PV1 stops working after loud effects on Denon 2310

[Dialogue]

I'm wondering if I can get some advice as I am new to home cinema. I have a recurring problem with my new B&W PV1 sub (part of an MT-30 package).

It all works well on most ocassions, but sometimes the PV1 stops working out during playback of a loud scene in a movie - the green light stays on, but the sub stops making sounds. If I take out the plug and reinsert it, or even switch it to standby and back to (A)uto, it starts working again.

It's almost as if the sub switches off to protect itself from damage. I'm playing back at +5.0db, but the amp is rated at 105W per channel so I wouldn't have thought it would cause a problem. In fact, as the sub is driven by its own amp, surely it protects itself from damage? I do sometimes see the driver moving quite a distance (say +/- 1cm) for low frequency effects - is that usual?

I have set the amp to LFE+Main, 80Hz crossover, set the crossover to 70Hz on the sub, and set the volume on the sub to just under mid-way. The amp is set to +1.5db for the sub, which seems minor.

Could this be a fault in the sub? It has happened when watching movies at 'reasonable' volume levels but for 1.5 hours.

It all works fine for music and normal TV.

Any ideas?

 

[Prize78]

Firstly, welcome to the forums
LFE+Main?? You should have this setting to LFE only, as I believe LFE+Main means that the bass is sent from the amp, to the subwoofer AND the main speakers....which is only really used if your mains are able to handle really low stuff. For the masses, LFE only is employed, meaning the bass gets sent to the sub only. (which is what you want)
What you need to do is find out the frequency response of your speakers to know where to set the crossover. If your speakers are for example 80Hz-20kHz, then the crossover should be set in the amp at around 90Hz, meaning that anything under 90Hz would get sent to the sub.
On the sub itself, (if it has one) the crossover dial should be set to max.
I don't know why it would be cutting out as you describe, but if you try the settings i've mentioned, maybe that will change something.

Playing back at +5dB (is this master volume) sounds a bit much really to be fair....have you ran audyssey to set up? For instance, on my denon amp, i never go any louder than -18dB.

 

[Dialogue]

Thanks for the quick reply and warm welcome!

The M-1 speakers are set to Small, and run from 80Hz-20kHz, so I think I have the crossover about right, although I will definitely experiment as you suggested. The PV1 manual recommends running the satellites for their full range, and I was told by my dealer to set the sub at a slightly lower crossover due to the fact the filters gradually tail off on both speakers and you want to avoid a spike in the freqency just below the cutoff. I'll remove the "+Main" setting as you suggested.

I only tuen up the volume to +5.0db when listening to snippets of a movie to feel the full efects (and it's kind of fun!), but I listen to TV at about -20db and generally 0db for a full movie in the few days I've had the setup.

But...I'm just thinking that none of this should be a problem for the PV1. Surely it can cater for the volumes I'm throwing at it, and surely it should be elegantly handling any problems, i.e. reducing the volume if it would damage the drivers, but still soldiering on in the quieter pieces?

It just feels wrong and worrying that the green light is on, and the amp is sending a signal (as it indicates on its front panel), and yet nothing comes out until the sub is reset...

 

[edgeman]

I’ve had a similar but more damaging experience – check out http://www.avforums.com/forums/subw...49431-3-different-b-w-subs-keep-breaking.html
Where I went through3 B and W subs, on my 4th and 2nd PV1.
I have a suspicion that Audyssey may have been sending too high levels on the 2310 and therefore have turned off all Dynamic EQ and Volume settings to see if that will solve the issue, too early to tell yet, as I have no explanation as what in my setup was blowing up the subs when playing at moderate levels.

 

[plata0190]

how is the sound on the 2310 ? is warm like harman kardon 225 or marantz 5004 6004? or not?

 

[Dialogue]

Well, I've (a) increased the crossover frequency to 110Hz on the Denon, and to 120Hz on the PV1, (b) changed the input offset to 0db (it was -12db, which explains the high master volume necessary), and (c) switched off all the Audyssey MultiEQ settings.

I've been told the higher crossover frequency puts less strain on the subwoofer as it is easier to generate loud noise with the higher frequencies.

To test this I then played two movies loud (between -12db and -3db on the new settings) and I could not reproduce the problem - it all sounded great. I certainly would never want it any louder without damaging my ears!

So, I'm happy, and I agree that Audyssey may have been part of the problem.

BUT - I still can't explain why the PV1 would stop working and stay on green. Why would a subwoofer with its own 500W amplifier have a problem with the signal sent from the amp? Surely it would just shut off (to standby) or attenuate the signal to prevent damage?

 

[khushty]

Hi,

I recently bought my PV1 subwoofer and MT-30's brand new in october 2009 and now the PV1 has a problem of not powering on properly!
Whenever I switch on my home cinema amp (Denon 2310) the PV1 has a Red light on (it should be Green), I have to unplug the mains cable of the PV1 and re-connect again to have the Green light on, I am sure that there is a electronic fault with the PV1, now the PV1 always has a red light on.

PV1 is set on the Denon 2310 to (SW Mode = LFE, LPF for LFE = 80Hz)

I have spoken to the retailer I had bought it from and he mentioned of going through the following steps with the Denon 2310 by sending a signal to the PV1:
Menu
Speaker Set up
Channel Level
Select Test Tone Start (this will send a signal to my MT30's and PV1)

I received signals from my MT30's ok but nothing from the PV1, hence the retailer has asked me to bring back the Denon 2310 and the PV1 for investigation.