Bass leaves after amp warms up?


I don't understand-after my Musical Fidelity M6i amp warms up for about an hour I notice the deep bass & kick drum aren't the same.
They sound less musical with loss of weight/depth.The notes are there but the moving of air have left.Sound is has much less impact and boreing.
I had the same problem with Bryston amp so there is no defect with amps nor with the rest of my equipment/
PSB Synchrony one speakers,AQ cables,Bryston CD Player.
My question has anyone heard similar & is there a plausable reason?
fishing716
3D bass sounds exactly what is leaving
When I haven't listened to music for at least 1 hr.
The bass is 3d sounding wide & deep
After about 30 minutes or so the music changes and bass looses full sound becoming anemic.
Also Dynamics have decreased.
Sound goes from robust to comprimised
What is the solution?
"What is the solution?"

Hasn't changed.

Need to change amp or speakers, until you find the combo that floats your boat. It's called a system upgrade, right? Assuming speakers stay for now and amp changes, switching to a more beefy dedicated power amp that can double down to 4 ohms would be the most effective strategy to follow to help cut to the chase.
Fish, until you make a change to try a more effective pairing of speaker and amp, not sure there is much else to say.

Once you have that in place, then additional tweaking may or may not be needed as well from there. IT all depends on how "finicky" you are able getting a particular sound that you seek. Its the typical scenario for any "audiophile" . It may take some time and money but if enjoying your music to the max is your goal, it should be worth it in the end.
I expect to try Musical Fidelity M6 amp 250w next week
I also have someone coming over with SPL meter
In addition,CablePro Revelation power strip to try.
Otherwise I'm exhausted
Thanks to everyone
I will report back
One thing to add is that a less than optimal speaker/amp pairing does not necessarily mean that either device is faulty or defective. Just that they are not the best match for each other electronically.

Given that, depending on how long you have owned the amp or speakers, the best one might expect from a dealer is perhaps some trade-in value towards an upgrade. That's fine. Live and learn! If it has not been too long, a good dealer might offer full trade value, but even that is not a guarantee.

So if you want to move forward, find out what your dealer can and will do for you, but consider other buying options as well, including buying used to help minimize the loss when you try something that may or may not work out, which is often the case when one has discriminating ears.
"'I can't assume a dedicated power amp will solve the problem till I try."

It's an assumption until you try but based on sound supporting evidence that the amp is not the best amp for those nominal 4 ohm load speakers. Other than this, pretty much all else is pure speculation at this point. So address the known issue first. It will persist no matter what else you try or do otherwise.
"What was the most recent change to your system"?
Nothing,just a different cd player

Musical Fidelity integrated amp & phono preamp
PSB Synchrony Speakers
Rega P5 TT w/dynavector cart
Audioquest cables
I can't imagine that the amp (unless it's defective) is the problem. Most of the Musical Fidelity stuff is designed and advertised to drive difficult loads. That M6i is supposedly rated at 400 watts into 4 ohms and the poster has said over and over, it never gets warm. Seeing that the poster had the same problem with other amps makes me wonder if we will ever get to the bottom of this.
What was the most recent change to your system before the missing bass syndrome.
Fishing716: I just looked at the internals of your M6i amps on Google images and I must say for a 200wrms per channel amp the power supply does look a bit on the thin side to what I would like to see, esspecially the amount of storage caps. And a single dual winding transformer for such a high power rated amp should really two tranise of the same size. Suggest you try another amp to see if fixes your problem.

Cheers george
I'm auditioning Meridian 508.24 cd player with my current setup.It's easy to think this player is just average when dynamics are not working.The sound changed after 15 minutes of being a great player with taut bass to sounding uninspired.
The bottom dropped out before finishing the same track.
Green River/CCR
I'm sure everyone can appreciate how disappointing this phenomema would be.
I will be trying Musical Fidelity M6 250w amp next week.If the problem is not resolved then it's time to part company with PSB.
Which I am very satisfied with when things are working.
IMO the amp should not dictate what speakers you own. It's the other way around. I refuse to believe that there is not an amp out there that will do a great job of driving the PSB's without losing some bass control as it warms up. In reviews that I've read the Musical Fidelity's are an excellent product but they are not known to have the best bass control. Each of us have a different set of priorities when we put together our systems. After listening to both of the "good and bad" recorded tracks, IMO, "Fishing" needs an amp that maintains very tight control of the bass. Hopefully the larger Musical Fidelity will keep all of the sonic properties of the smaller but maintain better control of the bass by virtue of it's higher cuurent capability and bigger probably "stiffer" power supply. Only time will tell.
Is there any conceivable way that. after some playing time, one speaker's crossover is having a major phase shift in the bass that is creating this problem?
to "Drubin". IME designing and building custom speakers I have found that excessive heat (in the voice coil, inductors and resistors) will not affect woofer phase nearly as much as the total Qts of a ported speaker. It can change enough to make the bass port tuning looser. However I have been exploring that possibility with the OP and his responces do not suggest that he is getting the speakers nearly hot enough plus he is using the tuning plugs in the lower woofer ports which would minimize any changes in the speakers Qts.
"What was the most recent change to your system before the missing bass syndrome?"

The reason I asked this question is because it is easier to backtrack than moving forward and continuing to try new equipment. There is some point where it all began. So, what did you change last? This should give you a clue of where the problem is.
I changed amp but previous two gave same result
I changed from PSB Synchrony II to one with same result
It effects all sources cd,tt,video

I added a phono preamp last but took that out with same results
So did you ever NOT have this result? If so, what was the system/environment then?
Have you tried a power regenerator, like the PS Audio P5 or P3 power plant? Wiring could be fine, consistent and clean delivery of power might not be.

Buy from a dealer that accepts returns. If it doesn't do the trick, return it.
"I've had this result since putting the system together 1 year ago."

The plot thickens.

I'm sticking with my original assessment. There is nothing wrong with your system other than you don't like it after it warms up. You want a richer tonal balance. How you get there is up to you. Try Vandersteens, Sonus Faber or any other speaker that is on the warm side.
The sound & bass are 3D even hollographic at times.
Watching a dvd is like being at the movies..Then the bottem drops out,sound is flat & 2D.
Someone said normal bias allows music to get better when warmed up.
I feel my amp draws additional power & my speakers being 4ohms are a mismatch.
This may be important:
I took out the power conditioner yesterday & my system has not had the usual bass/dynamics drop out:
I have pluged everything into the wall before,of course.
But this time I had the power conditioner unpluged from the wall.
Question:
Could the line conditioner have been robbing dynamics even if no components were pluged into it?
I'll know in a few days if the sound continues to stay dynamic or not.
But this time I had the power conditioner unpluged from the wall.

On the 3rd page of your thread, I posted:

"-power down the whole house (including tenant)using breakers except for the outlet for audio. If there are other items on other outlets running off the same circuit unplug them. Plug just your amp directly into one wall outlet and just your CD player into the same wall outlet. Retest."

Intentionally or unintentionally I think you are just wasting everyone's time.
I must have tried w/o conditioner pluged into the wall but not sure.
It's too soon to know if this is the problem but seems to be on the right track
I'm Exhausted with this nonsense and mabye am waisting everyones time.
It sounds like when other stuff is plugged in that your amps can't get enough clean power delivered to them.

I'd guess you're getting a voltage sag and the line conditioner as well as other things in the house are contributing.

A PS Audio P5 would solve that.
I second that. You'll find my comment on the PS Audio P3 on page three but the P5 will be the same.

Good luck
Could the line conditioner have been robbing dynamics even if no components were pluged into it?
Seems extremely unlikely to me. Your AudioPrism Power Foundation Conditioner appears to simply provide a bunch of outlets and some passive noise filtering.

With nothing plugged into it, unless it is defective it should be drawing negligible current, and have no effect on line voltage. If it were defective and drawing enough current to affect line voltage, it would be getting hot and/or its breaker would trip.

Assuming that it was turned on when you made these observations, I suppose it is remotely conceivable that it could have some effect on noise conditions on the line, that might affect noise entering components plugged in elsewhere. I suppose it is also remotely conceivable that if it is located close to susceptible cables or components it might affect them to some small degree by radiating EMI or RFI to them. And if either of those effects were occurring, I suppose it would then be remotely conceivable that the sensitivity of your audio components to those effects might change during warmup.

How remote is "remotely conceivable", IMO? If I were a betting man I would be happy to offer 1000:1 against those possibilities.

Regards,
-- Al
Fishing, I'm pretty sure I suggesting removing the power conditioner on page one.

The problem with most power conditioners, whether passive or active, is they force you to use a common power cord. If you get a voltage drop over that cord, it will rob the amplifiers of full output power. This is audible and measurable. If your amps draw more power after warmed up, there could be a tipping point. Maybe that takes about 1/2 hour?

Our amplifiers are quite unhappy with most power conditioners, especially the regenerator kind.

If the lack of a power conditioner continues to fix the problem, ditch the conditioner, or just use it on your source components.
I ordered cablepro revelation power strip from Gene rubin audio.
This has no filters switches or fuses in it
I need the convenience of 8 outlets
Are you familar with this product?
No. But if you have problems again when you install it, you will know what to do.
yes,send it back..
I'm sure I tried the system w/o conditioner more than once.
I don't understand why dynamics seem to be regular this time.
About 36hrs
Sound has now changed again..
This will be my last post till I have a solution.
Thanks
Hopefully the new amp is coming this week and will help pave the way out of hifi hell into utopia.
Dang, poor guy. I can't believe this thread went eight pages. I would have thought it was a joke if he hadn't tried so many fixes.

I hope you get it figured out Fisher.
"It ain't over till the fat lady sings."

..without losing the bass and dynamics! :^)
Open letter to Dan @ Modwright
Hello Dan:
Thanks to Kristin as well
I have a long standing problem where bass is anemic sounding along with the rest of dynamics.
All of a sudden the bass comes through like a flood and the system sounds great.But it comes and goes throughout the day.
I have no explination & have changed eqiupment all year with the same result
Question
My speakers are 4 ohm and there is some debate on audiogon that these are difficult to drive.
Is that why your integrated amp doubles into 4 ohms
I currently have in my audio setup:
PSB Synchrony one speakers
Meridian 508.24 cd player
Rega P5 Turntable w/dynavector cart
Musical Fidelity M6i integrated amp 200 watts w/Kimber PK10 pc
DVD,TV w/cablew/
Audioquest comet speaker cables,biwire
Audioquest columbia interconnects RCA
Cablepro Revelation Power strip w/kimber PK14 pc
We designed the amp to double-down into 4 ohms because we wanted it to have TRUE power, capable of driving MOST ANY speaker. I wanted a beautiful looking and sounding integrated with POWER and available dig. and analog options to make a no-compromise integrated solution.
Thanks and in look forward to your reply.
Sincerely,
Dan W.
I saw that you had listed your system for sale. Did you get to the bottom of the problem or have you just given up?
Fishing716... understandably you're selling the amp, but why the Synch One's?
He might be giving up which is understandable after a year of HiFi Hell, but I think he wants to start over with a different system. He obviously had a bad match. This is a common problem when reading reviews and assembling a system based on magazine recommendations.
The OP'r has a post in another section asking about headphones. Maybe he has decided to take another approach to enjoying his music.

Either way I hope that he can get back to enjoying the music instead of wrestling with his system.
Currently listening to Denon 1650ar cd player w/grado headphones-
I've been getting the music message this way.
I'm switching to Bryston separates w/Synchrony One's
If this don't work,options to try:
Different brand of cables than Audoquest
8ohm speakers @ Joseph audio
Differnt living situation
Thanks for everyone's patience w/numerous posts.
I've considered there may be a defect in my judgement.