Noise/rumble from sub

G

ginger_ninja

Member
Joined
Jun 22, 2024
Messages
25
Hi all, have just bought a 2nd hand sub (Cambridge Audio Minx X201), and when it gets a signal from my Amp Pro, there is a low level kind of burble/rumble when nothing is playing (and also when there is silence in a track). I have the sub set to ½ way, phase to zero, crossover to max (see pic). In the app, crossover is at 80, gain +3db. The rumble is just loud enough to be noticeable & very annoying from my sitting position. The seller has been super helpful & genuine & he never had any issues with his AVR

Anyone got any suggestions? The sub is plugged into a separate power socket to the rest of the system. Is there a known issue?
1000024907.jpg
 
ginger_ninja said:
Hi all, have just bought a 2nd hand sub (Cambridge Audio Minx X201), and when it gets a signal from my Amp Pro, there is a low level kind of burble/rumble when nothing is playing (and also when there is silence in a track). I have the sub set to ½ way, phase to zero, crossover to max (see pic). In the app, crossover is at 80, gain +3db. The rumble is just loud enough to be noticeable & very annoying from my sitting position. The seller has been super helpful & genuine & he never had any issues with his AVR

Anyone got any suggestions? The sub is plugged into a separate power socket to the rest of the system. Is there a known issue?
View attachment 14295
Click to expand...
What happens if you turn down the subwoofer volume to -15 in the WiiM app and then turn up the volume with the knob on the sub side? (or please try it the other way around, too...)
 
It doesn't make any difference - the 'burble' remains (at the same volume, regardless of increasimg/decreasing levels). Hmm...I'm sure I read something about interference from the Amp, something to do with grounding maybe?
 
ginger_ninja said:
It doesn't make any difference - the 'burble' remains (at the same volume, regardless of increasimg/decreasing levels). Hmm...I'm sure I read something about interference from the Amp, something to do with grounding maybe?
Click to expand...
I don't know the details, but please try playing a bass test signal and see if you can hear noise or distortion.

Poor cable contact is another possibility: clean the RCA plugs and sockets and insert the plugs all the way in (Power plug too).
 
ginger_ninja said:
I'll give it a go. Have tried 2 different rca cables. A faulty Amp Pro perhaps, is this worth raising a ticket?
Click to expand...
Have you ruled out the possibility that it's the sub that is faulty?

I wouldn't just go with what the seller has told you, without testing it with another source.
 
Well usually I would have doubts, but this guy is hands down the best seller I've ever come across. He's mortified that I'm having problems, and has been googling the issue today, and has even contacted Cambridge Audio to see if they can help! I really hope there is an easy solution here, this is my first 2.1 system and it sounds great apart from this issue
 
ginger_ninja said:
I'll give it a go. Have tried 2 different rca cables. A faulty Amp Pro perhaps, is this worth raising a ticket?
Click to expand...
Yes, there is nothing wrong with submitting a ticket.

But as @dangermouse said, can you test the sub in any other way?

Unless you have a device other than the WiiM that has RCA outputs, please try plugging the sub into the WiiM line out and see if you get the same problem. If you get the same noise from the sub, then there is most likely a problem with the sub.
 
Am on it. Dumb question, can I plug....anything into the sub? Ie the output from an iPad for example via RCA? I don't have another amp to test this with
 
ginger_ninja said:
Am on it. Dumb question, can I plug....anything into the sub? Ie the output from an iPad for example via RCA? I don't have another amp to test this with
Click to expand...
Connect the RCA-OUT of the WiiM to the sub; set the line out level to 200mVrms in the audio settings of the WIIM app and turn down the volume of the sub and the WiiM sufficiently before testing.
 
Actually I have a Denon mini system with a sub out, I'll test it out on that. And if that is ok....the Amp Pro is the issue I guess? Might even double check all connections, power leads, speaker cable etc in case something isn't right.
 
ginger_ninja said:
Actually I have a Denon mini system with a sub out, I'll test it out on that. And if that is ok....the Amp Pro is the issue I guess? Might even double check all connections, power leads, speaker cable etc in case something isn't right.
Click to expand...
How long is your sub cable and is it coiled up? I had a similar issue with a coiled up 5m cable. Uncoiling it made a big difference.
 
The first question should be (and sorry if this has already been answered and I didn't see it) if the noise goes completely away whe you unplug the cable.from the Amp Pro sub output and what happens if you just touch the center pin. If the noise can be forced in any other way the problem is not with the Amp Pro, of course.

More things you can try:
  • Power cycle.the WiiM Amp Pro. Physically remove it from the mains power, wait at least 30 seconds and reconnect it.
  • Increase and decrease the sub level in the WiiM Home app. Does the rumble get louder and softer? Or does it stay the same? If the latter, it's more likely to be related to grounding or cable issues.
  • Try to revert the power plug at the sub's input. It's not very likely to make a difference, but just in case.
  • Try a different RCA cable, if you can. Double and triple check it is really fully inserted (and not coiled up, indeed, even if it's just a 2m cable).
  • Temporarily try to connect the sub to the same power outlet as the rest of the system, even if you know you cannot use it that way. Just to check if the problem goes away.
Good luck, keeping my fingers crossed.
 
I've tried 2) and 4). Adjusting the level in the app makes no difference to this background rumble. It remains as a quiet low 'burble' audible if nothing playing and also during quiet passages. Have tried the braided SVS cable the guy included with the sub and also an Amazon basics one. No change. Thanks for the other suggestions, will check these out
 
ginger_ninja said:
I've tried 2) and 4). Adjusting the level in the app makes no difference to this background rumble. It remains as a quiet low 'burble' audible if nothing playing and also during quiet passages. Have tried the braided SVS cable the guy included with the sub and also an Amazon basics one. No change. Thanks for the other suggestions, will check these out
Click to expand...
If I have the gain on my sub too high then I can hear a pulsing sound probably related to the Amp processor with my ear close to the subwoofer driver. Reducing the gain on the sub lowered the volume. I think you said that didn't work for you.
 
ginger_ninja said:
Hi all, have just bought a 2nd hand sub (Cambridge Audio Minx X201), and when it gets a signal from my Amp Pro, there is a low level kind of burble/rumble when nothing is playing (and also when there is silence in a track). I have the sub set to ½ way, phase to zero, crossover to max (see pic). In the app, crossover is at 80, gain +3db. The rumble is just loud enough to be noticeable & very annoying from my sitting position. The seller has been super helpful & genuine & he never had any issues with his AVR

Anyone got any suggestions? The sub is plugged into a separate power socket to the rest of the system. Is there a known issue?
View attachment 14295
Click to expand...
If everything else failed, return your sub and check another brand at comparable price.
 
You must log in or register to reply here.

Similar threads

K
Sub woes
Replies
2
Views
251
krismusic
K
Dennis from Venice
Sub out question
2
Replies
35
Views
2K
Burnside
Burnside
T
Sub crossover setting
2
Replies
26
Views
1K
mach
M
S
Subwoofer phase adjustment
Replies
7
Views
767
harkpabst
harkpabst
J
Need to wake up my Sub
Replies
11
Views
696
harkpabst
harkpabst
Back
Top