Infinity Primus PS312

Powered subwoofer

Item #: 108PS312BK

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27 Reviews


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Add more life to your movies and music

Infinity's Primus PS312 powered subwoofer pumps up your movies and music with thunderous bass you can feel as well as hear. A massive 400-watt amplifier powers this sub's 12" woofer to fill even large rooms with punchy, well-defined lows. The combination of a patented Metal Matrix Diaphragm® driver and a low-resonance enclosure ensure this subwoofer can rock out without introducing any audible distortion.

Infinity's exclusive Metal Matrix Diaphragm driver

The PS312 features Infinity's exclusive Metal Matrix Diaphragm ("MMD" for short) driver technology in the 12" front-firing woofer. It consists of a stiff aluminum core, anodized on both sides for increased strength and rigidity. The result is extremely fast, accurate response, giving you distinctly cleaner, more realistic bass, even at higher volume levels.

Product Highlights:

  • bass-reflex design
  • 400-watt RMS amplifier
  • 12" front-firing MMD® (Metal Matrix Diaphragm™) driver
  • frequency response 25-150 Hz (±3dB)
  • continuously variable 50-150 Hz crossover
  • phase switch
  • line-level stereo RCA inputs
  • unfiltered LFE (Low Frequency Effects) mode for connection to a home theater receiver's subwoofer output
  • auto on/off
  • black wood grain vinyl finish
  • 14-3/8"W x 17-13/16"H x 20-1/16"D
  • warranty: 5 years driver, 2 years electronics
  • Our 60-day money-back guarantee

Why add a powered subwoofer?

A powered subwoofer gives you bass you can feel as well as hear. Our customers love the depth and impact their subs add to music and movies. We hear comments like "it brings out sounds I didn't know existed in discs I've watched a million times." Powered subwoofers aren't just for big bass that rattles your picture frames; they can also deliver tight, accurate lows. If you haven't shopped for a powered sub in a while, you might be surprised at how small they get. Look for an ultra-compact model if you want to tuck your sub away under an end table or in a corner.

Hands-on research

What's in the box?

Download owner's manual

  • Black powered subwoofer
  • 6.5' AC power cord
  • Back cloth grille (installed/removable)
  • Owner's Manual (En/Fr/Sp)

Features and Specs

Enclosure Bass Reflex
Video Shielded No
Woofer Size (inches) 12
Woofer Composition M.M.C.
Firing Direction Front
Wireless No
Preamp-Level Inputs Yes
Speaker-Level Inputs No
Speaker-Level Outputs No
Low-Pass Crossover Freq 50-150 Hz
High-Pass Crossover Freq N/A
Phase Switch Yes
Amplifier Output (watts) 400
Frequency Response 25-150 Hz
Height (inches) 17-13/16
Width (inches) 14-5/16
Depth (inches) 20-1/16
Weight 44.7 lbs
Speaker Parts Warranty 5 Years
Speaker Labor Warranty 5 Years
Amplifier Parts Warranty 2 Years
Amplifier Labor Warranty 2 Years

Product Research



Metal Matrix Diaphragm (M.M.D.): Derived from the C.M.M.D. material used in Infinity's flagship Cascade series, M.M.D. features a stiff aluminum core, anodized on both sides for increased strength and rigidity. M.M.D. transducers conduct sound faster than paper, polypropylene, and Kevlar, pushing unwanted resonances beyond the operating range of the transducer. M.M.D. drivers deliver crystal-clear, distortion-free sound from dynamic digital sources, even at high listening levels. The PS212 is equipped with a front-firing, 12" M.M.D. woofer.

Amplifier: This subwoofer is powered by a 400watt (RMS) amplifier, rated at 35Hz - 150Hz with no more than 0.1% THD. The maximum (peak) power output is 700 watts.

Surround: For a smoother response and improved durability, the woofer uses a rubber surround.

Bass Port: There is one rear-firing bass port that allows deep bass with high acoustic efficiency and low distortion.


Gain Control: The subwoofer has a rotary control on the rear panel for adjusting the level of the bass.

Low-Pass Crossover: The subwoofer features a continuously variable 50Hz-150Hz low-pass crossover that determines the highest frequency at which the subwoofer reproduces sounds. The crossover has a 24dB/octave slope. The crossover is bypassed when the "LFE/Normal" switch is in the "LFE" position.

Phase Switch: The subwoofer's phase switch allows you to control the phase of the subwoofer's output relative to the front speakers. If the bass sounds muddy or unclear, toggling the phase control can sometimes strengthen the bass "attack."

Auto On/Off Circuit: The auto on/off circuit turns the power amp on when a signal is sensed and turns the amplifier off and into standby mode approximately 10 minutes after a signal is no longer received. An LED indicator on the rear panel glows green when the amplifier is on and red when the amp is in standby.


Line-level Inputs: The subwoofer has a gold-plated LFE input (single RCA) and gold-plated stereo RCA inputs. If you have a Dolby Digital/DTS receiver or processor with a low-frequency-effects (LFE) output, you should use the LFE input on the subwoofer. If your receiver/processor does not contain a Dolby Digital or DTS processor but has a subwoofer output, you must use the stereo RCA inputs. If the receiver/processor has a mono subwoofer output, a "Y" adapter is recommended to maximize performance.

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.

Infinity Primus PS312 Reviews

Average Customer Review:

27 reviews
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Fantastic Sound - Questionable Quality

Written By CliffordJ, Detroit, MI on Tuesday, February 24, 2015

Crutchfield Customer Review (What's this?)

Let me start off by saying that this thing sounds Awesome (5 stars). It woke up my home theater system. It fills up my basement entertainment room with strong, clear bass and rattles my house quite nicely. It is the perfect compliment to my system. However, the quality is quite suspect. I first bought this unit in March, 2013. It lasted until January, 2014 when the built in amplifier burned out. Fortunately, the unit was covered under warranty and it was replaced. The second unit lasted until February, 2015 (same failure mode). It, too was replaced under warranty. I am now on my third unit. Frankly, I am worried that this unit will last only about 10 - 12 months like the last two units. This time, I'll be out of the warranty period and I'll be on my own. I do not drive the unit hard at all as I like a balanced sound that is not too "bass heavy". There is no way the first two units should have burned out with the way that I ran them. This new unit was made in late 2014 so I am hopeful that Infinity got their quality act together and that this unit will actually last. So while I am still pleased with the sound of the unit, I am now wary of the quality. Until I know that the quality has been improved, I can't in good conscience recommend this sub woofer (0 stars for quality).

Pros: Strong, clear sound. More than enough power for my home. Crutchfield's service has been impeccable in helping me deal with the difficulties I encountered with this unit

Cons: Suspect quality (Two sub woofers burned out on me within 10 - 12 months. I am on my third unit now)

Excellent! 5+++ Stars

Written By Chuck, Maryland on Sunday, February 22, 2015

Crutchfield Customer Review (What's this?)

Exceptional power. Superb sound quality. Extremely Fast shipping! Just the right size - not too big. Will likely purchase another one exactly like it in the near future.

Very satisfied!!!

Written By Tim, Upstate, NY on Saturday, January 24, 2015

Crutchfield Customer Review (What's this?)

I finally decided to finish buying the Klipsch Reference series speakers. I have the 62's in front and 52 surrounds (5.1). I bought a new receiver rate at 100W/channel and found that my Sony powered sub simply couldn't keep up at all. After reviewing the options available with the helpful Crutchfield staff I chose this sub. Not only does it keep up with the other speakers, it is capable of overpowering them. I went from lacking, to being capable of too much. After some playing around with the crossover levels and volume controls with different sound sources I have it set up so it blends really well. I'm re-watching a lot of movies and listening to my favorite music and hearing sounds that I never knew was lacking before. Probably what impresses me the most is that even at low volumes levels the bass is still present. I am shocked at how much sound it produces for a single 12". I was accustomed to running around with 2-12" at 600W in my car (as a teen) and so I was not expecting as much as it is capable of. It hits hard and fast!!! It keeps up fast hitting sound tracks from my music CD's. I would buy this again without hesitation. I would recommend it to anyone interested. Well worth what I paid. I did choose the "scratch and dent" offer because I knew it would hard to see even were it a bad scratch. Turns out, if I didn't know to look, I wouldn't have noticed anything wrong. Performance is not affected at all.

Pros: capable of producing audible sound at low volume levels (where the Sony couldn't be heard) and yet when turned up, it is capable of producing A LOT of nice sounding bass at high volume levels.

Cons: I haven't found any yet. Although... it rattles all the pictures on the walls through the WHOLE house. oh, wait... that isn't a con... my bad.

Love it!!!

Written By Jay, Mississippi on Friday, January 02, 2015

Crutchfield Customer Review (What's this?)

Ordered this product in anticipation of having my surround sound system installed. Once everything was up and running the Infinity Primus PS312 was simply the icing on the cake!!! Amazing have that deep bass in the background during movies or just rumbling with the music is AWESOME!!!!!! I highly recommend this product.

Pros: Nice deep bass sound. Great looking product.

Cons: I ordered this from the scratched and dented section. (The scratch was minimal). The only con I have was that the power cord wasn't in the box. I notified Crutchfield and a cord was immediately sent to me. If you order from the scratch and dented section be sure to ask Crutchfield to verify that everything that supposed to be in the in the box.

Infinity Primus PS312

Written By philipgene, New Jersey on Friday, January 02, 2015

Crutchfield Customer Review (What's this?)

out classes anything in its price range outstanding sound reproduction

Pros: more than enough volume rock hard punch well crafted

Cons: no variable phase adjustment

ps 312 sub

Written By dan, Alabama on Monday, November 24, 2014

Crutchfield Customer Review (What's this?)

first sub went out at 1 year old, Harman replaced it, second sub went out in 10 months, do not buy this sub. they will not last. I cannot believe that people rate this sub so high

Pros: nothing

Cons: made in china.

Infinity Primus PS312

Written By Dennis, New Cambria, MO on Tuesday, November 04, 2014

Crutchfield Customer Review (What's this?)

Awesome product sounds great more power than most people need lol it rocks the house

sub woofer

Written By bill, edgewater, fl on Monday, September 29, 2014

Crutchfield Customer Review (What's this?)

love this. it makes my home theater system rock out

Infinity PS312 subwoofer

Written By Bruce, Rio Ranche, NM on Friday, September 26, 2014

Crutchfield Customer Review (What's this?)

Very well made. Smooth response. Gets down to the lowest octaves as advertised. Blends very will with the Polk wall speakers in our 7.1 surround system using a Denon receiver. Operates in a far corner of our great room (18x37 ft. with vaulted 12 ft. ceiling) via twisted pair plus shield and drain wire connection through our custom switch panel. Shield connected to ground at receiver end to configure unbalanced cabling connection. No hiss nor hum. Very nice product. So far have not shaken anything off surrounding shelves, but might try for this with the next rock and roll party (ha!).

Pros: Prompt delivery. Good packaging. No shipping damage. Excellent product!

Cons: None that I can think of.


Written By Mashado, Chantilly, Va on Saturday, September 13, 2014

Crutchfield Customer Review (What's this?)

This produces some insane bass. Shakes the heck out of my living room.

Infinity Primus PS312

Written By Jay, FPO AE on Wednesday, September 03, 2014

Crutchfield Customer Review (What's this?)

I just love the deep sound for music and movies with my Sony 7.2 steroe

Pros: Great base to rock this 5000sq ft Villa


Written By Terry F, Pueblo West, CO on Friday, August 22, 2014

Crutchfield Customer Review (What's this?)

Replaced a 200 watt Sony. The Infinity Primus PS32 was by superior!

Pros: This is my second sub from Infinity. Excellent!

Cons: None

Cool Story Bro

Written By Pimp Master J, Norfolk, VA on Wednesday, May 28, 2014

Crutchfield Customer Review (What's this?)

Simply amazing.

Pros: When it's set to less than a quarter power, it fills my 15'x15' theater room with a 22' ceiling with subtle, full, CLEAN bass. When it's turned up 3/4 it shakes the room. I have not yet found a need to turn it up louder than half-way for any reason other than experimentation with vibrating the lights that hang from my ceiling.

Cons: None. Best home theater sub I've ever owned.

Infinity Primus PS312

Written By Buck P, Closter, NJ on Wednesday, April 16, 2014

Crutchfield Customer Review (What's this?)

Liked this product a lot - it exceeded my expectations. Shook my livingroom without effort!

Pros: Excellent product

Cons: None


Written By Bald VADER, Las Vegas, Nevada on Tuesday, March 04, 2014

Crutchfield Customer Review (What's this?)

We never realized how much bass we were missing with the old Polk Sub.

I can not give you tech spec talk. But I can tell you that we had to adjust power to half after rattling all the windows and blowing my son out of an easy chair. Just like the "Blown Away Man".

Pros: Incredible clean sound. I can not hear my wife talking during the movie.

Cons: Infinity Sub Woofers do not come with recliner seat belts

great bass

Written By lilsue, cleburne, TX on Saturday, February 01, 2014

Crutchfield Customer Review (What's this?)

Love the bass, ease of set up & the appearance of cabinet. I have it set to 50%, any higher and it will crack the foundation :) It compliments my existing speakers (Energy-Connoisseur) to a Tee.

Pros: ease of set up, appearance, great sound.

Cons: it is HUGE!

Infinity Ps312 subwoofer

Written By Mac, Indiana on Friday, January 31, 2014

Crutchfield Customer Review (What's this?)

This sub woofer is very good. It handles LFE's very well with clear crisp sound. I have the unit hooked up to an Anthem MRX 500 7.1 receiver with paradigm speakers. This sub woofer fits right into the system.

Pros: Clear, crisp LFE sounds.

Cons: I haven't found any yet.

excellent product!!!

Written By Giankarlo, San Juan, PR on Monday, January 27, 2014

Crutchfield Customer Review (What's this?)

waaw realmente me encanta la bocina, suena bien clara y solido. Y Crutchfield!! los adoro!! ustedes son lo maximo super rapido el envio y free shipping 2nd day to Puerto Rico, so very nice!!! sound very deep and clear. If i need to buy it again, will do trust me. You will feel the air of the subwoofer running through your legs aah man what a great speaker.

Wooow! I love this sub - it's got a solid, clean sound! And Crutchfield, you guys are awesome! You guys are the best - 2 day shipping to Puerto Rico, so very nice! If I need to buy it again, will do, trust me. You will feel the air of the subwoofer running through your legs! Aaah man, what a great speaker.

Pros: look, sound, size

Cons: mmmm well... noooothiing!! jaja really nada mmmm well... noooothiing!! Hehe, really, nothing.

Crutchfield response on Wednesday, January 29, 2014 Translation provided by Crutchfield's Spanish Sales & Support team. Visit our new Spanish-language site at

primus ps312

Written By Jeff D, oakdale, ny 11769 on Friday, January 24, 2014

Crutchfield Customer Review (What's this?)

Very rich bass right out of the box. The ps312 replaced an infinity 15" sub that got fried during the sandy storm. I spent a lot of time reading reviews and getting input from others with surround systems. I came back to infinity because of how well the last sub preformed. This time I'm using a surge protector. Also, I'm using an onkyo receiver so, the set up and integration was simple. All in all I'm very happy with this sub and occasionally it goes on sale.

Pros: rich, complex bass. I didn't need a break in period that others have talked about.

Cons: none at this time.

Exactly as promised

Written By Elecshop, Jacksonville, FL on Tuesday, January 07, 2014

Crutchfield Customer Review (What's this?)

I've been looking for a powered subwoofer to compliment my Bose Acoustimass 10 surround system for some time. I read the reviews for this item and no one anything critical to say about the performance or quality so I waited until the sale the item went on sale. When I received the item I was completely satisfied. Well worth the money at regular price .

Pros: Excellent sound and craftsmenship.


Written By Mike, oak island, nc on Saturday, December 21, 2013

Crutchfield Customer Review (What's this?)

This is my second infinity sub, I replaced a 150 watt with this beast and its awesome.... easily handles a load... huge upgrade for my man cave....

Pros: Quality

Cons: None

Infinity Primus PS312

Written By stewartT, Little Rock, AR on Wednesday, May 01, 2013

Crutchfield Customer Review (What's this?)

This powered sub hammers deep low bass like a sledge hammer! I have owened a Klipsch ref12 and the infinity preforms stronger and deeper. I have a Yamaha Receiver, along with Cerwin vega bookshelf, and center channel speakers and Cv ve 15s for the front. I thought the vegas pumped out the bass, I can hear and feel the infinity over them. The vegas are powered 500 rms per channel through a Qsc gx5, and 3rd octave EQ with the 31.5hz gain up 4db. The Infinity is built solid also, and I like the way the grill extends out away from the woofer. I highly recommend it! buy one or two for your system, you will not need tower speakers. after hearing the Infinity center channel, and bookshelfs, I am making my whole system infinity.

Pros: compact solid design and easy to use.

Cons: In today world it's always the price is a drawback for most of us, but thats ok Crutchfield has this Item on sale often. So no cons on the Infinity Primus PS312!

Awesome Product and Awesome Customer Service

Written By Mark, Hawaii on Tuesday, April 23, 2013

Crutchfield Customer Review (What's this?)

First off, I purchased the PS212 from outlet and after 2 weeks it started to make a rattling sound. Called Crutchfield Tech support and, without any hassle, gave me an option to return and get a refund or to upgrade to PS312. Of course, I upgraded and they also upgraded the shipping to 2day delivery. For people who live in Hawaii, 2day air is expensive for something that weights 50+ pounds but they said "sorry for the inconvience" and shipped it that day. Awesome tech and customer support. I will always buy from Crutchfield. About the product, I upgraded from a 6 year old 12" MTX audio home theater sub which is working still but I needed something with a little more tighter bass. I have the Infinity Primus towers, center, and rear surrounds which is the best for quality and price. Now I have the Primus Sub and its fantastic! The best home theater sub by far! No regrets going with Infinity and with Crutchfield!

Pros: 400 watts RMS. Not cheaply made. Bass is tight and accurate. Worth more than the cost!

Cons: None

Infinity Primus PS312

Written By Ruben, Vega Baja, PR on Monday, April 15, 2013

Crutchfield Customer Review (What's this?)

Es una excelente bocina de bajo, muy poderosa y facil de instalar.

This is an excellent subwoofer, very powerful and easy to install.

Crutchfield response on Wednesday, April 17, 2013 Translation provided by Crutchfield's Spanish Sales & Support team. Visit our new Spanish-language site at


Written By Mike, MN on Sunday, March 24, 2013

Crutchfield Customer Review (What's this?)

I am not one of those techy guys but I know a little bit about a little bit about audio tech.. This sub does everything that I want it to do. It does get a little distorted if you turn everything way way up but kind of to be expected I guess. I would buy another one if these if and when this one dies on me! :)

Pros: LOUD- if you want it to be

Cons: None. It's kind of big, but if you buy This sub you know what you are looking for.

Awesome Bang for the Buck

Written By Joshua J, Minneapolis, MN on Friday, September 28, 2012

Crutchfield Customer Review (What's this?)

Growing up listening to movies and music through my JBL Soundgear 3030, I have always held Harmon International products in high regard. When it came time for me to finally assemble my own home theater system, I was expecting no less from these Infinity speakers. I've created a system of 4 P363's towers, 2 P163's bookshelfs, a C351 center, and a PS312 sub, all powered by a Harmon/Kardon AVR3650. Being a bargain hunter, I waited for these to go on "sale" to obtain the best price (well this side Black Friday sales prices).

I have had the speakers hooked up for about two months now, and all I can say is WOW! The sound reproduction and tonal quality is incredible. Everyone has their own opinions on what sounds good, but ultimately the quality of the sound comes down to the quality of the receiver and the quality of the speaker components. I've utilized various mediums ranging from music, movies and video games, and in each medium, even with works I know quite well, comes alive- whether connected via HDMI, fiber optic or composite. There are qualities to the sound that I did not know existed- that is how incredibly clear the sound is. I would definitely recommend these speakers to someone looking to obtain the best sound for the price, while still having a high quality product.

Infinity Primus PS312

Written By JoeH, Sedona, AZ on Thursday, June 28, 2012

Crutchfield Customer Review (What's this?)

I really like my new sub woofer. It is a replacement for an older unit. This speaker sounds so much richer than the old one. It has changed the dynamics of my home theater system. I would highly recommend it to everyone.

Get everything you’ll need to enjoy your new Infinity Primus PS312

Use a high-quality subwoofer cable for bass that draws you into your movies and music. A cable is not included with this sub.
Have your new equipment installed by qualified professionals.
Protect your investment from power surges and interference.
Monster Cable® 400sw

Monster Cable® 400sw

Subwoofer cable (4 meters/13.2 feet)

Item #: 119SW4004M


Add to Cart
AudioQuest Black Lab

AudioQuest Black Lab

Subwoofer cable (16 meters/52.5 feet)

Item #: 703BLAB16M


Add to Cart
Monster Cable® 400sw2

Monster Cable® 400sw2

Subwoofer cable (12 feet)

Item #: 119140711


Add to Cart
CableTruth 303S

CableTruth 303S

Subwoofer cable (9 ft.)

Item #: 865SBCBL9F


Add to Cart
AudioQuest Irish Red

AudioQuest Irish Red

Subwoofer cable (12 meters/39.4 feet)

Item #: 703IRED12M


Add to Cart
AudioQuest Boxer

AudioQuest Boxer

Subwoofer cable (2 meters/6.6 feet)

Item #: 703BXER2M

Add to Cart
Panamax MD2

Panamax MD2

Space-saving surge protector with two outlets

Item #: 299MD2


Add to Cart
Monster 400df02

Monster 400df02

Optical digital audio cable (4 feet)

Item #: 119140713


Add to Cart
AudioQuest NRG-2

AudioQuest NRG-2

High-quality replacement AC power cable (6 ft.)

Item #: 703NRG26F


Add to Cart
AudioQuest Hard RCA Splitter

AudioQuest Hard RCA Splitter

1-male-to-2-female audio splitter

Item #: 703M22FRHD


Add to Cart
AudioQuest FLX-X RCA Y-Adapter

AudioQuest FLX-X RCA Y-Adapter

1-male-to-2-female audio Y-adapter

Item #: 703M22F


Add to Cart
AudioQuest FLX-X RCA Y-Adapter

AudioQuest FLX-X RCA Y-Adapter

1-female-to-2-male audio Y-adapter

Item #: 703F22M

Add to Cart
AudioQuest SorboGel Q Feet

AudioQuest SorboGel Q Feet

4 pack

Item #: 703SQFEET

Add to Cart
AudioQuest G2 Speaker Cable

AudioQuest G2 Speaker Cable

16-gauge cable, connectors optional (50 feet, White)

Item #: 703G250W


Add to Cart
AudioQuest X2 Speaker Cable

AudioQuest X2 Speaker Cable

14-gauge cable, connectors optional (30 feet, White)

Item #: 703X230W


Add to Cart
MartinLogan SW2-TRD

MartinLogan SW2-TRD

Wireless subwoofer adapter kit

Item #: 839SW2TRD


Add to Cart