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Tuning your subs

How to make the bass in your car sound its best

Buck Pomerantz was born and raised in Philadelphia. His parents bought their first television set when he was born. He figured out how to run it by the time he was two. Besides athletics, his formative interests included electronics, amateur radio, music, and stage crew work. He got his BA in writing from Brown University. Then he joined a rock 'n roll band as their soundman and moved to Charlottesville, Virginia. After that venture failed, he spent time in Boston, New Orleans, and Berkeley. He worked in a music store in Austin manufacturing, installing, repairing, and operating sound systems for recording studios, clubs, and bands. He moved back to Charlottesville, ran a little recording studio and finally joined Crutchfield as a copywriter. He has 2 grown children and 3 grandchildren, but after a good nap he can still rock out.

More from Buck Pomerantz

Kenwood subs in a Sound Ordnance subwoofer box

One of the things I like most about subwoofers is that I can feel the musical emotion directly with my body. The low frequency beat often forces me to dance around, or, at the very least, nod my head along with the rhythm. That's why we all like music in the first place — it moves us.

It can take a little time and effort to get the exact bass sound you want from your subs, but the rewards of a well-tuned subwoofer system are overwhelmingly cool and physically satisfying.

Before we get started...

This article discusses how to tune your subs and amp to get the best sound you can. If you are looking for information about buying subwoofers, please read our Subwoofer Buying Guide and check out our selection of top-rated subwoofers, then come back here to learn more about setting them up to deliver great sound.

First, set your speaker level

Keep in mind, distortion is the enemy: it destroys speakers, subs, and eardrums. Distortion sounds like crackling, flapping, crunching, or hissing that interferes with the distinct sound of a musical instrument. If you power your full-range car speakers with an amplifier, it is crucial that the amp's gain is properly set to prevent distortion. [Need an amplifier? See our full selection.

Step 1: Remove the distortion

With the amp gain set low, play some music and turn up your receiver's volume until you hear the music distorting; then back off the volume until the music sounds clean again. Note or mark where the receiver's volume is. This setting is the maximum volume your receiver can go to and still play cleanly.

Now, turn the amp's gain up until you hear distortion again; then back off the gain slightly until the distortion goes away. The amp gain is now set, so you can lower the receiver volume to a more comfortable level. Even if your speaker system does not have an amplifier, you still need to find that maximum volume point on your receiver by turning it up to just below distortion level.

Now you're ready for some bass

Step 2: Flatten the signal, open the low-pass filter

Turn your sub amp's gain to its lowest, most counter-clockwise position. Switch its low-pass filter on and set it as high, clockwise, as it will go. If it has a bass boost, turn it off. If it has a remote level control, set it to its middle position so, later, you have the choice of boosting or cutting the bass on an individual song.

Adjust your receiver's bass tone control to its middle, zero, or "flat" setting, whichever it's called on your stereo. If it has a subwoofer level control, set it, also, to its middle, or "no gain" setting. Sometimes receivers have a crossover, low-pass filter, or bass boost on their subwoofer output. Make sure those are all turned off, too.

First, turn the gain down

Start by turning the gain down, and turn off your filters and bass boost.

Note: Do not use the low-pass filters, crossovers, or bass boosts on the receiver and the amplifier at the same time. Use one or the other, but not both. The reason is that something called phase distortion generates around each filter or boost's crossover frequency, muddying up the sound.

Step 3: Adjust the subwoofer gain and low-pass filter

Play music through your receiver at about one-quarter volume. Turn up the gain of the subwoofer amp until the sound from your subwoofer completely overpowers the other speakers, without distorting.

Turn the gain up

Turn the gain up until it distorts, then back it off until the sound is clean again.

While listening to the music coming out of your sub, slowly adjust the sub amp's low-pass filter downward until all the high- and mid-frequency notes disappear.

low-pass filter

Adjust the low-pass filter downward to eliminate high- and mid-frequency notes.

The low-pass filter eliminates the notes you don't want your subwoofer to play. It also acts like a tone control to capture the "edges" of the kick drum's sound; the attack and release of its boom. Filter out the cymbals, strings, vocals, and guitars. Leave the bass and the low drums.

Step 4: Bass boost and subsonic filter

If you have a bass boost, try carefully turning it up to hear what the bass drum sounds like when you do. Applying just a little bass boost will bring up the kick a lot. Be careful with the bass boost, if you choose to use it — this is where distortion is often introduced into a system. If you hear distortion, lower the sub amp's gain until it goes away. Use the bass boost to feel the beat in the air your sub moves.

bass boost

Now play with the bass boost.

For ported subwoofers, use a subsonic filter on your amplifier to tame any overly loud low notes. This will help decrease the levels of the notes at which the enclosure resonates. Fine-tune all the filters some more to make the bass drum sound tight and dry or loose and reverberant, according to your personal taste. I like reggae and soul, so my bass is plenty loud, but it's a bit drier than most people might like. The important thing is to keep adjusting your system until you hear something you like. When you're satisfied with the tone of your system's bass and kick, turn the sub amp's gain all the way down.

Blending all the frequencies

Now that each piece of the puzzle is set, it's time to bring all the music into focus. 

Step 5: Matching the subwoofer level to the receiver volume

Turn up the receiver's volume to its maximum, distortion-free position. Then slowly turn up the subwoofer amp's gain until the bass sounds balanced with the rest of the music. That should do it.

Run your remote bass boost or level control up and down a little to hear what it does. Because of the size of the acoustic space in a car, subwoofers sometimes don't combine their sound constructively with the rest of a system's sound waves. If your bass has plenty of volume but seems to lack punch, you can sometimes help it by reversing your sub's speaker leads. This reverses the subwoofer cone's forward and backward movements, which might put all the sound waves together better than the other way. Whichever way sounds best is the right way.

Troubleshooting any problems

If you hear distortion coming from your subs, turn down the sub amp's gain. If, at this point, you cannot get enough bass out of your subwoofer to keep up with the other speakers without distorting, then you will need to get a bigger subwoofer and amplifier combination, with higher power-handling abilities.

Do not lower the gain of your full-range amplifier to try and match your lack of subwoofer volume. This would endanger your full-range speakers (when the amp sends out a clipped signal) without achieving the goal of clean, full sound, which is why you put in a subwoofer to begin with. More power, especially in the bass, is always better than not having enough.

Now you should be able to enjoy the robust fullness and beat of your music with your sub tuned up to match your system's capabilities and your ear's preference. Just remember to be polite, and turn your boom volume down when it might bother other people.

Learn more about sound tuning

For more information on how to tune your car sound stystem, see Adding a 4-Channel Amp. To learn more about getting the best sound out of your amplifier, take a look at our Amplifiers FAQ and Glossary articles.

Last updated June 15, 2016
  • Matthew W.

    Posted on 5/20/2015 3:22:39 PM

    "Note: Do not use the low-pass filters, crossovers, or bass boosts on the receiver and the amplifier at the same time - use one or the other, but not both." Great advice! This just confirms my suspicion of why the left channels of both of my BRAND NEW subwoofer amplifiers would stop playing after less than 30 seconds of being powered on. Once I disabled the bass boost and low-pass filters on the amplifiers, everything appeared to work just fine. However, I still felt that I was being short-changed because my amplifiers would only work if didn't use certain features. But just as the above article mentions, I was attempting to use the low-pass filters on both the amplifiers and the head unit. I've never been so happy to know that the issue was user error. Thank you for the confirmation.

  • Awinash Ragothaman from Durham, NC

    Posted on 6/10/2015 9:46:13 AM

    Part1: First a little insight: With all the little money I could muster, and splitting the cost of the car into monthly payments, I bought a 2005 Nissan Maxima (with aftermarket Premier radio and OEM Bose speakers) in May 2014. Music is my heart and soul and I wanted to invest in a good subwoofer and mono amp for the setup. I saved for months and bought an Alpine MRX-M55 amplifier and a Rockford Fosgate P2-1X12 loaded enclosure and had them installed at Best Buy. I was told to not play around with the gain setting as that would void the installation warranty. It was installed in a tight space and I would've had to physically remove the amp to actually get to the settings and I didn't bother doing it. I tinkered around with whatever settings I could find in the head unit but it just didn't sound right. There was this artificial boom and I had to keep changing settings for every song I heard. I initially thought it was the RF enclosure (it was ported) and bought a sealed enclosure hoping to get a bit more precision. But that didn't help either. Well, the Nissan died on me in May 2015, but I had saved up enough to get myself a brand new Hyundai Sonata Sport (touchscreen radio without Nav). I removed the Alpine and RF from the Maxima and had it reinstalled at a Best Buy in another state I moved to.

  • Awinash Ragothaman from Durham, NC

    Posted on 6/10/2015 9:46:44 AM

    Part 2: The Best Buy professional there did a great job and was kind enough to let me play around with the amp's settings. He even had it installed on the back of the seat where I could reach the settings easily. I played around with the amp's settings and was able to somewhat reach a setting that I could've grown into liking. But it still wasn't the way I wanted it: tight, repsonsive, precise and balanced. I noticed a lag between my subwoofer and the actuall song, the bass was still boomy, I could feel the bass but not hear it and lots more issues. It was then that I stumbled upon this guide. I followed it verbose and I must say, I am very VERY pleased with the outcome. I was able to get the exact same sound quality that I had dreamed of for years. I am now able to have audiophile quality sound in my car every single day. Heck, it even sounds better than my home theater. Thank you very much Crutchfield and Buck Pomerantz. Your contribution is very much appreciated.

  • Rick

    Posted on 7/20/2015 7:15:07 PM

    " Do not lower the gain of your full-range amplifier to try and match your lack of subwoofer volume. This would endanger your full-range speakers (when the amp sends out a clipped signal) without achieving the goal of clean, full sound, which is why you put in a subwoofer to begin with." This confuses me. Wouldn't lowering the gain reduce the chance of clipping?

  • Buck Pomerantz from Crutchfield

    Posted on 7/21/2015 12:26:33 PM

    Rick, The section you quote from concerns how to react to a situation where the bass is inadequate. Turning down an amp's gain indeed reduces the chance that the amp will clip the signal, but it increases the chances that a person trying for louder bass will clip the signal coming from the receiver by turning up the volume, and that could be dangerous for speakers and subs. The solution for when full-range speakers are overpowering a sub is not to turn the speakers down but to get a more powerful amp for the sub.

  • kevin Ha'aoto from Honiara,Solomon izla

    Posted on 8/18/2015 8:24:02 AM

    Hi,my name Kevin and I'm from Solomon island. Well I have a situation here which I bought an sound stream amplifier 4000 watts 1 ohm stable.then I want to use its max power rating which is 2000 RMS x 1@1 ohm. Well how many sub would you reccommend to use or how many watts sub should I use if I want to use between 2-4 sub? Awaiting your answers

  • Buck Pomerantz from Crutchfield

    Posted on 8/18/2015 11:09:57 AM

    Kevin, There are a few ways of wiring multiple subwoofers together to form a 1-ohm load so that amp can put out maximum power. You can browse through some subwoofer wiring diagrams at this link to see a good selection. One that could apply to your situation is this diagram that shows two DVC 4-ohm subs wired to a mono amp. You'd want each sub rated for between 750 and 1200 watts RMS.

  • Sam from Rockport

    Posted on 8/24/2015 2:52:56 AM

    I have no idea what you were saying in the article. The sentences and definitions used don't fit the names of the adjustments so its no good for me. I have 2 10 in subs (probox) under my back seat in my Dodge ram. Pioneer with GPS and 7" screen and a 1000 watt amp for the subs and 8oo watt amp for my 6x9s in all 4 doors. I have 2 2" tweeters in my dash. It freekin kicks but I want more sound from my doors to match my dash sound. I spent too much already but my right dash speaker comes on sometimes and don't know what's up with it. I had it replaced once but I guess it wasn't the speaker.

  • Buck Pomerantz from Crutchfield

    Posted on 8/24/2015 1:40:16 PM

    Sam, If you bought your gear at Crutchfield, you could call Tech Support for free help troubleshooting your system. Their toll-free number is on your invoice. If you purchased your equipment elsewhere, you can still get expert Crutchfield Tech Support - 90 days-worth for only $30. Click on this link for details.

  • Kyle from Shelbyville

    Posted on 8/26/2015 4:30:16 AM

    I have a 10" 4 OHM 10C104 Comp KICKER sub with a 500 watt Legacy amp. Is that the only 10" sub that I can hook up to that amp?

  • Buck Pomerantz from Crutchfield

    Posted on 8/26/2015 1:46:30 PM

    Kyle, If you're asking whether or not you can hook up a different subwoofer to your amp, then the answer is yes. If you're asking whether or not you can add a second sub to your system, the answer is maybe. It depends on the amp's capabilities and the impedance and power ratings of the subs.

  • James from Homestead

    Posted on 8/31/2015 7:00:12 PM

    Yes I have a question, what if I have my gains about 25% and I have loudness on, is it ok if loudness is on and will it do any harm to my amp and sub? I heard it's bad but when I put loudness it rattles my car a lot more but the volume is less ,I have a 1200 watt kicker amp and a 1200 watt dual comps loaded box so in total its 600 rms watts .can I use bass boost better or loudness ?

  • Carlos from San Jose

    Posted on 8/31/2015 10:57:52 PM

    what about the HPF???

  • Buck Pomerantz from Crutchfield

    Posted on 9/1/2015 12:01:41 PM

    James, There is nothing wrong with using your loudness setting or bass boost to make the bass sound the way you like. Loudness is usually employed when listening to soft music in order to improve bass and treble response, but if you like it keep it.

  • Buck Pomerantz from Crutchfield

    Posted on 9/1/2015 12:27:33 PM

    Carlos, A HPF or high-pass filter blocks low notes from getting to a speaker, so using one for a subwoofer won't do any good.

  • Randy from Missouri City

    Posted on 9/8/2015 6:44:18 PM

    Hello Buck, I am sure my questions are pretty simple and I am just over looking them. I just purchased a Alpine Type R SWR-10D4 and want to wire it into a 2ohm (I know how to do this). Now my amp is a Pioneer GM-D9601 and it is rated at 800w RMS @ 2ohm load. So on my headunit (Kenwood DDX-719) I have both a subwoofer and bass setting. I have been reading around and some say to set the SW setting to max (0-15) and leave the bass setting on 0. Which do I do here? Now with the DMM I would want to turn the gain up to a bit under 40 volts since the SWR-10D4 can handle 1000w RMS peak. correct?

  • Buck Pomerantz from Crutchfield

    Posted on 9/9/2015 12:45:27 PM

    Randy, You have a lot of different controls for your bass, The subwoofer control on your receiver lets you adjust the volume of your subwoofer for each song you play. If you think you may turn the bass up all the way sometimes, go ahead and set up your gain-setting with this set to full volume. The bass control is a tone control, a boost/cut at 100 Hz. Your amplifier also has a bass tone control, the wired remote bass boost (0-18 dB at 50 Hz). Set one or the other of these to whatever tone sounds best to you. Then, if you set the amp gain using a 60 Hz 0 dB test tone and a volt meter, a 40-volts AC RMS reading would result in a full 800-watt output into 2 ohms.

  • Randy from Missouri City

    Posted on 9/9/2015 5:59:53 PM

    Thanks for the reply. Ok so I am understanding that when I adjust my gain on the amp I should turn my (headunit) SW setting all the way up to 15 so I won't clip on different songs? (I mainly listen to Electronic Dance Music if this helps at all). I had the bass boost on my old sub, but decided to remove it this time around. Also on the headunit I have my bass frequency setting set to 50hz. It doesn't go any lower than 50hz btw. I usually use a 50hz tone, but I will use a 60hz tone and run my gain up to 39.XX volts. Now on the bass control adjusting this (0-8) it won't bring the voltage up at all on the sub and cause it to clip?

  • Buck Pomerantz from Crutchfield

    Posted on 9/10/2015 12:02:36 PM

    Randy, You can indeed clip the amp if you apply bass boost after setting the amp's gain. Set your tones, boosts, and sub level to the highest you'll ever set them, then set the gain, then lower the levels and boosts to where you'd usually set them. Now, you can be assured that any time you apply boost, the amp won't clip.

  • randy from missouri city

    Posted on 9/10/2015 12:23:11 PM

    Buck, I went ahead and bought the Oscilloscope ARM DSO Nano DSO201 so I can really tell if I am clipping. At $60 that is a steal and I know I will be using it in the future on other equipment. Thanks again for the replies.

  • Kornel from Vancouver

    Posted on 10/6/2015 12:31:53 AM

    Hello, I have 4 Alpine speakers 60 and 80RMS in front and back powered by head unit (Sony). I have a kicker 300.1 Amp powering my Sub (Not connected to speakers) Im wondering if I should have my Input level set to Hi or Lo. Also my XOVER option to OFF or LO. If I have it set to OFF i hear music coming from my sub, if its on LO I just have BASS.

  • Buck Pomerantz from Crutchfield

    Posted on 10/6/2015 12:59:11 PM

    Kornel, If your amp gets its signal from speaker wire connections, set the amp's input to Hi. If you're using RCA cables from the receiver's preamp output, set it to Lo. And because you're using this amp for bass, you should engage the low-pass filter by setting the Xover to Lo. Following the five steps described above will help get you great-sounding bass.

  • Nishaan from Johannesburg

    Posted on 10/19/2015 10:35:24 AM

    Hello, i have been hunting high and low online for ways to tune my system and stumbled accross your website. I have a series of questions: firstly my system comprises of, Digital Designs C5C amplifier, Digital Design 512 subwoofer in a spec enclosure that I built, and Focal PS165v splits for front stage. I do not have any sound matting done at this stage nor do I have a high output alternator for better voltage. my reciever is the sony GT620UI due to that i have one amplifier to tune my entire system it is difficult to set the gains. first question: does the radio equelizer need to be on 0 or must it be on -6? 2nd: does the settings on the EQ effect how the sub plays? 3rd: while reading your artical you never mentioned after tuning do you set the eq as in pick up the trebble or lows etc or do you just leave it? 4th: I have a backboard will that cause me loose bass in the cabin ( car is a hatch back) 5th: I have heard the proper way of setting a system is to use a multi meter but obviously this artical is for those that have correct me if im wrong.

  • Buck Pomerantz from Crutchfield

    Posted on 10/19/2015 1:02:31 PM

    Nishaan, I assume you're using that 4-channel amp to drive your front soundstage with two channels and your sub with the other two channels bridged together. The amp has separate gain controls for the front and rear channels, so there should be no problem setting the gains. Set the gain for the full-range speakers first, with the EQ settings set to flat. Add your tone settings and reset the gain to compensate. Then work on the subwoofer channel's gain and tone settings. You can set amp gains using a multimeter and test tones, if you know how to use a meter and can figure the target voltages, but tuning by ear and with music often ensures a cleaner, more distortion-free setup than can be accomplished by reading numbers off a meter.

  • kyle davis from Pocatello

    Posted on 10/25/2015 1:11:51 PM

    so i have a Boston Acoustics GTA-704. I want to bridge both the rear channel and the front channel both at 4 ohms to power a Alpine SWS-10D4. In the manual, do i set it up how it is in example 3? Link: manual

  • Buck Pomerantz from Crutchfield

    Posted on 10/26/2015 12:05:49 PM

    Kyle, You can wire that subwoofer to that amp like you propose, but you need to be careful of a couple things. Both voice coils of that DVC sub need to get the exact same signal or the sub will distort. That means the identical signal needs to go to the front and rear channels, and that the gains need to get set identically as well.

  • Ian from South Bend, IN

    Posted on 10/26/2015 4:03:16 PM

    Randy, How would you suggest I wire two DVC / 4 Ohm woofers to a one-channel amplifier delivering 1000/1Ohm. Currently, they are seriesed. Is that a bad idea? Thank you.

  • Buck Pomerantz from Crutchfield

    Posted on 10/27/2015 10:50:20 AM

    Ian, You wire two DVC 4-ohm subwoofers to form a 1-ohm load like this. Not knowing what exactly you currently have "seriesed" - voice coils, subs, or both - I can't say whether it's bad, good, or indifferent.

  • jeetu

    Posted on 11/12/2015 5:57:09 AM

    Step 3 Play music through your receiver at about one-quarter volume. Turn up the gain of the subwoofer amp until the sound from your subwoofer completely overpowers the other speakers, without distorting. This one quarter volume is one quarter of previously set reciever's volume while tuning full range speaker or one quarter of reciever's total volume?

  • Buck Pomerantz from Crutchfield

    Posted on 11/12/2015 4:41:36 PM

    Jeetu, Those directions mean for you to turn the volume of the receiver down, from the previous setting, to one-quarter full volume. This is so you can isolate the sound of the bass from the full-range sound so you can tune it clearly.

  • Jeetu

    Posted on 11/15/2015 1:11:18 PM

    Some subs have wide freq response for eg 20hz-1000hz and some subs have narrow freq response for eg. 20hz-125hz. Which of these are better? And my sub has freq response 20hz-125hz. Does this mean that i should set low pass filter of amp on 125hz or below. And if i set my amp lpf above 125hz ,will it distort?

  • Buck Pomerantz from Crutchfield

    Posted on 11/15/2015 5:13:37 PM

    Jeetu, I recommend you set the low-pass filter of your amplifier to clear high- and mid-range sounds from your subwoofer according to how this article says, not according to the specifications published by subwoofer manufacturers. In other words, you should tune a system using your ears, not with your eyes looking at numbers. Different subs have different frequency responses and sound different and the only way you can tell which is better is to listen and find out which sounds better to you. And the only way to tell if your system is distorting is to hear it.

  • sumit

    Posted on 11/17/2015 2:41:58 AM

    My friend's car has one 15' kicker L7 1200rms and one kicker 1000rms amp. Lot of money spent. But it hurts my eardrums when I sit in his car. Is it due very high bass or power(1000rms) or his system is not tuned properly? How to rectify it?

  • Buck Pomerantz from Crutchfield

    Posted on 11/17/2015 10:51:02 AM

    Sumit, Your eardrums hurt because your friend plays his stereo too loud. I'd say you could: a) Ask him to turn the volume down; b) Wear earplugs when you're in his car; or c) Don't get in his car.

  • Mark Gray

    Posted on 11/20/2015 9:44:21 PM

    Hello, good question, hypocritical, a single dvc subwoofer, rated 500 watts RMS at 4 ohms. Now I know you can power each coil with a separate channel or two separate amplifiers if the amplifiers are identical and output/frequency match precisely. But since the sub is rated 500 watts, is that 500 watts per coil? Or does the manufacturer rating assume both coils are energized together so the combined coils see an input of 500 watts RMS regardless of impedance? So, again hypothetically, using two amps for the one 500w rms DVC Sub, would I use two amps rated at 500w rms each or 250w rms each? This question has bugged me for a long time....Thank you Regards please email me as well as post your response.

  • Buck Pomerantz from Crutchfield

    Posted on 11/23/2015 2:13:03 PM

    Mark, When a manufacturer describes their subwoofer as DVC 4-ohm rated for 500 watts RMS, they mean that the sub has two voice coils, each of which has a nominal impedance of 4 ohms, and that the sub has a total power rating of 500 watts RMS, 250 for each voice coil.

  • Kai

    Posted on 11/27/2015 4:49:47 AM

    Quick question, I installed a Boston subwoofer in a ported box in my car and noticed a large gap in the 50-75 hz range where the sub isn't very loud at all compared to frequencies higher and lower. My crossover is set to around 110 hz and the box is tuned to 34 hz. Is this due to it being out of phase with my speakers? Or is the box just unable to play that particular range? Thanks

  • Buck Pomerantz from Crutchfield

    Posted on 11/30/2015 2:22:19 PM

    Kai, It's possible that a phase problem can make certain frequencies not play well. Have you tried tuning a high-pass filter for the full-range speakers to see if that clears up those low notes? Is there a subsonic filter or bass boost on the sub amp that needs adjustment? It's also very possible the sub and enclosure just can't play those notes without some heavy EQ boosts in the areas that need it.

  • James Brown from Middleburg

    Posted on 12/6/2015 9:02:01 AM

    I recently installed a Kenwood KSC-SW11 powered sub under my seat and a Pioneer DXT-X2769UI head unit. Even though I'm an old dog (58), I've never had or installed a sub and have just a couple of questions. 1) The HU has settings for HPF and LPF, should they be set the same (eg. both at 80), or should the HPF be set lower, or set to off? 2) The Kenwood only has volume, frequency and phase for controls. I'm assuming if I LPF is set to 80 on the HU, then the frequency control knob on the sub should be set at 80 also? Kind of hard to tell exactly where 80 is on the sub's dial that ranges from 50 to 125. Thanks for the help, James.

  • Buck Pomerantz from Crutchfield

    Posted on 12/7/2015 2:36:40 PM

    James, You should use the high-pass filter on your receiver to clear low bass notes from your full-range speakers, and use the low-pass filter on your powered subwoofer to clear high frequencies away from the bass tones. A good place to start is with both set around 100 Hz, but the printing on most electronic devices is rarely exactly accurate for pointing controls. Follow the steps in this article and you should be able to dial in the tone you're looking for in your system.

  • Clay318 from Columbia

    Posted on 12/11/2015 5:16:57 PM

    Hi, a few months ago I install a 12 inch Orion XTR subwoofer and I'm using an older kicker amp that is 780 watts if I'm not mistaken. The sub is in an enclosed box that is pretty thin and seems to be made for a jeep, not my suv. I am getting some rattle and I'm positive that it is not blown. Is the box too small or are my settings not correct. I don't have a LPF option on my amp, I have a sub setting on it that includes dials that have X-Over Freq.(HZ)(50-200), a gain setting from 0-11, a bass boost setting from 0-18. And then two knobs that say Amp next to them with X-Over Freq again with 50-200 and another gain setting with 0-11. On my radio receiver, I have a group in settings called detail set and it has two different settings in that. Including LPF SUB-W that lets me change it from 85-160HZ, and a SUB-W Phase button that lets me do Normal or REV. Please help me, I don't know what these things mean and where to set it.

  • Buck Pomerantz from Crutchfield

    Posted on 12/12/2015 11:01:17 AM

    Clay, Not knowing exactly what amplifier or subwoofer you have make it impossible to give advice on how to set the gains and filters. If you bought your gear at Crutchfield, you could call Tech Support for free help with your system. Their toll-free number is on your invoice. If you purchased your equipment elsewhere, you can still get expert Crutchfield Tech Support - 90 days-worth for only $30. Click on this link for details.

  • J

    Posted on 12/31/2015 5:39:22 PM

    Hey Buck, I have read all of the different "tuning" articles on here and I am still at a loss. I think I am on the opposite side of the spectrum in that my front stage is being totally over-powered by my subwoofer and I am struggling to bring balance to the force. I read so many positive reviews on the Polk DB6501 components and how if you put power to them they will really crank out the sound but I have them on a Rockford Fosgate P300x2 and I am not sharing that experience. I have cut the gain and db back on the sub alot is there anything else I can do to get these highs and mids up to scratch with the lows or did I just go overboard with the bass it's a 12" 4ohm dvc being powered by a Kenwood KAC 9106-D.

  • Buck Pomerantz from Crutchfield

    Posted on 1/4/2016 10:05:14 AM

    J, Following all the steps in this article should lead you to a balanced sound. Did you set your receiver's volume and full-range amplifier's gain for maximum signal before distortion? If your sub amp is getting its signal from the receiver's subwoofer output, maybe lowering the subwoofer volume in the receiver's menu will help bring the bass in line.

  • Eugene from Beirut

    Posted on 1/4/2016 5:17:14 PM

    Hi, I newly installed an 8" Bose 8 Oms subwoofer sealed under passenger seat and bridged it with 2 channels out of 4 channel boss 3000w amp. I am assumming that the amp is very powerful so I am lowering the gain and all to bare minimum and not even one quarter and I'm not getting any clear sound out of the Bose, it distorts and about to blow up in pcs. Anything you could recommend with the investment I have done here without re-investing again with a smaller amp? Thanks

  • Buck Pomerantz from Crutchfield

    Posted on 1/5/2016 12:03:56 PM

    Eugene, It sounds like you're using a subwoofer originally from another vehicle or a home stereo system, and it has such a high sensitivity that even a little amplification overwhelms it. Try running it off of just one channel of that amp, unbridged, and see if that works better. Maybe your source is distorting and turning down the volume of the sub out of the receiver or line output converter will solve the issue. Otherwise you should look into getting a subwoofer and amplifier more suited for each other and a car application.

  • Keith Etheredge from Columbus, IN

    Posted on 1/5/2016 9:07:21 PM

    Thank you Buck! This article, and your other on 4 channel full range amplifiers, just kicked my 2013 RAM 1500's system up several notches of awesome! I had a question, although I am not likely to change any settings on the system now... I'll ask anyway. In my system I have two kicker 3.5" dash speakers powered by the factory 8.4 inch touchscreen head unit. Along with those, are pairs of kicker 6.5" front doors and 6x9" rear doors, and a JL Audio 10TW1 subwoofer. All doors and the sub are powered by a JL Audio XD700/5v2 amplifier. My question is... how should we properly blend in the speakers powered by the aftermarket amplifier with those dash speakers driven by the head unit? Since I have no gain adjustment on the head unit, I basically ignored them and followed your instructions for the other speakers. I'm beyond pleased with the results, but did I just get lucky? Thanks!

  • Buck Pomerantz from Crutchfield

    Posted on 1/6/2016 12:53:17 PM

    Keith, There's very little luck involved in car audio tuning. Your listening and tuning skills are probably a lot better than you thought. When you found the receiver's maximum volume before distortion, you in effect set the levels for your dash speakers. If you find that the amplified speakers are overwhelming them, you can turn down the amp gains to achieve a better blend.

  • Brian

    Posted on 1/6/2016 10:36:56 PM

    I have jvc stereo with mono amp for 2 12inch install. Amp is R500X1D N sub is Mtx 2 12in. Sub. What I try figure out that do I need put sub level on stereo high it goes up to 0-8? Then ajust the gain? Also I have LPF setting on sterreo says through-55hz-85hz-120hz. Which should I put it on? Also bass boost on amp should just be on min? It has LP on amp from 50-250hz where should it be at? THANK YOU

  • Buck Pomerantz from Crutchfield

    Posted on 1/8/2016 3:14:31 PM

    Brian, Start with the sub level set as high as you'll ever want it before setting the amp gain. Same with the bass boost. You can always safely turn the levels down later, but raising them after setting the gain could result in dangerous clipping. Use the low-pass filter on either your receiver or amplifier but not both at the same time. I suggest turning the filter off on your receiver and use the variable low-pass filter of the amp. Follow the steps in the article and start with it at 250 Hz and lower it slowly until you hear the bass sound clear..

  • Moawiya Al Anazi from Cairo

    Posted on 1/18/2016 7:35:59 PM

    Hi there, let me get straight to the subject. i've noticed when i set the LPF on my receiver (headunit) to 120HZ i can feel the bass getting boomier and augemented while setting it on 50HZ gives a tight and accurate bass. My question is: when the LPF frequency goes up does it mean more bass or is it the other way around?

  • Buck Pomerantz from Crutchfield

    Posted on 1/19/2016 12:28:32 PM

    Moawiya, When you raise the frequency setting of an LPF (low-pass filter, also known as a high-cut filter), you're allowing higher frequency tones to play along with the low notes.

  • Aaron from Largo

    Posted on 1/20/2016 11:03:34 PM

    can using a high/low converter effect tuning an amplifer? Or can I still adjust the highs out of the sub through the amp?

  • Buck Pomerantz from Crutchfield

    Posted on 1/21/2016 11:21:24 AM

    Aaron, I think you're asking about the use of a low-pass filter - right? To remove the highs from a subwoofer's signal, you should use the low-pass filter on your receiver or your amplifier but not both at the same time.

  • Ethan J Spinks from Buford

    Posted on 1/29/2016 10:41:49 AM

    Absolutely awesome step by step instructions. Thank you so much. this helps me out a lot. I just got 2 polk MM1240 Subs and the polk MM6501 Full-range speakers for my f150 and i have been having some issues with the subs cutting out at times. I have the polk PA660.4 and the PA1000.1, so i was very confused on why things were not sounding the way i was expecting them to.

  • James from Rubicon

    Posted on 2/15/2016 9:49:52 PM

    I purchased a Sound Ordnance 8-BP Powered Subwoofer last August. Would these instructions also apply to that sub?

  • Buck Pomerantz from Crutchfield

    Posted on 2/16/2016 9:59:32 AM

    James, Assuming you're referring to a Sound Ordnance B-8P, yes - following the steps in this article should help you attain good-sounding bass.

  • Jordan Wetz from Denver

    Posted on 2/18/2016 5:39:16 AM

    Got a question for Buck. I have my amp tuned correctly I think and have no clipping but my head unit (kDC x895 kenwood) has a bass frequency setting that is stumping me. I have tried every setting and notice that when the frequency is set to 50hz on my head unit the bass is really low volume and doesn't seem to hit hard but when I turn the frequency up to its max of 150hz the bass seems way louder and more responsive but only seems to play more of the mid range bass. What setting should I use here? I want deep and mid bass but can't find the right combination of amp tuning and head unit tweaking. Any advice or further info needed to give correct advice? My amp is a hifonics brutus 1200w and the subs are 2 rockford fosgate p3 12's if that helps any. Thanks in advance.

  • Buck Pomerantz from Crutchfield

    Posted on 2/18/2016 1:27:29 PM

    Jordan, That receiver has about nine different controls that adjust the sound of the bass, including subwoofer level, bass boost, bass EQ center frequency and level, and a low-pass filter. You'll need to experiment with each one to hear what effect it has on the sound in order to dial in the best tone. If you bought your gear from Crutchfield, you could call Tech Support for free help tuning your system. Their toll-free number will be found on your invoice. If you purchased your equipment elsewhere, you can still get expert Crutchfield Tech Support - 90 days-worth for only $30. Click on this link for details.

  • sumit

    Posted on 2/20/2016 3:43:02 AM

    Do digital signal processors improve and increase the vocal and bass in a car system? I am planning to buy a pioneer dsp. Should I buy one?

  • Buck Pomerantz from Crutchfield

    Posted on 2/22/2016 9:58:36 AM

    Sumit, I'm not familiar with the particular DSP (digital signal processor) you're referring to, but with a lot of patient tuning, most DSPs will improve the sound quality, including that of vocals and bass. Give us a call and one of our Advisors can help you pick out the best DSP for your vehicle and system.

  • Steve Stockland from Amery, WI

    Posted on 2/23/2016 3:25:44 AM

    Hi Buck. Thanks for the great info. I have a Pioneer HU with 2 sets of Pre-outs; Front and switchable Rear/Sub. The Front is ran to a 4 channel Sony amp using Y-cables. This powers my Pioneer 6.5's in the doors and 6x9's in the rear deck. Settings on the amp are "HPF@80Hz or OFF" for 2 of the channels, and "LPF@80Hz or OFF" for the other 2 channels. Since I want HPF on all 4, i have the amp's settings "OFF" and use the HU's HPF. The Rear/Sub-out runs to a monoblock amp to power my Sony sub. If I have the HU set to "Sub" it forces LPF, and I can't turn the LPF off on either the HU or the amp. If the HU is set to "Rear" then I have HPF on my sub, and therefore no bass. If I turn the LPF all the way up to 200Hz on the HU, will I be able to use the variable LPF on the amp with minimal effect of the phase distortion you mentioned?

  • Buck Pomerantz from Crutchfield

    Posted on 2/23/2016 1:11:17 PM

    Steve, If you want to use the low-pass filter in your subwoofer amplifier and you can't defeat the low-pass filter of your receiver, then what you describe is the way to go. The effects of each filter ought to be far enough away from each other in frequency to not interact badly.

  • Brandon guess from Clarksville

    Posted on 3/1/2016 11:08:28 PM

    Hi buc im wondering if it's going to hurt my two subs that have a power rating of 1000 rms a peice ,hooking them up to a one channel mono block re audio amp power rated 700x1 rms @ 2 ohms since I have two dvc 2 ohm subs I can only wre them down to two ohm or 0.5 ohms my amp is 1000x1 rms at 1 ohm my subs are 10 inch spl glw 10 2 ohm dvc wat should I do ive heard of underpowering subs hurt them

  • Buck Pomerantz from Crutchfield

    Posted on 3/2/2016 11:57:31 AM

    Brandon, Wired like this, that amp would be able to send each sub about 350 watts RMS, 700 watts total, which, as you note, is a lot less power than their RMS ratings. But you should be alright as long as that 700 watts RMS output is loud enough for you. Under-powering by itself causes no harm to a subwoofer - after all, you can turn the volume of a sub down without hurting it. Problems arise when the top clean output doesn't sound loud enough and the source or bass boost gets turned up beyond distortion levels sending clipped signals through the subs possibly damaging them.

  • Brandon guess from Clarksville

    Posted on 3/3/2016 6:26:00 PM

    Thanks the setup is only loud enough for me when I turn the gain and bass boost all the way up so does that mean I should get another amp .......cause since im turning my bass boost all the way up that means im distorting the signal rite????? And does using low out put converter robbing me of sound vs. Using a preamp cd player im using my factory cd player I have the l.o.c left and rite channel running from my factory sub also is it okay to run my power wire from the main fuse box post our do I need to run it straight from my battery

  • Buck Pomerantz from Crutchfield

    Posted on 3/4/2016 1:10:20 PM

    Brandon, Running a subwoofer amplifier with the gain and bass boost on full are usually indications that you need a larger amp. And you should definitely not use your vehicle's fuse box to obtain power for your amplifier. The positive power cable should connect directly to the battery, through an in-line fuse mounted near the battery. Use 4-gauge wire and a 70- to 100-A fuse.

  • Brad from Hollidaysburg, PA

    Posted on 3/10/2016 8:05:31 PM

    I have a question regarding my subwoofer crossover settings. I recently got a kicker 12cx300.1 mono amp tied to a 10" Rockford fosgate P1S2. I kept my stock head unit and used the kicker KISL to tap into my rear speakers and come out to the RCA input of the amp. The amp input level is set to high. The stock head unit has no subwoofer settings, just a graphic equalizer for sound adjustment. When I play back bass test tones it seems the sub plays regardless of what I set. For example if I set the crossover as low as it goes at 50hz, and then play a 100hz test tone, I still hear it come out of the sub. It just seems like the amp crossover settings are ignored and its playing everything it can. Is this because of the speaker level input? Can it be better set up?

  • Buck Pomerantz from Crutchfield

    Posted on 3/11/2016 12:43:06 PM

    Brad, The amp's input has no effect on the crossover/filter. When set to 50 Hz, a low-pass filter attenuates, turns down, all the frequencies above that setting. At 50 Hz, the crossover has turned it down by 3 dB. One octave higher, at 100 Hz, the signal will have been turned down a total of 15 dB. That's low volume, but not entirely off - so it's normal to hear a 100 Hz tone with the low-pass set at 50 Hz. The purpose of the low-pass filter in a subwoofer amp is to remove the higher frequency sounds, and I think that's best done by listening to music rather than test tones.

  • John from Sooke, B.C.

    Posted on 3/17/2016 5:04:37 AM

    Hello Buck, I am getting a Pioneer FH-X721BT , Kenwood KAC-7005PS, Polk Audio db1040DVC and 4 Infinity Reference 6032si. My intention was to run everything off the 5 channel Kenwood but I have my old Kenwood KAC-629s sitting there so I was wondering if it might not be better to have the infinitys running from the 5 channel and using the KAC-629S to run the sub... what would be the best way to hook this up?

  • Buck Pomerantz from Crutchfield

    Posted on 3/17/2016 3:43:48 PM

    John, You have a tough choice with that gear. Either under-power the sub with up to 120 watts RMS wired to the 2-channel amp like this. Or use the subwoofer channel of the 5-channel amp, driving the sub with up to 500 watts RMS wired like this. Either way will work as long as you don't play loud distortion through the sub. You're the only one who can decide which way is better.

  • Zack

    Posted on 3/19/2016 10:55:42 PM

    I have 2 kicker comp r 12 inch subs and they have switchs on the bottom of each sub that say ether 2 ohm or 8 ohm depending on what position you put them, i have a 2700 spl amp power them which would beat the most efficient way to wire them and which switch position is better

  • Buck Pomerantz from Crutchfield

    Posted on 3/21/2016 12:03:48 PM

    Zack, I'm not familiar with that amplifier, but you should be alright switching each sub to its 2-ohm setting and wiring the subs to the amp like this.

  • Dave from Sherbrooke

    Posted on 3/23/2016 1:58:28 PM

    Hi Buck. When you start your tutorial, you say to turn up the volume till it distorts. Do you have the receiver's bass and treble set to 0 or do you have them set to how you usually listen to your music?? Thanks

  • Buck Pomerantz from Crutchfield

    Posted on 3/23/2016 3:15:25 PM

    Dave, This article focuses on bass tuning, but you are correct that that information should have been included. For finding your receiver's maximum clean volume you should indeed first set the filters and EQ the way you normally listen to music.

  • Glen from North Bay, ON

    Posted on 4/24/2016 4:51:45 PM

    Hi Buck. Appreciate you answering questions on this very helpful tutorial. I was wondering if test tones can be used in place of the music, and if that might provide more accurate distortion points?

  • Buck Pomerantz from Crutchfield

    Posted on 4/25/2016 1:49:41 PM

    Glen, Many people use test tones to set amplifier gain, but using them for tuning a system's sound wouldn't work or tell you anything about the sound except at the exact frequency of each test tone. Maybe you're thinking of multi-frequency pink noise, which many people use along with a real-time analyzer (RTA) to equalize a system's frequency response, but that doesn't measure or prevent distortion. Your ears are the best things for perceiving distortion: it makes smooth voices hoarse, strings hiss, and drums crackle. The ultimate goal is for music to sound its best - that's what we listen to, not tones.

  • Clairice from Knightdale, NC

    Posted on 4/28/2016 3:53:15 AM

    Buck, thanks for your reply to my post on your blown sub page. I now have a question about my own car. We will be installing an lc7i with accubase in my stage 3 Ford focus st Saturday, of course leaving the stock head unit in. The lc7i will be between the stock Sony amp and a rockford 400 rd. The converter is adjustable, so is the process for tuning roughly the same?

  • Buck Pomerantz from Crutchfield

    Posted on 4/28/2016 1:27:53 PM

    Clairice, The AudioControl LC7i is a line output converter with gain controls and bass enhancer. I suggest reading the owner's manual carefully - it's well-written and informative. It says to set the LC7i's gains with the amp's gain turned all the way down at first. After that, you can follow this article's advice on tuning the bass, knowing that you have extra gain stages and a bass enhancer (like a bass boost) to tune.

  • Chip OBrien from Hackettstown

    Posted on 5/8/2016 11:47:05 AM

    I have a 2008 Durango with a Kenwood KDC-BT955HD head unit, Infinity Reference 6.5" speakers, with the fronts being components. I have an uninstalled Alpine MRV 353 5 channel amp (50X4 and 150X1) that I was thinking of having installed (have a 10" Box with MTX BT xtreme and 12" MTX also), but then I saw the Kenwood KSC-SW11 powered under-seat amplifier. I'm not looking for earth shaking bass, so I wonder if this is the better way to go. I also like the idea of the sub being out of the way.

  • Buck Pomerantz from Crutchfield

    Posted on 5/9/2016 1:24:49 PM

    Chip, I can't tell you what to expect with that MTX sub without knowing what model it is, but if you're satisfied with that Kenwood powered sub's 75 watts RMS output, then go ahead and get that - you'll definitely save space.

  • James from OLATHE

    Posted on 5/21/2016 9:33:53 AM

    Hey man, love these instructions and how helpful you've been to folks. I've got a small question. You mentioned tuning to get the edge of kick drums, and bass hits, is there a way to tune it to get less of the kick drum hits, but still just as much of the resonating bass? I feel the bass hits over power the resonating bass a lot in my setup.

  • Buck Pomerantz from Crutchfield

    Posted on 5/23/2016 11:21:07 AM

    James, If you were asking in a pro audio forum, I'd say you'd need a limiter or compressor to soften the kick drum's initial, very steep transient noise but leave the bass reverberations alone. In car audio, you do it with crossover or EQ filters. Try turning down the frequencies around 1000 and 2000 Hz, to soften some of those hard hits.

  • Rob

    Posted on 6/3/2016 2:21:19 AM

    I installed 8 Polk DB651 (2-wired parallell) powered by an Infinity Kappa Four in a boat. I have my settings on the HP crossover turned up to 260HZ because I only want highs to filter through. At this range I had no clipping or distortion at all but unfortunately I cooked all 8 tweeters 3 hours into playing (literally could smell them) In setting up the next batch how do I make sure as to not overpower them, like I said, they sounded great.

  • Buck Pomerantz from Crutchfield

    Posted on 6/3/2016 11:50:19 AM

    Rob, Setting an amplifier's gain (input level on your amp) properly is the best way to prevent speakers from blowing. Check out this article for some guidance there. If you bought your speakers or amp at Crutchfield, you could call Tech Support for free help troubleshooting your system. Their toll-free number is on your invoice. If you purchased your equipment elsewhere, you can still get expert Crutchfield Tech Support - 90 days-worth for only $30. Click on this link for details.