Room treatment advice needed...

[deilenberger]

Got the very slightly used Source's home - hooked up - seem to work fine.. except too much bass (I know not a common question..)

I have a problem room. It got a lot of discussion on AudioAsylum when I was thinking of Maggies for the room.. then that thread sorta wandered off topic.

Here's the room:



It's a shoebox sort of shape. My desk used to be under the top window in the layout, but that meant the old speakers (McIntosh ML-2C's) were on the long wall, facing another wall a few feet away, and behind my chair, so - I rearranged it as in the drawing.

The walls do have some bookshelves on the upper part (starting about 5' up, going to the ceiling - which is 7'8") on the side walls near the window on the short wall. Finish on the lower wall is unique - the 1950's stirated plywood popular at the time. The upper wall and right side wall step out 5" at the bottom up to about 30" - due to a foundation wall.

Right at the moment - there is no rug. The underside of the desk facing the speakers is wide open.

My first thoughts are to add some sound absorbing panels to the bottom part of the wall directly behind the speakers, and perhaps some on the bottom of the two sidewalls.

Upper frequencies are quite good (might be able to be made better) - imaging isn't wide, but it appears fairly accurate.. but first thing to be worked on is the overwhelming bass. It's listenable with my bass tone control cranked down about 6 dB.. but I know it could be better. I did change the base so the speakers are vertical instead of tilted back, given how close I'm sitting I don't need to send sound up (I think..)

Ideas? Thoughts? Impossible?

Anyone ever added damping plugs to the rear ports?

 

[twich54]

one general rule of thumb for treating bass freq is start with the corners of the room, given your rather small room that's where I'd start first. Bass traps floor to ceiling if you can

 

[MrBT]

"Anyone ever added damping plugs to the rear ports?"
I used to have similar problem with Vista and closing ports helped a little with bass quantity but not with quality. Bass traps made real difference. It weren't even "real" bass traps just big bales of Knauf (OC703) insulation which I bought for different project.

 

[Rich]

Bass traps floor to ceiling in the corners behind the speakers would make a huge difference. Because of the small size of your rooms and the setup you have, those corners are acting like bass wave amplifiers, and your seating position is probably right smack dab in the middle of a bass wave "hump." About the only thing that is going to smooth out the response for you is going to be some quality bass traps, properly placed.

 

[shakham]

Did you decouple them from the ground?

 

[deilenberger]

Did you decouple them from the ground?

Nope.. but it's parquet flooring over concrete.. so I don't think they're exciting the floor.

 

[Brad225]

Your room is definitely in need of bass traps. The more you have the better. Not only in the corners floor to ceiling but any wall to floor or ceiling corner.

For an easy temporary test to see what trapping will do many DIYers have purchased big bundles of standard fiberglass insulation. The type you would find at Home Depot.
You can take the bundles unopened and stand them in the corners and lay them on the floor at the wall/floor corner to see what effect traps would have. The insulation is something you can return once you see the difference it will make and then make your own or purchase ready made traps.

 

[beek]

Got the very slightly used Source's home - hooked up - seem to work fine.. except too much bass (I know not a common question..)

I have a problem room. It got a lot of discussion on AudioAsylum when I was thinking of Maggies for the room.. then that thread sorta wandered off topic.

Here's the room:

View attachment 15278

It's a shoebox sort of shape. My desk used to be under the top window in the layout, but that meant the old speakers (McIntosh ML-2C's) were on the long wall, facing another wall a few feet away, and behind my chair, so - I rearranged it as in the drawing.

The walls do have some bookshelves on the upper part (starting about 5' up, going to the ceiling - which is 7'8") on the side walls near the window on the short wall. Finish on the lower wall is unique - the 1950's stirated plywood popular at the time. The upper wall and right side wall step out 5" at the bottom up to about 30" - due to a foundation wall.

Right at the moment - there is no rug. The underside of the desk facing the speakers is wide open.

My first thoughts are to add some sound absorbing panels to the bottom part of the wall directly behind the speakers, and perhaps some on the bottom of the two sidewalls.

Upper frequencies are quite good (might be able to be made better) - imaging isn't wide, but it appears fairly accurate.. but first thing to be worked on is the overwhelming bass. It's listenable with my bass tone control cranked down about 6 dB.. but I know it could be better. I did change the base so the speakers are vertical instead of tilted back, given how close I'm sitting I don't need to send sound up (I think..)

Ideas? Thoughts? Impossible?

Anyone ever added damping plugs to the rear ports?

Off topic question ? What software did you use to draw this up?

Thanx

 

[beek]

I would say get a spectrum read of the room (iphone app) & play some noise to see where the humps are
before you put out cash on traps you can over do traps..

 

[deilenberger]

Off topic question ? What software did you use to draw this up?

Thanx

Actually - on line and free: http://floorplanner.com - it has a few bugs, but it's easy to size and drag things around... and it allows for 3D viewing of the finished result.

 

[deilenberger]

Speaking of traps..

http://www.amazon.com/Corner-Bass-Trap-SoundProofing-Deadening/dp/B004QM420C/ref=pd_rhf_cr_p_t_4

Any comments? Seem cheap enough to buy and just play with them a bit..

One thing - it's starting to sound better on good recordings. Bad recordings are simply dreadful.. (badly mixed - one local performer who has a problem that way, her bands seem to think they're in a contest to drown out her voice.. the performer is Nicole Atkins, if you haven't heard her live you've really missed something.)

BTW - since I'm doing some construction in the room, which has the potential to create dust, I figured I'd put the covers ML provides with the speakers on to keep the dust off the ES panels. Surprisingly - they don't greatly effect the sound from the panels. My WAG is the material is porous enough that HF sound is just passing right through. I know in the main forum there was a discussion on covering the panels for dust.. :rocker:

 

[Rich]

you can over do traps..

Actually, this is a fallacy. You can over-do absorption of the highs. But you cannot over-do bass trapping. Especially so in a small room like this.

 

[deilenberger]

I would say get a spectrum read of the room (iphone app) & play some noise to see where the humps are
before you put out cash on traps you can over do traps..

Have to see what's available for Android.

Interesting app idea - but wonder how it compensates for the microphone non-linearity. (Which is intentional.. back from my Bell Labs days - there were a series of studies back in the 30's to see how to restrict bandwidth on voice, for both understandability and to allow multiplexing multiple channels over one wire.. Back in the 70's they were tossing out the 78 RPM studio recordings used for the testing and I snagged them before they hit the dumpster. Dunno what ever happened to them.. long story short - intelligible phone convos actually are much better done with a tailored response curve..)

 

[Rich]

Any comments? Seem cheap enough to buy and just play with them a bit..

Looking at them won't tell you anything. Make sure you see a chart that shows their absorptive coefficient by frequency. If they don't absorb decently between 20 and 200 hz., they aren't going to do you any good.

 

[beek]

Actually - on line and free: http://floorplanner.com - it has a few bugs, but it's easy to size and drag things around... and it allows for 3D viewing of the finished result.

Thanx for that....

 

[beek]

Looking at them won't tell you anything. Make sure you see a chart that shows their absorptive coefficient by frequency. If they don't absorb decently between 20 and 200 hz., they aren't going to do you any good.

Agree that's what I did after studying where the humps are & staggered the trap sizes
To fit response.

 

[beek]

Funny you should mention this some of the newer wireless phones have ability to tweak the response

 

[beek]

Jacking them up will change the bass response too.

 

[beek]

Audio Tools by Studio Six not sure if it spins on android

 

[deilenberger]

Went looking for Android apps:

"FrequenSee" - free. Shows a simple o'scope type display from 0-20KHz. Price is right.

There is another one called "Spectral Audio Analyzer" - that one costs.. (or you can run a version that's limited to an 8KHz view). Does waterfall views.

Found "AndroSpectrum" which looks very complete ($6.95)

"AudioTool" ($6.99) Does dB meter, RT60 meter, spectrum analyzer, signal generator and polarity checker.

Also found "SoundForm" - (Free) - an audio signal generator for the Android. Offers White/pink noise, since wave, square wave, triangle wave, ramp and impulse.

Wonder if I can run SoundForm (output via the audio out jack) and one of the spectrum analyzers at the same time.. ? Unfortunately - nope. Can't do..

Another company, Radonsoft offers a spectrum analyzer (Free for 32 band, 40, 60, 120 on paid version), RTA Audio Analyzer that allows for calibration (temporary on free version, saved on paid version). $5.49. They also offer a program called "Noise Gen" which can create an WAV file of pink, white, sine sweeps (user selects duration) that can be burned to a CD, so I can create a test CD. Cool. The paid version of RTA is $5.49 (and lets you save sessions/info and all sorts of other neat stuff...)

I think I'm springing for this one.. will let you know how it works out. Meanwhile, off to bed, it's getting late..