phase correction for records?


I am probably asking this out of pure ignorance, but is it possible that some of my records were encoded in a different phase than others in my collections? I ask this because given the identical setup, some of my records have a very open sound stage while others seem very compressed. This variance occurs with records of the same production year and condition. I have compared the LPs to CD versions and found that certain LPs are far more open than their CD equivalents and vice-versa but have no other explanation.

My setup:

vpi Scout with TNT platter, Grado Sonata cartridge
Musical Fidelity X-LPS phono stage
Audio Aero Capitole 24/192 cd player
simaudio moon i3 integrated amp
mbl 121 speakers
mbl subwoofer
bybee power conditioner
various decent cables, only the tonearm cable being shielded

There's a lot I'd like to improve on in this setup and suggestions are welcome.
jennyjones
I think , please educate me if i am wrong, phases (invert or non-invert) are not responsible for the size of soundstage.

The soundstage of a recording depends on how that particular recording was made (recorded, mixed, processed and mastered) and reproduced (what your system are capable of, how well you set up your speakers in your room and the acoustic character of your listening room...etc).

As along as your speakers are in-phase with each other (either inverting or non-inverting), then the soundstage only depends on the forementioned conditions.

If the speakers are out-of-phase with each other, then the soundstage, imaging are screwed up, diffused and impossible to locate the musicians within that acoustic space. This maybe responsible for the illusion of bigger soundstage.

Back to your experience, I believe that my Mobile Fidelity LP "Companion" by Patricia Barber was produced out-of-phase (also experienced by some other listeners ). When it is played , everything fused together in a very strange way.
Hi Jennyjones,
let me add my few pennies worth.
I can invert my pre-amp (includes phone-stage) as well as my CD-player. I mention this so as to comment on the result when doing this.
VERY, very, small difference in my system it is. A top of the rack Hi-End system will make it more noticeable I am told, and have no reason to question this.
I have SME 10, SME V, ML 326S, Pass 350.5 and Burmester 961, so I guess a bit better than Mid-Fi just to have the facts.

If the phase is inverted, I could argue to hear a little less upper bass, but would but bet on it doing a blind test.
Inverted phase makes e.g. the woofer 'suck in' rather then 'push out' if a drum is hit, etc.

But now comes the rub!
How many genuinely ALL IN PHASE recordings are out there?! Sloppy recording technique can have some of these multi-tracks recorded inverted and others in phase.
So in some, say "Duelund approved", super Hi-End system you now will enjoy one track better than another... invert the phase and some other track portion is now best, hey where to go next?

As regards to "compressed" replay: I VERY often get this doing an A/B vinyl vs digital, and it is NOT the players fault that many more CDs than LPs sound compressed. It's the crappy/sloppy mastering for digital, I say --- what else could it be? YMMV
(My player is a ML-390S and it CAN sound almost analog... when the software gives it a chance)

Hope to have added some perspective.
Greetings,
Axel
You can check to see if it's a phase (polarity) issue or not by playing one of your
problem records and then reversing the speaker cables* to BOTH speakers (at
the speaker end). See if you can hear a difference. This will also tell you
whether the speakers are polarity-coherent. Count your blessings if they're
not, because unless you want to go through the bother of constant speaker
cable switching -- and if you're really sensitive to the effect -- you'll have to
get a preamp with a polarity switch. I don't know of any integrateds that have
such a switch, but there may be some. Good luck, Dave.

* I assume you know to power down before doing this.
Dear JJ: Yes it is possible that some come with different phase/polarity.

+++++ " some of my records have a very open sound stage while others seem very compressed. This variance occurs with records of the same production year and condition.... " +++++

here you have to remember that each record pass for a different recording session where the engginers make changes according what they like or the producer want and these are reasons for the differences i playback.

Now, with a " dipole " speaker like the one you own the phase subject is almost dramatic: yesterday I was at my friend's Guillermo place who owns big Soundlabs speakers ( great speakers ) and we try several LPs ( any kind and " vintage " ) making changes on polarity and in all the records we heard a " dramatic " change for the better/worst. I comeback to my home and try the same with my system but the change here was/is really tiny.

It is more often on CDs that come with a change on phase than in LPs.

Like Dopague say: you have to be sure that your system is " wired " with absolute polarity through a test record. Of course that a polarity switch help a lot here but I think you don't have it in your preamp.

Regards and enjoy the music.
Raul.
That's odd, Raul. I have a friend with those giant Souindlabs AND a preamp with a polarity switch and he disabled the switch because he was never able to hear the slightest difference with it in either position.
Raul

Do you know of any test record that has a pulse signal to check for absolute polarity?

Thank You

Tom
Dear Dopogue: Rare that that happen because Guillermo and I were 4-5 hours working on.

Maybe that friend's switch was out of work and we have to take in count to the system's differences and room interaction.

It is much a coincidence that in two different " bipolar " ( JJ and Guillermo ones. ) speakers we can heard those differences that like JJ point out are heard mainly on the soundstage presentation.

In my speakers I can't hear almost nothing but that with inverted polarity the music comes with less " emotion ".

Anyway, it could be interesting that other bipolar speaker owners try on it and see what happen.

Regards and enjoy the music.
Raul.
Dear Tom: These test records have it:

Vanguard StereoLab Test Record ( VSD-100 ), HI-FI Sound Stereo Test Record, OmniDisc by Telarc ( DG-10073/74 ), Stereo Review SRT-14, CBS Laboratories STR-100.

I hope this could help you.

Regards and enjoy the music.
Raul.
Thanks to everyone for their comments. I performed the following experiment to see if I truly understood phase:

I found a record that I did not feel had any phase problems.

1. I switched the polarity of one of the speakers. The sound had a very unusual timing problem, as if one speaker were reaching my ear at a different time than the other.

2. I switched both speakers. I can't explain why, but suddenly the LP sounded like a CD. It was decidedly colder and transitions seemed choppy by comparison to having correct polarity.

The difference between switching only one speaker is far more pronounced than switching both.
Well, Jenny, you gain nothing by switching only one speaker cable. This
should merely produce out-of-phase sonics with a "diffuse and
directionless quality," to quote what the guy says on an ancient Shure
test record. I can't account for what you're hearing by switching both speaker
cables. It should have an effect, yes -- assuming your speakers are polarity-
coherent -- but nothing as dramatic as what you're reporting.

When you say you picked out a record that didn't have any phase problems,
you should bear in mind that records were originally recorded in
"normal" (absolute, if everything is hooked up properly) polarity,
in "inverted" polarity, in mixed polarity, or in some combination of
the above. Engineers either didn't care or figured the listener wouldn't hear
the difference or wouldn't care either.

Some records were recorded with a vocalist, say, in different polarity from
everything else. So depending on how you reproduce it, you can bring the
vocalist out front, or push him/her back into the mix. This is a maddening,
complex subject. One of my audiobuddies simply refuses to play the game
(he can hear the difference but ignores it). Frankly, If I were you, I'd follow
his lead :-)