Room treatment question with SDA's

gmcman

I'm looking into some bass traps and was also quoted for some panels to go behind the speakers.

Speakers in question are 2.3TL's, I dont know if this will take away from their imaging or bass response.

My room has a high amount of bass energy and the waterfall graph enforces this.

I can treat other areas if placing any panels behind SDA's is not recommended. I was going to use the GIK 244 behind the speakers, 1 panel each.

Has anyone added sound absorbing panels directly behind their speakers with any negative effects?

machone

I have 2.3TLs and I have bass traps but not behind the cabinets.
My experience is that the results may be unexpected and trial and error is what worked best for me.

Mike Reeter

I have 2" Panels directly behind the SDA's and Bass Traps in the corners. I hear no "ill" affects from this set-up.

machone is spot on when he states "trial and error is what worked best for me".

codycatalist

Are standing waves your main issue? If so I would focus on the corners in the room, stack the bass traps from floor to ceiling. That is at least what I have read numerous times when it comes to bass traps specifically. I have heard that either first reflection point to the left and right of the speaker is good for imaging, same with in between the speakers.

I vaguely remember someone describing a way to find the first reflection points with a mirror. Take what I say with a grain of salt, I haven't applied ANY room treatments but have researched it a bit as it is something I am in desperate need of but $$$ says no no for now.

Mike Reeter

codycatalist wrote: »

Are standing waves your main issue? If so I would focus on the corners in the room, stack the bass traps from floor to ceiling. That is at least what I have read numerous times when it comes to bass traps specifically. I have heard that either first reflection point to the left and right of the speaker is good for imaging, same with in between the speakers.

I vaguely remember someone describing a way to find the first reflection points with a mirror. Take what I say with a grain of salt, I haven't applied ANY room treatments but have researched it a bit as it is something I am in desperate need of but $$$ says no no for now.

Have someone hold a mirror up on the sidewall, while you are setting in the listening position. They move the mirror until you see your speaker reflection in full view, that's the First Reflection point.

SCompRacer

Treatment behind speakers depends on speaker type. Dipoles, or box speakers with rear midrange openings, folks may like the rear reflection effect off wall. Treatment behind that type of speaker would cancel that. I had dipoles and ended up cancelling rear reflecion and the sweet spot became narrower and more focused. Even though SDA's are sealed in back, try it both ways, behind speakers and in corners.

Bass is omnidirectional so as mentioned, corners are usually best for bass traps. Bass frequencies have length. In my room, bass is great in sweet spot, bass nulls out -disappears- in center of room and comes back as you get closer to speakers. Neat to experience if you never have.

I have two GIK Tri Traps stacked in one corner and single Tri Traps in opposite corners. You can also walk/crawl around the room and find where the bass is good, isn't good or isn't there.

I find one between speakers really tightens center imaging. I just got a GIK 2" 2' x 4' art center panel with a pic of our cat on it. I haven't hung it yet. My speakers have the option of open or closed rear midrange. I like them open and took the treatments from behind the speakers.

The room is open to main level so no side wall to right (just a short chimney wall in corner). Over 10,000 cubic ftet so subs are needed to enhance 25-35Hz bass.



This was a previous set up with ESL speakers. Turning treatments on side allowed some rear wave reflection.

machone

One good thing about acoustic treatment is that the results are immediate.
No burn in required

gmcman

Mike Reeter wrote: »

codycatalist wrote: »

Are standing waves your main issue? If so I would focus on the corners in the room, stack the bass traps from floor to ceiling. That is at least what I have read numerous times when it comes to bass traps specifically. I have heard that either first reflection point to the left and right of the speaker is good for imaging, same with in between the speakers.

I vaguely remember someone describing a way to find the first reflection points with a mirror. Take what I say with a grain of salt, I haven't applied ANY room treatments but have researched it a bit as it is something I am in desperate need of but $$$ says no no for now.

Have someone hold a mirror up on the sidewall, while you are setting in the listening position. They move the mirror until you see your speaker reflection in full view, that's the First Reflection point.

Unfortunately the left side is a fireplace....would need a floor standing panel.

I have treatments on the walls, behind and to the right, going to try to work on the low bass energy which is prominent in the corners and the rear wall as it should be. Wasn't sure if it was bad juju or not to treat behind the SDA's but looks like it's going to be a trial and error.

machone

I needed stands for my first reflection panels. I built these using mohagany from
Home Depot.

pitdogg2

Very nice Machone

SCompRacer

Those are very nice stands Machone! High marks!

schwarcw

My bass changes from the sitting to standing position is most places in the room. I've been curious about using diffusers behind the fronts. My Legacy Focus speakers have rear firing (active) woofers. I have them about 22" from the rear wall. The rear reflection does a lot for the overall bass response and the width of the soundstage. I don't want to lose that as Rich noted. A diffuser behind the speakers may help blend the bass in the room height.

Here is a link to the GIK diffusers: https://www.gikacoustics.com/product-category/diffusion-products/

Some cool looking stuff. Anybody using these?

gmcman

machone wrote: »

I needed stands for my first reflection panels. I built these using mohagany from
Home Depot.

Nicely done!

gmcman

codycatalist wrote: »

Are standing waves your main issue? If so I would focus on the corners in the room, stack the bass traps from floor to ceiling. That is at least what I have read numerous times when it comes to bass traps specifically.

Yeah, the wood paneling and low ceiling (91") surely don't help any. Playing some 50Hz sine waves I have a large amount of bass in 3 of my 4 corners, but this is expected. The decay time is around 400-500 ms from 40-60Hz.

I took some of my wall mounted panels and piled them in the corners..3-4 in each corner and listened to a few tracks...the results were somewhat dramatic...I wish I tried this earlier. Granted my panels are not tried and true bass traps but it's a testament to how much blurring these uncontrolled bass waves really take away from the SQ.

Debating the Monster traps over the Tri Traps...Tri Traps are a cleaner install but lose a little bit to the Monster traps when straddling a corner.

machone

I saved a lot of money building my own.
I will post a link to my thread when I am not using this cell phone.

machone

gmcman,

Here is the link to my panel build.

http://forum.polkaudio.com/discussion/177293/acoustic-panel-build#latest

gmcman

@machone, nice work, those came out great. Thanks for the link.

@DSkip, I like those traps, I think I just need a different house....lol. Point taken on panels behind speakers, will save that for a trial when all else is done

gmcman

As far as the corners go, I caved and ordered some Tri Traps for 3 of the corners, the 4th corner is at the base of the stairway, but will see how these 3 do first.

Was going to try the DIY stacked triangle arrangement but my free time right now is slim.