ASC tube traps: effect of their absence

Al M.

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Congratulations on getting that ever elusive "3D" sound stage we all want, it is a tough nut to crack. Can I ask - did you have to change your speaker position much +/- the tube traps? I often find a subtle adjustment to my speakers to be beneficial for tuning. Although not so much with my 30.1's - you can pretty much plonk them anywhere and they will sound pretty decent. Unfussy. Easy to get to sound good, really hard to get to sound great.

Andrew, I always had my speakers at more or less the same position, about 6.5 feet from the back wall (or front wall, if you want to call it that). I tried playing around with positioning at diverse stages of room treatment, and once, before I had the window plugs but everything else, moving the speakers one foot forward greatly increased energizing the room and increased depth even more, at the expense of bass output. Yet with the window plugs installed, the standard position once more turned out to be the best. I also played a bit with the spacing apart of the speakers, but also this was not influenced to a large extent by the room treatment.
 

Al M.

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EDIT: actually while I sit here enjoying my coffee, I have been musing about ceiling height, and how, particularly with choir or vocal music, high ceilings seem to help no end with a sense of "air". IIRC Mike has a "dome" ceiling - but Al. what height is your ceiling and is your room fairly regular dimension? I seem to remember it opened out onto a hall way?

With height I am not as lucky as you are, but lucky enough ;)

Room dimensions are 24’ x 12’ (small window bay next to the left speaker 13.5’) x 8.5’. The room is a closed unit, not opening out to another room anywhere.
 

c1ferrari

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To Al: which specific tube traps are you employing?
 

Al M.

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To Al: which specific tube traps are you employing?

Corner traps:
stack of two 16" traps, 4 feet high each

Middle traps:
stack of two 13" traps, 4 feet high each

***

Since I have a subwoofer, Art Noxon suggested the new Isothermal Traps to me which have better low bass absorbtion:

http://www.acousticsciences.com/products/isothermal-tubetrap

Given my current experience with how much the tube traps matter for the bass, I am inclined to follow that suggestion at some point. My deep bass is great, but I have no doubt that it could be even better.
 

c1ferrari

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Oops...sorry -- I hadn't noticed your reference to them! :eek:
 

Al M.

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c1ferrari

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Perhaps then he needs more of them . . .
He consulted ASC...unsure if he derived any MATT(?) data, though.
I think he has four of the IsoThermals, 2-4 full rounds (don't recall the d), and a smaller pair on stands.
They're for his mastering studio.
 

Frank750

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Wow, 34 tube traps. That's impressive Frank! You must have quite a large room.

It's only a room on my lower level that I turned in to my sound room. Not the greatest set up but it's working for me. The entry to the room is open, no door, the front of the room is 18' wide and the back half of the room opens to about 22' wide, the room is 32' long.

Here's a picture of the trapping in the front of the room. The picture is about a year old and I've moved traps and turned them over the past few years but I'm basically back to this set up. The black ones in the corners behind the speakers are 24' round and weigh a ton. They're tough to move.
There's a bunch of 16" rounds lined up against the back wall behind the chair and in the corners, also some 11' rounds to the left of the chair along the side wall. There's a large sliding glass door to the right of the chair with only wooden blinds covering the doors. I tried some traps over there but not real noticeable. I added the Stillpoints Apertures last year. They replaced a stack of 16" round tube traps, made it easier to use the outlets that were unfortunately being blocked by the tube traps.

Right now I have the reflective sides turned out on all of the traps but at times I'll turn a couple of stacks around and the tuning of the room changes dramatically.

Room View.jpg
 
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Andrew Stenhouse

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I took another look at your system thread Al. It is lovely mate. Hey - you get a dedicated room. You are already ahead of most of teh audiophile population :)

@Frank - wow - that is an impressive set up mate. Very, very nice. I see the big Pass labs driving..?? I'd say Kharma's but I know better. Sorry I don't recognise them (waaay over my piggy bank level of hi fi ha ha :) )


EDIT - saw your system list over the page Frank. Holy Mother of God :p :p

View attachment 26089
 
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Rodney Gold

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A lot depends on how you used the trap .. generally a tube trap has 2 sides , 1 reflective and the other absorption .. you can orient them to provide either .. the increased absorption can have a lot to do with imaging etc.. removing the traps decreases that area.
The big issue with bass is that swings of 15+db in the bass under 100hz are pretty common bass traps do not really work well at very low freqs and taming a 10db peak requires some seriously big stuff

The easiest and often the only way to get great bass at listening position if you dont have the leeway or desire to extensively treat , is DSP... the best way to smooth the whole room's bass is multiple subs

you also have to remember that flat bass is terrible , you need to impose a target curve on the bass and that is purely a taste based thing
Measuring is fine to identify the massive problem areas .. once you identify them and applied fixes , then you sTILL need to tweak to taste.
 
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Fitzcaraldo215

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A lot depends on how you used the trap .. generally a tube trap has 2 sides , 1 reflective and the other absorption .. you can orient them to provide either .. the increased absorption can have a lot to do with imaging etc.. removing the traps decreases that area.
The big issue with bass is that swings of 15+db in the bass under 100hz are pretty common bass traps do not really work well at very low freqs and taming a 10db peak requires some seriously big stuff

The easiest and often the only way to get great bass at listening position if you dont have the leeway or desire to extensively treat , is DSP... the best way to smooth the whole room's bass is multiple subs

you also have to remember that flat bass is terrible , you need to impose a target curve on the bass and that is purely a taste based thing
Measuring is fine to identify the massive problem areas .. once you identify them and applied fixes , then you sTILL need to tweak to taste.

Excellent advice, and I agree. But, many might say, if the ears are the final arbiter, then why waste time on the measurements? Well, there are a whole lot of reasons to do the measurements. Time is one reason. I think measurements can quickly get you into the ballpark of where you want to be, much more so than by listening to music recordings with unknown specific response properties or even listening to test tones, boring and imprecise though that is. Yes, tweak it if you wish after the measurements.

The nature of room acoustics is clearly and indisputably influenced by strong modal response variations in the bass. These are narrow band swings, usually of very significant magnitude, as Rodney points out. I have seen the very same thing in my own measurements of many different rooms. They are hard to identify with any specificity by ear. But, alleviate them, and it makes a world of improvement.

I also agree that just throwing bass traps and absorbers at the problem is no solution, though I am not disputing that can alter the sound. And, yes, they are ineffective in the bottom octaves, unless they are huge structures. Off the shelf absorbers just do not have sufficient measurable response that goes much below 100Hz. Floyd Toole also said it best when he pointed out that passive absorbers are a broad frequency band solution to a narrow band problem.
 

Ron Resnick

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Frank, the room looks fantastic! Thirty-two feet long is great!
 

Frank750

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Frank, the room looks fantastic! Thirty-two feet long is great!

Thanks Ron!

I edited my last post a little while ago. I measured the large black traps in the corners behind the speakers again, I forgot they are actually 24" in diameter, not 20".
They're absolute beasts. ASC shipped via freight truck directly to my house. I'm a fairly strong guy but I can barely lift one to stack them, it's a struggle.
 

MadFloyd

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Thanks Ron!

I edited my last post a little while ago. I measured the large black traps in the corners behind the speakers again, I forgot they are actually 24" in diameter, not 20".
They're absolute beasts. ASC shipped via freight truck directly to my house. I'm a fairly strong guy but I can barely lift one to stack them, it's a struggle.

Let me also echo the compliments on your room. I drool over it. In some ways I really wish that I had a dedicated room that didn't have an opening and that I could employ 30 tube traps.

24" circumference - wow. The 16" ones that I have from Al are light! I could shoulder press them easily :)

Spent some time this morning playing with them. Put one in the right corner and listened - I think it's an improvement. However, as soon as I put one on top of it (stacked), the presentation gets anemic - very very noticeable - kick drums sounds like a toy.

So I tried moving the top one onto the floor in the center (just behind my amps) and I really liked the soundstage and while the bass was not as anemic as when they were stacked in the right corner, it was still too light.

I sense that the soundstage improvements are not just the reduction of mid-bass - that just eliminating a corner helps for intelligibility and creating space and air between instruments. Perhaps I just need a version that doesn't absorb as much bass.
 

Frank750

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Ian, make sure you have the side with the silver button facing out into the room, that's the reflective side. Just turning one stack with the abortive side (side with the seam) out can deaden your room dramatically if you already have rugs, drapes and big pieces of furniture in your room. Especially behind your speakers!
 

Steve Williams

Site Founder, Site Owner, Administrator
Ian, make sure you have the side with the silver button facing out into the room, that's the reflective side. Just turning one stack with the abortive side (side with the seam) out can deaden your room dramatically if you already have rugs, drapes and big pieces of furniture in your room. Especially behind your speakers!

Frank

Your room is gorgeous

My last room in Northern California was all ASC. I agree completely about the buttons facing into the room. That produced the best sound for me


What I liked about ASC is that all you needed to do was submit a room schematic drawn to scale as well as where your equipment is and your sitting position. They then do a computer rendering with the size and placement of the traps. Of note I was told to point the buttons to the rear of the room. I pointed them directly at my ipsilateral ear. I also agree about the weight of the huge traps in each corner.
 

Al M.

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Let me also echo the compliments on your room. I drool over it.

Yes, that room is fantastic, Frank!

24" circumference - wow. The 16" ones that I have from Al are light! I could shoulder press them easily :)

Spent some time this morning playing with them. Put one in the right corner and listened - I think it's an improvement. However, as soon as I put one on top of it (stacked), the presentation gets anemic - very very noticeable - kick drums sounds like a toy.

So I tried moving the top one onto the floor in the center (just behind my amps) and I really liked the soundstage and while the bass was not as anemic as when they were stacked in the right corner, it was still too light.

I sense that the soundstage improvements are not just the reduction of mid-bass - that just eliminating a corner helps for intelligibility and creating space and air between instruments. Perhaps I just need a version that doesn't absorb as much bass.

Ian, then perhaps you need 13" ones (like I have in the center) or even thinner ones, such as 11" or 9", with progressively higher-frequency bass cut-off:

http://www.acousticsciences.com/tubetrap-standard-models

These might also fit better with your room aesthetically.
 

Al M.

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My last room in Northern California was all ASC. I agree completely about the buttons facing into the room. That produced the best sound for me

It does for me too.
 

MadFloyd

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Ian, make sure you have the side with the silver button facing out into the room, that's the reflective side. Just turning one stack with the abortive side (side with the seam) out can deaden your room dramatically if you already have rugs, drapes and big pieces of furniture in your room. Especially behind your speakers!

Interestingly enough, I find I have so much high frequency energy in the room that the absorption works better. My room is pretty live sounding, especially with the traps reducing the low end.
 

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