Hey... I got an email that member "almarg" posted to this thread, but I don't see the full post here. The partial post I got in the email is below. Almarg, if you are out there I would like to know your full response. Not sure why it didn't get posted here.
"Given the 180 mv sensitivity of the Marantz receiver and the 2.1 volt maximum output level of the DacMagic+ unbalanced outputs, it seems very conceivable to me that the problem may be due to overdr....."
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If they are ported, seal the port with a rag. Repeat.
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Yes, they're ported. What will blocking the ports do??
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Almarg, if you are out there I would like to know your full response. Not sure why it didn’t get posted here. I deleted my post a couple of minutes after I submitted it, because when I composed it I hadn’t noticed your statements to the effect that the problem only occurs when the volume is turned up to loud levels. That fact makes what I had said in my post inapplicable, since it indicates that the cause of the problem is "downstream" of the volume control. FWIW, though, what I had said is as follows: Given the 180 mv sensitivity of the Marantz receiver and the 2.1 volt maximum output level of the DacMagic+ unbalanced outputs, it seems very conceivable to me that the problem may be due to overdriving whatever circuitry in the Marantz precedes (i.e., is "upstream" of) its volume control.
As an experiment, and conceivably as a permanent solution, try enabling the DacMagic’s digital preamp function, reduce its volume control setting significantly, and increase the volume control setting of the Marantz to provide preferred volume levels. See if the problem still occurs.
Alternatively, you could try enabling the DacMagic’s digital preamp function and connecting it to the input jacks of the power amp section of the Marantz (initially with the DacMagic’s volume control set low!), while disconnecting the Marantz’ pre-outs from those jacks.
If one or both of those experiments confirms this diagnosis, an alternative solution would be to insert a pair of Rothwell attenuators between the DacMagic and the Marantz.
Again, none of this appears to be applicable, given the sensitivity of the problem to the setting of the volume control. Not sure what to suggest at this point, beyond what the others have said. Good luck. Regards, -- Al |
Al, Thanks for reviewing your original response. Most here seem to think that the amp is clipping. Is that what you are describing by saying:
"...Given the 180 mv sensitivity of the Marantz receiver and the 2.1 volt maximum output level of the DacMagic+ unbalanced outputs, it seems very conceivable to me that the problem may be due to overdriving whatever circuitry in the Marantz precedes (i.e., is "upstream" of) its volume control."
On the other hand, Rodman thinks:
"...You might be hearing the woofer voicecoils, bottoming out, or- when woofers exceed their max excursion, things can sound really nasty...."
If the woofers were really bottoming out, wouldn't that mean the speakers were being seriously overdriven (too much power)? Simao, disagrees with that and says this:
"...The Hales are 86db at 8ohms - that might be a pretty difficult load to drive at high volume for most amplifiers less than 100 watts..."
The Marantz was bench tested recently at about 85 wpc. Therefore it may not be driving the speakers efficiently enough.
Am I understanding all of these comments correctly? Thanks! |
