ASC tube traps: effect of their absence

[MadFloyd]

Out of curiosity, how does the reflective side work? Apart from the silver button there doesn't seem to be any difference in the material. For the life of me I can't see how one side would reflect more than the other...

[Frank750]

Out of curiosity, how does the reflective side work? Apart from the silver button there doesn't seem to be any difference in the material. For the life of me I can't see how one side would reflect more than the other...

It should definitely feel different. The reflective side is a diffuser while the other side simply absorbs. You should be able to hear the difference immediately, it's kind of like an adjustable diffuser depending on how you turn the trap. You can kill the life in your system with the absorptive side very quickly.

[Frank750]

Out of curiosity, how does the reflective side work? Apart from the silver button there doesn't seem to be any difference in the material. For the life of me I can't see how one side would reflect more than the other...

Off their website:
TubeTrap^™ Technical Details

Unlike any other bass trap, the physics behind the TubeTrap are based on a capacitive-resistive circuit. The acoustic capacitor (C) is the air chamber inside. The bigger it is, the more efficient the TubeTrap is at low frequencies. The acoustic resistance (R) is DC impedance matched to the radiation (LC) impedance of a freely radiating soundwave. Because of this design feature, the TubeTrap is more than 100% efficient.Another unique feature is the adjustable diffusion grid built into the TubeTrap. The specular diffusion panel that covers half of the TubeTrap is an acoustic choke (L) which is sized, ported and mass loaded to backscatter the treble range.
Absorption Coefficients
	*Tested in corners with reflector panel facing into the room
Design Rolloff & Crossover Frequencies
Diameter Rolloff Frequency Crossover Frequency 9" 110Hz 400Hz 11" 90Hz 400Hz 13" 70Hz 400Hz 16" 55Hz 400Hz 20" 40Hz 400Hz

[Steve Williams]

I had all 5 diameters in my last room

The other I recall Art Noxon told me when I was installing them is that there is also a top and bottom to each of them depending on the label in the center. Because i had tall ceilings I was using two of these on top of the other. It was suggested that the top one be turned over so that the top of each trap touches one another

[PeterA]

I had all 5 diameters in my last room

The other I recall Art Noxon told me when I was installing them is that there is also a top and bottom to each of them depending on the label in the center. Because i had tall ceilings I was using two of these on top of the other. It was suggested that the top one be turned over so that the top of each trap touches one another

That is most interesting. I have had not previously heard about that. I have four 16" traps, but also four corners on the front wall because of the fireplace, so I have found the best result in my room is one trap in each of the four corners with the reflective dots facing each other rather than rotated out to the room or in toward the corners. I also have Acoustic Revive diffusion panels on the front walls between each set of Traps. Photo below:

[bonzo75]

How are the Acoustic revive panels, were they a big positive difference?

[PeterA]

How are the Acoustic revive panels, were they a big positive difference?

Yes, my friend ordered them and had them delivered to my house because he was on vacation. I opened them up and tried them in my system and immediately ordered a pair for myself. In my installation, they increased the sense of space and depth behind the speakers which is quite challenging because of the protruding fireplace. I have not experimented lately with removing them since other changes to some of my components, but I am very pleased with them. Perhaps they are the reason that the Traps sound better without the reflective side facing the listener. That might introduce too much reflection from the front of the room. Right now the balance seems right, though my bass still has some humps. I would like to try 20" Traps or at least four more 16" Traps so that I could stack them, but I have always hesitated because my wife still uses this room and it might be just too much.

[Steve Williams]

I had double 20" in each corner.

[Frank750]

Pricing for full round tube traps;

Full Rounds* Sized up to:	2′	3′	4′	5′	6′	7′	8′
9″ (110 Hz)	$380	$472	$498	For Long TubeTraps, please call for availability and price.
11″ (90 Hz)	$386	$488	$512
13″ (70 Hz)	$462	$518	$542
16″ (55 Hz)	$594	$648	$688
20″ (40 Hz)	$718	$764	$854
24″ (25 Hz)	$859	$918	$1046
	(ship via truck freight)

[Ron Resnick]

. . . The other I recall Art Noxon told me when I was installing them is that there is also a top and bottom to each of them depending on the label in the center. Because i had tall ceilings I was using two of these on top of the other. It was suggested that the top one be turned over so that the top of each trap touches one another

This is interesting. I stack three Tubetraps to reach almost to the top of my ceiling. Do you know why it was suggested to have the tops meet in the middle? (What is happening acoustically?)