps produce clear, sparkling highs without a trace of edginess. You'll easily hear the subtle high-frequency details in your music, like the sound of wire brushes gently sweeping the snare head, or the bell-like ring of a brass cymbal.

pure aluminum dome

A second-generation pure aluminum dome tweeter yields smooth, extended treble.

It's all in the details

Definitive paid close attention to other important design elements, too — both visible and hidden. At its heart, the StudioMonitor 45 uses a sophisticated crossover network with audiophile-grade components that include over-sized inductor coils and Mylar film capacitors. These give you a smoother, flatter frequency response, more powerful dynamics, and faster transients, for sound with real presence and immediacy. Sturdy, vault-like cabinet construction also plays a big role in this speaker's performance. The '45's well-damped, cross-braced enclosure features a specially contoured front baffle with tapered sides to minimize diffraction and vibrations that can color your sound and reduce accuracy. Plus its rear-firing, double-flared port is specially designed to enhance low-frequency impact, while keeping bass distortion low.

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Did you know?
Your new speakers will probably sound better after several weeks of use than they do right out of the box. That's because the material surrounding the woofers will loosen up, allowing the drivers to move more fully. Definitive Technology estimates a break-in period of 24 to 48 hours of playback before the speakers will deliver optimum sound quality. For more information and helpful tips, check out this article from Definitive's website about conditioning your speakers.

Product Highlights:

  • bass-reflex (ported) design
  • second-generation Balanced Dual Surround System (BDSS) 5-1/4" mid/bass woofer delivers clear, accurate sound at high volumes
  • Linear Response Waveguide technology smooths off-axis frequency response for broad, even sound dispersion and more realistic imaging
  • second-generation 1" pure aluminum dome tweeter for clear, extended highs
  • crossover network features oversize inductors and premium Mylar capacitors for audiophile-grade sound quality
  • non-resonant braced construction ensures clean, uncolored sound
  • wood grain matte black enclosure with high-gloss, anti-diffraction baffle and detachable cloth grille
  • frequency response: 35-30,000 Hz
  • sensitivity: 90 dB
  • impedance: 8 ohms
  • recommended amplifier power: 20-150 watts
  • one pair of heavy-duty 5-way binding posts for convenient and secure wire termination
  • 11-5/8"H x 6-3/4"W x 11-5/8"D
  • warranty: 5 years
  • Our 60-day money-back guarantee

What's in the Box:

  • Black bookshelf loudspeaker
  • Detachable black cloth grille
  • 4 Self-adhesive rubber feet
  • Owner's Manual
  • Online Product Registration card

Just breaking in these newly purchased speakers but so far the sound is excellent!

Jack, Dahlonega, GA


Definitive Technology StudioMonitor 45 Reviews

Average Customer Review(s):

(54 Reviews)

Great sound, style, and size

RAYMOND from Columbus, OH on 6/11/2018

Crutchfield Customer Review (What's this?)

I bought these speakers because I have have a very small living room, and not much space. These speakers are the perfect, price, size, and work well with my NAD receiver/stereo. The sound is much more than I expected with speakers this size. I highly recommend these speakers when space is important, and want great sound.

Pros: Range is great and is a quality built speaker.

Cons: I do not have any cons for prospective buyers

embelishing the sound in my garage

Ron from Millstadt, IL on 6/4/2018

Crutchfield Customer Review (What's this?)

As usual, ordered and delivered on time and in perfect condition. That is par for the course with Crutchfield. I needed additional speakers in an over-sized 3 car garage to add to 2 Bose bookshelf speakers. These Definitive Tech StudioMonitor 45 were just the ticket. I placed them on the far sides of the garage and the immersing of music permeated the entire garage. These speakers enhanced the high and mid-range with a clear and authentic sound. Surprisingly, I am even satisfied with their base composition. All in all a wise addition to the sound of music in my garage. I am happy with the results.

Pros: Great high and mid range sound with acceptable bass output. Very clear and concise sound generated when listening to 50's through 70's music.

Cons: none

Definitive Technology StudioMonitor 45

Jack from Dahlonega, GA on 6/3/2018

Crutchfield Customer Review (What's this?)

Just breaking in these newly purchased speakers but so far the sound is excellent!

Pros: Clear, precise sound from a relatively small bookshelf speakers.

Cons: None so far.

Definitive Technology StudioMonitor 45

Anonymous from Apex, NC on 6/3/2018

Crutchfield Customer Review (What's this?)

Loved the sound. Can't beat these for the money.



'WOW' sound out of box, but with some shortcomings

Michael from Chattanooga, TN on 6/3/2018

Crutchfield Customer Review (What's this?)

These speakers, right out of the box, wowed me. But the more I listened to them, I began to detect some flaws. My reference speaker is the KEF LS50 (regarded by many as THE best speaker of it's type and size). At $1300 a pair (LS50), not fair to compare to SM45's...okay that's true. So I bought and compared them to the ELAC Debut B5. Here's what right with the SM45's IMO. AMAZING out of the box sound that only 'eased' as they broke in--for this price! They have MUCH better low frequency extension than most (if not all) of the competitors and image very well indeed. The narrow front baffle reduces reflections contributing to the SM45's center image depth of field and detectable front-to-back dimensionality (e.g. vocalist in front of snare) on the right recordings. Fit and finish is much better than other speakers at this price--including the ELAC B5's. And here's what are the only real shortcomings IMO. First, the tweeter. Ya, I know, much has been made about 2nd generation aluminum tweeter in the SM45's. And it does some things well. But if you think of a cymbal crash in three parts--attack, body, decay--there is a raggedness about the 'attack' on this tweeter that annoyed me the more I listened to them. Back-to-back comparisons with the KEF LS50 and ELAC B5's on several types of music confirmed. My daughters heard the same thing, so it's not just me. Planning to keep the B5's

Pros: - Deep bass for a speaker this size - Excellent fit and finish - Better imaging than most

Cons: - A 'raggedness' in tweeter on certain instrument attacks (detectable by some, maybe not by other) - Very deep cabinet

Definitive Technology StudioMonitor 45

Anonymous from Rochester, NY on 6/2/2018

Crutchfield Customer Review (What's this?)

Good size for fitting in anywhere, with crisp highs and more bass presence than you expect!



Definitive Technology StudioMonitor 45

Anonymous from Butler, PA on 5/30/2018

Crutchfield Customer Review (What's this?)

For the money this speaker by far beats any out there on the market. For a speaker this small the frequency response is extremely wide. Where can you get a speaker that goes this low for even three times the cost. High end audio at an affordable price. The company also makes its own drivers. I am not surprised. Definitive Technologies has a stellar reputation having had Sandy Gross as one of its founders.



Excellent bookshelves!

John from Hamilton, NJ on 5/23/2018

Crutchfield Customer Review (What's this?)

My 45's Sound terrific. Good bass for the size. They are deep speakers. 3" deeper than my Klipsch R-15M's. The Klipsch have an edge in sensitivity also. A difference that is noticeable. Overall great sound for the price and size.



Great range and clear sound while handling all the volume I push.

Jim from Topeka, KS on 5/16/2018

Crutchfield Customer Review (What's this?)

These did not disappoint! The sound in the room is fantastic and is everything I wanted.

Pros: Looks, performance, size

Cons: none

Great Value - Good Sound

Tom from Villa Rica, GA on 5/1/2018

Crutchfield Customer Review (What's this?)

Great little speaker and an excellent value if you catch them on sale. These speakers have a neutral and balanced sound that I desired. The range is good for a small bookshelf speaker. I use them in a our bedroom as a second zone for music but toyed around with them as fronts in my surround sound paired with sub. We're looking to move and downsize and these speakers definitely fit the bill. I plan on getting a couple more to replace some other larger speakers.

Pros: Neutral and balanced sound, great value

Cons: Not much of a con, however the speakers are a bit long in the depth dimension. For bigger spaces will need to be paired with a sub.

Definitive Technology StudioMonitor 45

Anonymous from Butler, PA on 3/27/2018

Crutchfield Customer Review (What's this?)

This speaker is about the best bang for the buck I've seen yet. Sound stage, huge! The imaging is real and wide. Wide audio spectrum. I would call it a full range speaker. It works best with a 140-150 watt amplifier. Get some good electronics behind it and you will be amazed. Happy listening.



Definitive Technology StudioMonitor 45

Anonymous from Saint Louis, MO on 2/16/2018

Crutchfield Customer Review (What's this?)

couldn't be more pleased with the speakers . well made, solid cabinet, great sound, and a nice compact overall dimension for easy placement in the room. I would recommend to a friend.



Excellent Sound!

Dana from Nitro, WV on 2/6/2018

Crutchfield Customer Review (What's this?)

I have had a set of StudioMonitor 55's for years and they are so good I knew what to expect from the 45's. I use the 45's as my side channel for Dolby surround but they really come to life when I turn my Marantz to multi channel stereo. The response is excellent, the sound in my opinion is unmatched by other makers' smaller speakers. At the sale price, they are a must! Don't wait too long or they will be gone.

Pros: Sound and size

Cons: None

Very nice

john from Stratford, CT on 2/1/2018

Crutchfield Customer Review (What's this?)

Tyler recommended these. After break in ,that he told me about,could not be happier. Do use with sub but is set at lowest setting.

Pros: Sound great once broken in. Well made and I like look.

Cons: I use with cover off and does have holes.

Perfect fit

paul m from Mars, PA on 12/15/2017

Crutchfield Customer Review (What's this?)

Hooked these up to a onkyo 8260 receiver. A small footprint was important to my wife cause we have a older house with small rooms by todays standards. We are a interesting couple I've been blessed with incredible eyesight better than 20/20 she has been blessed with equally incredible hearing and she loves her music sometimes been known to crank it up. First time she listened said these are really nice the vocals are really clear she can hear the music instruments that she wasn't hearing with our old system. She must be picking up sounds on the fringe of my hearing so if she is saying these are good take it to the bank

Pros: Perfect for smaller rooms

Cons: None

Definitive StudioMonitor 45

Tom from Roanoke, VA on 11/29/2017

Crutchfield Customer Review (What's this?)

As usual Crutchfield advisor and service were excellent. I wanted surround speakers with a good low frequency response because I didn't want, or have room for, a sub-woofer. I also wanted a speaker with higher than average sensitivity. Technically, the SM-45s met my criteria. Initially I placed the speakers on the floor toward the rear of my recliner love seat. I was not impressed, even after conditioning (breaking them) in a few days. I decided to lift the speakers up by placing them on a 9-inch foot stool. I immediately heard a difference. Although the Definitive Technology speaker stands look nice, I thought the manufacturer's pricing was significantly overpriced, so I ordered generic glass/metal 18-inch speaker stands from another vendor, which positioned the SM-45s tweeters close to ear level. Now the speaker is impressive; providing clean, clear sounds and smooth bass. For front speakers, I would go up a level or two to get the larger woofer. I would purchase Definitive Technology speakers in the future without hesitation.

Pros: Clean, clear sound. No sound coloration. Well constructed.

Cons: Definitive Technology pricing for their matching speaker stand.

Definitive StudioMonitor 45

Anonymous from San Antonio, TX on 11/14/2017

Crutchfield Customer Review (What's this?)

After weeks of researching and reading bookshelf speaker reviews from numerous sites, I arrived at Crutchfield. Tyler, my technical adviser, recommended the DF 45's after giving him my price range. My 7 year old pickle jar size Polk's are no comparison to the 45's. A multi-instrument ensemble sounded cramped with the Polk's. Now, the DF's define each instrument with clarity. Each instrument is distinguishable as if in a concert hall, instead of crammed in a shoe box. Great speakers for the price. There was no bias or pressure from Tyler in the exchange of several emails. Thank you Crutchfield!



Nice small speakers

Reviewer from Chesterfield, VA on 11/14/2017

Crutchfield Customer Review (What's this?)

Jovial sounding speakers. Easy to set up. Have not broken in yet. My research showed this speaker has the best bang for the buck.

Pros: Smart looking.


Excellent sound for their size!

GARRY D from Battle Creek, MI on 10/22/2017

Crutchfield Customer Review (What's this?)

The Definitive Technology Studio Monitor 45 speakers are an excellent value. Crutchfield had these for an outstanding price and they were delivered quickly. They look great with or without the front covers hiding the drivers. They handle a good amount of power with ease. They do sound a little tight and flat at first, but they loosen up and smooth out after a little break in. I have about twenty or so hours on them and the bass has increased, along with a more detailed, smoother and larger sound stage. The bass and overall range of these small speakers will surprise you. I bought these for a smaller work shop and they fit perfectly and fill the room with quality sound. If you have the room and budget, I would recommend the larger studio monitor 55 or 65 series, for even better bass, but these are awesome sounding speakers for the size and cost involved. A subwoofer could be added for even more dynamic sound and lows, but I am quite happy with these on their own for my work shop.

Pros: Sound stage and range. Power handling. Compact size. Great looks and price.

Cons: Rear bass port not ideal, if they are too close to the back wall. No bi-wire speaker terminals.

The Best Speakers I Have Ever Bought!

Scott from Tampa, FL on 9/22/2017

Crutchfield Customer Review (What's this?)

After recently upgrading my receiver (to an Onkyo TX-RZ610) I still felt there was something lacking in the detail of what I was hearing from my Klipsch Reference R-15M. Looking at the specs of many speakers, I liked what I saw in the Studio Monitor 45. On paper, it certainly had a more expansive range. Purchased from the Open box\Scratch and dent at an incredible savings (and the speakers arrived in perfect, as new condition) I figured it was a no-lose situation. I have purchased a lot, and I do mean A LOT, of speakers over the decades. I've paid 5X or more for speakers than I paid for these. I have purchased speakers big enough to require a dolly to move them. I've bought "out of sight out of mind) speaker systems. None of these come close to the ear-joy I got when I fired these speakers up for the first time. Every improvement I anticipated would be present was there, and then some. These speakers will transform your audio experience.

Pros: Detailed, expansive sound Incredible price Bookshelf size with floor-standing performance


Definitive Technology StudioMonitor 45

Don from Beaverton, OR on 9/18/2017

Crutchfield Customer Review (What's this?)

I was looking for some small speakers to use as primary speakers in a small space. These seem to be doing the job quite well. I would describe the sound as clean and accurate. Bass, while not as strong as a full size unit, is surprisingly good and much better than most speakers this size. If you want to rattle the windows with a special effects movie, these are not going to do it by themselves, but for a movie with an orchestral score or a music CD at moderate volume levels, I find these very satisfactory even without a sub woofer and noticeably better than the old speakers they are replacing. For the size and price I think they are very good. I am happy with the purchase.

Pros: Good sound Small size Reasonable price

Cons: none really

Definitive Technology StudioMonitor 45

Alfred from Tuscaloosa Alabama on 8/17/2017

Crutchfield Customer Review (What's this?)

The definitive studio monitor 45 speakers are fantastic speakers great sounds great price and just the size I need I highly recommend these speaker

Pros: Fantastic sound quality

Cons: None at all

Love the sound.

Michael from Decatur, GA on 2/5/2017

Crutchfield Customer Review (What's this?)

I decided to update and upgrade my music system from a simple R, L, subwoofer set-up to a fuller home theater system. After finally buying a AV receiver I could now add a center channel. I settled on the DT ProCenter 1000 speaker and was delighted by the addition. My next step was to upgrade the main speakers and after much research and consideration over cost, size, quality, and what my actual needs were, I picked the StudioMonitor 45s. I live in a condo with shared walls and the space is not large, so I don't need a loud system with big thumping bass, and this system will be used for listening to music as much as it will be used for movies and TV. Loudness is not important but accuracy and natural sounding reproduction is. When I got them I first hooked them up to my old receiver to try them out as stand alone speakers with a variety of music. I was impressed. They hit the mark on all counts. Great bass, great highs, I get details and timbres and overtones that I wasn't hearing before. I think a subwoofer is beneficial but not an absolute necessity. They are now hooked up with the center channel and new receiver and the sound is amazing. I could have spent more and got incrementally "better" sound (it's all subjective anyway), but I am thrilled with these speakers and I'm not having to dread the coming CC bill. I'd recommend Def Tech to anyone who is looking for something better than the mass market brands but don't want to spend a huge fortune to get it. .

Pros: Great accurate sound, nice design and build quality, price

Cons: none

Better Deals ...

MYKAL from California on 12/7/2016

DT's are ofcourse pedigree speakers. But, in this price range they cannot compete with ELAC B5, B6, etc. It's not even a close competition. For the price, buy a pair, not 0ne, a pair of ELAC B5's. To appreciate DT you hafta buy an upper level pair model & up. Otherwise, look to ELAC B5, JBL 230 & you'll be thanking me.

Pros: They're DT's.

Cons: Price to real world performance.

Amazing Speaker and Even Better Service

Joseph from Clark, NJ on 11/11/2016

Crutchfield Customer Review (What's this?)

I have always loved Definitive Technology speakers although I never owned any. After speaking to the sales staff at Crutchfield they very highly recommended the SM45. I was told that there was a 60 day return policy but I still wanted to listen in person. I went to my local retailer to listen and was blown away. Of course, I then went back to order with Crutchfield because of their customer service and knowledgeable team. I have ordered many things with them over the years and they have always been top notch. When I got these speakers home and set up the sound was even better than when I previously heard them. Awesome speaker, great soundstage, amazing bass for a speaker this size. Don't waste your time looking at other speakers. Saw

Pros: Sound, bass, sound stage, clarity, price

Cons: None!!!

Definitive Technology StudioMonitor 45

Jose R. from Coamo, PR on 9/1/2016

Crutchfield Customer Review (What's this?)

it is a joy enjoy from the lowest frequency to the highest frequency in a speaker that their appearance is not so and less to the cost of them !!!



StudioMonitor 45's

Jim B from Brentwood, TN on 8/23/2016

Crutchfield Customer Review (What's this?)

Purchased these as the rear channel for a 7.1 system. Excellent size and performance for the price. Sounded clean and crisp out of the box. Provided the detailed enveloping sound for my home theatre system. Voice matched to my Studio Monitor 55's mid channel and my Studio Monitor 65's front channel. Def Tech makes quality speakers. Highly recommend this speaker for rear channel. Powered by a Denon AVR-3311ci.

Pros: Excellent sound reproduction for the price.

Cons: None.

Def Tech 45s great value

Shubie from Stockton, CA on 8/4/2016

Crutchfield Customer Review (What's this?)

purchased these to upgrade 20 year old speakers in my den. I was greatly surprised by the sound quality. The bass is especially tight for such a small speaker. I feel the bass is better than the Bose system with sub that I have in another room. I think that says a lot. These speakers have great full range sound. Do not hesitate to buy them.

Pros: small size, great sound, good price

Cons: none so far

Definitive Technology StudioMonitor 45

Robert from Phoenix, AZ on 5/5/2016

Crutchfield Customer Review (What's this?)

Nice speakers



Definitive Technology StudioMonitor 45 Speakers

Rabi51 from PA on 4/1/2016

Crutchfield Customer Review (What's this?)

I very much like these speakers. Having been familiar with the Definitive Technology products all ready I knew that what I wanted was their product. The speakers though small have a very good bass and treble sound. I wanted something that would allow my older Sony SE system to bring the sound upstairs and still sound great. These speakers definitely fit that bill. A little pricey but you get what you pay for.

Pros: Very good full range of sound from the bass to the treble. For their size I was surprised to see the heft of the product. Very well made and a nice appearing product!

Cons: None that I can see so far.


Skyking from kokomo, IN on 3/24/2016

Crutchfield Customer Review (What's this?)

These studiomonitor 45 Denifinetive speakers sound super good. I an very pleased with them.

Pros: Small size very great sound.

Cons: None

Crystal Clear

Randall from denver, CO on 3/12/2016

Crutchfield Customer Review (What's this?)

Well I live in a condo so I was looking for something loud & clear but not as much bass. Im so happy I picked these speakers up!! For bookshelf speakers they sound amazing.

Pros: Crystal Clear,Great for a smaller place.

Cons: If you want rumbling effects your gonna wanna get a subwoofer,But in my case I don't need a sub.

Really excellent, welcome to the new century

Richard from albany, NY on 3/5/2016

Crutchfield Customer Review (What's this?)

I love these speakers. I had Definitive column speakers that were 4 feet tall, kind of clumsy but great sound for 14 years. I wanted to clean up my living room and go for smaller speakers I could hide, with a receiver that played CDs. Your staff recommended the perfect rig for me. I am really happy with the sound and the functionality of a modern receiver. If you are thinking about buying, talk to the staff for a recommendation, I never would have figured this out on my own. The staff choice was perfect.

Pros: sweeping sound with a good amount of bass, surprisingly. The overall tone is good. I filled a pretty large living room with sound no problem. I'm very happy with these speakers, and I am pretty picky.

Cons: none.

Great Speakers, Great Price!!

Jeff from Earlville, New York on 2/1/2016

Crutchfield Customer Review (What's this?)

I needed smaller speakers for my kitchen which are a second set of speakers for another room's stereo set up. I called my Crutchfield Rep, Buzzy, who previously steered me to Definitive Technology Speakers when I was setting up a new Home Theater System last year. The Home Theater and my Stereo system are powered by Onkyo receivers. The Home Theater speakers are Definitive Technology ProCinema 400 System Speakers---and very, very happy with their output for a smaller living room, like more than adequate. So when I wanted to redo my stereo system I called my rep at Crutchfield again and he put me into another set of Definitive Technology speakers but this time called Definitive Studio Monitor 45's. While the Home Theater Speakers function with a subwoofer the Studio Monitor 45 set are without subwoofer but you would never know it as it pounds like my Home Theater System with subwoofer. In other words, I highly recommend Definitive Technology speakers!!

Pros: Pros are included in my review

Cons: and cons are not mentioned in my review as I cannot think of any cons!!

Great Little Stereo Speakers

Mike H from NY on 12/17/2015

Crutchfield Customer Review (What's this?)

Sounds unbelievably large and articulate with ridiculously good bass, I'm more than satisfied

Pros: Relatively small speakers yield big, beautiful, clear sound, beautiful design, heavy and well constructed

Cons: Zip

Very happy with purchase

rodm from Maryland on 9/22/2015

Crutchfield Customer Review (What's this?)

These are excellent quality speakers. I have never owned a pair of Definitive Tech speakers before and new little about them. I couldn't be happier. The highs and mids are crystal clear with little or no scratchiness. The lows are actually quite good even as small as the bass speakers are. If you crave artificial boom boom in your music or TV, you'll want a sub, but otherwise I believe you'll be quite satisfied with these. Quality of construction seems quite good and they look very nice either with or without the grilles.

Pros: Excellent sound quality and construction.

Cons: None.

Great speakers

Manuel from Puerto Rico on 9/3/2015

Crutchfield Customer Review (What's this?)

The clarity and spaciousness of the sound from these speakers is excellent. To me they sounds as good as my Grado sr325e headphones! I placed them a couple of feet from the wall to get great bass. A bit large for a "bookshelf" speaker, but sound quality more than compensate for the size. They are also attractive and very well made.

Pros: Efficient. Excellent frequency response, great soundstage and clarity. Great construction quality. Low cost.

Cons: None so far.

This is a great speaker!

Jim E. from Washington on 12/20/2014

Crutchfield Customer Review (What's this?)

After listening to these speakers for about a month, I'm amazed at the clarity, imaging, and fullness of the sound. I don't want to gush over a $400 pair of speakers, but the sound is so clean and accurate that I find myself just wanting to keep listening. I appreciate them more and more as I continue to listen. There are musical nuances that I haven't noticed before in other speakers. Truly a pleasure to hear. I have no need of a sub with them. Thanks to Buzz for taking my order, and Crutchfield for making this an effortless and pleasant purchase!

Pros: I don't know of anything else this good at this price.

Cons: None.

Definitive Technology StudioMonitor 45

Anonymous from santa clara, ca on 11/6/2014

Crutchfield Customer Review (What's this?)

Excellent clarity



Studio 45 Spreakers - Great & Crutchfield Too

Wayne from Ark on 9/2/2014

Crutchfield Customer Review (What's this?)

Great sound for my small listening area. Speakers are impressive right out of the box but are getting more responsive after 8-10 hours use per day. Can't beat for the price. BTW - Can't beat Crutchfield either - they deliver customer satisfaction.

Pros: Small footprint but delivers great sound.

Cons: None

Definitive Technology StudioMonitor 45 Review

PeteD from Cape May, NJ on 9/1/2014

Crutchfield Customer Review (What's this?)

Excellent speakers for the money




Lance L. from New Orleans, La on 6/18/2014

I recommend this product due to clarity and natural sound paired up with a Yamaha AS 500. The treble is not tinny at all and the bass isn't too boomy. However one might consider pairing up with a Definitive Technology ProSub 1000, considering the price range of the subwoofer, if in a medium to larger room.

Pros: Size for smaller rooms, clarity, engineering design, natural sound.

Cons: Bass can be a little short without a sub.

Sound way better than you would expect for this price!

cellhead from Amery,WI on 5/5/2014

Crutchfield Customer Review (What's this?)

These speakers are amazing, unbelievable value for the money! I have a 9.1 surround system powered by a Yamaha RX-A720 Aventage receiver. Every speaker I had was Polk up until I bought these. I was concerned that they might not voice match my system but the reviews were so glowing I decided to give them a shot and I am so glad I did. I replaced my front "presence" speakers with these and the improvement in the overall sound of my system is beyond impressive. These speakers do everything well: great accuracy, stage depth imaging, etc. They are equally impressive for listening to music as they are for surround sound, adding so much depth and richness to the sound. Can't recommend them highly enough.

Pros: Acccuracy, dynamic range, sound stage, imaging, do everything well!

Cons: None, and the manufacturer says they sound even better after a few days of burn in, can't wait!!!

Big Sound Small Pakage

Robert from Greensboro, AL on 4/17/2014

Crutchfield Customer Review (What's this?)

These sound very good. Better bass than other speakers large or small. Someone said grills don't fit snug. Wrong! They fit very snug. It just takes extra effort to get them on all the way.



Perfect for our needs

TimM from Durham, NC on 4/11/2014

Crutchfield Customer Review (What's this?)

One of the three of us is a professional musician, another is a very active amateur. We make and hear a great deal of live music, and these speakers sound very accurate to all of us. Even without a sub-woofer, they deliver a full bass sound. They would be 5 stars but for the covering grilles that don't clip on quite snugly.



Definitive technology studio monitor 45

ogl from Terre Haute, In on 12/30/2013

Crutchfield Customer Review (What's this?)

excellent speakers, Highly recommended

Pros: excellent speaker that delivers. highs and lows are reproduced perfectly. A best buy!

Cons: none

Great sound in a great package

gnakasato from Louisville, KY on 12/8/2013

Crutchfield Customer Review (What's this?)

I placed these speakers on the bookshelves on each side of the fireplace in my 22-foot tall living room. And they have absolutely no trouble filling up the room with amazing sound clarity without distortion at maximum volume. I use them to listen to music and watch movies (TV above the matle). And I am very impressed. The amount of bass coming from them is impressive given their relatively small size. Even the Audyssey equalization system in my Onkyo "THX Ultra"-certified receiver detects them as "Full Range" (maybe because they are encased between levels on the bookshelves which helps increase the lower frequencies reproduction). The previous Mythos Gem XL (compact) speakers I had in the same location had a recommended crossover point of 120Hz by the same Audyssey MultiEQ system, so it's not all down to location. Big step up in sound clarity and reproduction. I use them with a subwoofer while setting their crossover point at 60Hz (per DT recommendations) and the fullness of sound is just about perfect. You will be hard pressed to beat that for $400 delivered. And unbeatable for close to $300 (I got open box ones and they arrived in mint condition). Highly recommended.

Pros: Excellent sound quality, amazing value, great looks, full range sound reproduction.

Cons: None, zero, nada.

DT StudioMonitor 45s

PB in VA from Northern Virginia on 9/23/2013

Crutchfield Customer Review (What's this?)

As I fully expected, DefTech delivers the goods again. I've owned 3 other DT speaker sets over the years, including the awesome Mythos STS towers, BP8s and StudioMonitor 450s and am always pleased with their performance. DT has long mastered the art of big bass from small enclosures, but have significantly improved their tweeters in recent years for more pleasing highs, making for better long-term listening. I needed small but relatively full range speakers for a recently-completed 20x16 exercise room so I purchased these along with Sanus NF30 stands. I paired with my 15 year old Adcom GFP-565 preamp and GFA 500 amp, total overkill at 200 wpc but a great way to break them in. I've since moved to a Yamaha A-S500 integrated which is really more appropriate for these speakers, with the bonus of an i-pod dock and subwoofer out to which I am adding a Polk PSW 111 to supplement the bass a bit. Right out of the box the StudioMonitor 45s visually impress with a slightly arched top and rock solid feel, fit and finish. The grills with the flimsy plastic plate at the bottom are the only design misfire in my opinion. Music comes across with as impressive detail and imaging as you could hope for at this modest price point, and they are remarkably full-range with great punchy bass. You simply can't go wrong with DT in general and the 45s in particular for a budget system - highly recommended! Oh, and Crutchfield ordering is seamless and shipping is super fast!

Pros: Attractive speakers, and remarkably full-range. Can handle the power and fill a room without strain. DT is renowned for bass output but are getting it right in the mids and on the top end as well these days with a more refined metal dome tweeter and improved crossovers. Binding posts are of high quality as well.

Cons: Grills have a flimsy plastic bottom nameplate that detracts from the otherwise nice aesthetic, but this is just a picky detail that has no bearing on performance.

2 Channel Goodness

JamieB from Long Island on 7/2/2013

Crutchfield Customer Review (What's this?)

My 20 year old got me to dust off the old turntable so he could play some new vinyls. I had been playing music through a modest 5.1 speaker system powered by a 10+ year old home theater receiver. I decided to build up a 2-channel music system and I needed better speakers. After a fair amount of research, I decided on the DefTech SM45s based on reviews and my budget. I paired them up with a separate pre-amp and amplifier combination and I could simply not be more impressed with the sound quality. They reproduced LPs, CDs and digital music with more clarity and depth than I would have thought possible for such compact, reasonably-priced speakers. At realistic music levels, they were crystal clear. The definition of cymbals, vocals and acoustic instruments was studio quality. I blasted them on 70's rock standards and they played cleanly even at uncomfortably loud volume levels. Their deep bass extension was completely unexpected despite the published specs.. There was well defined kick to drums and natural reproduction of acoustic and electric bass instruments. Mids and highs were well balanced. I discovered nuances to my music that I had forgotten or never knew were there. The new vinyls were amazing sounding...even though they were not always my genre. The ordering process was painless. The shipment arrived in 2 business days. I will NOT be using Crutchfield's return policy.

Pros: Great Sound quality. Quality/dollar ratio off the charts.

Cons: If your amp has the power, and you push beyond what you should, the mid-woofer can bottom out before you hear any other audible distortion.

Great Companion...

VictorA from San German, PR on 5/21/2013

Crutchfield Customer Review (What's this?)

You can use this beauties as the main and surrounds of a sub-sat system. I`m using them as surrounds with the sm-55 as the main. It`s a match made in heaven. Great sound and good bass for its size. Its ported design works great... Highly recomended...

Pros: Style, construction, performance

Cons: None

Very Pleasing Sound Quality

Bob L from Ballwin, MO on 1/2/2013

Crutchfield Customer Review (What's this?)

These speakers deliver very pleasing overall sound, especially given their size. I have them mounted on 30" stands which I highly recommend. My rating is based on owning many speakers over the years including currently a pair of Golden Ear Technology Triton Two speakers (very highly rated). I would buy the Def Tech Studio Monitor 45s again.

Pros: Great sound, build quality and finish. Very reasonable price for what you get.

Cons: None

Good stuff

Anonymous from san jose, ca on 11/9/2012

Crutchfield Customer Review (What's this?)

They sound terrific!!!! love the clarity, my main cause for purchase was in music listening, and they deliver loud, crisp sound



Audiophile Speakers For Sure

roscoe from Los Angeles on 11/7/2012

Crutchfield Customer Review (What's this?)

Awesome speakers for the size. Deep bass that is every bit as good as my JBL G300, I am upgrading to SM 65 & therefore my 45's have been returned to Crutchfield. Anyone who gets these speakers at an open box price is very lucky as they have been treated with TLC & are completely broken in.. Thanks Crutchfield for the 60 day mbg.


Cons: I am not to crazy about the gloss front but that is a secondary matter of personal preference.

Great Sound, Great Price - A Steal!

SV from Falls Church, VA on 8/22/2012

After the surrounds got worn out on the woofers and bass radiators of my old speahers, I got tired to listening to CDs on portable players and headphones. My music tasted go to classical and classic rock. My requirements: musical transparency. Add nothing, subtract nothing. Powerful response down to the very bottom (Pipe organs) to the very top from a whisper to a roar as required by the music, all at a price I can afford (low). After listening to several systems at various price ranges, I settled on the Def Tech SM 45s and a prosub 1000. The 45s are amazing! Excellent musical transparency, clarity, tonal balance, and a sound stage that is both wide and deep. The SM 45s could please me on almost all my recordings even without the subs. I played a classical guitar recording without the sub, and I could visualise the guitarist in my room. Yes, the sub adds the bottom end seamlessly, but the SM 45s played by themselves at a good sound level (and they will play loud) have a surprising amount of bass, especially considering their small size and low price. As I said - a bargain at twice the price, a steal at their price!

Pros: Great sound, wide & deep imaging, good looks, flexible placement options, very affordable

Cons: not a con really, just a result of their size: Lacking the only the very deepest of bass, but has more bass than you would believe from a speaker this small. If your receiver has a "Loudness" button, use it. If you don't need the bottom octave, buy them or buy a (very good) sub to go with them!


Hands-on research

Features and Specs

Enclosure Bass Reflex
Video Shielded No
Tweeter Type Dome
Tweeter Size (inches) 1
Midrange Size (inches) N/A
Woofer Size (inches) 5.25
Woofer Composition Polymer
Woofer Surround Rubber
Power Range 20-150
Sensitivity 90 dB
Impedance (Ohms) 8
Frequency Response 35-30k Hz
Connector Type 5-way post
Bi-amp Inputs No
Height (inches) 11-5/8
Width (inches) 6-3/4
Depth (inches) 11-5/8
Weight (pounds) 12.95
Mounting Bracket Included No
Recommended Stand Height (inches) 28.5"
Parts Warranty 5 Years
Labor Warranty 5 Years

Product Research

Driver Technology
Enclosure Design
Mounting Options

Driver Technology

StudioMonitor Series: The Definitive Technology StudioMonitor 45 is a compact bookshelf loudspeaker designed for use in audio/video entertainment systems. Because the StudioMonitor 45 is a true full-range speaker with extended low-frequency response, it delivers superb performance both as stand-alone speaker and when combined with a separate subwoofer. Due to its compact size, wide-range, high-power handling, and natural articulate clarity; the StudioMonitor 45 loudspeaker is ideal for use as front, center, or surround speaker in a home theater environment.

2-Way Loudspeaker: Each Definitive Technology StudioMonitor 45 loudspeaker features a 5.25" second generation BDSS midrange driver and a 1" pure aluminum dome tweeter.

  • 2nd Generation BDSS Midrange: The 5.25" midrange driver features Definitive's patented Balanced Double Surround System (BDSS) technology that supports the speaker cone at both the inner and outer edges allowing longer, more linear excursion for greater clarity and finely textured inner detail.
  • Pure Aluminum Dome Tweeter: The 1" tweeter is a pure aluminum dome, which has been heat-treated to relax the crystal structure and then coated with a ceramic to produce smooth, extended highs. A new patent pending Linear Response Waveguide smoothes off-axis frequency response and disperses sound over a wider area for crystal clear intelligibility for every listener in the room.

Phase-Coherent Crossover Networks: The crossover network is the real heart of a loudspeaker as it is responsible for perfectly blending together the sound of the various drivers into a musically seamless whole. The sophisticated crossover network design used in the StudioMonitor 45 loudspeaker features premium audiophile-grade components; such as oversized inductors and Mylar capacitors for audiophile-grade sound quality, with linear phase and frequency response. An integrated Zobel network flattens the impedance of the system so that even budget amplifiers will be able to drive the StudioMonitor 45 loudspeaker (although a premium amplifier will bring out all the performance it has to offer). As a result, the audio signal's phase coherence, transient response, and dynamic integrity is preserved for absolutely lifelike music and home theater reproduction in your home.

Enclosure Design

Non-Resonant/Low-Diffraction Cabinet: The Definitive Technology StudioMonitor 45 bookshelf loudspeaker employs a non-resonant MDF braced enclosure that ensures pure, uncolored performance. The specially contoured high-gloss baffle around the drivers and the tapered enclosure sides enhance sound quality by minimizing diffraction distortion.

Bass Reflex Design: The Definitive Technology StudioMonitor 45 loudspeaker utilizes a doubled-flared, rear-firing port for extended bass response with low distortion.

Note: Due to the rear-firing port, the speaker must be placed at least 2" from the wall.


Heavy-Duty Binding Posts: Each StudioMonitor 45 bookshelf loudspeaker is equipped with a pair of heavy-duty, binding post speaker terminals to attach your receiver's speaker wire. The binding post speaker terminals will accept bare wire (up to 10AWG), pin-connectors, spade-connectors, and banana-plugs (single only).

Color-Coded: The speaker's binding posts are color-coded (red/black) for easy identification between positive and negative.

Mounting Options

Table-Top Mounting: The StudioMonitor 45 loudspeaker can be simply placed on a bookshelf, table-top, or speaker stand (such as the Definitive Technology StudioStand, sold separately ). Four self-adhesive rubber feet are included to protect your furniture's surface.

Wall Mounting: The optional PinPoint heavy duty side-grip wall-mounting bracket (121AM41B, sold separately) can be used to wall mount the speaker.

Note: The speaker does not include any type of wall-mount bracket, threaded inserts, or keyhole slots.

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.

Q & A

Customer Q&A

Crutchfield asked  
Why did you buy this?

great reviews, good price, right size [ James  Jun 07, 2018 ]
I love definitive technology speakers, and this price was too good to pass up. [ Darrell F.  Jun 05, 2018 ]
At the sale price, these are the best value I could find. The combination of the extended bass response (35 hz claimed with a 5.25" woofer), an aluminum dome, plus Definitive reputation for sound quality and nearly 50 4/5 star reviews, made this speaker for me (actually for my daughter, a musician, for college). [ MICHAEL  May 20, 2018 ]
They're awesome [ Mario  May 17, 2018 ]
My second purchase of these speakers from Crutchfield. Love the sound and quality. [ Jeffrey  May 11, 2018 ]
Bass response seems excellent for this size of speaker. [ Mario  May 04, 2018 ]
Reviews, attractive pricing, Crutchfield experience over the years. [ ROBERT W  May 01, 2018 ]
I am using a pair of these speakers for my computer music through the AudioQuest Dragonfly DAC into my mid 90s Denon 2 channel receiver and they simply sound amazing. Upgrading my Bose Acoustimass 7 with non-matching rear speakers for my Denon AVR-3802 system. At a later time I'll look into a subwoofer (can't now due to migraine patient in the house). [ Gary  Mar 12, 2018 ]
Recommended by Definitive Technology for my particular and budget application. [ Armando  Mar 10, 2018 ]
I wanted a small speaker with good sound. Through research and reading reviews I decided to give these a try [ Krista  Jan 24, 2018 ]
Receive high praise from Crutchfield advisors and from comments from buyers. [ JOHN C  Jan 18, 2018 ]
Great reviews, size and pricing [ Edwin  Dec 03, 2017 ]
We have a pair of DT's BP7001SC home theater speakers. These are simply amazing. No hesitation in a "no-hear" purchase for their bookshelf speakers. [ Steven  Nov 27, 2017 ]
Fantastic speakers, I already have one set of these, at an amazing price! [ BRIAN  Nov 26, 2017 ]
The DefTech 45's were recommended last year by Wes for my old system but the Polk Tsi200's (also a good match) were on a good sale, so got those, now replacing some coffin size, original speakers with the DefTech's. [ Heidi  Nov 19, 2017 ]
Awsome price on a quality product [ James  Nov 14, 2017 ]
Great sound and great build quality. [ Kelvin  Oct 30, 2017 ]
Price, Specs, and I have a Definitive Tech Sub [ John  Oct 23, 2017 ]
Size and reviews. [ STEVEN  Oct 09, 2017 ]
prior experience with definitive tech speakers [ Gerald  Aug 12, 2017 ]
Excellent specs, great value! Even more so with this special sale! [ Donald  Aug 02, 2017 ]
Researched and for our application, looks like an excellent choice. Have past experience with Definitive Tech - extremely pleased. thus, buying more! [ Richard  Jul 04, 2017 ]
I chose these to go with my new DT center channel speaker, which I am very pleased with, and as an upgrade for my front R & L speakers. These are just the right size and price for my needs. [ Michael  Jan 22, 2017 ]
Meets our need for size and ohms and the reviews make it clear that these are outstanding value for bookshelf speakers. Plus, the credits for previous purchases, the superb website, and customer service keep us coming back. [ Diana  Nov 26, 2016 ]
Price + freq response for surrounds [ George  Nov 24, 2016 ]
Home stereo system upgrade [ FRANK  Oct 15, 2016 ]
sensitivity, frequency range, height of speaker enclosure, reviews, reputation, cost and ratings [ Gregory  Jul 17, 2016 ]
quantity and quality of reviews, price. [ Steven  Apr 14, 2016 ]
I heard these in a Store not gonna list the name. These speakers make amazing sound for being so small..Ive heard some pretty good speakers & after hearing these even I was impressed. If you want great sound but don't have the room for big speakers,These speakers are what your looking for. (35Hz to 30K Hz) That's better then most Tower Speakers. [ Randall  Mar 07, 2016 ]
Purchased because of the recommendation of an advisor. I wanted a smaller scale stereo, and he recommended these speakers with a receiver. [ Richard  Mar 01, 2016 ]
Compactness and overall value for money, considering the sound quality from the available reviews [ Benedict Amaebi  Feb 09, 2016 ]
Awesome Fr-Rep, nice size, good price. [ MARK  Jan 16, 2016 ]
Positive reviews by Stereophile and Absolute Sound [ Oliver Brent  Dec 18, 2015 ]

1 question already asked

My use: high quality, crisp, full range, bookshelf speakers for music in a 12x16 room; would not hesitate to buy them again for this purpose. Given their size (depth especially; approx. 7"W x 11"H x 11"D), I guess you have quite a bit of space in the room you are going to use them in as rear surrounds... Good luck! [ Glenn  Feb 08, 2018 ]
I have these set up as front speakers and I love them. They have plenty of bass and in a small room you could easily get by without a sub. I think they would be just fine as rear surrounds. [ Ronald Pezda  Feb 08, 2018 ]
Absolutely these are the best sounding bookshelf speakers I have come across in 30 years of searching. Full spectrum and amazing clarity make these a great choice for surrounds or even mains in a smaller setting. [ Timothy  Feb 08, 2018 ]
Hey John: Up Front: Significantly bigger than purpose-built satellites but with deeper, more fulfilling sound quality. I have these guys and they have a fantastic sound. Truly a sweet speaker. But, they are fairly large to get that sound. There's no doubt they would do a great job as satellites but I would make sure to consider their physical depth and my space. If you have time to put together a bit more scratch, consider DefTech's 9040s. I have the former version, SR8040BPs and love them. They're built to disperse sound into a wider field, are more compact(depth and weight wise) and will allow a bit more flexibility in room size I think. If you should decide to go with the 45's, you won't be disappointed with the sound for sure. John W [ John  Feb 08, 2018 ]
Hi John K These would be a great choice for your rear surrounds. They do take some time breaking in before the full sound becomes relaxed. Remember they have a port in the back so placement of the back flat on the wall will cut the bass output in half. I hope this helps. [ EUGENE  Feb 08, 2018 ]