Less bass in my 1060?

[Brian4561]

I was just wondering if it is possible that a Marantz 1060 would produce less bass response than a Marantz SR-5100? I just got my 1060 back from the shop, where it was checked out and given a clean bill of health, and set it up in my main system. Everything else about the system remained the same.

Somehow, it just seems as if the bass is thin--less punch. Can this be the amp, or do I need to fiddle with my speakers or something?

 

[dr*audio]

On a unit that old, it's likely at least a few of the electrolytic caps are gping bad. This causes the bass response to roll off. Additionally, this amp has output capacitors and those could be bad.

 

[Brian4561]

D'oh!!

I emailed my tech about the 1060, and he told me that he checked the amp on the bench and it operated fine. He would have noticed and replaced the caps if they needed it. He suggested that perhaps my speakers were wired with the wrong polarity.

Sure enough, I went home, looked at my speakers and they were indeed wired in reverse.:stupid: It seems I can never remember whether which lead goes to terminal 1 and which goes to 2 on AR speakers.

 

[marty-alex]

Good enough.
Everything fine for now? I love my 1060...

 

[Fred Longworth]

Brian,

Wrong polarity per se won't cause a reduction in bass, but if the two speakers are out of phase relative to each other it will cause a dramatic reduction in bass response.

* * * * *

When confronted with this kind of complaint, in the past I've hooked up a signal generator to the integrated amplifier and hooked an RMS-measuring voltmeter to the speaker terminals (with speakers attached.) I've also placed a sound pressure level meter at the customer's preferred listening spot.

Then I set all the controls on the integrated amplifier (or preamp/power amp combo) to FLAT, and I run the system at a few watts out. I sweep the generator from 30Hz to over 10kHz, looking for peaks, troughs and other anomalies.

The lack of bass response will then show up either as a low value at the speaker terminals (voltage) or as a low value at the listening spot (SPL). That informs me exactly where in the system the corrections needs to be made.

Fred Longworth