You can't have too many bass traps...


Hej

I've read that you can't have too many bass traps. Is that really true? 
simna
Subs. You can't have too many subs.
Nope.

It does take considerable amount of bass traps to improve an enclosed space. If you are unwilling/unable to use EQ you'll need more to get a perfect room, but yes, you can over-dampen not just the bass, but the mid/treble as well.

4 of the GIK acoustics Soffit Traps are a good start for a modest room. 
Best,
E
The trick with bass traps, gentle readers, is knowing exactly where they should go. It helps to have a method to determine the exact location of the standing waves in the room, a test tone and SPL meter or even an empty shoebox will alert you to the standing wave while a test tone is playing by vibrating in the presence of the standing wave. As it turns out sometimes the bass trap should be placed a foot or two away from the room corner. If one puts bass traps around willy nilly without measuring it’s very possible to degrade the sound, fair warning ⚠️ You feel invincible, like the more tube traps the better the sound! 🤗
Well you can accidentally kill yourself by drinking too much of something as seemingly innocuous as water, so I’m guessing answer to question is no, as it is 99.999% of time with absolute questions of the sort ; )

Systems-you can’t have too many separate music systems!
Post removed 
i am the poster child for too much bass trapping. and it only took me 10 years to figure it out.

i did a clean sheet of paper built room in 2004 in a barn. it was a room inside a room. with bass trapping along the front walls (15’ x 9’ x 1’) and the rear wall in 4 places (2’ x 9’ x 1’), and the whole drop ceiling was a bass trap (21’ x 29’ x 18"). my designer said he would add all the bass trapping i might ever need, and i could remove it as i needed to.

what i did not know is how much i would need to learn to understand what i needed to do. i removed the front side wall trapping in 2010-2011 and some of the ceiling trapping. then in 2015 i removed the rest of the ceiling trapping. only the rear wall trapping now remains.

i had to evolve myself to be able to get it right.

the good news is i have been happy for the last 5 years, and fully satisfied now. the room breathes and has the most awesome bass you would ever hear.

but.......you can have too much bass trapping. but don't forget that 'you' and your understanding of what you are hearing is an essential part of getting it right.
Good advise given already.

First you have to define what a bass trap is, to answer the question. If a "bass trap" reduces 60hz by 5% of what's needed but reduces 30% of 2k level, then what would happen to your sound after installing the 20 bass traps you need for the 60hz? "Bass trap" is a tool. Use the right tool for the job.
Bass traps are actually not the right tool for 60 Hz. The right tool for 60 Hz is a Helmholtz resonator. A big one. I built a fifteen foot long S-shaped Helmholtz resonator from 6” diameter PVC for a stubborn 60 Hz standing wave. That’s the way you get rid of a 60 Hz standing wave. 🤗
Bass traps are actually not the right tool for 60 Hz.


Well, that's why in my original post I said one needs to define what a bass trap is. Generally speaking, people buy "Bass traps" to tame all that low  bass output. Whether they are right or wrong, that's what people do..... 
Bass traps are actually not the right tool for 60 Hz.


Maybe not the best tool given infinite money and space, but I disagree they are not a very good tool. First, some specs:

https://www.gikacoustics.com/product/gik-acoustics-soffit-bass-trap/

As you can see, these traps are very effective in the range of 40 to 100 Hz, and plenty effective at 60-ish.


Mind you, a Helmholtz resonator is certainly the most effective at specific frequencies, but a bass trap doesn’t have to be perfect to work. All it has to do is tamp down the ringing a little (like placing your finger on the side of a bell). You only need it to be partially effective, and then you can EQ the rest. I think that bass traps can be a lot easier to install and move with you than a HR.  The combination of bass trap + EQ is a room mode assassin.


This is what the pros say. De-energize the room modes just a little and EQ can suddenly become effective, and I’ve proven it in my own spaces repeatedly.

Best,
E
The big/thick bass traps can help some, but they still do not absorb much down low (such as 50-60hz).  Also, since they are broadband, they will tend to suck the life out of the room if too many are implemented.  I have actually found that Owens 703 FRK panels work very well down to about 85 hz.  And they are not huge (only 2 " thick).  Very light.   The have a metal foil that covers the front surface and acts like a tuned-membrane bass trap, but still reflects the upper mids/highs.  The foil resonates with the bass frequencies and the fiberglass behind it will absorb that resonate energy.  You just have to be careful not to put too many in your room because it can start getting to bright/harsh.  They are excellent for handling the upper bass and midbass.

Tuned membrane bass traps or limp mass bass traps are the only ones that I have found effective for lower frequencies.  I tried a variation of helmholtz resonators and it was a pain and didn't do anything.  I didn't do the 6" / 15foot design, though.

You can build your own tuned membrane (but don't use dense panels for the inside):
https://www.gearslutz.com/board/bass-traps-acoustic-panels-foam-etc/743040-tims-limp-mass-bass-absorbers.html

Or you can get GIK's version, which are the Scopus bass traps.

I have also tried the GIK bass traps with the FlexRange limiter.  They are okay, but don't work as well as the 703 FRK panels.  The FlexRange limiter is really just a 1/8" piece of cheap wood that is loosely held in front of the acoustic material.
Well, that's why in my original post I said one needs to define what a bass trap is. Generally speaking, people buy "Bass traps" to tame all that low bass output. Whether they are right or wrong, that's what people do.....
Bass traps will absorb bass frequencies.  The idea is to absorb this energy so that it does not get reflected back into the room.  The biggest problem are when reflected bass hits the generated bass from the speakers and cancels itself out, creating a bass NULL.  This can be heard as a significant drop in bass around certain frequencies.  Bass traps will reduce this reflected energy and reduce the bass NULLS, therefore allowing more bass to be heard.
The biggest problem are when reflected bass hits the generated bass from the speakers and cancels itself out, creating a bass NULL.

I'm going to disagree.  I've measured 20 dB peaks as well in a modest living room.  That peak prevented the subwoofer level from coming up. Nulls, if narrow enough, may not even be heard, peaks though are ugly to listen to. 



I'm going to disagree. I've measured 20 dB peaks as well in a modest living room. That peak prevented the subwoofer level from coming up. Nulls, if narrow enough, may not even be heard, peaks though are ugly to listen to.

Not disagreeing with you.  peaks can also be a problem.

Mike Lavigne, 

Just looking at pictures of your amazing room. Where are the bass traps in the back hiding? Is there scrim on the back walls?
I recently treated my room with GIK products.  All my panels are called bass traps but they are used for multiple things.  I have 3 first reflection point panels.  Bass traps on the front wall sitting on the floor and diffusion panels on the back wall.  I had previously bought some corner foam traps from Amazon but not sure how effective they are.  I feel this was a very nice improvement in bass and soundstaging.  A question I have had though is that I have a Type A decibel meter but it only seems to pick up mid range accurately.  Do I need a Type A/C? 
In the house we recently sold, my "man cave" was a 24’x26’ room. I got the system with the main speakers "dialed in", sounding awesome. Then when I added my sub woofers I discovered that the room had terrible acoustics in the bass region; regardless of the bass line in the music, the room added one loud bass tone.

I eventually purchased a " miniDSP UMIK-1 USB Measurement Calibrated Microphone" (I found it on Amazon), a mike stand and the REW (Room EQ Wizard) software ( https://www.roomeqwizard.com/ ), which guided me to purchase and position what eventually turned out to be 10 bass traps, to mostly control the errant bass response from the room.

I probably could have used two more traps, but the love of my life began asking if I was headed for my "padded cell" when going for my nightly listening session.
Absolutely incorrect! I would think that you can have too many of any treatment. 
Depends upon the bass trap' design in question.
You can't have too many bass traps...[?]

Unequivocally: yes, you can. Too many of them and put the wrong the places they eat away of proper soundstage fill/size and kills overall energy and (natural) liveliness of the sound. It's about strategically placed bass traps, smaller ones at that and used sparingly - as I see it. To much bass trapping may have an alluring sense of bass control, but I'd rather live with the occasional unevenness of response to have a more natural overall presentation. I'd include diffusion predominantly over the Schroeder frequency and, again, light absorption below it to deal with bass modes.  
I know I'm grave digging here, but the information is so egregiously incorrect, I had to say something.

I'm going to assume we're not talking about tuned traps, but rather absorbers.

You cannot have too much bass trapping, for the simple reason that at a certain point, with enough traps, all reflections will be totally absorbed.

There's one major problem with most of these replies, they seem to assume the OP has a decent sized room, but chances are the room is small.

There are two approaches to eqing a room, tuning it by targeting problem frequencies, or damping until the whole thing is flat.

If you have a small room, approach 1 probably isn't going to work. Chances are the acoustics are so bad, you just need to remove them all. The only "liveliness" a small room has is the janky kind.

Thinking about most untuned traps, they are actually cutting the high end at a more efficient rate. So if you only put a few in, you'll end up effecting the high end first. As you add thicker and thicker trapping the low end starts to catch up, until finally you get to the point were everything is absorbed.

So the problem most people on this thread are probably having is using no where near enough bass trapping. Question: is it feasible to use that much? It doesn't take thaaaaat much. I mean you'll have to sacrifice real space, but trying to hang Owens corning here there and everywhere isn't terribly space efficient either.

Cheapest way, take a small room, measure off 1 meter, make a false wall with cheap timber and fill the entire cavity with cheap fluffy fiberglass insulation between 4000 and 6000 rayls/m (most is, but check the GFR first). You'll loose a meter of space, but you can use much cheaper insulation and it will be better down to waaay lower frequencies. Now test the room, if it's not pretty flat, add more and make them thick.

Option two is to strategically try and tune the room, good luck with that.
Right. Bass traps are worthless as tits on a bull. You need an intelligent room, subwoofers and digital bass management. The wavelengths are too long for anything the size of bass traps to do anything. All they do is absorb and redirect higher frequencies. If you decrease higher frequencies the bass becomes relatively louder. This give the illusion of more bass. Nice racket.
All of you who think you know what you are doing need to get yourselves a calibrated mic and impulse measurement program. Learn what is really happening rather than falling prey to myths and marketing.
Replaceablehead is pretty tuned in. That would be two puns for me today. I believe I am at my limit. Damp almost all reflections and the room is near flat.
Find the GFR in rayls/m3, or pa.s/m2 and match the thickness to the GFR. Use a calculator http://www.acousticmodelling.com/porous.php

"Get the rayls, use the calc, get the rayls, make them thick". Don’t guess, don’t use density kg/m3. Get the right figures. Thick is good.


Getting a suitable mic, small condenser, or proper measuring mic and using Room Eq Wizard is a good idea. But I would still say accurate GFR is the single most important thing to know. Room Eq Wizard graphs are hard to interpret and can make you feel hopeless. I’ve seen plenty of guys use Room Eq Wizard and then proceed to do a very poor job of treatment followed by another REW test that they interpret positively because they’re inexperienced and desperately want to see an improvement. If you get the rayls, use the calc, make ’em thick, and use plenty you should get good results.

And one last time, you cannot have too many, the only issue you’ll run into is having just enough to screw up the high end and not enough to tame the low end. Again, assuming you’re not trying to surgically target frequencies in an already pretty good room ie. an actual recording studio. If it’s a small room in your house, you need to take a deep breath, accept that you have limited options and make ’em thick son.
I disagree with mijostyn. I believe one should address room issues passively instead of adding more electronics be in the mix.