Subwoofer boom is too much for me...

Could I tone down the boom on my subwoofer by plugging the port with something like a washcloth?  Have you ever tried this and had success?

Thanks for your thoughts.




Try it. 
I’ve done it with different results but IME a properly built sub (ported) should not have a stark difference than a properly built sealed one.

Might try the gain first, and the crossover settings and slopes may have more immediate effect than plugging the port

Placement and EQ are your best friends, followed by a good corner bass trap.

Use the AM Acoustics room mode simulator and try to keep your listening location and sub out of the lowest room modes if you can.

An EQ and/or bass trap then is your friend.  Boomy bass is usually caused by narrow and tall peaks, which ironically, keeps you from turning up the subwoofer!

Yes, you can plug a subwoofer, but honestly good to measure if you can.  Tailored DSP/EQ for your problem can often be required.

I’ve done it with different results but IME a properly built sub (ported) should not have a stark difference than a properly built sealed one.


The issue isn’t the quality of the sub. The issue is the amount of bass in the room with this particular sub. Sealing a port will raise the lower cut off, and this may help the OP balance the bass properly.

As I’ve written lots of times, audiophiles are conditioned to think we can glean insight into a system’s response by specs, but in truth bass response is hugely variable and specs go out the window when it comes to integrating a sub into a room.

Below ~ 60 Hz speaker specs don’t tell you a thing once they are in the room.


I should have made it clear that only after extensive room treatment (bass traps)

I suppose I have tunnel vision that way…

I would not even consider positioning of sub or subs until after bass traps and/or treatment…

I did do it once that way though…

The room shape was atrocious as well- 15w x 28L x 7.6 high (all plaster walls also bad hard no lossy surfaces) 

only became somewhat acceptable after 4 subs…but the ringing was still generally unacceptable…

Well, I have to say I took two washcloths and stuffed them into the ports of both my subwoofers and there is a big improvement in sound.

I have subwoofer in from DAC amp and out to bookshelf for both channels.  Sounds great now.

I still think a good pair of floor-standers would sound better, but for now, I'm happy.




1) Auralex Lenrd bass traps from floor to ceiling in the corners of front wall (see pic in my virtual system)

2) An isoacoustics or ASC stand for your sub 

3) The DSPeaker 8033 sub eq device

This has worked for me every time I've set up a sub, whether it be REL or another brand. The idea of keeping the crossover as low as possible while volume high was tough to swallow at first, but now makes sense. 

Subwoofer tuning

And yes, I have bass traps and such. 

less likely your port is the problem and more likely you have incorrect slope and x-over frequency relative to your main speakers. fixable to a certain extent. 

+1 @baylinor 

I switched from ported (for literally 25 years) to sealed and am much happier with the sound.

There's little, if any, substitution for not locating the subwoofer/s in or very near the rooms greatest bass modes.

Playing a low frequency test tone through a subwoofer placed at the listening position while walking the room noting areas with the loudest bass is a simple means of locating the rooms mode location/s.  

If you insist on front wall corner or next to the speakers location, good luck.  

I take it from your post that you are only running one sub.  I know that many people advocate two subs, but I have had very good results with a single SVS 2000.  Plenty of grunt when called for (by a movie typically) but pretty invisible in supplementing the bass response of my La Scalas, which are not known for great bass.  

Either you've got the wrong sub-woofer, else it's in the wrong place in your room or you've got it turned up too high.

Sorry for so many options, but I've got all the basses (ho ho) covered.

This has worked for me every time I’ve set up a sub, whether it be REL or another brand. The idea of keeping the crossover as low as possible while volume high was tough to swallow at first, but now makes sense.

A horrible compromise at best and only recommended if you can do nothing about the response of your mains. Meaning, no high pass filter and won’t/can’t plug your port.

Many A'goners have gone the other way and been much happier.

Spend $10k on dsp, bass traps, diffusers, and absorption. Or, get a pair of athletic socks, ball them up and stuff them in and send me the $10k.

Also think placement then crossover setting/gain key. Perpahs four is too many?

Much has to do with the quality of your sub , I went from the $500 Svs pro 

to the 1000sb $1000, to the $svs 4000 sb $1800

and the 1000 had much more control and articulation ,

then to the 4000 SB-Sealed box. It took it to another level altogether the bass much faster,more articulate and controlled. ,No boom whatso ever .

you didnot mention what subwoofer you were having issues with.

I've done this on three subs with great results. Had the same issue as you describe. Now I have a subtle more controlled bass response. I just used sturdy paper tapered coffee cups pushed in snug. Washcloths didn't seal enough for my liking.  Some people have cautioned against this as they worry the sub amp will overheat without the designed airflow in and out of the port. Since I am trying to tame the boom I don't have the power on it too high to begin with and haven't noticed any heat build up even after all day of running this way. Good luck I think you'll like what you hear. If you have the budget a sealed sub is what you are after. This "conversion" creates a sealed sub but with a typically larger enclosure than a sealed sub would be in.  

You can add an equalizer and just turn down all the sliders especially on the higher end and the low end you can lower the sliders to reduce the bass. It works I use an eq and achieve the same results

Ported subs are for watching Avengers movies, not for serious listening.

Boomy works for explosions, but not so much for listening to Ray Brown.

1. Sell the ported sub.

2. Buy 4 sealed subs.

3. Do some research on distributed bass arrays.

4. You're welcome.

Real curious about what sub you have.

Years ago, my first sub, was nothing but boom. It was a low price Yamaha. 

Next sub was a Definitive Technology prosub 1000. It was better, but still had a little boom to it. In hindsight, I figure it was intended to serve in HT.

Got tired of playing that game and went to a REL 10" sub and found nirvana. Properly set up, a good sub is hard to notice, except for a little more depth and better definition of low frequencies.

I would think that a port needs to be plugged with something that seals it, like the foam plugs that come with some subs.  Maybe cut a piece off of a solid foam pool noodle.

Stuffing the port of a sub will make it less of a sub. The lowest notes of a ported box come from the port, not the driver. And if the box was not designed to be used stuffed as well as a higher bass cut off you could get boomy bass even from a 'sealed' enclosure if the new Q of the system is high.

Plus good ported bass sounds different from good sealed box bass. It tends to be richer due to more overhang than a good sealed box, A sealed box will tend to be more detailed but drier sounding.

I happen to have big bass boxes with 18" woofers designed to be used both sealed and ported because the designer was afraid of too much bass in some rooms. I discussed what I heard as described above to him and we totally agreed on what we heard. But I ended up with a closed box(with 10 Hz less bass extention). And even though he knew the closed box was more accurate he used the ported format.

I am using two subs.  My girlfriend has an old pair of JBLs with an old 80s era receiver, which sounds way better than my rig.



@erik_squires My sub doesn't have a port; however, I've been running a cable into the low pass with my Ragnarok as Schiit says their speaker terminals are both active (and thus I don't use their REL cable). However, most guidance says to avoid the HPF altogether. What do you recommend?

However, most guidance says to avoid the HPF altogether. What do you recommend?

Either plug your MAIN speakers or use a high pass filter, or both.

Here’s the deal. Audiophiles get all squirrelly over ethereal sounding qualities of sound but somehow manage to ignore the really big changes. I mean 10 dB or more changes. As a result they are averse to good subwoofer integration.

Here are the problems:

  • In the room, the bass output from the main speakers can be wonky. Too much, or peaky, often extending well below 30 Hz even for 2 way speakers. In fact so many users have problems they should deal with acoustically or by placement but they buy a sub instead... :D
  • As a result, the only way to use a subwoofer is to fill in that very small range, 16 Hz to 30 Hz or so, and to attempt do do it while side stepping any other room mode problems from the main.
  • Distortion in the main speaker is never reduced.
  • Dynamic range of the main speakers and amplifier is not increased.

They buy a subwoofer but then treat it like the unloved stepson that barely gets to do anything positive. So audiphiles go through the expense and toil of getting a subwoofer but refuse to use the high pass filter for fear it introduces more noise and distortion, which if true, would be hundreds of times smaller than the problems it fixes. They want a pure benefit, no downside solution only. Never mind the pure benefit is so vastly superior to the downside.

Kind of reminds me of my father, an avid cigar smoker, who claimed he never inhaled, just liked the flavor.

So, high passing the main speakers improves the frequency response by ensuring the mains are out of the way of the worst room modes. Then there’s the distortion benefits. Reducing the bass in a speaker reduces distortion. Subwoofer’s have much better distortion/dynamic range profiles in the 20-80Hz range than your mains. So if you let them overlap you have your main speakers distorting long before the subs do. Especially bad with 2-way speakers as IM distortion/Doppler distortion in the mid range can be pronounced.

The truth is that for your average floor stander to 2-way speaker everything gets easier and better sounding if you limit the output of the main speakers, either by plugging ports in the mains or by using a high pass filter or both. Everyone else is just screwing around.

Certainly we do not want a booming sub but that is not even the critical issue.  The critical issue is NONE of the subwoofers I have tried, including SVS SB 1000 & 2000, Rel T5x and my long-term Audio Research sub could render satisfactory bass in terms of its pace and texture to match with my main speakers.  I am not sure if the servo controlled sub could because I have not tried.  But I could tell you it is so damn difficult to integrate a large woofer controlled by a its own amp with the main speaker/amp. system.  You could mess around with the DSP to address the nulls / humps but the sub would never be able to be nimble enough to catch up with the main and also to match its texture with the main speakers.  Sandy Groves said the same thing and that is why GoldenEar floorstanders come with its built-in sub.  

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+1 for old JBL's, you should marry your girlfriend, you will have a high WAF for future audio needs. 

Before Christmas I bought 2 more sub for my system? I already have one.Now I have 3. What I do I will put all the volume of my sub down including the crossover .Then I will start adjusting each one, through volume and crossover? This is how I am able to control bass .It works for me.

There is little to no substitute for a speaker that does bass properly to begin with. You don't need a sub.

If it’s boomy, it’s not located properly, crossed over properly or set to the correct level. 

@audioguy85    Yeah.  But many cannot fit in or afford the necessarily huge and expensive speakers that do bass properly.  And there is still a cross-over to the bass driver(s).

["audioguy85    There is little to no substitute for a speaker that does bass properly to begin with. You don't need a sub."]

'Properly,' must be the reason why I often see manufacturers of statement speakers demonstrate them with subwoofers.  



If it’s boomy, it’s not located properly, crossed over properly or set to the correct level. 

I kind of disagree. I mean, this all depends on how many options we have available to us to fix a problem.  One of the most common is that there are big peaks that need to get clipped.  OK, so what if I can't move the sub?  Well that forces us to choose too low a level for the sub.  An EQ though, with or without bass traps suddenly opens up a range of possibilities.

While I agree that the room and treatments has a lot to do with the overall sound and quality of bass and Erik consistently puts out a lot of good information, I am sometimes a bit confused at what some think good (true) bass should sound like. When I hear the terms quick or solid when connected to deep bass, I have to kind of scratch my head - since there is nothing quick or solid about deep bass. The closer to 20Hz the frequency drops the less solid, the less perceived as quick and the less directional it becomes. For more impactful and solid bass you would be looking for an emphasis on the 100-200Hz range. For me the quest has been to find the right balance between mid, impactful bass and deep, full bass, so when the deep bass is on the recording it is heard and felt, making it easy to distinguish between a double string bass, an electric bass guitar, synthesized bass or an organ peddle. Finding that balance with the mid. and deep bass is the key to achieving good bass and hearing and feeling what’s there. Again, there is nothing quick, fast or solid about deep bass - don’t expect it to be so........Jim

I remember hearing Richard Vandrsteen at AXPONA and laughing. He said the irony of subwoofers is, you spend all this money on them, then, ideally, if they're set up correctly - you don't even notice them!

What is your sub? Are you using for dual purpose (ht)? I would say get a new better sub. My REL tx9 disappears in my system and added to the sound across the room..before my REL I tried using my infinity ht sub in my two channel. I had to turn it all the way down to only one click to avoid the boom that washed out the speakers.