SH Spotlight SH Forum members: Are your speakers in correct phase?

Discussion in 'Music Corner' started by Steve Hoffman, Oct 25, 2004.

  1. Doug Sclar

    Doug Sclar Forum Legend

    Location:
    The OC
    Back in the 70's I went with the artist to a very well known VP in the top story of a Century City high rise. I went to make sure he heard the recording in it's best light. Well his speakers were out of phase. When I corrected the situation he was shocked. He even said that he thought something was not right. He was very embarrased, but also very thankful.
     
  2. Doug Sclar

    Doug Sclar Forum Legend

    Location:
    The OC
    Absolute phase is a strange concept to me. As Steve pointed out, many amplifiers invert phase. The problem is that in a recording console this happens all the time. A single instrument can go through dozens of amplifers from mic preamp to multitrack and back to mix, and each one may or may not be an inverting stage. It is pretty hard to instantly tell if the phase of a track is inverted unless there is something to compare it to. When recording tracks in stereo, of course, this is not an issue. But mono tracks may have no correlation to anything.

    On top of this we have the fact that there is no standard for phase in microphones. At least back in the 70's there wasn't. Some microphones have positive voltage on pin 2 with a positive movement of the diaphragm, and some have positive voltage on pin 3.

    My point is that unless a recording is a simple recording there is often no such thing as correct absolute phase. Maybe the kick is in absolute phase, but the piano might not be. It is surely possible to keep absolute phase in multitrack recording but it would take a lot of work. I'm not sure that many records were made with this in mind.
     
  3. daveman

    daveman Forum All Star

    Location:
    Massachusetts
    Same here...but I ain't changing it :)
     
  4. Steve Hoffman

    Steve Hoffman Mastering Engineer Your Host Thread Starter

    None were. Get your playback system in correct absolute phase and at least that's a start.
     
  5. Dave

    Dave Esoteric Audio Research Specialistâ„¢

    Location:
    Greater Vancouver
    Acccording to Buddy and Brian, I'm in phase. :righton:
     
  6. daveman

    daveman Forum All Star

    Location:
    Massachusetts
    Heres to that :righton: I play "Wouldn't It Be Nice" to make sure I'm in phase, and I am.
     
  7. Doug Sclar

    Doug Sclar Forum Legend

    Location:
    The OC
    I want to make another point about phase and speaker wiring. Steve mentioned making sure that the wire is physically connected correctly, but this doesn't always guarantee that your speakers will be in phase. It is possible, and I have seen cases, where either the amplifer or the speaker has been wired wrong internally.

    But listening for a phantom image seems to be almost bullet proof. It takes all factors into consideration. As mentioned this can be either a mono recording, or simply something known to be in the center of the mix.
     
  8. Doug Sclar

    Doug Sclar Forum Legend

    Location:
    The OC
    Not Steve here, but absolutely (or relatively) :) the phase can be inverted at the cartridge tonearm connection.
     
  9. Grant

    Grant Fight The Power

    Location:
    United States
    Hi Steve,

    I had to chuckle when I read your post, but then realized it is no laughing matter! It also makes me realize why these record company people can't hear the determental effects of all this compression and NR.

    This one of the things I make sure I do when I hook up a stereo system, ensure that the cables are hooked up correctly. Both my wife's and my stereos are hooked up correctly.
     
  10. Grant

    Grant Fight The Power

    Location:
    United States
    Just think of how much fun those new Beatles CDs are going to sound with all those stereos out of phase! :laugh:
     
  11. Grant

    Grant Fight The Power

    Location:
    United States
    I have that CD too! I should pull it out and play it just for fun!
     
  12. HGN2001

    HGN2001 Mystery Picture Member

    I've been 'in phase' for many years. Hearing speakers out of phase drives me nuts, and I'm very sensitive to it.

    There's a set of speakers that are out of phase at the Sam Goody store in Admore, PA. It's been that way as long as I can remember!
     
  13. stereoptic

    stereoptic Anaglyphic GORT Staff

    Location:
    NY
    thanks for the link. Lots of opinions thats for sure. I'll check my cables when I recheck my polarity (I just checked it a few weeks ago after there was a similar phasing thread. Unless the cables moved by themselves, I should still be in phase! :D ) If the speaker wires are not in the right direction, it will probably take me an hour or so to turn them around because it will involve moving furniture, hiding the wires again, etc.
     
  14. thegage

    thegage Forum Currency Nerd

    Silent Running Audio has a chart (available for download on their homepage: http://www.silentrunningaudio.com/home.htm) listing their determination of absolute phase for a number of record labels. I haven't done any serious listening to confirm or disprove their findings, but if you take it at face value the conclusion is that essentially half the record labels put out recordings in reversed absolute polarity. Depending on your listening habits you could be doing a lot of speaker wire switching! :laugh:

    John K.
     
  15. posieflump

    posieflump New Member

    Location:
    .
    A relative of mine bought a really cheap mini-system for his son several years back. The speakers were out of phase. Unfortunately, they were hard-wired at both ends. I had to cut one lead to fix the problem.

    (Oh, and this wasn't some odd pseudo-surround "feature", either!)

    Mart.
     
  16. Tim Casey

    Tim Casey Active Member

    Location:
    Boston, MA USA
    I can't believe you actually have to have this thread. Then again, I can't believe anyone in a record company could have wired their speakers out of phase. Jeez, it sounds so obvious when they're not in phase.

    Then again, I met the heads of A&R at MCA Universal and (I think) Sony at the NEMO 2000 conference; they were in their twenties. One of them got the job because his father was a vice president at the company; the other one was slumming until he could get a job in film, which was what he was "really into". Neither of them listened to music all that often....
     
  17. Nobby

    Nobby Forum Resident

    Location:
    Birmingham, UK
    Clothes shops bug the hell out of me.... they're the worst offenders over here!

    I'm one of those people whose ears are very sensitive to out of phase stuff.

    Just don't get me started on Q Sound :)
     
  18. Veech

    Veech Space In Sounds

    Location:
    Los Angeles, CA
    Can't you tell if a stereo recording is o.o.p. by copying to something like CEP and comparing the R channel and L channel wave files? If the L and R channels appear to mirror each other, the original recording is o.o.p. If the peaks and valleys generally match, then the recording is in phase. Someone correct me if that theory doesn't work..
     
  19. ubsman

    ubsman Active Member

    Location:
    Utah
    So some pre-amps invert phase intentionally rather than on request? What's the deal with that? I have an "Invert" button on my Wadia unit, but it's my choice whether it's "on" or "off", so I leave it off.
     
  20. Gary Mack

    Gary Mack Active Member

    Location:
    Arlington, Texas
    Cheap wire is OK as long as it is thick. Get the thickest you can find - it really does make a difference.

    GM

    You've got a lucky phase, the end! - John Lennon in Around The Beatles, 1963 :laugh:
     
  21. Metralla

    Metralla Joined Jan 13, 2002

    Location:
    San Jose, CA
    That may not be the best advice. At CES in January, the mad scientist from Audio Consulting (Switzerland) was running a $70k rig through two pairs of 24 ga. silver wires between the battery-powered power amp and the external crossover. The sound was to die for.
     
  22. chip-hp

    chip-hp Cool Cat

    Location:
    Dallas, TX
    Thanks, Gary, for your input ... I admire your courage :) ...
     
  23. Grant

    Grant Fight The Power

    Location:
    United States
    Same here!
     
  24. Ken_McAlinden

    Ken_McAlinden MichiGort Staff

    Location:
    Livonia, MI
    If you have a 5.1 set-up and any DVD with the "THX Optimizer" feature (like the Star Wars films, for instance), you can check whether or not your surround speakers are in phase with a series of mono "pink noise" signals. I can't remember if it has signals for a center surround speaker or not, but you definitely would want to turn off dolby digital EX processing before testing the signal between your left and right rear speakers.

    Strangely, the initial audio test signals before the phase test are never calibrated properly for level setting, and I have no idea why. The phase testing stuff works great, though.

    Regards,
     
  25. Gary Mack

    Gary Mack Active Member

    Location:
    Arlington, Texas
    It would sound just as good with the cheap stuff, I betcha. He used a DC power supply for his amp? Yep, that might account for it.

    There can, of course, be a measurable difference in the lab, but in your home???? For almost everyone, the regular stuff at your local hardware store is just fine. The pricey "cables" are what helps the Best Buy/Circuit City folks stay in business.

    GM
     

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