Subwoofer operation seems to be related to volume level

[admin_exported]

Please take it easy with me as I am new to home cinema.

I have a Denon AVR 1909 connected to a media center via HDMI. My graphics card supports audio over HDMI and I am having no problems with either video or sound with the exception of sub functionality. My speaker package is a KEF 2000 series with a Kube 2 sub.

If I play a blu ray disc then all seems well but playing hard drive sourced music or streamed music (spotify as an example) or when I play the radio in the amp then it is as if the sub goes to sleep. Occasionaly it "wakes up" for a while and then the base disappears again after a time. It seems that if you increase the master volume on either the media center or the amp then the sub wakes up again. So the fact that this happens with both media center and the avr 1909 radio suggests an amp or sub related issue. Unless of course you need the volume up to keep the sub active, and while that is great most of the time, it's not always appropriate.

I used the Audyssey auto set up and the measurements were accurate. I have the amp set to LFE, speakers set to small. LFE Crossover frequency is 80Hz. I think these are correct but welcome the expert comments from members of the forum

Thanks for reading

 

[matengawhat]

do you have your sub set to auto - ie turns itself on and off when recieves a signal - some sub need quite a lot of power/volume to wake up and if its a sources that doesn't have a dedicated lfe track for example music/normal stereo tv it will turn itself off - as t feels it not receiving a signal then will bounce back into life - really annoying my arcam used to do the same thing! Turn the auto switching off so on all the time

Also turn the crossover up to 120hz then rerun audyssey

 

[Messiah]

I agree with Mat in that sometimes the Sub needs a little 'kick'. My sub is on Auto and sometimes does not come on at low volumes.

 

[Big Chris]

'Auto' sucks for the very reasons you state. I leave mine on 'On' 24/7.

 

[Anonymous]

Thanks matengawhat

By sub "set to auto" would this be a switch on the sub itself? I have an on/off switch only which KEF refer to as a vacation switch. I had assumed that this means that unless you plan to not use the sub for extended periods (i.e.vacation) then you leave it switched to on. So I don't see an auto function. Am I missing something here? Maybe I should switch the power off manually when not using the sub? I have an AC outlet switch on the Denon so could I power the sub from here so when the amp is pwered off then so is the sub?

I changed the LFE crossover frequency ro 120Hz as you suggest and re ran the Audyssey set up and....this seems to have helped and I have not noticed bass dropping out and coming back as it was before so maybe this has solved the problem.

Thanks for the help and any further new questions above would be gratefully received.

Best regards

 

[Andrew Everard]

It's probable that the output from the amp's sub connection isn't enough to trigger the sub's auto on/standby switching. It's a common problem

Try turning the sub's volume down a bit, and increase the subwoofer output level a few dBs in the amp's speaker set-up menu to compensate.

Bear in mind, too, that unless you specifically set the amp to use the sub for all sound formats, it may not send any signal at all to the sub when playing, for example, stereo music or movie soundtracks without a dedicated .1 channel.

 

[Anonymous]

Thanks Andrew

I'll give that a try as well.

All input sources are set to use the sub

 

[Anonymous]

Thanks to all for your help.

Made all the suggested changes and have just spent a great hour listening to music from the media center.

I've never heard U2's "The Refugee" sound so clean with the bass so well defined and constantly present - yeeha!

Must lock it down now to prevent accidental changes by fiddling figures (teenage kids). Still I guess they already know how to bypass such things.

Best regards