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Subwoofers going into standby with low volume listening (New Integrated Amplifier).

Hello,

Just got a new Integrated amplifier (Technics SU-R1000) and have dual stereo subwoofers connected via the amplifiers preout R/L RCA connections (RCA Y-splitter at each Line In R/L connection) on my KEF 12b sub's.

While listening at low volume my subwoofers keep going into standby mode and turn off. The subwoofers also don't sound very lively at all. I have the crossover and volume at "Max" just to try to hear them and they don't sound loud or overly bass heavy at all, which at max volume would've sounded very over the top with my previous integrated amplifier. I've adjusted the crossover and volume numerous times and the subwoofers are just extremely soft and quiet. I've also adjusted the volume control on my Innuous sense (volume down) and upped the volume on the i-amplifier with no effect at low volume listening.

Wondering what could be causing this, and how to potentially fix it? Would the amps volume attenuator have anything to do with it? Also before I was running my sub's of my power amp loop outputs, which I'm not using now. Then again the technics is rated at 150w@8ohm/300w@4ohm where my power amp was 200w@8ohm/350w@4ohm, so I figured I wouldn't need the power amps yet.

Speakers are JBL L100 Classic 75th Anniversary. And cables are RCA SVS subwoofer cables with a y-splitter off each R/L RCA cable to then you nnect in to both line level R/L ports on my subwoofers.

But dually concerning is that even when I crank up the volume on the subwoofer, they sound extremely tame and subdued.

Any help would be appreciated.

Thanks!
128x128ja_kub_sz
rocray's avatar
rocray
1,448 posts
 
Have you tried different cables? I looked up your equipment thinking maybe it was an issue with bass management.  No bass management eliminates that possibility.  
ja_kub_sz's avatar
ja_kub_sz OP
273 posts
 
I will be able troubleshoot this more tomorrow but I did try a single RCA to 1:2 Y cable to one of the subwoofers instead of the SVS cable and Y connector, but no difference.
millercarbon's avatar
millercarbon
12,531 posts
 
Your subs are not getting enough level. The level they are getting is so low that unless you are playing loud it is below threshold and that is why they shut off. This is also why they don't play loud no matter what you do with the volume on the subs. When the input is too low no amount of turning it up will ever be enough. They only have so much gain. You can forget about cables and splitters and how they are wired, your problem is line level.  

You can check this with a meter across the RCA while playing music or a test tone. Line level should be around 1v to 3v. In your case it is probably a tenth or less of that.   

A big clue by the way, this all started with the new integrated. If you can't get enough signal from its pre-out the next move would be to run the subs off speaker level using speaker terminals on the amp. If the subs don't have speaker level input then you get a $20 Line Out Converter.   

That amp is plastered with doo dads and features. If you are really lucky you just need to change a setting to allow pre-out. Wouldn't that be something if that was all it was?  
atmasphere's avatar
atmasphere
11,841 posts
 
Should I ditch the Y splitter (not use the line inputs) and just run the single RCA to each sub's LFE port, setting the crossover to "LFE" on the subs?
Yes. The splitter isn't helping.


But since there isn't enough output, I'd consider using the speaker level inputs instead.
ja_kub_sz's avatar
ja_kub_sz OP
273 posts
 
So after just going to 1 RCA cable per sub with R and L pre out to line in connections it has seemed to help. I also switched the sub phase from 0° to 180° and that also has added some volume.

I'm gonna try speaker level connections, and I still need to try my bi-amped dual mono power amps, which also could solve this issue.
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