Alpha imaging problem

Discussion in 'Speakers & Subwoofers' started by Gordon*K, Jul 6, 2004.

  1. Gordon*K

    Gordon*K Auditioning

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    I've been browsing this forum for about a year, and learned a LOT! Lately however, I have been noticing my fronts (PSB Alphas, about 10 years old) don't seem to image well in stereo mode. I use my system for about 90% HT, but I would like better music performance.
    For example, listening to music, the position of the instruments seems poorly defined, mostly between the speakers, and the instruments seem to "move" around a bit.
    This has started to bug me, so I'm in the market for a speaker upgrade. BTW, in DD mode, flyovers, effects, etc, seem localized well, extend "outside" of the speakers, etc. Like many here, my HT, though modest, is easily better than the movie theater [​IMG]
    On to my setup. I picked my condo partially for the living room's HT friendly shape, not perfect, but good. It's a rectangle, (with opening thru to kitchen/dining room on one side, and stairs at the rear)about 14X18, with TV and LRC along one short side, seating in the center, rears on the back wall facing forward.
    My gear: PSB Alphas, and 100C center, JBL n24II rears, Denon 1603 AVR, Pioneer DVD player, Sony WAM40 sub, Tosh 32A32 TV (need a bigger screen!!), digital cable, etc.
    The fronts are spaced evenly apart, on 24" stands, slightly less distance apart than the distance to the listening area, decent interconnects and wire, etc. ( I did my homework).
    So, any ideas on the imaging problem? I have tried further apart/closer together, etc. My Denon dealer says it's their age, newer speakers will sound better.
    The room acoustics aren't great, I guess, a hand clap produces that kind of echoey "ring", but the room is carpeted, with blinds, pictures, bookshelves, part of the prob may be the openings to DR, and stairway, but I can't change that.
    At this point, I really want an improvement, I am even considering going 2.1 for now, to get a better sound stage.
    (with an HSU STF-2 replacing the Sony)
    I am considering Paradigm for a 5.1 setup, Titans, Atoms, and CC170, based on an audition many years ago, I preferred them to the Alphas, should have bought 'em then.
    I auditioned Polk RTi6's and like the "airiness", but they were a bit too "crisp" I thought.
    LSi7's sound like they would work well for me, but I would have to go 2.1 for now, and add center and rears as I go.
    Ascend acoustics also interest me, but I have not found any used (probably a good sign), the others I could get on ebay for a considerable savings.
    I could go JBL, E30s would probably match my N24II rears ok, (same tweeter), but I can only audition them at BB (horrible listening area)and have heard they might not be a step up in terms of imaging and "musicality"
    Also,the Ascend and LSi7 are 4 ohm, my dealer says okay with the 1603, but I think I read a post that said they may not run so well with my Denon.
    So, The paradigm setup seems a good choice, but will the stereo imaging satisfy me? I know this is a tough question, but any help you all can give would be MUCH appreciated.
     
  2. Kevin C Brown

    Kevin C Brown Producer

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    How far are your front speakers from the back wall and side walls?
     
  3. Chu Gai

    Chu Gai Lead Actor

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    What is to the side of the speakers that are facing you? Also, what's between the speakers and you? Coffee table?
     
  4. Gordon*K

    Gordon*K Auditioning

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    Guys,
    the speakers are 15" from the back wall, 18" on either side of the TV. To the sides of the speakers are the side walls, and in front of the listening position is a coffee table 19" high. I will try listening w/out the coffee table when I get home tonite.
     
  5. JamesCB

    JamesCB Second Unit

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    There's your culprit. In order to acheive a stable soundstage with proper imaging, there should be nothing between the speakers. This is one of the biggest downfalls (compromises?) of combining an HT with a two-channel listening. With a TV between the speakers, it breaks downd the imaging due to relections off the TV cabinet.
    As a little experiment, try pulling your speakers forward, so they are at least a few feet in front of the tv. Listen to some music and you will be very surprised at how well your speakers image.
    And BTW, of course your dealer told you "it's their age, newer speakers will sound better", he want to sell you new speakers. There is nothing wrong, or "old" with your PSB's.

    Good Luck,
    James
     
  6. Kevin C Brown

    Kevin C Brown Producer

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    That could be it. In my case, I have my speakers closer to 24" out from the rear wall, so they actually are sticking out in front of the TV.

    But ... how far are the speakers from the side walls? Plus, 15" might not be far enough from the front wall. Typical suggestion is 2 to 3 ft.

    But, I also like what Richard Vandersteen suggests: FIrst, find the length of your room. Then divide that length by 3. Try that distance out from the front wall. Next try length by 5. Try that. Then 7. Try that. Dividing by 3 might be too far into the room anyway. (I use 7 in my room.) Using an "odd nodal" point helps with how the speakers interact with the room. Oh yeah, the distance you end up with is not from the front wall to the back of the speaker, but from the front wall to the acoustic centers of the drivers. Probably an inch or two back from the front face of the speakers.
     
  7. Gordon*K

    Gordon*K Auditioning

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    wow, I expected to be told it was the speakers! I tried listening w/out the coffee table last night, didn't notice a LOT of difference. I will measure and pull the speakers forward tonight, and try that. But for HT the doctrine is to line the fronts of the speakers up with the front of the display, so I will be back to sqaure one. But, I guess all HT's have that problem? Thanks for the responses!
     
  8. JamesCB

    JamesCB Second Unit

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    Not neccessarily. Ideally the front L, R, & C should be the same distance from the listener. This usually puts the center slightly behind the front L & R. In addition to that, the front face of the center channel should be ahead of the display, at least 1/2" or more. Pull the center forward so the front overhangs slightly (putting the center on a stand in front of the display is better yet).

    James
     
  9. Kevin C Brown

    Kevin C Brown Producer

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    Similarly to the distance from the front wall, if you can with your room, you should try and leave 2-3 ft between any side wall and the speakers too.

    Having the front speakers even with the display isn't such a big deal now, because you adjust for that distance in the receiver's setup menu anyway. Delays and such. Although equidistant for the L, C, & R is usually recommended to be the best way.
     
  10. Gordon*K

    Gordon*K Auditioning

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    Well, I pulled the speakers forward, and listened to some music last night, about the same result. I am stumped now. I guess I need to try a different pair of speakers, and see if that improves the imaging.
     
  11. Brian Fellmeth

    Brian Fellmeth Supporting Actor

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    One last thing to check- make sure they are not wired out of phase. Nothing kills imaging like that, and its easy to do.
     
  12. JamesCB

    JamesCB Second Unit

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    Hmm..

    I thought about mentioning the out-of-phase possibility. Have there been any repairs of modifications to the Alpha's? If so, maybe one of the drivers is wired out of phase? It's a guess.

    Maybe a dealer will let you take home a pair of speakers to demo.

    James
     
  13. Kevin C Brown

    Kevin C Brown Producer

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    PSB Alphas are pretty good speakers at their price point. And unless the foam surrounds have degraded, a speaker's imaging doesn't just "change" over time. You might have the same problem with anything else you try.

    One more thing to try though: the speakers' tweeters should be at or just above your ear level when you're listening.

    I had a CD once that was recorded/mastered/something out of phase. Man, it was easy to spot that *something* was way wrong. (Just ripped it, inverted one of the channels, burned it back to a CD-R, and problem solved.)
     
  14. Gordon*K

    Gordon*K Auditioning

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    well,
    speakers are at the correct height, tweeters just above ear level. I DID replace the spring clip connectors w/ binding posts, but I checked to make sure the wires were reconnected correctly. That was one of the first tests I did, reversing the polarity of one of the speakers, not much difference (no better). I had this problem even before I replaced the spring clips though.
     

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