Corner placement of stereo system


I have actively bi-amped, Krell driven B&W800's. I now have them placed along the long wall of a 25'X15' room.

To gain more space in the room for non-audio needs, I am considering reorienting the system so that it would be centered on one of the corners. The speakers would be unchanged in relation to themselves; but, they would be slightly closer to the rear wall, but the front plane would be much farther from the back corner.

Does anyone have any comments on what would be the sonic change.

Thank you,
Richard
drrdiamond
I am posting to this old thread just so I can mark it in to learn about options for our family/rec room I am beginning to re-do.
My system at least partly is adjustable for the most serious potential problem, uneven bass. I have the Stereophile 'B' rated Acoustic Research AR-1. They sport an efficiancy rating around 95 dB, largely in part due to the 500 RMS Watt Bob Carver subwoofer built in. The subwoofers have a adjustment for level on the back of the speaker, and using Stereophile test disks and the Rat Shack meter, have pretty good flat responce from each speaker individually after Ive tweaked them out, and even FLATTER when measured together.
The biggest problem with standard rectilinear set-ups is the existance of standing waves, or room nodes. This just doesn't happen the same way with a corner set-up.
Stereophile had something to say on the subject a while back. Anyone remember what?
As far as questions about symetry or mirror images, there is a great deal of symetry with a proper corner setup along the center line. True the 'two different back wall' lengths are different, but this is precisely the PROBLEM with conventional set-ups. Besides, the room needs to be properly set-up with appropiate wall damping and reflection absorbers anyway.
Finally, these discussions seem to be getting to the point of 'a picture is worth a thousand words.' We need the ability to attach pictures, diagrams, bmp's and jpg's. Any suggestions on that?
This is something Deano taught me: "Speaker placement is free."

Go ahead, move things around and learn...
Ok in responses to your questions/statements "Drrdiamond", if you have a 15 X 25 room, and you are using a corner placment, it's acoustically impossible for both your speakers to be in the same SYMETRICAL acoustical space in that room!!!...can't happen! (infact give me the speaker placment spot measurements in relation to each wall and I'll tell you what your frequency response is going to be precisely with those speakers!!!...but draw me a room picture first, so I can factor any oppenings, doorway's and windows and such)
Because your room isn't a perfect square(i.e, 25X25, etc..which would have different problems acoustically). infact, you will probably be putting your speakers much closer to the respective walls in this corner scenario, correct! That's defitely going to give you boomier and more peaky sounding bass response, as the closer you get to any wall/boundary with either your chair or speaker, the more uneven and unatural the bass response is going to be!...and that afects the overall spectal tilt you hear, and potential overshadows the midrange and treble.
Again if you want to test this, just place some saller, even inexpensive modest sized yet smaller, monitor speakers on stands where you're considering placing your seakers in a "corner" placement, and measure!!! The response from both speakers in the bass reigion will be VERY DIFFERENT! Then try putting the same speakers in a symetrical long wall or short wall set-up(considering other openings), and you'll see EQUAL MEASUREMENTS AND BALANCE FROM EACH SPEAKER!! (In fact you can call Thiel, Dunlavy, Wilson, Logan, B&W or others and they'll tell you a lot of the same!)
Also, YOU WILL DEFINITELY BE HEARING REFLECTIONS FROM THE SOUND FROM THE WALL SPOTS TO THE IMMEDIATE LEFT AND RIGHT WALL BESIDE/BEHIND YOUR SPEAKERS IN A CORNER PLACMENT SCENARIO, MUCH EARLIER THAN YOU WOULD IF YOU KEEPT THE "LONG WALL" SET-UP YOU STARTED WITH!(that is unless you had your speakers ultra wide or close to the front wall with your "long wall set-up"! With a corner placement you are forced inTo placing the speakers near the walls dirrectly behind/beside the speakers. And its those locations where your going to have to treat and deal with first order reflectons! ...mostly much earlier and "simultaneously"(which is a problem) than if you followed the "Dunlavy" recommended symetrical speaker placment arrangement along a long wall(or even short wall) symetry!
I've been around this stuff for 20 years, and have set-up more systems than 99.999999999% of all living beings on the planet, so I've delt with it all time and time and time again, and nothing ever changes! So my recommendation would be to call any high end speaker manufacturer, and tell em your quandry! Tell em you would like to consider their speakers, and want to know about placement chioces and results! You'll get a huge majority of them recommending the "long wall" or "shot wall" SYMETRICAL ARRANEMENT, but a staggeringly very few recomendng "corner placement! Is a corner placement workable?..perhaps, but not likely with such large speakers in a relatively small acoustic space as yours!...and,yes, 25 X 15 is still a relativey small enough acoustical space. At any rate, it couldn't hurt to try your corner theory ultimatey(that is unless a 250 lb speaker tips over on ya that is...he he.). But when you do, try measuring both speakers like I mentioned, YOU WON'T GET EVEN CLOSE SIMILAR RESULTS FROM 20HZ-300HZ!!!!! One speaker will measure decidedly high in one frequency, and the other will measure either flat or low in a lot of frequencies. Try it, you'll see/hear! Bass will tend to seem stonger, or at lest different from one speaker than the other, which makes an accurate pressentation impossible ultimately
Actually, if what your saying is the dimmensios are a perfectly closed in rectangular 25 X 15, and you tell me where your placing the speakers in exact distances from each speaker to each wall, I can tell you what your measurements are going to be!!!!!!!....to within very accurate measurements!!!!...and trust me, you'll not get the same balanced response from speaker to speaker in that corner location, believe me. Or simply try it and you'll find out really.
Anyway, if you could see your room from an acoustical "bass wave" standpoint, you'd understand why I say what I say. From right to left, from front to back, from ceiling to floor, you have very different bass response in all different spots in that(or any) room! If I could draw you a picture I would
Anyway, good luck with it.
I don't understand several points that have been stated by LTHKEEPR.
When I place a mirror along the wall that would be behind the speakers, the speakers are not seen because with the set-up the walls flare out with respect to the speakers/listening position, so I assume there would be virtually no 1st reflections and therefore little smearing of the imaging. Also, since the set up (speakers/listening position) is symetrical with respect to the corner and the both walls behind the speakers will be treated the same, why would the speakers have a different frequency response.

If I had a nice small system, I would just move things around a try it out; but with 250lb speakers and over 250lbs of amplifier, not to mention dedicted outlets that also will have to be moved, moving around my system is hugely difficult.

Also, BRTRITCH: What type of speakers do you use; big or little?

All comments are greatly appreciated!!!!!
Richard
If you are in doubt about the scenario, you can, of course, always move things around and try! however, if you want to see how differnt things really are between each speaker in that set-up, place the speakers where you want, and just measure the differences with a test tone disc and sound level meter! what you'll find, is that likely your getting more bass overall from one speaker to the next, and one speaker will read a lot different at various frequencies than the other! This leads to lots of soundstage shift and inconsistencies, and phase challenges, etc. Also, you'll still have to contend with not quite as good of immaging and immage blur from simultaneous(or close) wall freflections back to your ears, from the wall besides/behind each speaker!
anyway, experiment and find out!
have fun
I've set my systen up as you descibe, and am very pleased. I only listen from one position, although sound is 'acceptable' along the line that is equadistant from the two speakers. Set up is crucial, as always. My speakers and listening area form an equilateral triangle. The speakers are each the same distance from their respective back walls, and each speaker is the same distance from the other speakers wall. Imaging and focus are great, and depth often surpasses what is possible with a standard arraingement because there actually IS physical depth in the center of the stage. On good recordings, soundstage extends well past the confines of the speakers.
You will have a very difficult time, for one, getting even response between the two speakers, from any given seating possition most likely. With the long wall placement(probably ideal in your senario..although you can make short wall placement work if careful), you can both get the speakers in the same symetrical/acoustical locations in the room, (potentially, as you didn't mention complete room symetry, nor openings, doors, windows, etc), equa-distant from the boundaries, and also find the same for your seating possition in relation to your symentrical speaker set-up.
Another issue is that you'll definitely have to be much more concerned about potential wall reflections near the speakers, as you will otherwise DEFINITELY be dealing with the problem of hearing the reflected sound off the wall at very close intervalls to the dirrect sound from the speakers!...bluring the immage, focus, and soundstage!!!
So, you'll likely end up with a great challenge in getting one speaker to sound the same as the other in frequency response(causing soundstage and phase shifts, etc) from most potential seating possitions between the speakers. And, you'll end up with some rather inherent acoustical reflection difficulties!
My experience suggest that pulling off a workable "corner placement"(and I've done 1000's of systems over the years) is better suited to smaller mounted satalite/sub systems, where you have greater placement flexibility! With two large stereo floorstanders, it's a dunting task to pull off well. Infact you potentially risk the sonic overall integrity of your system, bringing it down in overall quality level, simply by poor speaker placement!
If you have to compromise, and must alleviate the existing "long wall" set-up, because things are crouding your room too much, may I suggest even downsizing your system to more manageable sized gear instead! You might find that with even smaller floorstanders, or especially small monitors(and or sub set-ups), that you can keep a more "sane" "non-room-dominating" set-up, and still get great sound!...it's always compromise in the end.
Good luck