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Discussion Starter · #1 ·
Receiver/Amp: Yamaha RX-V1065

Sub: MartinLogan Dynamo 700W


Sub replaced: Polk Audio DSW400


Connection from receiver to sub: LFE coaxial (preamp out)


Problem: no output on sub unless volume on receiver is elevated momentarily


So, here's what I think is happening. The sub is not sensing a signal from the Yamaha preamp out and because it has an "auto on" feature it doesn't wake up until the amplitude of the preamp out reaches a certain level. After that it is fine until it goes to "sleep" again. In other words, if the listening level is low then the sub is inactive (evidenced by the red light on the sub). Increasing the volume on the receiver makes the sub turn on (light turns blue) and bass is clearly enhanced. Even after the volume is returned to a low level the sub remains active and the bass rumble is great (and appropriate) even at low volumes.


I think it was happening with my Polk Audio sub as well though it was a little harder to tell because that sub didn't hit like the new one.


According to the Yamaha manual the preamp out is 1.0V/1.2kohm. I can't find a corresponding input sensitivity threshold for the subwoofer.


Has anyone else run into a similar problem with an "auto on" subwoofer? If so, how did you deal with it? Do I just need to tell my wife to turn up the volume for a second to kick the sub on? That doesn't sound like a very appealing solution especially knowing that my wife will complain and claim that our new sub is defective. This is an argument I'd rather not get into.


Thanks
 

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The fix is quite simple. Go to the speaker setup screen and raise the subwoofer level until the auto on works consistently. Then cut the level back at the suboower using its volume control.
 

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Discussion Starter · #3 ·
Hmm...good thinking. I'll try that and will report back. It will have to wait though. The wife is in the middle of getting her Zuma fix.


Trial and error may take a while since I'll have to wait for the amp to "sleep" each time. I don't know if there's a way to force it to that state. Maybe turning off the receiver will work. Dunno. I'll experiment.



Thanks.
 

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Quote:
Originally Posted by tweezak  /t/1508444/subwoofer-not-coming-on#post_24133537


Hmm...good thinking. I'll try that and will report back. It will have to wait though. The wife is in the middle of getting her Zuma fix.


Trial and error may take a while since I'll have to wait for the amp to "sleep" each time. I don't know if there's a way to force it to that state. Maybe turning off the receiver will work. Dunno. I'll experiment.



Thanks.

Just power the amp completely off to reset the auto switch in between each trial...


You could just leave the sub on all the time, with some subs there's not even much difference in power consumption....
 

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EZ to validate....

Go to the 3 position slide switch on the back of the subwoofer, move from AUTO to ON...

Note that this will force ON the subwoofer...

Now what happens?
1. If the subwoofer is working normally, increase the subwoofer output level slightly on the subwoofer or AVR. The LED should be GREEN.
2. If the subwoofer is not working, try another RCA connecting cable


Be sure to use a source, that has an LFE (.1) track..


Just my $0.05.... 👍😉
 

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Discussion Starter · #6 ·

Quote:
Originally Posted by FMW  /t/1508444/subwoofer-not-coming-on#post_24133510


The fix is quite simple. Go to the speaker setup screen and raise the subwoofer level until the auto on works consistently. Then cut the level back at the suboower using its volume control.

Genius! This worked perfectly. Thank you!
 

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Discussion Starter · #7 ·

Quote:
Originally Posted by lovinthehd  /t/1508444/subwoofer-not-coming-on#post_24133563


Just power the amp completely off to reset the auto switch in between each trial...


You could just leave the sub on all the time, with some subs there's not even much difference in power consumption....

Indeed. I wasn't sure if the amp would come up in the "on" or standby mode when first powered on but it does come up in standby so this worked for testing.


Note that for my amp there isn't an "always on" mode. It's only "auto" or "off". Kind of annoying.


Thanks for the reply.
 

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Discussion Starter · #8 ·

Quote:
Originally Posted by M Code  /t/1508444/subwoofer-not-coming-on#post_24133585


EZ to validate....

Go to the 3 position slide switch on the back of the subwoofer, move from AUTO to ON...

Note that this will force ON the subwoofer...

Now what happens?
1. If the subwoofer is working normally, increase the subwoofer output level slightly on the subwoofer or AVR. The LED should be GREEN.
2. If the subwoofer is not working, try another RCA connecting cable


Be sure to use a source, that has an LFE (.1) track..


Just my $0.05.... 👍😉

You must have a different sub. Mine only has a 2 position switch: auto/off.


Thanks tho.
 
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