ASC Tube Traps

[rasmaudio]

My room is 29' long x 19' wide x 11' high cathedral ceiling. I use 16" ASC bass traps in the front corners, floor to ceiling. The back corners have 20" ASC bass traps (with resonating cans inside to lower the effective range) floor to ceiling. Between each side wall there are two 16" bass traps, floor to ceiling. I place all the front speakers along the long wall with the Martin Logan Summits 7' apart and 6' out from the front of the room. The Magneplanar Tympani bass panels are next to the Summits (the woofers on the summits are disconnected). The center speaker (Martin Logan Logos) is mounted above the video screen with a ASC 16" half round bass trap directly above, to prevent early reflections and bass build up. At the listening location there are two 16" ASC half round bass traps directly above to eliminate early reflections and bass build up. Mid range tube traps are placed around the entire perimeter of the room, each one being 3' apart. The reflective surface on all the traps are utilized to keep the acoustic qualities of the room from being too dead. The 16" and 20" full round bass traps have been adjusted to provide a wide sound stage. The half round traps have offset reflective membranes to aid in ambience and are placed in such a way to prevent early reflections. Also directly behind the left and right speakers I added hard wood flooring across the entire length of the room for retention of ambience. I have a total of (8) speakers equally spaced in the back and sides of the room for surround sound. Thats a lot of traps, but the result is bass that has great definition, power and depth. Spacial reproduction is awesome and one can walk around the round and feel like your in the hall. Bass is quite flat and the RT60 decay rate is very good for all types of music. It took a lot of time, but the result is amazing.

 

[rasmaudio]

More pictures

More pictures of room layout.

 

[rasmaudio]

Additional pictures

Back of the room showing mid bass traps and large 20" half round bass traps.

 

[rasmaudio]

Traps above listening position

ASC tube traps work extremely well.

 

[churchill]

Excellent looking and sounding (I'm sure) room! I'm also a believer in traps as I'm up to a total of 5 ASC bass traps and many other ATS panels as well.

Good stuff!

 

[Rich]

Wow! Nice setup. I'm sure it sounds incredible. So you are using the panel of the Summits for highs and mids, combined with the Tympani panels for the bass, along with the rotary subwoofer for the sub frequencies? Interesting. Did you have someone professional help you get it all set up and dialed in or did you do it all yourself?

 

[rasmaudio]

Audiophile for over 50 years

Wow! Nice setup. I'm sure it sounds incredible. So you are using the panel of the Summits for highs and mids, combined with the Tympani panels for the bass, along with the rotary subwoofer for the sub frequencies? Interesting. Did you have someone professional help you get it all set up and dialed in or did you do it all yourself?

I have been involved with audio and acoustics for 50 years. Acoustics has been my number one priority for accurate sound and have worked with many different rooms and acoustical devices. In the past I have built many different types of bass traps and diffusers. Through the many years I have tried many different types of speakers, electronics and modified many pieces of equipment. The pictures of some of my past projects will show what I have done to improve the acoustical properties of rooms. The bass traps I built are called poly cylindrical diffusers, slat resonators and membrane resonators. These worked very well, but some were very difficult to construct. However, I have found that ASC tube traps work the best and can be adjusted (rotated) for optimum reflectivity and diffusion. Putting speakers well away from the walls is also very important to reduce the effects of comb filtering and also gives one a huge depth of field and a very large soundstage. Maintaining ambience in recordings with out introducing early reflections gives one the feeling of being there (I call it the feeling of space). The Magneplanar Tympani bass panels were modified to match the Martin Logan electrostatic speakers. Even though the bass section on the Martin Logan speakers work well, they fall short on blending with the very fast electrostatic elements. The Magneplanar Tympani bass panels being a dipole matches the electrostatic character of radiating sound (both line sources.) Also the Magneplanars are very quick (very low in mass) and mate extremely well with the electrostatic sound. The crossover networks on the Magneplanar speakers were modified and also the frame was bolted together and to the floor (do not move at all). Thank you for the comments. Bob (rasmaudio)

 

[rasmaudio]

Another picture

To the left of the bed is what is called a slat resonator.

 

[Bernard]

Rasmaudio, great setup, and I would love to read your posts, but would you please consider breaking them up into paragraphs so that they are readable. It is especially a problem when I access this site on my iPhone.

 

[User211]

The Magneplanar Tympani bass panels were modified to match the Martin Logan electrostatic speakers. Even though the bass section on the Martin Logan speakers work well, they fall short on blending with the very fast electrostatic elements. The Magneplanar Tympani bass panels being a dipole matches the electrostatic character of radiating sound (both line sources.) Also the Magneplanars are very quick (very low in mass) and mate extremely well with the electrostatic sound. The crossover networks on the Magneplanar speakers were modified and also the frame was bolted together and to the floor (do not move at all). Thank you for the comments. Bob (rasmaudio)

Absolutely what I've been thinking would be a great idea to try, as I have posted before, and indeed you have done. I'd really like to hear that to see how well it works.

Top marks. Enjoy...

 

[rasmaudio]

Magneplanar bass panels

Absolutely what I've been thinking would be a great idea to try, as I have posted before, and indeed you have done. I'd really like to hear that to see how well it works.

Top marks. Enjoy...

I power these bass panels with an Audio Research D400MKII power amp via a Mark Levinson 380S preamp that has a very fine volume adjustment of .1 db. All the other speakers are driven by an Arcam AVR600 receiver. The Arcam has great current capabilities that drives the electrostatic speakers with ease, and between the two I can balance the complete system to my liking.

 

[Bernard]

The Magneplanar Tympani bass panels being a dipole matches the electrostatic character of radiating sound (both line sources.) Also the Magneplanars are very quick (very low in mass) and mate extremely well with the electrostatic sound.

Rich, wasn't it you who recently pointed us to a link about woofer speed vs electrostatic speed? I can't find the thread right now.

 

[Rich]

Rich, wasn't it you who recently pointed us to a link about woofer speed vs electrostatic speed? I can't find the thread right now.

Yes, that was me. The idea that woofers can't keep up with the speed of a panel due to greater mass is a myth. The difference in sound between the two is due to the character of dipole vs. monopole, phase relationships, and the tendency of a woofer toward overshoot and ringing, which the panel doesn't have. Regardless, it makes perfect sense that the Maggie bass panels would be a great match with MLs ELS panel.

 

[RUR]

Rich, I get the advantage @ and near the xover point, but, as one wanders farther from xover, those advantages should diminish, no? Below transition, I can see some serious disadvantages, principally as regards location flexibility (Geddes & Harman's work).

What am I missing?

 

[Gordon Gray]

JonFo must be envious.

GG

 

[Rich]

Rich, I get the advantage @ and near the xover point, but, as one wanders farther from xover, those advantages should diminish, no? Below transition, I can see some serious disadvantages, principally as regards location flexibility (Geddes & Harman's work).

What am I missing?

Sorry, just noticed this post. As far as location flexibility, I don't see how it is any different in that regard than a hybrid, or the CLX, or the big Soundlabs.

 

[Bernard]

On the ASC web site I see that they have a special trap for the Aerius. It looks like you push the structure directly into the back of the speaker, killing the back wave completely.

I always thought that killing the back wave completely was not a good idea, ambience-wise.

On a related matter, I've been trying to sell my wife on the idea of my purchasing a pair of ASC Tube Traps to place directly behind each speaker as I have glass for a front wall. She asked me if I could instead place them on the tops of the woofer cabinets. An 11" diameter 42" long trap would fit the back of my SL3s perfectly. Any opinions on this placement?

Or would you use 9" diameter traps in the same position, not killing the back wave as much ?

 

[RUR]

Bernard, depends on whether you want to create artificial ambience via the backwave or, by absorbing it, maximize the ambience (and imaging) to be heard in the recording. All a matter of preference but, after experimentation, several of us absorb most, if not all of the backwave with fantastic results.

FYI, placing tube traps directly behind SL3's was one of the ASC treatments which impressed Gayle Sanders here:

But Bruce was on a roll. To my amazement, he put a 10" Trap directly behind each speaker to absorb the backwave. Details previously lost in the ambient murk leapt out vividly.

http://www.stereophile.com/content/martinlogan-sl3-loudspeaker-california-brisson-and-soundroom-doom

/Ken

 

[Bernard]

Thanks for the link, Ken. I had read that article a long time ago.