I find curtains and old towels very cheap. You start slapping "acoustic" on things and it gets a lot more expensive. The ideal fix would be a few sheets of OC704. It's a lot better than blankets and not that much more expensive.
Stereo image abnormalities
- Thread starter HowardMil
- Start date
I find curtains and old towels very cheap. You start slapping "acoustic" on things and it gets a lot more expensive. The ideal fix would be a few sheets of OC704. It's a lot better than blankets and not that much more expensive.
tomlinmgt
Lunatic Member
I’ve done both the equilateral triangle configuration and otherwise and have experienced a strong center image with each...but only in rooms with a deliberate and comprehensive acoustic treatment scenario (all early reflection vectors treated with absorption panels).
tomlinmgt
Lunatic Member
I’m curious as to why you have such an extensive acoustic treatment program, but absolutely nothing on the front wall?
I at first though that maybe you were attempting LEDE, but that can’t be the case because you said you have diffusers on the back wall. What type of diffusers are they, by the way?
With regard to the asymmetrical room, alcove and window causing the image shift...I’ve worked with asymmetrical rooms that have windows or glass and openings to other areas/alcoves and have been able to get a strong center image without covering all the glass so long as the early reflection vectors are treated with absorption and all opposing hard surfaces have absorption on at least one of those surfaces to kill the bounce. Your window is (mostly) behind an absorption panel and has the glass covered by fabric...the alcove has an absorption panel in it to attenuate any possible resonance issues and is a good distance away from the listening spot (so any reflections coming from there are late arriving and relatively inert). I think you’ve addressed these potentially problematic areas appropriately.
Your listening spot is fifteen feet from the front wall (wall behind the speakers)
and that puts you almost in the center of the room...not ideal. Try moving the listening spot closer to rear wall by a few feet and also moving the speakers further into the room the same distance....maybe six feet into the room from the front wall for the speakers and seventeen feet for the listening spot (as a starting point). This will get you and the speakers further away from the alcove and reduce interaction with the window by moving the first reflection off of it. Don’t forget to relocate the absorption panels at side wall first reflection locations. This will remove a panel from in front of the window, and though it will no longer be an early reflection vector, I still think it a good idea to cover up the glass as much as possible...so maybe take the panel in the alcove and move it over in front of the glass.
Also, unless you have a few reference recordings you routinely use to test and dial in a system, you need some sort of reliable reference tool. I like this one...
https://www.audiocheck.net/
Michael
I at first though that maybe you were attempting LEDE, but that can’t be the case because you said you have diffusers on the back wall. What type of diffusers are they, by the way?
With regard to the asymmetrical room, alcove and window causing the image shift...I’ve worked with asymmetrical rooms that have windows or glass and openings to other areas/alcoves and have been able to get a strong center image without covering all the glass so long as the early reflection vectors are treated with absorption and all opposing hard surfaces have absorption on at least one of those surfaces to kill the bounce. Your window is (mostly) behind an absorption panel and has the glass covered by fabric...the alcove has an absorption panel in it to attenuate any possible resonance issues and is a good distance away from the listening spot (so any reflections coming from there are late arriving and relatively inert). I think you’ve addressed these potentially problematic areas appropriately.
Your listening spot is fifteen feet from the front wall (wall behind the speakers)
and that puts you almost in the center of the room...not ideal. Try moving the listening spot closer to rear wall by a few feet and also moving the speakers further into the room the same distance....maybe six feet into the room from the front wall for the speakers and seventeen feet for the listening spot (as a starting point). This will get you and the speakers further away from the alcove and reduce interaction with the window by moving the first reflection off of it. Don’t forget to relocate the absorption panels at side wall first reflection locations. This will remove a panel from in front of the window, and though it will no longer be an early reflection vector, I still think it a good idea to cover up the glass as much as possible...so maybe take the panel in the alcove and move it over in front of the glass.
Also, unless you have a few reference recordings you routinely use to test and dial in a system, you need some sort of reliable reference tool. I like this one...
https://www.audiocheck.net/
Michael
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Yeah, and I believe symphony orchestras usually put a piano on the left in front of the first violins.
I agree, you both make some valid points.
Hi Howard.
I figured, but made the comment because it's so easy to overlook some issues, make quick checks that can be confusing, and begin working on the wrong thing. Of course, neither you nor I would ever proceed in such a haphazard way. Except that I have a couple times.
Good thread; I missed whatever drama may have been posted previously.
I believe the issue was someone making a duplicate post lol.
As for the magic triangle and toe in, I've found many speakers work better aimed straight forward, especially vintage and large speakers. That said, my Infinity Modulus are small and also benefit from facing forward in larger rooms, smaller rooms definitely improve with a bit of toe in.
If I've learned just one thing in this hobby, it's that nothing is cut and dry.
Again, try moving the equipment to the long wall, you'll be amazed at how much larger the soundstage will be, and improves depth.
If I've learned just one thing in this hobby, it's that nothing is cut and dry.
Again, try moving the equipment to the long wall, you'll be amazed at how much larger the soundstage will be, and improves depth.
tomlinmgt
Lunatic Member
So that last part is cut and dry...or???
No it's not, it's whole and wet.
Let's take a room 300' X 400', I don't think it would make any difference, but with the OP's setup I'm fairly certain benefits will be gained.
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tomlinmgt
Lunatic Member
I don’t disagree with anything you’ve said, necessarily...but I’ve not found the setting up on the long wall thing to be a cure all. It has its merits, but some are quick to suggest it as the optimum configuration without acknowledging that many times it leads to increased SBIR and also locates the listening spot sufficiently close to the rear wall that it creates a strong early reflection from that location...both or either of which can negate all the benefits of moving the sidewall reflection vectors further away from the listening spot.
tomlinmgt
Lunatic Member
Fiddle with the balance knob, and start listening to the music instead of trying to pick apart the details. Trust me, you'll enjoy it a lot more
There you go. My dedicated listening space was highly tuned with a host of acoustic treatments and after marveling at the results for a few years came across an Acurus preamp that had a balance knob...which I hadn’t had in years...AND the balance could be controlled on the remote. Friggin’ game changer right there.
Hold the phone...no balance control? On a preamp???
Not that I have to use mine often, but I'd feel naked and alone without my tone and balance controls.
tomlinmgt
Lunatic Member
Oh for sure. I was once a hard core opponent to tone controls/balance knob on preamps...and could get away with thinking that way since I had the luxury of a dedicated, well tuned and acoustically treated listening space....
But getting control over balance with the Acurus proved to me how powerful and useful that simple feature can be. And now that I’ve been setting up systems in rooms with little to no acoustic treatments, have come to appreciate a good set of tone controls (love my Schiit Loki), as well.
The OP's room is wide enough none of this should be an issue.
tomlinmgt
Lunatic Member
I agree...so long as he gets the speakers off the front wall at least three feet and absorption on the wall directly behind him.
I've found heavy drapes work great, no window required lol. I've even used vertical blinds turned at a 45 degree angle in the past when those were popular.
tomlinmgt
Lunatic Member
I just re-read the OP’s comments and missed the part about the shift only happening as a song is fading out. Is this accurate? You only experience the image shift during fade out, HowardMil?
This is my guess: the reflections are frequency dependent, so the effect on the stereo image will depend on what music you're listening to and what its frequency content is at the time. Or maybe the reflections are level dependent, in which case the effect will depend on the volume at which the music is playing. The second guess seems less likely to me.
More generally, if you can't be about the same distance from the speakers as they are from each other, you are better off being closer to the speakers rather than farther away.
More generally, if you can't be about the same distance from the speakers as they are from each other, you are better off being closer to the speakers rather than farther away.
Hi Michael:
Your comments have addressed the issue perfectly!
Now a question or two and some observations.
The left alcove has actually (3) moving blankets HANGING.
I was thinking of buying a STURDY “ small divider” ( http://nymag.com/strategist/article/best-room-dividers.html )to this opening and hanging (professional?? Lol) >> absorption blankets
https://www.vocalboothtogo.com/product/vb-80-group-product/
hanging them over straight down the divider or partition as these blankets have better absorption quality. Question being : does the partition need any requirements regarding material or build quality?
2. You’ve got my right window down to a pat!!!
I’m wanting to order some EVERY DAY blinds ( material or wood? ) OR: should they be some sort of sound absorptive or sound deadening blinds (drapes) . Then either leave them bare with no absorption blanket or test out a blanket on half window; or either or? The first right reflection panel as you said is covering a bit of it.
Should there be a 1st left side reflection blanket behind left drywall 1st. Reflection panel as well?
The back wall has 3 GIK Alpha5 diffusers spread along 14 foot short wall. Along with lots of unopened boxes behind my listening chair. I have those GIK 244 ceiling bass traps midway between me and the speakers/ but ironically- still getting a bit of SLAP ECHO..... I was told that front wall behind speakers is the LAST place to treat if nothing done so far kills a bit more echo (GIK) .
Another irony is that the first thing I put up were the monster bass traps in front ceiling corners- with Range Limiters..... essentially damping bass but leaving mid/ high frequencies absorbed much LESS!!
Lastly- moving speakers out a bit more and listening position as well: a good thought but would that eradicate the alcove-window- image situation? Or to proceed with that as well??
Lots of thoughts here....!
Thanks
Howard
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tomlinmgt
Lunatic Member
Before you put too much effort into DIY projects, I suggest you experiment with relocating the speakers and listening position since it will take a very small investment of time and resources and produce definite changes.
Along with what I suggested, I also like @rothwellaudio ’s suggestion to create a near field arrangement to remove as much of the room influence as you can (without the chore of setting up on long wall). Leave the speakers more or less where they are, but maybe create an equilateral triangle with 6’ legs. That will put the listening position at roughly 10’ which locates you damn close to a room dimension 1/3...so modal beavior will be less erratic.
And although it may seem like GIK is suggesting that treating the front wall is a low priority item, I can assure you they would not underempahsize it’s influence on a proper acoustic treatment scenario. There’s a lot going on there (acoustically), and my experience is that addressing it appropriately creates improvements that are not negligible...particularly to image resolution and mid/upper bass clarity.
I’m also a little confused by the suggestion that the only bass traps in the room be located at the mid way point on the ceiling when it’s common knowledge that low frequencies accumulate most where boundary surfaces converge (corners).
Are your absorption panels and diffusers hung/mounted or can you move them around easily?
Michael
Along with what I suggested, I also like @rothwellaudio ’s suggestion to create a near field arrangement to remove as much of the room influence as you can (without the chore of setting up on long wall). Leave the speakers more or less where they are, but maybe create an equilateral triangle with 6’ legs. That will put the listening position at roughly 10’ which locates you damn close to a room dimension 1/3...so modal beavior will be less erratic.
And although it may seem like GIK is suggesting that treating the front wall is a low priority item, I can assure you they would not underempahsize it’s influence on a proper acoustic treatment scenario. There’s a lot going on there (acoustically), and my experience is that addressing it appropriately creates improvements that are not negligible...particularly to image resolution and mid/upper bass clarity.
I’m also a little confused by the suggestion that the only bass traps in the room be located at the mid way point on the ceiling when it’s common knowledge that low frequencies accumulate most where boundary surfaces converge (corners).
Are your absorption panels and diffusers hung/mounted or can you move them around easily?
Michael