Too much SDA effect

allstock

So this is a good one. After relocating my two channel into a dedicated room, I've got a soundstage 180 degrees wide. I've got guitars coming from RIGHT beside me, to the point it is distracting. I've moved the speakers around, as well as my treatments, with little effect to taming an unrealistic soundstage. Of course disconnecting the IC causes the soundstage to collapse back into "regular" stereo. Thoughts?

Mike Reeter

Not trying to be a smart a$$, but is your new room big enough for the 1.2's ? I would think they need some real estate to really have some breathing room. Was the soundstage more realistic in their former spot?

inspiredsports

Can you elaborate on room size, room furnishings, location of speakers in relation to walls and hard/reflecting objects, wiring scheme (bi-wired/etc.), type of SDA interconnect, distance between speakers, listening area distance from speakers, distance from wall behind speakers, nature of surface directly behind speakers, who did crossover upgrades.

Thanks

allstock

Diagnose will continue tomorrow. I may have a level issue between L and R, not sure if it's an electrical or acoustical issue yet. I can tell you its annoying. Short version, room is 15' X 30', 4' apart, 12' listening distance, I modded them four years ago, problem did not exist in previous room, which was an acoustical nightmare, new room is slightly over damped I feel at this point. I see if I can find anything obvious tomorrow. I've owned these speakers for fifteen years and they have been in a few rooms with a few different rigs and this issue is a new one to me! Thanks for the responses so far.

inspiredsports

Are speakers on 15' or 30' wall?

A bit more than 4' of separation would be better at a listening distance of 12', but should not cause the effect you are describing.

Be sure of basic setup requirements like same distance from back wall, no closer that 3' to side wall (or side reflecting surface of furnishings or gear), perfect 90 degree vertical angle from floor and perfectly parallel to each other and back wall.

Face

Is 4' apart a typo?

F1nut

4' apart, 12' listening distance

There's part of the problem.

Phasewolf

Not sure if they are on the 15 or 30 foot wall but they need room to work correctly as you may know. If the are on the 15' wall then with 3' away from each side wall and they are around 22" wide each that would leave just 5'4" between them which is not really idea at all.

Now I thought that with the SDA you were to sit around the distance that they are apart to be in the sweet spot but I maybe wrong on that.

allstock

Yes they are on the 15' wall, no option in that department unfortunately. They are level/plumb/square within an 1/8". I've had them in narrower rooms before without this weird 180 soundstage. If you get them too close to the side walls sda effect lessens, not increases. And yes about 5 1/2' feet between them. They SHOULD work in this set up, I'm not new at this. I'm chasing a level issue which may be at the root of it. They are currently 6" off the back wall. I've moved my bass traps and panels out for now while I chase it.

TennMan

Have you tried moving your seating position back farther away from the speakers. Seems like that should get you out of the sweet spot and the SDA effect would diminish drastically at some point as you move back from the speakers. At least that is what happens with my 2Bs.

PolkieMan

6 feet apart minimum measured from the inside edges of the speakers.
Your close.
3 foot from side side walls and 6" minimum from rear wall.
This all includes stereo/tv cabinets, they are walls if tall enough 36"+
and protrude past the front of the speaker.

Are you drivers and x-overs okay?

leftwinger57

Generally not knowing what I'm talking about I would think a 4' spred would be way to small and maybe that's why 1 side totally overpowers the other. Mine are at 7' and my listening position couch is centered at 9' almost an equilateral triangle and was told that's a good spred and should be no more than 10 feet apart.I've seen many showcases here and not to many are spaced at 4' or way farther than 10/12' apart.

stretchl

Very interesting thread. As you guys contribute, I'd be interested to hear what kind of soundstage, in degrees, you have for your own systems.

Thanks.

allstock

leftwinger57 wrote: »

Generally not knowing what I'm talking about I would think a 4' spred would be way to small and maybe that's why 1 side totally overpowers the other. Mine are at 7' and my listening position couch is centered at 9' almost an equilateral triangle and was told that's a good spred and should be no more than 10 feet apart.I've seen many showcases here and not to many are spaced at 4' or way farther than 10/12' apart.

Sorry they are actually 5 1/2' feet apart. Which is as wide as they will go in a 15' wide room. The owners manual states a minimum of 4'. It also recommends closer rather than wider in a "small" room. All drivers seem to be functioning normally. Moving closer makes the problem worse, I start to hear things BEHIND me. Moving them to 12" from rear wall helped some, but it's still not right. I will continue reporting as I have time to play with it. Spent the day at TAVES listening to some great gear, these things will be on the market if I can't get them to work in a 15' x 30' room.

drumminman

I thought that kind of imaging is what draws folks to these speakers.

allstock

drumminman wrote: »

I thought that kind of imaging is what draws folks to these speakers.

It is, but for whatever mysterious reason, I now have TOO much of a good thing!

nooshinjohn

allstock wrote: »

Sorry they are actually 5 1/2' feet apart. Which is as wide as they will go in a 15' wide room. The owners manual states a minimum of 4'. It also recommends closer rather than wider in a "small" room. All drivers seem to be functioning normally. Moving closer makes the problem worse, I start to hear things BEHIND me. Moving them to 12" from rear wall helped some, but it's still not right. I will continue reporting as I have time to play with it. Spent the day at TAVES listening to some great gear, these things will be on the market if I can't get them to work in a 15' x 30' room.

It's not the speaker's fault if you cannot get a handle on them. I would suggest you do everything you can to get them on that long wall. I would also suggest a half-dozen pictures of the room and a list of the associated gear you are using. Baring a crossover problem/internal wiring issue, the problems you are experiencing are not the norm by any means.

inspiredsports

Yeah, that's why I asked who did the mods. So far, what I've heard hints at something being wrong in the phase arena.

TennMan

I hope someone figures out what is causing this big problem because it want to do it to mine.

nooshinjohn

inspiredsports wrote: »

Yeah, that's why I asked who did the mods. So far, what I've heard hints at something being wrong in the phase arena.

Yep... what mods were done, using what components, and by whom would also be very beneficial at this point.

PolkieMan

I hear things behind me even outside the room. So if you unplug the SDA cable they sound okay?

allstock

Problem solved. Something up with my pre. Changed it out with my spare (An old Bryston bp.5) and the system is back to its old glory!! Damndest thing I've ever seen (heard). Btw I did the mods, three years ago. Dynamat, mills, sonic caps, rdo 198's,etc, all the usuals. I knew going in this issue was "not the norm" which was why I posted it. Threw all this I did learn a lot about positioning and to what extent is has on the sound. Thanks again for all the responses. When (if) I figure out what is up with my pre and why it affected the "SDA effect" the way it did I will let you know. Possibly a tube issue. The Soundstage vacuum two pre-amp is not an expensive piece to start with, so I will likely not spend a ton to have it diagnosed. I will roll my old tubes back in it and give it a whirl. Failing that, looks like I will be in the market!

dudeinaroom

Is this effect happening with all recordings, or one specific? I have a few recordings where it sounds like instruments are playing all around you, and others that have a more normal sound stage. Crap, SDAs can do a convincing surround effect from a movie only using 2ch, it all depends on the recording. You said you had a channel imbalance, did you check to see if you bumped the balance, or a input/output level control? Did you wire channels backwards...i.e. right output running to the left speaker and vice versa? Do any of the interconnects swap channels in between components?

For the imbalance, besides what I said above, you can swap speakers from channel to channel to see if is the speaker or the amp. If one speaker is quieter than the other no matter which channel it is hooked to, it's the speaker. if that is the case go up to your speaker and put your ear near each driver with music playing at a some what lower level, and listen to hear if music is coming out of all drivers. If not you either have a dead driver, or wiring might have come loose. You can check wiring buy pulling out the drivers (preferably 1 by 1) and seeing if there are 2 wires attached to each. If the problem follows the channel (goes from left speaker to right) it is in the amp, or further upstream. Swap the left and right inputs to the amp, and if the problem changes from left back to right speaker (or vice versa) the amp is fine, and the problem is further up stream, if not the problem is the amp, you can swap inputs L to R all the way back to source components to find where the imbalance is coming from.

Sorry that this is written so dumbed down, but I thought it would be a nice reference for newbs who are not used to trouble shooting.

dudeinaroom

Awesome...double post...nothing to see, move along.

dudeinaroom

Nice to see you figured it out. what tube compliment does that pre have? Could have been a tube gave up the ghost.

allstock

dudeinaroom wrote: »

Is this effect happening with all recordings, or one specific? I have a few recordings where it sounds like instruments are playing all around you, and others that have a more normal sound stage. Crap, SDAs can do a convincing surround effect from a movie only using 2ch, it all depends on the recording. You said you had a channel imbalance, did you check to see if you bumped the balance, or a input/output level control? Did you wire channels backwards...i.e. right output running to the left speaker and vice versa? Do any of the interconnects swap channels in between components?

For the imbalance, besides what I said above, you can swap speakers from channel to channel to see if is the speaker or the amp. If one speaker is quieter than the other no matter which channel it is hooked to, it's the speaker. if that is the case go up to your speaker and put your ear near each driver with music playing at a some what lower level, and listen to hear if music is coming out of all drivers. If not you either have a dead driver, or wiring might have come loose. You can check wiring buy pulling out the drivers (preferably 1 by 1) and seeing if there are 2 wires attached to each. If the problem follows the channel (goes from left speaker to right) it is in the amp, or further upstream. Swap the left and right inputs to the amp, and if the problem changes from left back to right speaker (or vice versa) the amp is fine, and the problem is further up stream, if not the problem is the amp, you can swap inputs L to R all the way back to source components to find where the imbalance is coming from.

Sorry that this is written so dumbed down, but I thought it would be a nice reference for newbs who are not used to trouble shooting.

Sorry you had to type all that! Yes I checked all the usual connections etc. Twice. The problem was worse on tracks that generally had more Sda effect. It was crazy, like instruments RIGHT beside me. It was worse on the left side, but the right speaker was down 2 db. I corrected that with gain controls on the amp but it made little difference. The channel imbalance was what led me to the pre.

drumminman

Glad you got it sorted out, but I would have liked to have heard it with the problem - Interesting!

MAD

If you wanted to tone it down, could you not just place maybe 1ohm (0.5ohm…) resistors on each SDA Speaker (mid/woofers), leaving the stereo speakers alone (or place a resistor on each lead of the sda interconnect)
I would think that it would do less cancelling of the opposite channel, and the sound stage would not spread as wide.
Or cooler yet, couldn't you have a variable resistor that you could adjust?

Please let me know if my thinking is incorrect.

Face

Generally, placing a resistor in front of a woofer is a big no no in speaker design. I doubt you'd be able to find an L-Pad to be used in this application either. The only way to do this sensibly would be to go active.

TennMan

MAD wrote: »

If you wanted to tone it down, could you not just place maybe 1ohm (0.5ohm…) resistors on each SDA Speaker (mid/woofers), leaving the stereo speakers alone (or place a resistor on each lead of the sda interconnect)
I would think that it would do less cancelling of the opposite channel, and the sound stage would not spread as wide.
Or cooler yet, couldn't you have a variable resistor that you could adjust?

Please let me know if my thinking is incorrect.

Interesting. I have been wondering if the SDA effect could be increased by basically doing the inverse of what you suggest.

MAD

Face wrote: »

Generally, placing a resistor in front of a woofer is a big no no in speaker design. I doubt you'd be able to find an L-Pad to be used in this application either. The only way to do this sensibly would be to go active.

Just wondering, is it too much power going through it that it would fry the resistor, does it alter the sound?

New idea then…. place some sound absorbing material over (or partially over) the sda drivers. You could experiment by draping a towel over them (only the sda side) and see if the sound changes to your liking, try different thicknesses of towel/cloth?
Mostly joking but still would be an interesting experiment.