# Bass trap advice



## Wull (Apr 7, 2010)

Hi there.

I am thinking of having a go at making some bass traps, so need some welcome advice :help:.

My living room is 24'L/13.5'W/7.5'H

When listing to bass heavy music I am finding that if I walk from one side of the room to the other, the bass is a lot louder, dare I say boomy right down the whole length of the room. 

So I was wandering what DIY bass trap's would be recommended. Am I right in thinking that dense Rockwool is best used for this purpose.

I can at my local builders merchants either purchase rockwool which is compact and made for floor insulation, or rockwool which is not as dense, that is made for stud wall insulation but thicker.

I may also have a go at a 'super chuck bass traps'

Let me know what you think......

Thanks for your time.

Will


----------



## bpape (Sep 14, 2006)

Not sure exactly where you're saying the additional boom is. All down the length but in the middle, against the walls, fully from side to side?

Density requirements vary with thickness. The thicker you go, the less density plays a large part in effectiveness. 

Bryan


----------



## Moonfly (Aug 1, 2008)

Hi Will, 

Bryan is the guy I was telling you about that will be able to help, good to see him chipping in so quickly :T

Cheers Bryan :clap:


----------



## bpape (Sep 14, 2006)

:nerd:

Nerd for hire 

Bryan


----------



## Wull (Apr 7, 2010)

Cheers Dan.

Hi Bryan.



> Not sure exactly where you're saying the additional boom is. All down the length but in the middle, against the walls, fully from side to side?



What's happened is I have just installed an IB in my living room ceiling at the weekend, this is positioned to the front left hand corner if facing the TV. I have run REW, and from my seating seat all's is good, however I changed seats on Sat night whilst listening to music, this seat backs up to the outside wall, this runs the full length of the room. I found the bass to powerful whilst sat their, this louder bass ran the full length of the room, but was at it's loudest in front right hand corner 'if facing the tv' opposite the IB.

So I wandered about bass traps, but I haven't got the foggiest what materials I should use if one or a few would help, hence the 'super chuck bass traps'

Will


----------



## bpape (Sep 14, 2006)

Corner mounting of the IB is maximally exciting all of the room modes. The longest 'axial' (not really axial but 1 dimensional) mode is the diagonal from upper left to lower right or the other way around. It's also the lowest and hardest to deal with.

Chunk style absorption in the rear corners will help with this as well as overall decay time. 

Seats right against a boundary will always have issues with bass buildup since the boundaries are where this happens (and why corners are an efficient place for absorption as it's at the end of 2 different room boundaries)

Bryan


----------



## Wull (Apr 7, 2010)

I had to put the IB their as I was limited by the amount of free loft room, it was a compromise. I have to say the bass has not been as bad tonight, but I will still have a go at a trap or two.



> Chunk style absorption in the rear corners will help with this as well as overall decay time.


Can I make these out of 4" rockwool, and just cut and stack triangles to see if it works first before making a speaker frame type affair?


----------



## bpape (Sep 14, 2006)

Understood on the placement. Was just explaining what was occurring.

4" mineral is fine cut and stacked. No need for high density depending on the size of the triangles. If you cut each one into 8 triangles (17x17x24") per 2'x4' piece, you'll have 32" per 4" thick piece. 2.5 or 4.5lb density will be sufficient at this size and thickness.

Bryan


----------



## Wull (Apr 7, 2010)

> Was just explaining what was occurring.


Cheers Bryan, thats was a great explanation, it's stuff like that I don't understand to well, so I appreciate being told :T



> 4" mineral is fine cut and stacked. No need for high density depending on the size of the triangles. If you cut each one into 8 triangles (17x17x24") per 2'x4' piece, you'll have 32" per 4" thick piece. 2.5 or 4.5lb density will be sufficient at this size and thickness.


I shall invest tomorrow. Will let you know how I get on..

Thanks again.

Will


----------



## Wull (Apr 7, 2010)

Hi Bryan, Well I've finally started. :flex:

I ended up moving my IB out of the corner which has improved things no end, however I have the superchunk bug so here goes..... Also, I am making bass trap panels, these look a bit rough in the pic but I have high hopes for the finish on these.

Will post more pic's as things crack on :boxer:


----------



## bpape (Sep 14, 2006)

Looks like a good start. They should work great.

Bryan


----------



## Wull (Apr 7, 2010)

Bryan, for the side panels I will be using 2" rocksilk, should I use RS45 or RS60?


----------



## bpape (Sep 14, 2006)

Either will work fine in a 2" application.

Bryan


----------



## Wull (Apr 7, 2010)

Hi Bryan.

I finished my traps at the weekend. The results are better, but I still have a problem. Having run the room mode calculator I seem to have bass at around 40hz which is reinforced by the room. 
Within my seated area I ended up calibrating an antimode in the loudest part, this reduce the bass problem dramatically. I have since managed to get my hands on an Audyssey Sub EQ + Pro Installer Kit. Do you think EQ is the way forward now or do I still need to introduce more traps do you think?

Would heavy thick curtains help, I have windows running the length on one side of my room which at the mo I use roller blinds with. The opposite wall I wouldn't think to be as bigger problem as it is slate stone faced so I thought this would act like a diffuser.


----------



## bpape (Sep 14, 2006)

If you move the mic forward or backward does the null change in frequency or intensity? Moving is the easiest and best thing to do. 40hz is pretty tough to deal with via porous absorbers. You may need to EQ. 

That all said, more bass control could still be beneficial in terms of decay time control.

Bryan


----------



## Wull (Apr 7, 2010)

bpape said:


> If you move the mic forward or backward does the null change in frequency or intensity? Moving is the easiest and best thing to do. 40hz is pretty tough to deal with via porous absorbers. You may need to EQ.
> 
> That all said, more bass control could still be beneficial in terms of decay time control.
> 
> Bryan


forward and back wards is not a problem, it's side to side. From the central seated position I have 3 feet either side which is fine, go any further than that 'the last 3 feet either side' and the bass really kicks in.



I re-measured my room and it is only 12.5 feet wide not the 13.5 I first thought it was 'lost a foot'?


----------



## Wull (Apr 7, 2010)

forgot to mention I ended up moving the IB. It now is situated 5 ft out from the back wall, and 3 ft in from the side so well out of the corner now.


Just to add, my seating position is 8 ft off the rear wall, so I am not seated central to the front and back walls


----------



## bpape (Sep 14, 2006)

Well, sitting in that last 3' close to the wall isn't recommended anyway - not just your room. Sitting next to any boundary is a problem to be avoided.

Bryan


----------



## Wull (Apr 7, 2010)

cheers Bryan.

I will let you know how I get on with the EQ when it turns up.


----------



## Wull (Apr 7, 2010)

The weather here in the UK has gone South Bryan, so this gave me the opportunity to Spend a fair bit of time listening to music instead of trying to find fault from every listening position.
From the sweat spot I have to say the bass from the IB is something else, those traps have certainly added something. I have no EQ in the system and it still sounded fantastic, the bass notes are so tuneful, listing to stuff like 'Finley Quaye - Even after all' is to die for. Switching back and forth from full range to crossovers is quite staggering. Even the OH was impressed :T


----------



## Moonfly (Aug 1, 2008)

I still cant get over how much difference really high end bass can make to even the most average of systems. For DIY'ers you can simply transform your system for the best value outlay there is. I'm glad to see my ranting about IB has proven a success (I'm convinced there are those who have little regard for anything I say  ), and Bryan certainly comes through time and time again.

You got any pictures of the final setup Magic?


----------



## Wull (Apr 7, 2010)

Pics


----------



## Wull (Apr 7, 2010)

Moonfly said:


> I still cant get over how much difference really high end bass can make to even the most average of systems. For DIY'ers you can simply transform your system for the best value outlay there is. I'm glad to see my ranting about IB has proven a success (I'm convinced there are those who have little regard for anything I say  ), and Bryan certainly comes through time and time again.
> 
> You got any pictures of the final setup Magic?


moonfly your comments have been invaluable to me time and time again. I can not believe how much I have learn't this past year, and what I have achieved. Your a top man :T

Once I get the EQ figured out I will post back to let you and Bryan know how it is sounding.


----------



## bpape (Sep 14, 2006)

The bottom end can make or break the home theater experience IMO. Solid, deep, quick, tight bass is a must. It imparts that 'jump factor' and lets you feel the experience rather than just hearing it.

Bryan


----------



## Moonfly (Aug 1, 2008)

bpape said:


> The bottom end can make or break the home theater experience IMO. Solid, deep, quick, tight bass is a must. It imparts that 'jump factor' and lets you feel the experience rather than just hearing it.
> 
> Bryan


I agree. I see the bass as the foundation of a system. Foundations are a critical part of any build.

That room looks the business Magic :T, I bet the misses really likes the 'invisible' subwoofer now eh.


----------



## Wull (Apr 7, 2010)

Moonfly said:


> I agree. I see the bass as the foundation of a system. Foundations are a critical part of any build.
> 
> That room looks the business Magic :T, I bet the misses really likes the 'invisible' subwoofer now eh.


Cheers moonfly, to be fair the pictures don't really do it justice, the panels all though bright are not in your face, in fact it adds warmth to the room. The best thing is the misses loves them, she is also a bass head, more so than me, and now that it's invisible she couldn't be happier  win,win,win :T


----------

