how to eliminate boomy bass...

[manoj.p]

Yes, I meant right side, not right speaker per say.

The problem is because your room is not symmetrical and that's not going to change. And the whole purpose of using the mains for bass is because you got the new carpet + speaker spikes? If there is no boominess with sub-woofer, then you are just introducing a problem in your system by enforcing bass through mains.

whether you use spikes or put the bass through mains or use subwoofer does not matter. Let your ears decide which option sounds the best and go for that.

As for locking the bass in dead center by using mains, then it does not matter below 80Hz because those frequencies are not localizable. That's why a sub can be placed anywhere in the room.

 

[manu4panjab]

Yes, I meant right side, not right speaker per say.

The problem is because your room is not symmetrical and that's not going to change. And the whole purpose of using the mains for bass is because you got the new carpet + speaker spikes? If there is no boominess with sub-woofer, then you are just introducing a problem in your system by enforcing bass through mains.

whether you use spikes or put the bass through mains or use subwoofer does not matter. Let your ears decide which option sounds the best and go for that.

As for locking the bass in dead center by using mains, then it does not matter below 80Hz because those frequencies are not localizable. That's why a sub can be placed anywhere in the room.

with subwoofer option is best but still no matter how much i reduced sub's own dail or av processor subs volume i can still hear uneven bass from right side which lead to my right ear become heavy every time i play bass heavy scene(n keep in my my ears r in perfect conditions )
i have also checked ur home theatre pics awesome job man ....pls tell me where u get acoustic treatment what kind of foam n did u use 4 inch foam on ur side wall in horizontal manner

n why u treated ur front wall i mean wall behind speakers ??

 

[captrajesh]

they are very close like only 9inches space n not an option for me to place inward in the room ...

Is your speaker rear firing port type? If yes, then 9 inch is way too less. Increasing that 2 feet should produce wonders. Please experiment. Even for non-rear firing, it's still good to keep sufficient space behind (and to the sides of the speakers).

Hi Manu,

Front port or rear port, 9" breathing space is way too low for floorstanders. I pull my speakers about 2' into the room during listening session and push them back at the end to the wall to reclaim the space and I suggest you do the same. If bass persists, you can move around near the corner and find where bass is getting reinforced and make a provision to hang thick towel there. I've personally experienced this bringing down bass overhang at Dr. Bass's place.

R

 

[HTuser]

Thanks for your reply

Will a 10" bass trap absorb all frequencies below 80Hz and make the sound dead !!

I don't think 10" trap will absorb 80Hz as per the calculation I posted earlier. I wanted to know whether it will affect the frequencies below 80Hz.

Adding another subwoofer is not an option as of now

Measuring using an SPL meter can give you dips and peaks and take action to rectify specific peaks or dips.

When measured, I found that most of the frequencies below 55Hz is producing high dB values. Looks like there is a high room gain in the low frequency range.

I won't be able to install a bass trap of 1 meter or 2 meters thick. I wanted to know whether the room gain reduce if I install corner bass traps?
ie whether corner bass traps are effective for frequencies in the 20-60Hz range?

To take care of peaks and dips in the below 80Hz frequencies, one can either use very thick bass traps, like 10" or something. That will make the room sound dead though and the subwoofer amp will have to overwork to get more db.

A better option is to use another or more than one subwoofer.

The best way to start on this whole thing is to invest in a SPL meter, use it with Room Eq Wizard and find out the room response. That will make the situation more clear and the solution will be better informed. Otherwise, its only shooting in the dark and see if it hits the target. We spend lacs on audio equipment but the SPL meter goes a long way in setting the equipment right. Even a Radioshack SPL meter is a good start and its only $50.

 

[manoj.p]

with subwoofer option is best but still no matter how much i reduced sub's own dail or av processor subs volume i can still hear uneven bass from right side which lead to my right ear become heavy every time i play bass heavy scene(n keep in my my ears r in perfect conditions )
i have also checked ur home theatre pics awesome job man ....pls tell me where u get acoustic treatment what kind of foam n did u use 4 inch foam on ur side wall in horizontal manner

n why u treated ur front wall i mean wall behind speakers ??

thanks for compliments on the room.

I used Certainteed (Certa Pro CB300) rigid fiberglass insulation. It's equivalent to OwensCorning 703.

When I started out doing the treatments, I didn't had much idea. So most of it came from reading on the forums, seeing other people's theater and most importantly, talking with Sanjay Durani. He has been very helpful in explaining things, audio setups etc. Much easier than reading on forums and trying to figure it out. The insulation on the back wall is 2". Sanjay did tell me to put more there and on back, but I could only put 2". Sure, I can pull them forward and use the air gap trick. Each of the front corners have more fiberglass stuffed in it, sort of acting as corner bass trap.

 

[manoj.p]

Thanks for your reply

Will a 10" bass trap absorb all frequencies below 80Hz and make the sound dead !!

I don't think 10" trap will absorb 80Hz as per the calculation I posted earlier. I wanted to know whether it will affect the frequencies below 80Hz.

No, it does not. But you can use the air gap trick. Pull the panel away from the wall. So, the sound goes through it, hits the wall, reflects back and goes through the bass trap and then comes out again. This effectively makes the 10" bass trap act like a 20" one. That again may not be all sufficient for absorbing all.

When measured, I found that most of the frequencies below 55Hz is producing high dB values. Looks like there is a high room gain in the low frequency range.

I won't be able to install a bass trap of 1 meter or 2 meters thick. I wanted to know whether the room gain reduce if I install corner bass traps?
ie whether corner bass traps are effective for frequencies in the 20-60Hz range?

Okay, I think Sanjay can give you better answer but let me try.
The idea is to get smooth, flat response from 20 to 80Hz. Having the room gain, sometimes is actually good. The sub driver needs more power to deliver the db's as the frequencies go lower. If there is a room gain, then you can use parametric eq to bring the extra loudness caused by room gain down.
So, the first step would be to plot a graph of freq response. Find out the peak below 55 hz. Then use parametric eq on the sub to that freq, width as the width of freq zone where you want to pull it down and reduce the gain on it. Try new setting and measure again. Try till you get it flatter.

Another option is to try different sub placement. Usually corners make the subs louder. People use it because then the amp has to work less, but that can cause some peaks in frequency response. I had the subs in corner first but that was making it quite boomy. Moving those little away from corners made the boom go away. Bass lingers more near corners, walls etc. If your seating position is closer to wall, then it will make sound more boomy.

Try these different options and see if it helps.

 

[marsilians]

my room is i guess not fully symmetrical,i also swap speakers but same thing its from right side of the room i have spikes that comes with rti a5 speakers lemme try these

Hi Just catching up with your post now.

Taming boominess requires a bit of a study. Its easy if you know at what frequency its becoming boomy. If you dont have this info, few things to try are:

1. Setup: Have you set your floor standers as "small" speakers via your AVR?
2. Have you set your subwoofer cross over or cut off frequency properly? anywhere from 70-120 Hz can be used. Usually this is at 80 but you could try increments of 10 Hz to tame it.
3. If you have an option of trying to re position your sub its worthwhile to do it. Also a bass management system would help a lot in this regard. The Outlaw audio ICBM or the SVS AS-EQ1 Subwoofer Equalizer are examples of this.
4. Bass traps - using insulation materials like Owen Corning 93 would be helpful. You can build this yourself easily.
5. Port Plugs: I see that you ahve used towels. These have a tendency to kill most frequencies due to density. Thats why many manufacturers like SVS and Rel and B&W offer this in hard sponge as they ahve to be porous enough to let the mid ranges to go through. T-shirts and towels are definitely not recommended.

Finally ensure your floor has carpeted heavily. This tends to tame such frequencies.

Let us know how this goes and then we can provide more suggestions.

 

[HTuser]

I don't think 10" trap will absorb 80Hz as per the calculation I posted earlier. I wanted to know whether it will affect the frequencies below 80Hz.

No, it does not. But you can use the air gap trick. Pull the panel away from the wall. So, the sound goes through it, hits the wall, reflects back and goes through the bass trap and then comes out again. This effectively makes the 10" bass trap act like a 20" one. That again may not be all sufficient for absorbing all.

Fair enough. What I understand is the basstrap with airgap trick can be used to reduce the boomy effect of frequencies below 80Hz, even though it cannot completely absorb it.

I don't want to install a basstrap if it is not going to do anything to frequencies below 80Hz. If it can partially absorb as mentioned above i would like to proceed with installing a basstrap with airgap.

 

[sdurani]

If it can partially absorb as mentioned above i would like to proceed with installing a basstrap with airgap.

Yes, it will partially absorb. You can make the bass trap more effective by having it straddle a corner.

Bass is stronger at room boundries (you can demonstrate this for yourself by standing against the wall while listening to bass heavy music). Where two boundries meet (corner), there is more bass to trap. Where three boundries meet (floor or ceiling tri-corners), even more bass.

If you can build tall (floor to ceiling) bass traps and place them stradling any corners of the room, then you're doing two things to improve effectiveness: getting an air gap behind the trap AND using a location with concentrated bass.

 

[manu4panjab]

gud news guys somehow by experimentiing n experimenting i tamed almost 99% bass boom :yahoo:

thanks for all ur ans.

 

[manu4panjab]

thanks for compliments on the room.

I used Certainteed (Certa Pro CB300) rigid fiberglass insulation. It's equivalent to OwensCorning 703.

When I started out doing the treatments, I didn't had much idea. So most of it came from reading on the forums, seeing other people's theater and most importantly, talking with Sanjay Durani. He has been very helpful in explaining things, audio setups etc. Much easier than reading on forums and trying to figure it out. The insulation on the back wall is 2". Sanjay did tell me to put more there and on back, but I could only put 2". Sure, I can pull them forward and use the air gap trick. Each of the front corners have more fiberglass stuffed in it, sort of acting as corner bass trap.

hey bhai from where you purchased fiberglass n at what price
so we need to use full wall treatment on front wall to make the front wall as false wall right...

 

[marsilians]

gud news guys somehow by experimentiing n experimenting i tamed almost 99% bass boom :yahoo:

thanks for all ur ans.

what experiments? Share the details so it may help other members.

 

[manoj.p]

hey bhai from where you purchased fiberglass n at what price
so we need to use full wall treatment on front wall to make the front wall as false wall right...

I bought it from an HVAC supply warehouse. I am not sure whether the exact brand is available in India, but ask any Air conditioning supply warehouses about the rigid fiberglass.

You can add more thick treatment compared to what i have. Don't have to be entire wall. Just behind the speakers would be good enough. If you plan to make a false wall, all you have to do is build a frame that will cover all wall, stick the rigid fiberglass where you want and then wrap with acoustic transparent cloth. From outside, it will be hard to tell the difference.

 

[captrajesh]

gud news guys somehow by experimentiing n experimenting i tamed almost 99% bass boom

what experiments? Share the details so it may help other members.

+1. Kindly share your experiences here.

 

[manu4panjab]

what experiments? Share the details so it may help other members.

experiments like ,i first i set floorstanders to full in umc-1 bass management n start to toe-in fs until boominess disappear to some extent n use measeurement tape so that both are same distance for their walls as opposed to each other n also spikes helps alot
then set all speakers to small n dail in subwoofer until u won't tell its direction ...
i also add small cushions on all 4 tricorners(not floor tricorners but ceiling tricorners) which help to tame boominess at largeextent
when i use cushions at speakers back it muddy the sound very very dull lacks the spark so i thought instead of floor why not add cushions to ceiling tricorners so it works luckily
basicallt toe-in speakers helps alot ......n measuring distance for both speakers ,first i just put them without any measurement that's why i guess one speakers is not placed at the same position as of other which creates uneven bass n boominess

future plan is to use front wall as false wall with proper insulation n use ceiling armstrong acoustic tiles n use proper bass traps made from rigid fiberglass which surely helps alot...
hope u guys understand my english is not that gud :indifferent14:

 

[sdurani]

i have tried spikes but no effect

also spikes helps alot

Are you using different spikes than before?

 

[manu4panjab]

Are you using different spikes than before?

naah same one its just i dun toe-in speakers before n i use toe-in yesterday with n without spikes n i can easily hear mopre tight bass with spikes i guess spikes intact the fs with carpet very well coz with rubber feets fs were not stable

so using spikes now for proper grip ...

 

[sdurani]

oic
_______________
Sanjay

 

[darshanjoshi]

My speakers has a Base Plinth so that speakers stay a little top from floor. Manufacturer has also supplied spikes with same. Would it help me in removing some bloatiness if i use the spikes.

 

[Hari Iyer]

hey bros. as u know i have polk rti series floorstanders my problem is they always sounded boomy i mean not the left speaker but right one u can hear boomy bass from right side of the room

tonite i added 1 pillow each in both corner n i reduce gud amount of boominess but not 100% so should i add more pillows like from floor to ceiling ,it will be hidden behind my screen curtain from both sides..
so pls help is it cheapest way to eliminate boominess or do u have any other solution ..

You can try the following,
1. Try moving the speaker away from the corners if possible to reduce the boomy bass. Corner placements adds from 3dB to 6dB of more bass to the room.
2. Try reducing the bass level in you amplifier and see if that helps. Alternatively you can increase the treble in your amplifier and see if that help to mask the boomy bass.
3. Try adding heavy curtains and thick carpets to your floor.
4. Try re-locating your listening position and move your chair, sofa to a less co-incident position to widen the foot print.
5. Try to angle the speaker into a 60 deg angle to have a more focused stereo image.
6. Try raising the speaker off the floor to reduce low frequency lift by another 1dB to 1.5dB.
7. Try other types of speaker system. Generally vented enclsoures are know to produce boomy bass due to their design. Try switching to Transmission Line type (TL) where there is no boomy bass reproduction due to its inherent design.