2. amps-preamps
  3. 170195-161963

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

Showing 7 responses by ja_kub_sz

ja_kub_sz's avatar
ja_kub_sz OP
254 posts
 
@atmasphere I have one sub in the exact same spot it was with my old system (didn't have this issue), also volume is cranked to max just to even hear anything from the sub.

What I'm doing different...

I am running a single RCA off the R out of the pre out of the amp to the right sub, and a single RCA off the L out of the pre out to the left sub. I have a Y splitter to then plug the single RCA into both my R/L line In inputs on the subwoofer.

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? I wanted stereo subs and thought LFE connections were for surround sound receivers with single RCA "sub out" ports and would not be stereo?

Someone suggested that using only a single side of the amp preout (R or L) sent to each sub might cut the power in half being fed to the sub, and might be causing the standby mode issues and low volume.

That a possibility?
ja_kub_sz's avatar
ja_kub_sz OP
254 posts
 
Appreciate the advice, thank you.

I'm gonna...
1. Mess with the phase (0/180)
2. Try the volume attenuator setting at low level listening.
3. Try different RCA cables.
4. Try running them off my power amp.
5. Try high level connections off the SU-R1000.
ja_kub_sz's avatar
ja_kub_sz OP
254 posts
 
@imhififan I did check the pre out being "on" in the settings, but haven't messed with the volume attenuation settings.

I'm getting sound, but just really quiet and underwhelming (not normal) compared to what I had before.
ja_kub_sz's avatar
ja_kub_sz OP
254 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.
ja_kub_sz's avatar
ja_kub_sz OP
254 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.
ja_kub_sz's avatar
ja_kub_sz OP
254 posts
 
Yeah, gonna try my power amps and a different wiring set up over the next week.

Thanks for the advice everyone!
ja_kub_sz's avatar
ja_kub_sz OP
254 posts
 
Just spoke to Kef customer support, they think its just low power signal in stereo configuration, but strange thing is they made reference to the Kef KC92 subwoofer and how it has line outs to daisy chain another subwoofer.

So I looked at the KC92 manual and it recommends LFE connections from the amplifier pre outs when attempting stereo connections of two subwoofers.

So...
RCA from R pre out to right sub LFE in
RCA from L pretty put to left sub LFE in

Gonna give that a try and see what happens.
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