Problem with soundstage up near ceiling.


This is driving me nuts. I have changed everything. The whole system and still have this issue. The room is about 14'x20'x6'8". When seated in the sweat spot, all the highs seem to be comming from where the wall meets the ceiling. I insulated the joists behind the drop ceiling tiles and tried use Owen Corning 703 in more places than I can count.
I you have ever seen this before, give me a clue.

Tim
flemke
I bet for a lot of audiophiles it is a sweatspot indeed...sorry, I couldn't help it :-)
Your overall low ceiling height might be the big culprit here. Have you tried playing with the feet adjusters (spikes or whatever) to position the tweeters at more of a downward angle rather than level to your listening position? Also toe in or tow out? My sound stage on good recordings ranges from 1/2 way up a 8' wall to the ceiling and I get down right upset if things like vocals are not at least 6~7 feet off the floor. On some recordings it almost washes over top of my listening position.
I lowered the monitors to about 16". This seemed to help little. The tow in/out did nothing. I did not tilt the speakers downward.

Tim
This sounds like a problem with the listening position. Try elevating your chair 4 feet higher on acoustically-dampened cinder blocks and your problem should be solved.
Post removed 
Elizabeth,

I don't know about editing a posted question, but you can edit your response as long as it's the last response. As soon as someone else posts a response after yours, you can no longer edit yours.

Chuck
Wow! I thought a bunch of know-it-all audiophiles would be able help out with an actual problem.

Tim
Several questions:
How far are you from the face of the speakers?
You say,"When seated in the sweet spot, all the highs seem to be comming from where the wall meets the ceiling."
That would be 'behind' the speakers at the joining of the 'rear wall' is that right?
If so, that strikes me as odd.
I think, to start, I'd try listening, more nearfield...as a matter of self defense.
Next experiment, this might sound really dumb, but, note how some concert hall, stage areas use vertical hanging's from the upper part of the stage.
Try, for a point of reference, hanging something absorptive from the ceiling (a towel for experimentation, if nothing else).
Put that hanging, parallel to the rear wall--starting a foot from the face of the speakers, then further and so on.
Maybe a 'team' sports banner would help a bit, but you've not got much room--I know I couldn't walk in that room with anything more than 5" or so hanging down.
This is very approximate, but we don't know enough yet.
If you'd like to discuss this, you can write me at my personal email, [email protected]. I'll be glad to give my phone number to talk more.
We can solve this somehow...no accoustic problem is too much when you're willing to experiment.

Good listening,
Larry
I finally fixed this problem by stripping the ceiling down to the joists. The ceiling effects the system in way I did not think possible. I called several people who are in to acoustic treatment and they said my problem was very weird indeed. No shit. I now need to figure out what to put back in.

Tim
I recently bought a new preamp that really opened up my soundstage and I was experiencing the same thing.
Everything seemed to be a couple feet above my head, especially the vocals.
I tilted my speakers slightly forward and it made a HUGE difference. It even helped in the dimension aspect.
Drop Ceiling? Wrap ceiling tile in grill cloth. Trim it, hot glue it to the panel on the rear. Looks great. You may need a slight pad of some sort for extra absorbtion, but this should work.
I have tried everything you can imagine. The only thing that worked was taking down the drop ceiling and the old furring strips from the old interlocking tiles. I may just paint the joists black.

Tim
With the limited information provided, I guess the undue soundstage height is due to disproportionately strong ceiling reflection. Due to low ceiling height, the reflected sound off the ceiling arrives at the ears very close to the direct sound of the speakers. The ears tend to integrate early reflection with the direct sound. This leads to perceived sound source broadening.

Just traps or absorbers would decrease the amplitude of the reflected impulse but would not spread out the reflected sound over time. The ceiling would still be very audible.

Combo tools (abfusors, skyline, hemifusors), or diffusors tend to help a lot in this situation as it would decrease the amplitude of the reflected and also spread out the reflection over the time domain. Having a softer, later reflected impulse tends to fool the brain into perceiving a boundary further away. I would think hemifusors or low profile skyline wound be excellent as they occupy less space and the slightly effective narrower bandwidth may limits beaming since listener is still close to the diffusor.

The brain composes the soundstage by reflection off all boundaries. If you have absorptive floor ( thick carpet), it wound further expose the soundstage broadening effect from the ceiling. Changing to wood floor would strengthen the reflection of the floor and would counteract the effect from the ceiling to some degree.

Changing the dispersion of the midrange/tweeter may also help. If it is an option, ribbon tweeters have broad horizontal dispersion but very limited vertical dispersion. This may yield a more stable/precise soundstage on the vertical plane but maintains a wide stage on the horizontal plane. Other ways including install a waveguide or using felt to limit vertical dispersion.

Good luck
The only other thing I could suggest, would be, try the whole system in another location in the house.

That will tell you a LOT.

Not that you can leave it elsewhere...but it grounds your acoustic thinking.

Larry
Whats the wall behind the speakers made of? How is it finished. Is there a soffit that drops from the ceiling that contains water pipes or HVAC hardware. Where are they located in relation to your seating position and speaker position. Tom