What to expect from MONO


I'm curious if when listening to a 'mono' LP, should I be hearing a completely symmetrical sound stage? I'm listening to Coltrane's Blue Train in mono and I have to say that it favors the left channel on some instruments like the cymbals. The horn is mostly centered. I'm using a VPI Scout with Dyna 10x5. It's new and set-up by the dealer. Could this indicate that something is not set correctly?

On a separate thought. Since everything else in a system needs to be broken in (cables, speakers, carrtridge, etc) does new vinyl need to played a few times before it sounds it's best?
Should be same response from both channels. Difference could be gain (balance) and EQ per channel. Depends how well the phono is matched. Also azimuth setting on cart.

Do you have a mono switch? This helps to cancel out stereo cart imbalances.

It may not be your setup or equipment but rather anomalies in you room's response resulting from playing a mono groove with a stereo cartridge. Having a mono/stereo switch on your preamp (switched to mono of course) can eliminate a lot of that. So does using a mono cartridge, but I wouldn't go that far unless I had a large mono record collection.

Can you clarify how a stereo cartridge could be to blame for room response?

Wouldn't the fact that he's using 2 speakers be more "to blame"? I mean, a mono cartridge playing a mono track through 2 speakers would output the same signal to each (in theory), and the room response could cause some variance in perceived 'location' of the sounds.

However, if I have it right, a stereo cartridge could actually be feeding 2 different signals to each channel, which could then be exacerbated by 2 speakers/room response.

Am I missing something? I guess you are saying anything that sends a mono signal (mono cart, mono-capable preamp) to stereo speakers will reduce the problem -- but the inherent problem is room response (assuming correct setup of the cartridge & rest of the system). Nothing in the analog setup will correct this.
Ebalog, when I said "anomalies in you room's response" I was referring to phasing issues and "floating" image (which is what Arch7 was asking about, I think). I wasn't referring to the room's frequency response. A mono groove only produces lateral stylus movement representing a single signal. When reproduced through a normal stereo system (maintaining 2 separate channels from cartrige to speakers) the two signals have phase differences (the "stereo imbalances" JH refers to.)

Using a mono switch combines the two channels at the preamp, and these phase differences (mostly) cancel, so you pretty much get the same signal out of BOTH speakers. However, a mono cartridge sends the SAME signal to both channels, so theoretically, you shouldn't need the mono switch.
a piece of vinyl wears from the first spin. make sure your records are dust free when played, so the heated vinyl doesn't cool with embedded particles.....break in -no...break down-yes.
For mono listening, I always turn my head 90 degrees either left or right of my normal stereo position. Because look, if you want true mono, even with a mono switch, even if you go to a single speaker system, even if you use a single-tubed amp/preamp, etc, you still have to listen with JUST ONE EAR. This is so often overlooked in the literature (but cf "The Van Gough Effect" published somewhere in Boston a couple decades ago). And the ear that sounds best depends on your 'handedness'. Try it for yourself.
Thanks for the responses. I do not have a mono switch in my system. I'm looking for a few other mono recordings and will try those out too see if there's any difference or the same response.
You really should not be hearing any sound stage at all. The sound should be perceived as coming from a vertical line between the speakers. No broadening of the image at all. Depth may be present, but no width. Unfortunately, most stereo audio rigs will not get this one right.
To simulate a mono switch and see if this impacts your perceptions, use a male Y connector from Radio Shack to blend the left and right channels and then another Y connector with a female end to split the blended signal to your phonostage
Hello Arch7

Your antiskating could be off. I have the Classic Records mono release and have played it with both a stereo & mono needle. The sound comes from the center. Try a stereo album with a strong singing voice you know should be in the center. If it is not then either your cartridge alignment is off or you are having other issues with your system. Also try near field listening. Move your speakers about 5 feet from your seating location this will eliminate many room issues you do have. I have had issues with my projector screen. It would cause the imaging to move or go to one side or the other no matter what pressings mono or stereo I listened. I found it moved ever so slightly while the music played causing the problem. I now use a tapastry over the screen to solve the problem. So I have learned rooms have a lot to do with imaging of your system and the further you are from your speakers the more it will affect it.
I have a ZYX mono cartridge on my VPI 12.5 arm and about 500 mono LPs. I use two speakers, rather than just one. I have tried it both ways and prefer two speakers, though I can see why some people prefer a single speaker. On my system, with two speakers, I do get a horizontal sound stage with mono, not just a vertical line. The mono horizontal soundstage ranges from 1/4rd to 1/2 of the size of the horizontal soundstage of the stereo version of the same recording played on the same arm with a stereo cartridge, a ZYX UNIverse.
For VPI users, i wonder if the anti-skating could be off. This table requires a twist of the tonearm cable to control anti-skate. I feel pretty confident that it's correct because when I lift the arm at the end of a record it every so slightly bounces back toward the right. I'm told this should be just enough anti-skating force, so I hesitate to adjust it. If I'm mis-informed let me know. Also, is there a good test record out there that can help with sort of thing? One that maybe gives a precise even soundstage with just a tone rather than actual music?
I use a Wallyskater to measure the anti-skate on my VPI 12.5. It is possible to get the anti-skate fairly close to optimum by just twisting the wires.

For a lengthy discussion of why test tones are not very useful for setting anti-skate please see the following thread.

Play some mono CDs if you have any to double check. Room anomolies, or issues with speaker positioning or unmatched speaker drivers (or pre/power amp tubes), should cause simmilar effects as with vinyl. If not, then it's probably alignment or cartridge related, or possibly phonostage (tube imbalance/resonance).

As for perceiving a strict vertical line or point of images when playing mono, I think this could only happen in an anechoic chamber, if even then. I think the ear/brain assigns dimensional qualities to images emmanating even from a single small driver.