Uneven soundstage help, please.


I've got a pair of ATC SCM40 v2's driven by a Musical Fidelity A308 (plenty of power) and overall I'm happy with this combination, given my budget, wife, and listening habits. My system is in an incredibly complex large room, with all sorts of variables in terms of reflection, absorption, etc. And these aren't exactly the same from one speaker to another. I have no choice about speaker placement, given the room configuration.
There's a phenomenon that concerns me, though, that I haven't been able to resolve. In order to get the center centered, I need to position the speakers and listening chair in such a way that the soundstage extends all the way to one speaker, but only three-quarters of the way to the other. It doesn't sound out of whack. It's just a narrower field than I had with my older KEF References, and I wonder if it would sound even better if this was resolved.
Has anyone else faced and solved this? What factors are driving it? I've been living with it comfortably, but I wonder.
Thanks ahead of time for any replies.
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Showing 7 responses by erik_squires

Erik, are you suggesting that I try narrowing the distance between my speakers or changing the toe in?

Normally we try to point the tweeters so they fire right at our heads and cross right between our eyes. I’m suggesting that you move this crossing point in front of your head, so the speakers are severely toed in, as if they started to point to each other instead of you.

This will minimize early side reflections, and perhaps improve the tonal balance.


Best,

E
I should point out that while an EQ will be better than not in the situation of uneven speaker placement, you still are going to have issues with uneven reflections. 

Controlling the room acoustics is always the best solution, but if you cannot do that, you are getting the second best approach.
Hey,

Look, at the point where your placement is so bad that you can't get a decent center stage, I promise you that a decent EQ will be the least of your worries.

If you want to be a purist, get a better room, with treatment.  If you can't do that an EQ is going to be a huge huge improvement by comparison.  I mean, do you want to spend years not listening to a great sounding system because you were worried about tone controls??

Honestly too, EQ's and tone controls are superbly better than they were in the past, so the benefits far outweigh the risks.

The issue you are having, as you point out, is that you need to treat both channels separately, and that's what ARC or a miniDSP will let you do.
Here's a cheap test:

Use blankets and pillows as acoustic panel proxies.  If this fixes your image, then you know what the issue is.
I doubt it's the porting, but it could very well be the dispersion, or how wide speakers maintain a flat response.

In a cluttered room, you want narrow dispersion.  In a big open room you want wide.

Best,

Erik
Well, to completely understand, you can’t move the speakers, and you can’t add better room acoustic treatments, like GIK Art panels which let you pick any artwork and put it on them.

Those are always my first two suggestions. You can try crossing your speakers in front of your head, minimizing side reflections.

Lastly, if none of this work it's probably becuase you are getting a very unbalanced frequency response.  Assuming it's not bad speakers, you will need to measure and adjust using EQ, either from a separate unit, or by using the built in EQ of Roon or similar. If you aren’t familiar with measurement and correction I suggest you get something that has room correction built in, like Anthem pre/receivers, etc. or a miniDSP unit with Dirac live built in.

Here's an example of how I corrected a much milder problem than you are having using the built in EQ from Roon:

https://speakermakersjourney.blogspot.com/2020/01/the-snr-1-room-response-and-roon.html

What you should do is pick a speaker with the least reflections around it as your baseline, and try to get your other speaker to match it.

If you use ARC, like Dirac or Anthem they will do it all for you.