New amps

NEVER

It's possible but not for any reason than to alter the speakers reaction, tonally, to the new amp. If, for example the new amp enhances the bass too much, then you might move the speakers a bit to change the bass tone. Ditto the highs. But it seems to me unlikely. FWIW.

As a dealer who has had to swap equipment often, yes, repositioning the speakers after an amp change (or other component or cable change) may help to improve your overall system performance. This is because no item is linear. Every change shifts the tone coming out of the speakers. If you make a change and have an increase in one subset of frequencies, that affects balance and reflections in the room. Typically the placement adjustments are subtle but worthwhile to achieving the optimal experience.

For this reason also I no longer believe in swapping a component out and seeing which is better. Living with a piece and trying to design the system with it in mind helps to further uncover its strengths and weaknesses to the rest of your system.  

@whataboutbob1 

Definitely.

When I got my new amplifier, I had to move my speakers to someone else's house.

@tony1954 Best response yet!

Actually the amp has little to do with speaker setup. It is a function of the room   I believe that audio physics had information on their website for speaker setup. Not sure if it's still there 

@whataboutbob1 yes! Emphatically yes. 

Most of the time, the answer is yes.

For this reason also I no longer believe in swapping a component out and seeing which is better. Living with a piece and trying to design the system with it in mind helps to further uncover its strengths and weaknesses to the rest of your system.  

True, lately we were experimenting with different Bryston power amps on same PMC speakers and with every amp change speaker positioning had to be altered slightly. I guess with a completely different voiced amp altering the positioning would be a tad more than that. Same scenario with power and speaker cables.

Normally when we find the spot for certain speakers in the room every change in positioning due to a component change would be small but still it is a change.

I just tried a new amp and I had to move the speakers to maximize its performance, but I am back to my Classe Delta Stereo now. No Hegel H30 for my main system.

@tony1954 Too funny!  That's the best response ever!  I've frequently and almost invariably had the same response ... new, better amp? Got to get new speakers!

@whataboutbob1 that is just too funny, I almost spit my coffee all over my screen when I read your reply, then I thought how true that is. I also moved my speakers to someone else’s house when I bought a new amp, now I have a totally new system-win win.

Never

Always…never…sometimes…what was the question?!

Changing an amp is fun!

if you decide to muck round with speaker placement. Allow the amp a month to warm up first.

THEN, if you do, only move an inch, toe in or toe out.

if it sounded good with last amp, why ?

IF IT AINT BROKE, …U KNOW THE REST

Agree with Bliss, If you go from high powered solid state to 8 watt 300B, or vice-versa, with the same speakers, you will probably be moving the speakers. 

Not sure why you would need to move the speakers because you have a new amp.

Aren't the speakers positioned so they interact properly within the room?

To best reproduce what is fed into them.

Their positioning should be the same regardless of which amplifier is connected to them.

If I am mistaken I would love for someone to explain it to me.

Thank you everybody for your input!

@tony1954 the speakers are positioned to beat interact with the room, but that also matters on what comes out of them, where an amp has a profound impact. Often in an upgrade path, a person may replace their amp with one that delivers more across the spectrum, added harmonics / richness, stronger bass due to amp confidence and control, etc. Sometimes it may be necessary to adjust the speaker from this. Sometimes, it is slight, and other times, it is more profound.

To add to my previous posts, amps are not always linear. And more so, how they interact with a speaker given the speaker’s impedance may affect its linearity. So if the sound output shifts, the way it interacts with the room also shifts.