New sound room woes

[newmill]

Another update;
Since I am not sufficiently happy with my room, I decided to learn as much as I could about how to make improvements in order to maximize my Audio Research gear performance. I experimented with many room treatment options offered by several manufacturers. I had come to the conclusion that, although some improvement could be achieved with tested room treatments, it could only improve my room marginally. The Ref 75SE needs a really good room to shine.
I started reading about Dennis Foley at Acoustic Fields. He had a different approach and his strategies seemed sound and based not only in physics but in his experience as a sound engineer. (I know that others have scientific data but it seems a bit more like snake oil to me, and I can only make conclusions based on what I hear).
I decided to contact Dennis and he began helping me with my room. During one of our phone conversations he told me what, in his opinion, was needed in my room. He has a data base of different room sizes he has tested/measured over the years and mine happened to be in his archive. What he had suggested to me would have been outrageously expensive. Dennis gave me a DIY alternative which I still had to modify in the interest of economics. I began building his diaphragmatic absorbers with activated carbon technology.

 

[newmill]

After some room design considerations I decided to make 6 of these absorbers which are capable of dealing with true low frequency energy, and place them across the front wall of my music room. I needed to elevate them a bit to achieve what I needed, so I built a little riser for them to sit on.
These units are 32" wide each and 60" tall. About 200 lbs each after filled with activated carbon.

 

[newmill]

At this point, I did not know what kind of result I was going to get with these units, but when I compared the sheer mass and engineering to what some other sound treatment options are, it made me think these have to better. Some companies would sell you a bass trap that was nothing more than a 2 X 4' foam panel to install on a 45 degree angle in the corners of your room. I can tell you from experience that this does not work. Nor do some other solutions.

 

[newmill]

My diaphragmatic absorbers are now built and installed and I have been living with them now for about 4 weeks. To sum up the results that were achieved all I can say is HOLY S#@T! I did not anticipate what was accomplished! Somehow by managing the bass frequencies in my room, I was actually able to hear more low level frequencies. The sound stage and imaging are absolutely incredible. I have never before or since heard a room capable of a musical presentation with this kind of definition, separation, and low end clarity. It seems like cleaning up these frequencies (down to 40 or 50 hz I'm told), the rest of the music presentation began to blossom. I can listen to anything and be amazed at what I hear. To keep things in perspective, The Ref 75SE does not give me the sort of bass that I had with my old 1000 watt monoblocks, and it makes yearn for a little more low end authority, but everything else is so good that I am able to look past that for now. Dennis told me that if I did these few basic things to my room, I would feel like I did a huge hardware upgrade that would leave me in awe. He was absolutely right. If anyone is wondering, Acoustic Fields is the real deal! (no affiliation .....lol)

 

[newmill]

One thing I have learned during this room build process is that the room is absolutely the most important part of the equation. I have in my opinion achieved incredible sound with extremely good, but not top tier gear. I do have another question for you guys. I have my Ref 75SE paired with the LS27 preamp. Is my best upgrade path with a new preamp like maybe the Ref 5SE? Will I improve the bottom end with this sort of upgrade? I have been told on different occassions over the years that the biggest improvement to your system is achieved with a better preamp versus a better amp. I know its quite a general statement that doesn't address many variables. Thanks guys for any replies.

 

[Bobvin]

I have not heard the LS27, but several years back I went from LS26 to REF3, and every part of the musical presentation was upgraded, not just the bass. I used a REF75 with KT150 tubes for several years, with REF10 pre. The amp drove Alexia v1. I had a significant upgrade in bass authority moving to REF16OM, but bang for buck I would say a pre-amp upgrade will give you more overall enjoyment as it will open the window and let more music come in. The REF75 is Ref class, not so your pre.

 

[asiufy]

One thing I have learned during this room build process is that the room is absolutely the most important part of the equation. I have in my opinion achieved incredible sound with extremely good, but not top tier gear. I do have another question for you guys. I have my Ref 75SE paired with the LS27 preamp. Is my best upgrade path with a new preamp like maybe the Ref 5SE? Will I improve the bottom end with this sort of upgrade? I have been told on different occassions over the years that the biggest improvement to your system is achieved with a better preamp versus a better amp. I know its quite a general statement that doesn't address many variables. Thanks guys for any replies.

One of the remarkable improvements in the current batch of Audio Research Reference electronics is in the bass. It's fully textured, like you'd expect from tubes, but it does not lag or blur. It's tight, gorgeous bass. So yes, I think the REF6 is your next natural upgrade.

 

[Bobvin]

Tell us a bit more about your panels... are they just cavities filled with activated carbon (and is it granular activated carbon or something with more form to it?) you appear to have grill cloth or similar on them... what is the face constructed of, i.e. what holds the shape of the face if the cavity is filled with granular carbon?

 

[newmill]

Thanks for the reply asiufy. Anyone esle want to second this opinion?

 

[newmill]

Bobvin: If you look at some of the pics you will see the sides and tops are dadoed out to accept some mdf panels. The activated carbon is in pellet form and is contained between 2 sheets of peg board that is fastened into 2 of the side and top slots. There is a real science to the dimensions etc.
Thanks for the interest and your previous advice.

 

[Bobvin]

I’d have put some low volume air moving fans in your support structures, and some venting through the top, into the bottom of your carbon traps... then you would have also had the freshest possible air in your room. Dual purpose sound traps!

 

[MJB]

I went from an LS27 to a Ref 5SE a few years back. This was a significant step forward in resolution, music presentation and better bottom end. Of course, the current model is the Ref 6 which is a terrific pre.

 

[the sound of Tao]

Bobvin: If you look at some of the pics you will see the sides and tops are dadoed out to accept some mdf panels. The activated carbon is in pellet form and is contained between 2 sheets of peg board that is fastened into 2 of the side and top slots. There is a real science to the dimensions etc.
Thanks for the interest and your previous advice.

Hi Newmill,
Really interesting concept, congratulations... if I may ask the chambers do look essentially all filled up with the activated charcoal or is this only to some depth within the frame, also how was that volume of the void determined and then is the carbon material filling out the whole void but so light that it doesn’t need bracing all up through the chamber to stop it from tending towards compacting down at the bottom and or causing the material to sag outwards at all. Fascinating stuff btw.
Tia Tao

 

[Hipper]

Very Interesting.

In the picture in your post 23, what is the material covering your absorbers?

I've seen some of Denis Foley's videos and I'm glad you've found success with his ideas. It's the first I've heard of using activated carbon for sound absorption but it makes sense as it's porous. Perhaps it's the weight that makes it less used in this area because it would make products less mobile, although it must be more pleasant to use then mineral wool.

I bought ready made products from GIK, mostly bass traps. What I found was that they, along with positioning, are a major help to getting where I want to be sonically, both with the frequency response but especially with decay times. However I needed careful use of an equaliser to complete the job. I used lots of measurements with microphone and software (Room EQ Wizard - REW).

I would recommend that if you want to make further progress you also take some measurements. You could just use your ears and a set of test tones instead but software is a lot more informative. Don't however get obsessed with measurements - it's what it sounds like to you that is important.

I also suggest you post a link to this thread on your Room Acoustics thread as posters there will surely be interested (perhaps even get this whole thread moved there).

 

[TooCool4]

Hi Newmill,
Really interesting concept, congratulations... if I may ask the chambers do look essentially all filled up with the activated charcoal or is this only to some depth within the frame, also how was that volume of the void determined and then is the carbon material filling out the whole void but so light that it doesn’t need bracing all up through the chamber to stop it from tending towards compacting down at the bottom and or causing the material to sag outwards at all. Fascinating stuff btw.
Tia Tao

Checkout this vid for explanation.

 

[Hipper]

Actually I just found a couple of videos!

 

[HughP3]

One thing I have learned during this room build process is that the room is absolutely the most important part of the equation. I have in my opinion achieved incredible sound with extremely good, but not top tier gear. I do have another question for you guys. I have my Ref 75SE paired with the LS27 preamp. Is my best upgrade path with a new preamp like maybe the Ref 5SE? Will I improve the bottom end with this sort of upgrade? I have been told on different occassions over the years that the biggest improvement to your system is achieved with a better preamp versus a better amp. I know its quite a general statement that doesn't address many variables. Thanks guys for any replies.

Hello NewMill - fwiw i went from a Ref5 to a Ref6. Very substantial improvement. At the time I had Maggi 20.7's. Everything improved. However I have always used big SS amps with the tube pre, like Krell 350 monos and Mac 601 monos. Macs will be replaced soon....