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Sound correction in small room

Hello All,

I’m having a hell of a time with the sound in my newly constructed sound room and have spent the past couple of months learning about acoustical engineering (4+ months in theory being proactive, the past 2 weeks reactive trying to solve specific problems). I know there are a multitude of threads, videos, and websites about the subject across the innerwebs and I have looked at many, but they start to blur together so I am hoping to get some tips on my specific situation. But first, a couple of disclaimers: 1) 5 months ago I knew nothing about acoustical engineering... I now know just enough to know that I don’t know… 2) I blew waayyyy (I mean wayyyyyyyyy) past my intended budget many many moons ago.. So please keep these two things in mind when commenting/making recommendations. I’m trying to provide the necessary information without being too verbose so apologies for the length of the post…


The main characters:

Raven Nighthawk integrated tube amp (I believe 2x20w…)

Tekton Double Impacts (yes, I put 5ft. tall speakers in a room with a 6 ft. ceiling.. no, I can’t change that fact..)

Denon dvd player for the source (it’s been around a while and was probably lower midrange 8+/- years ago…)

Supporting cast (My room…):

Dimensions are 15’1” x 10’2’x 6’3” (176.5x122x76.75) yes, the ceiling is just over 6 ft. tall as I did the decoupled thing and there was also venting in the way

carpeted floor, standard walls and ceiling (textured and painted drywall), components are on 5’x2’ table, and there is a 58 inch plasma mounted on the wall. Single seat glider/rocking chair and footrest, 5’x5’ cube bookcase, minifridge, and lamp. I’m skipping over the sound proofing measures used when building the room as I don’t think they are relevant at the moment..


The villains:

1) I have a bass tone (produced by the bass guitar) that just floods the room if I have the speakers at the 2 ft. by 1ft. and toed inward placement. Ironically, moving the speakers back to only 2-4 inches from the front wall helps with this, however, I lose the lower/bottom end almost completely. From what I have read this is completely backasswards and makes no sense but here I am…

2) I am failing the “clap” test which leads to lack of clarity/intelligibility (I believe acoustical panels should address this… see below)

3) Not getting that “wow” factor that I know these speakers can produce (I had them hooked up to my main system for a few days whilst building the room and it was definitely there.. I can best describe it as lacking the immersive power that I was expecting… maybe described as loud and clear with all sounds well represented without blasting at the same time???)..


1st attempts at sound management/correction

1) Speaker placement (2ft. from front wall/1 ft. from side walls, 3in.from front wall/~1ft. from side walls, as well as a multitude of other positions)

2) Seating placement (38% from rear wall.. can’t do it from the front wall, too close..) as well as further back and forward.. Farther back seems to sound better at the moment

3) Equilateral triangle placement of seat and the speakers (ironically very close to 38% anyway…) making sure the sound shoots behind me, not directly at my ears

4) Diffusion: 5’x5’ cube bookcase with CDs and whatnot on rear wall (also a minifridge and lamp…) A few of the resources either directly stated, or at least implied diffusion can be effective this way…


Forthcoming sound management

1) I am attaining the materials to build 6 panels (2’x4’ with OC 703 already purchased) and will put 4 of them at the 1st and possibly 2nd reflection points with the other 2 as clouds at 1st reflection. The only door to the room may impact that 1st reflection point on one wall though…

2) Considering bass traps but want to see how the panels affect things first.. Regarding this, I love that deep low bass but I want it accurate and appropriate, not that singular hum sound

3) Also considering more panels (the only real space left would be the front and rear walls. Possibly more on the ceiling)


The actual questions

1) Does it seem like I am on the right track?

2) What am I missing/what should I be attending to that I am not?

3) If I end up doing bass traps, what material???

4) Any other suggestions (speaker placement, seating location, more panels, etc…)

Thank you in advance, these forums are a great resource!

la10slgr
auxinput
2,920 posts
 

Thinking about this further, the very low bass is always hard and expensive to treat.  The general broadband panels (even if they are very thick) are only average at absorbing the bass.  However, if you know the target frequency, you can get an effective panel.

We know that you have a room nodes at 55hz, 75h, 90hz, 110hz, and 111hz.  The FRK or Monster Bass Traps will effectively handle anything 75hz and above.  If you wanted to treat the 55hz problem, I would call GIK and have them make you a custom Scopus Tuned Membrane Bass Trap that is custom tuned to 55hz.  They have off-the-shelf models at T40, T70 and T100.  You would just be having them build a custom "T55" model (they will do this).  I suspect the price would be somewhere between $230 and $250 for a 2' x 2' panel.  It would probably be about 7-8" thick.  I would get a couple of them (at a minimum) and put them on the side wall floors near to the back corners (since amroc tells us that the 55Hz node is loudest on the side walls).

This is somewhat similar to my limp mass panel that is tuned to 63Hz.  I also plan to make another two limp mass panels that are tuned to 50Hz.  In my room, the 50hz also occurs on the side walls.  I will say that all my treatments have significantly increased the volume and definition of bass.  I am sitting at about the 10 foot spot in a room 17 feet long.

la10slgr OP
44 posts
 
Alright, i did the cardas placement which had the speakers 33.67 (to center) from side walls and 54.53 (to front of speaker) from what i call the front wall...  it was doable but admittedly pretty much out in front of the tv and in the middle of the room, 1/3 anyhow... in my current state it didnt improve sound much, if at all, so gonna have to wait til some panels get built (and bass traps but still working on those logistics) and test again...
la10slgr OP
44 posts
 
Auxinput, totally missed your last two posts... will review and may have some questions
auxinput
2,920 posts
 

At 11:57 of this youtube review:

https://www.youtube.com/watch?v=nqgWHPv26L0

“A lot of people are going to look at this speaker and ignore the fact that the midrange is being handled by two 6” woofers and a tweeter array… and what that means is unless you have a big powerful amplifier, you’re not going to get the kind of dynamics out of this speaker that is just going to punch you in the chest.  Some people are going to be disappointed with that, some people won’t care, but you at least need to be aware of that”

 This is also going to be more constrained if you got the 4ohm version of the Double Impact, where your 20 watt tube amp may have a little more problems handling it (i.e. it’s not going to be the same as with a high current Class A/AB amp with a big power supply).

 He also talks about how a good amount of the midrange is actually reproduced by the outer ring of tweeters (6 tweeters).

la10slgr OP
44 posts
 

Been a while but figured I may as well finish this up...  Here's what I ended up doing:

1) 4 bass traps - 6' tall and essentially floor to ceiling (of course the air vents are right where these would go so had to leave some clearance) placed in each corner of the room.  They are 4 inches thick and are made of 2" thick OC703 and 2" OC703 FRK

2) 6 panels -  Each is 2'x4' and I placed 4 on the walls (1st reflection point, and to the side of listening position) and 2 on the ceiling slightly forward and/or above the listening position.  These are 2" thick and made of OC 703

Results:  Sound is now under control (huzzah!!!) as that bass tone that was overpowering the room is leveled out and I can pass the "clap test" with no echo when the listening chair is placed under the cloud panels.  However, if I move the seat closer to the rear wall I can still get an echo.. 

I continue to play with seating position and speaker placement and am constantly amazed at how an inch here and there can alter the sound so much.  If I move forward I get the soundstage but lose the bass and vice-versa when I move the seat back towards the wall.. I tried the Cardas placement for a rectangular room and for my situation it was just ridiculous as the speakers were essentially in front of the tv and it didn't sound so great either...  Also tried the equilateral triangle method and that met similar results...  So I turned to my own ear and trial/error... Lots of trial and error....

Overall, I give the effectiveness of the room treatment, and the sound presentation, a 9/10 and in some aspects a 10/10 but I can't seem to get that perfect sweet spot where I keep the bass and the soundstage and maintain it from one style of music to the next (said differently: I can attain 10/10 but then I put in a different type of music and that particular set up is no longer ideal so find myself scoochinig things around again...)  I'll keep tinkering with it but am happy that the problems are 90% taken care of and that last 10% is something that I don't mind playing with...

Thanks for all the help!!!  I  LITERALLY could not have done it without all the helpful suggestions and guidance.

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