Severe Imaging Problem

Since getting my Aleph-3 I have lateral imaging for the first time.My problem is my room.It is the only practical way I can have speaker set up.The speakers are the same distance from side walls.The left front wall is only 2 feet long then opens to a 5.5 foot wide X 3 foot deep,floor to ceiling window alcove.The right front wall is 6.5 foot long then opens to the alcove.The alcove has windows which are treated with heavy curtains.The alcove also houses myequipment.Obviously I have much more front wall in back of my right speaker.I have side wall treatment as well as front wall.The outside (lateral) imaging is excellent from the right speaker.I couldnt be happier! The left speaker there is little to no lateral imaging.I have reversed I.C.'s
(cont)when I do the imaaging I had 2 feet outside the (L) speaker now is on the inside of the left speaker.The inner imaging I had inside the left speaker is now outside the left speaker.I pretty much have no (L) speaker lateral imaging.I always thought side walls dictated lateral imaging.Could the alcove cause this?It seems so severe maybe its out of phase(?) Maybe a component problem? If its a room problem,any advice?More treatment on left wall?? HELP!!!!!!!! Thanks,Dave
Im sorry,let me correct my last entry.When I reverse the I.C.'s the imaging I had 2 feet outside the RIGHT speaker is now on the inside of the LEFT speaker plane.The imaging I had on the inside of the LEFT speaker plane is now 2 feet outside the right speaker. Sorry for the mess,Im so frustrated I cant think straight!
You'll need to use XLO test CD to verify all the phase polarities. I suspect you might have phave inverted problem taking place somewhere in the component chain. Does the preamp have phase inverting outputs? Good luck!
David, there are no simple solutions that will actually give you what you want in your room automatically (it'll always be trial and error), but I will say this. For one thing, ANY room asymmetries (due to system position, or room shape) will ALWAYS be problematic. The physics of sonic wave propogation, diffraction, and reflection, dictate this.................For another thing, it is not my experience that ANY room boundary "dictates imaging" at all. The direct sound coming from the speakers is what dictates imaging, and a correctly TREATED room's contribution to the perceived sound at the sweet spot is what adds the complex sonic signature that...although still subtracts from accuracy, IS most often a plus for "musical satisfaction" due to many factors, most of which (but not all) are "psychoacoustic"'s one reason why all experts who have listened to "stereo" in a big anechoic chamber NEVER like doing it (apparently, that experience is nothing like the positive delight it is to listen "in the nearfield" with small speakers, in a normal listening room)................................I AM NOT SAYING THAT COMPLETE ABSORBTION FOR THE WHOLE ROOM IS THE ANSWER, ONLY FOR ALL FIRST REFLECTION POINTS PRIMARILY ALONG THE SIDEWALLS (or in other cases, wherever the strongest reflection points are in the room, that will "see" the front, or direct radiation, of the speakers...that gets even more troublesome for dipolar radiating speakers like Maggies, so placement and treamtment must be combined in a "one-two" punch, to keep the rear radiation from overly contributing to the perceived sound at the listening chair).........................That is, unless you have a floor with no carpeting, then things get really complex, and the room is definitely going to have more contribution, no matter what is done with treatment...............................So, an inadequately treated room's "significant" contribution can only hinder system performance and imaging. That's why it is important to treat most first reflection points (especially sidewalls) with something that can AGGRESIVELY ABSORB those reflections...and not just diffuse them a little...........................Everybody will disagree with me on this, until they try it, and that's fine with me. What I am saying, is that the sidewall reflections are the loudest and EARLIEST reflections in any listening room (assuming you have carpeting on the floor, and a ceiling higher than 4 or 5 feet...and who wouldn't?), in an average given room volume. WHAT I MEAN TO SAY IS, the sidewall reflections must be REMOVED as completely as possible, for there to be accurate imaging. And room symmetry is also important, for the "complex secondary" reflections, which occur basically on every square inch of EVERY surface in the room (including floor, ceiling, walls, coffee tables and other furniture, etc.)..............................Also, I am wondering how you can love this new amp so much, if you have a "severe imaging problem"? Is it because you always knew you had the problem, but the Aleph is letting you hear the problem more clearly? I hope that's the case...
What I meant at the last was, if that isn't the case, then there's a mintute possibility that there could be something happening upstream, as suggested by Tom above. However, I don't think this is a polarity problem, because that would be more severe, than your description seems to me. BTW, you don't have to have a test CD to check phase continuity between channels, you can just connect one speaker positive to negative, listen, and hear the difference. Play a record with vocals that you know to be centered, and they should be spread all around, even outside the width of the speakers, behind you, above you, etc. I have that XLO/RR test disc, and it is terrific for this, and also for fine tuning the imaging (with the voice and correlated/uncorrelated noise tracks). And the Sheffield ATB "My Disc" is even more essential than the XLO, imo.
Carl,My Dynaco never threw a wide stage,rarely anything outside the speakers plane.I assumed one needed a super big buck system to get consistant imaging in "the outer limits" Anyway,I was floored when the Pass really started to purr and was throwing 2-3 feet images outside my (R) speaker.As I was only getting a hint of (L) sided imaging and only occasional 1 footers thats when I decided to mess with my speaker placement,but failed to improve the (L) side.I tried all types of remedies today.BELIEVE me,without going into all the detail,I spent 4 hours messing around.It appears the best sound is from the original placement and absortion locations.OHHHH, what a bummer!! NEXT??
Like I said, a lot of trial and error. I can't see or hear the system, so I can only be so specific. I too have spent many long hours, and even fractions of an inch make a difference for the midrange and low treble, with regards to how they image in a stable manner.
The more resolution you hear, the more you want to hear. At some point, you do have to tweak in other ways, besides placement. Beleive me, you have not done everything you can do with treatment.
David - Where od your sit in relation to the loudspeakers and the room. One thing you could try to help you determine if you have an equipment problem is so set yourself and speakers up for very close nearfield listening, which is another way of getting rid of room effects. I did this for a while while I familiarized myself w/ a new room and system (though I've sinced followed Carl's advice and gone for sound treatment at the first reflection points, etc). In nearfield, you should still get correct imaging if there is nothin wrong w/ your speakers. The actual set up is simple - the proverbial equilateral triangle, but a fairly small one (4-6 feet on each "leg") and basically in the center of your room. If you e-mail me ([email protected]) you room dimensions, listening seat height, distance from floor to woofer and number of woofers per speaker etc. I can run them thru the RPG Room Optimizer software and give you a rough set up to try. will also calculate all the first refeflection points
David, it sounds like you've tried this already but it sounds to me like a phase problem. I have an inverting preamp so I swap the leads at the speakers. I have experimented both ways with the speaker cables and on some recordings it makes a huge difference, images way outside and in front of the speaks, and on others it makes no difference. Be careful with the source material you are using, some recordings are not in absolute phase. The phase is often changed many times during recording, mixing, pressing, etc. That's one reason some recordings sound unbelievable in regard to imaging and some sound like crap. That's when most audiophiles like myself get out of the chair and start moving speakers around. Big mistake. Make sure your speakers are connected to your amp in correct phase with each other. Lastly, side wall reflections aren't causing the severe problems you've mentioned although they are the most important to dampen in my opinion. Your image may pull to one side or the other but not like you've mentioned. Hey, you are no doubt in audio hell but rest assured there is a way out. Good luck.
hi david, if i understand ewe correctly, reversing the interconnects leaves the same imaging problema at the left speaker, & the right speaker is still ok, even tho the channels have been reversed? i guess it *is* possible that the asymmetric location of your window alcove could be doing this, but w/proper room treatment, i'd be surprized that it's such a noticeable problem. are your speakers mirror-imaged, or can you switch 'em? assuming ewe are *sure* you've addressed *all* the proper-phase issues, and wall-treatment issues (try a sound-panel in front of the left-side opening of the alcove to mimic the right-side wall?), i'd try switching the speakers themselves... good luck, doug
One thing that the xlo disk helps with is checking every possility of phase probs, along with the solutions. If that doesn't seem to be the difficulty concerning l and r imaging, then you might want to consider hiring an acoustician. The guy will come in there with all the expensive equipment and properly install treatments. I just think for a really complex room situation, that that is a reasonable solution.
Sedond,I tried putting a sheet of plywood over the alcove.No difference.I have made some small speaker adjustments and presto! Lateral imaging to the left.Its not as good as the right side but I think thats a treatment issue that I will get to next.Thanks for all the help!
Correction to above.I made some major speaker adjustments not small.A foot farther from the side walls.4 inches closer and toed in 1/2 inch or so more.