Subwoofer amplifier auto-on issues.

[EJ257lvr]

Ok, so my issue is probably a common issue with subwoofer amplifiers that have the feature where if it detects no signal for maybe 10 mins it shuts off. First I'll list the components I have and what information I've been able to find on specs related to my issue.

I'm using optical audio from my TV with the audio in settings set to fixed since I'm controlling my volume via a sound bar which is a Martin Logan verse sound bar, it has it's own rca lfe sub out which I then have going to a Dayton audio spa1000 sub plate amplifier wired to four image Dynamics 15" subs at 4 ohms. The specs in the spa1000 manual say it needs a low level signal of about 3 millivolts or greater to turn the amplifier on. Also it says that the input impedence is 12k ohms.

The sound bar lists no specs on how many millivolts it outputs from it's lfe sub out.

Watching movies there's no problem keeping the amplifier turned on but when watching something more casual on tv like the news for example where there is less bass the amplifier is constantly turning off and on.

I tried setting the bass level on the sound bar to the max and it made no difference and besides when I'd go back to movies then it would have way too much bass. I've also tried using the wireless sub receiver that came with the sound bar and it still performs the same way as it does when there is a physical connection.

I've researched and all I've found is I may need some sort of line driver but personally I don't know which is why I'm here.

Besides getting another amplifier that doesn't rely on the auto on/off feature I don't know what to do.
It's a shame the amp I have only has auto on, it has no other option it's either auto on or off.


If anyone has any ideas or knows of a product that could correct my issue it would be greatly appreciated.

I also appologize if this is in the wrong section but since it contained multiple components I wasn't sure where to put it.

Thanks!

 

[snakeeyes]

One easy fix is to use a RCA Y cable on the end of the LFE so you can use both the left and right input. (Instead of the LFE input). This doubles the signal essentially.

One thing about that is to make sure that using the left and right inputs doesn’t engage any unwanted filters etc at the plate amp that need disabled or adjusted.


If that doesn’t work, there are smart power strips that have a designated power outlet that controls power to the other outlets when power is sensed as “on”, on the other outlet.

 

[lovinthehd]

Seems you've tried the usual remedy of raising sub output level. You could just leave the sub in normal on position. You could use a smart power strip keyed to your soundbar...snakeyes beat me on that one

 

[EJ257lvr]

Yeah I forgot to mention that I did try using a rca Y cable on the end of the lfe and then connected it to the left and right inputs and set the eq on the amplifier to 0 but it still did the same thing.

I'll have to research into the smart power strip. I still don't see how it would keep the amp on since the amps internal circuit determines if it will shut off due to not enough signal input coming through the RCA cable.

 

[snakeeyes]

Yeah I forgot to mention that I did try using a rca Y cable on the end of the lfe and then connected it to the left and right inputs and set the eq on the amplifier to 0 but it still did the same thing.

I'll have to research into the smart power strip. I still don't see how it would keep the amp on since the amps internal circuit determines if it will shut off due to not enough signal input coming through the RCA cable.

There is no always on? Hmm. Well not sure what else to try. Did you try a different sub cable? What length is the cable?

 

[EJ257lvr]

There is no always on? Hmm. Well not sure what else to try. Did you try a different sub cable? What length is the cable?

No, the on switch is auto on, it doesn't have a always on position like many do. The cable is about 8 ft. Long and I've tried three different cables as well as the wireless reciever that came with the sound bar to use with a subwoofer, the cable I used between that and the amplifier was only about 6" long and it still did the same thing.

 

[lovinthehd]

That's kind of disappointing they'd only provide the auto on option....but just took a peek at the SPA1000 and that's all its got....have you contacted parts-express/Dayton for assistance?

 

[EJ257lvr]

No not yet I haven't but I may, the amplifier is a few years old so it's out of warranty of course and before I got the TV and sound bar I have now I had a Mitsubishi DLP TV that had it's own lfe rca output that I ran to the amp and it worked perfectly for years, the issue only came about after I upgraded my TV and a sound bar.

I did look to see if there was something internal inside the amplifier to defeat the auto off feature and make it so it's always on but didn't come up with anything. It may or may not be possible but I'm not sure.

I know that the Dayton audio sa1000 amplifier which is a amplifier that is made for a rack does feature the always on option but I don't really want to pay over $400 to resolve the issue.

I'm sure there's a way to remedy the problem I'll just have to be patient until then.

As it is now I turn the sub amp totally off watching normal tv because it's cutting off and on every 10 mins. When I watch a movie where it's not a issue I just turn the amp back on. Who knows it may be my only option and it beats spending the cost of a whole new amp?

 

[EJ257lvr]

So I've been doing further research and I happened to come across this little device as was wondering if it may correct my issue. I'll post the link in my next post because it says I need to have posted five times and my current post count is four.

 

[EJ257lvr]

This is a link to the device mentioned above.

https://www.htd.com/LGB-1