Subwoofer output at low volume intermittent. Gate / Threshold?

[mattzildjian]

This is something I notice a lot when listening to podcasts at low volume, the subwoofer output intermittently cuts in and out, in response to the volume level of the voice. It behaves similarly to an audio gate, where the signal is only played when above a certain threshold.

I use a high crossover at 150hz, this is to fill in a gap I cannot fix otherwise due to SBIR. This means a lot of vocal content is played through my sub, and when that signal is not being played, vocals / dialogue sounds very thin and it's immediately obvious.

The issue also seems to be linked to the Wiim's built-in crossover. If I bypass the crossover by enabling "subwoofer bypass mode" and then set my subwoofer’s crossover at the same frequency (and slope at 24db, is that correct?), the issue disappears. Unfortunately it doesnt sound as good overall so I can't use this as a solution.

And to clarify, the issue is only present at low volumes, as I turn the volume up, the subwoofer output smooths out and becomes more consistant. (As if now all the signal is above the gate threshold)

I would appreciate it if anybody could try to reproduce this?

This youtube video is a good test (during the speaking parts). Lower your volume to around 16 or lower. By the time I hit a volume of around 22, the issue was mostly gone.

If it is already known that there is in fact a gate enabled to the subwoofer output, can we disable it?

Thanks!

 

[Wiimer]

This is something I notice a lot when listening to podcasts at low volume, the subwoofer output intermittently cuts in and out, in response to the volume level of the voice. It behaves similarly to an audio gate, where the signal is only played when above a certain threshold.

I use a high crossover at 150hz, this is to fill in a gap I cannot fix otherwise due to SBIR. This means a lot of vocal content is played through my sub, and when that signal is not being played, vocals / dialogue sounds very thin and it's immediately obvious.

The issue also seems to be linked to the Wiim's built-in crossover. If I bypass the crossover by enabling "subwoofer bypass mode" and then set my subwoofer’s crossover at the same frequency (and slope at 24db, is that correct?), the issue disappears. Unfortunately it doesnt sound as good overall so I can't use this as a solution.

And to clarify, the issue is only present at low volumes, as I turn the volume up, the subwoofer output smooths out and becomes more consistant. (As if now all the signal is above the gate threshold)

I would appreciate it if anybody could try to reproduce this?

This youtube video is a good test (during the speaking parts). Lower your volume to around 16 or lower. By the time I hit a volume of around 22, the issue was mostly gone.

If it is already known that there is in fact a gate enabled to the subwoofer output, can we disable it?

Thanks!

What are the volume settings for these two?

1) The position of the volume knob on your Subwoofer.
2) The position of the sub volume within the Subwoofer Settings in the WiiM app.

Turning 1 down and 2 up may solve the problem. I will check the video you posted later too.

 

[mattzildjian]

What are the volume settings for these two?

1) The position of the volume knob on your Subwoofer.
2) The position of the sub volume within the Subwoofer Settings in the WiiM app.

Turning 1 down and 2 up may solve the problem. I will check the video you posted later too.

Ah I see your logic, boost the ouput on the Wiim and reduce the output on the sub to possibly overcome the Wiim's gate (if that is the issue).

I will test this and reply back with the conclusion. Thanks for the suggestion.

 

[mattzildjian]

Yup the Wiims subs output level absolutely does affect this.

I previously had the Wiim to -2db sub output, turning it to 0db helped, but the problem was still there.
The more I turned it up, the more consistant the sub output was at low level.

At the moment I am experimenting with Wiim sub output to +10 and my Sub down -10 to compensate which seems to be fine so far.
However, I am concerned that boosting the Wiim sub out level could cause clipping / distortion to the subwoofer signal?

Out of curiosity, I tried doing the opposite, I turned the wiim sub output level down and turned my subwoofer's own level to max, and and sure enough, the sub signal was cutting in and out even with the volume up higher.

This has proven the issue is there, I wonder if a firmware update can fix this?

 

[Wiimer]

This has proven the issue is there, I wonder if a firmware update can fix this?

I don't know, but you can submit a ticket via the feedback section of the WiiM app.

 

[slartibartfast]

Yup the Wiims subs output level absolutely does affect this.

I previously had the Wiim to -2db sub output, turning it to 0db helped, but the problem was still there.
The more I turned it up, the more consistant the sub output was at low level.

At the moment I am experimenting with Wiim sub output to +10 and my Sub down -10 to compensate which seems to be fine so far.
However, I am concerned that boosting the Wiim sub out level could cause clipping / distortion to the subwoofer signal?

Out of curiosity, I tried doing the opposite, I turned the wiim sub output level down and turned my subwoofer's own level to max, and and sure enough, the sub signal was cutting in and out even with the volume up higher.

This has proven the issue is there, I wonder if a firmware update can fix this?

The issue seems to be the input threshold of the auto turn on/off of the sub. Nothing to do with the WiiM.

 

[mattzildjian]

The issue seems to be the input threshold of the auto turn on/off of the sub. Nothing to do with the WiiM.

good thought, but I have the auto on/off disabled on the sub.

 

[slartibartfast]

good thought, but I have the auto on/off disabled on the sub.

It shouldn't happen then. The WiiM will send a signal continuously. If the sub cuts out it must be the sub.

 

[mattzildjian]

It shouldn't happen then. The WiiM will send a signal continuously. If the sub cuts out it must be the sub.

Unfortunately I don't have a signal analyser to conclusively determine whether or not the intermittent signal originates from the wiim sub output or not.

What I do know is that bypassing the Wiims crossover, or boosting the wiims sub level both remedy the issue, however it would be a fair observation to point out that in both cases the signal going to the subwoofer has increased which could affect the subs behaviour. This is why I requested for others to try and replicate / reproduce this so it can be verified.

The sub is an SVS SB1000 Pro for anyone wondering.

 

[Krabin]

Unfortunately I don't have a signal analyser to conclusively determine whether or not the intermittent signal originates from the wiim sub output or not.

What I do know is that bypassing the Wiims crossover, or boosting the wiims sub level both remedy the issue, however it would be a fair observation to point out that in both cases the signal going to the subwoofer has increased which could affect the subs behaviour. This is why I requested for others to try and replicate / reproduce this so it can be verified.

The sub is an SVS SB1000 Pro for anyone wondering.

do you happen to have another device with rca inputs? maybe you can test it with that. there are also adapters to get rca to 3.5mm, but you might not have one of those

 

[Wiimer]

Unfortunately I don't have a signal analyser to conclusively determine whether or not the intermittent signal originates from the wiim sub output or not.

What I do know is that bypassing the Wiims crossover, or boosting the wiims sub level both remedy the issue, however it would be a fair observation to point out that in both cases the signal going to the subwoofer has increased which could affect the subs behaviour. This is why I requested for others to try and replicate / reproduce this so it can be verified.

The sub is an SVS SB1000 Pro for anyone wondering.

Please check 2 points.
1) Reconnect the cable and replace the cable
2) Various sound sources other than Youtube


I tried it with my Amp Ultra and Sub (Polk ES10SW),

My Sub's auto-standby did not work when your YouTube video was played at low volume.

So I set the Sub crossover to 150 Hz and played a 100 Hz sine wave. The result is that I can hear sound from the Sub even when the Amp volume is at 1%. Mine seems to be fine.


Some other tests performed.

1) Played a 100 Hz sine wave YouTube video on a TV connected to the HDMI input. As a result, no sound is heard from the Sub.

2) Played the same video on a Bluetooth connected phone. As a result, the sound was audible.

3) Played a 100 Hz sine wave on the Amazon music app on the TV. As a result, sound was heard.


Based on these results, the YouTube app on the TV may be the cause.
(To be honest, I'm not sure yet.)

When submitting a ticket to WiiM, you may wish to attach the URL of this thread.