difussor's


I "think" im in need of some sort of diffusing on front wall of small listening room...I would be really interested to hear some experiences of some that have been through it...don't think I need an absorber type...as I have some bass traps in lower corner...just lacking clarity of sound stage...diffusor?
digsmithd
Are there rules against using both?  Would absorbtion paired with some diffusion cause chaos? Would the sound waves be confused? Not trying to be funny. Seriously wondering if there would be any advantages.
digsmithd


Equipment racks in between the speakers are one sure way of killing image and depth, yes many glitz queens love to gaze at their lovely electronics while listening, but as I found it’s always better not to have anything between the speakers.
My systems depth and sound stage was so much better when all the electronics/rack was moved to the side wall of the room.

Cheers George
I also have a very small room. I found it's essential to use absorber to deal with early reflection (place them in direct reflection points). Diffuser will also help in establishing good soundstage.

I have yet to put a small couch in room...so that might help with some of the bass boom...and yes this to me is as much a near field experience I ever had to do.

bwaslo i think that i will try a diffusor on front wall for giggles...as well as some smaller absorb panel(s)...i dont think they do (diffusor) deaden either...so what the hey...i like the back (door) idea too

I've been playing with traps and diffusion for over two years and what I discovered about my listening environment surprised me completely.

- Room - 11.5 x 15 x 8ft (tall)
- Hardwood floor with 5 x 8 carpet in the centre
- system is at one end of the room on the short wall
- High wing back chair in listening position at opposite end of the room
- 7ft x 4.5 ft bow window is centred at the opposite end behind listening position
- Wall to the left of the listening position has a double doorway - so no reflected sound
- Wall to the right of the listening position has three seat sofa with high back + float mount pictures - so very little reflected sound
- To the right of the listening position is a 78" tall 14" x 36" book case
- To the left of the listening position is a second wing-back chair
- so there is a fair amount of absorption from furniture/carpet alone

In my case, it turns out there were three areas that caused problems...

- the wall behind the system had an echo, so I made 78" x 15" wide baffles that sit at 45 degrees in each of the corners

- at the wall-ceiling boundary behind the listening position there was significant reflections - I placed an 8ft vinyl roller blind at this point and only needed to unroll it about 12" to kill the unwanted reflections. Unrolling it further resulted in little to no improvement.

- I discovered that there was also significant "acoustic turbulence"  in the space above the book case - a piece of 1" thick foam on the top of the bookcase remedied this.

On my journey I had placed traps in the corners, at wall-floor boundaries, behind the speakers, under the sofa and bookcase.

I've since removed removed all but those that address the three problem areas above and my system has never sounded so good.

Moral of the story - i.e. in my case - less was definitely more

I have since helped a friend with his problems in a totally different room-space - 12 foot ceilings made of concrete, hardwood floor with very little carpet, open plan with kitchen cabinets to the right of the listening area, and again - we found the most annoying issues were resolved by placing traps and vinyl absorption materials at the wall-ceiling boundaries and dealing with reflections above cabinetry.

Turns out the vinyl is a great barrier that absorbs audio wave-forms - turning them into minute amount of heat - and it's cheap

It's not the answer to all the acoustic issues room might have, but with a little investigation it can sure eliminate a lot of those real ugly traps that have been known to "invade ones listening space".

Hope that helps 

Diffusers on the front wall would still be for "live front".  Diffusers don't deaden sound, they just make it more diffuse (break up the reflection to cause less interference with the direct arriving wave at the listener).  

Front-firing speakers (except for maybe horns) don't radiate only toward the front.  The *desired* wave is only forward, but there is still plenty going toward the sides and to their back, just aim a speaker away from you and see how loud it still sounds!  The higher frequencies are less toward the back, though, and unfortunately the lower frequencies are much less easily diffused (or even absorbed, for that matter) than the highs.

But a dipole speaker (most ESLs, Magnepans, Apogees, Linkwitz, etc) radiate the same toward their back as toward their front.  It is a good idea to deal with the back wave, either break it up with diffusers (if you want to keep the room sound lively) or absorb it (if you're ok with some deadening, or want an easier route than constructing diffusers).
I would also like to suggest you take a look at Acoustic Fields videos on you tube. Lot's of great information there available for free. Just my two cents.
If the the wall behind your listening position (back wall) is a folding closet, you can try using some fabric wall-hangings. Or something similar to stop standing wave reflections.
With the Adagio's 30" out, and the small size of the room, isn't this a near-field setup?
Diffusion panels on back wall, and ceiling is a good idea.
Absorbtion panel only on wall behind speakers to focus the image.
thats true rhl...work in progress and that does make more sense...but the back wall is a folding closet...sooo
I'm curious as to why one would wish to place diffusors on the front wall with forward firing speakers?  The rear wall and or ceiling would be the correct location.  I would tend to think live end front wall and dead end back wall would be the place to start.   
While checking back here, I noticed an error in my post above -- my DIY diffusor is a 1D diffusor,  Which is probably the kind you want, 2D diffusors tend to diffuse too much energy toward to floor and ceiling, so that much of it dissipates before it reflects around off multiple surfaces to reach your ears; not a lot different effect than just using an absorber, IMO.
Diffusors (at least 1D diffusors) will not deaden the sound in the room, but can clear up and stabilize imaging while leaving liveliness in. If you have dipoles, then diffusors behind the speakers is probably a good idea. Otherwise, they usually work best behind or to the sides (but should be at least 4 or 5 feet away from your listening seat).

If you don’t mind a little (actually very little) work, and are in the USA near some lumber or big box hardware stores, you might want to try my DIY 2D diffusor design (actually designed via computer simulations rather than math formula or cut’n’try). See: http://www.diyaudio.com/forums/everything-else/269366-making-easy-diy-depot-sound-diffuser-panels-st...

If you are in a metric country (and don’t mind a little more woodwork), take a look at Tim Perry’s "Lean Fusers" at: http://arqen.com/sound-diffusers/
I built five 2 x 4 foot quadratic diffusors for my front wall. I bought the plan from Acoustic Fields. Check out their website they offer a lot of good information. They really added depth, width and clarity to the soundstage. It was a lot of work but well worth it.

The bass traps off to the (front) center...not completely in corner have done a lot...first ref is going to be tricky...back wall will be some thing to deal w/though...im surprised nobody scolded me for having floor standers in such a tight little room...I read a thread were someone said a good speaker is a good speaker...no matter what room...as it is the room that you must regulate...im some were in between on that I guess...

I think its giving me a reason to try some atc’s standmounts?

Definitely diffusors behind you to, well, diffuse back wall reflections. I used two Aurelex diffusors in my former listening space and these really made the back wall recede.  And absorption of first reflections to the side walls is a must to reduce phase cancellations.  A couple of floor-corner bass traps won't hurt either.
In small squarish rooms, many have had success setting it up across a corner rather than a traditional setup. If you are free to give it a try, you've got nothing to lose. 

Generally I would agree that absorptive bass traps in corners and higher frequency absorption at first reflection point is your best bet for starters. A little absorption at center front wall between speakers can also help tighten up your imaging/soundstaging. Cheers,
Spencer
Given your small room, I think Erik is right. Some absorption panels are needed. To tighten the image, absorption (not diffusion) is needed on the wall behind the speakers.
Speakers 30" out seems to be good positioning with such a small room.
Usually, if you lack imaging you need more absorption in the axis of the imaging problems. Good bass traps work in different frequencies and they aren't located where you need them.

You need to eliminate strong and direct reflections, so start absorbing first.  If your image is too short, you need better absorption above and below the speakers and you.  If your image isn't deep enough, or clear enough front to back you need more absorption behind the speakers.  If your image left to right is unclear, you need more absorption to the sides of the speakers.

Diffusers are usually best behind you or to the sides of your listening location. It's also a matter of taste, but from what you've typed I'd say your issue is not enough quality absorption in the mid to high frequencies in the right location.

Reach out to GIK Acoustics.  Great prices with very effective and good looking products, and good help.

Best,


Erik
Yes i have done that in a previous room...i had it too dead (matt)...im am hearing things i have never heard before though..and its not far off...I do have them out 30 inches from back wall,they are toed in as well (adagios)...but you know... these might be the culprit (too big for room)...my room is miserably small now 10 by 11 and i might have to concede to standmounts...but you know they do not sound that bad in this room..im quite shocked...
Be careful here my friend....Too much front wall damping will kill the life of your sound, having a little "bounce" or "Liveliness" is a good thing! Lacking clarity in the system is from the bass crossed over to high so as to muck up the main speakers OR your speakers need to be turned or moved just a little to help kill the bad resonance, try checking your settings and go lightly on more room treatments.

Matt M
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