[keenween]

Hey all, I'm looking for some help/verification that my set-up is correct for HT. My system runs both my music and movies, but music gets priority.

I am using the new Oppo BDP-83 for movies using the analog L/R outs. I programmed it to know I run a stereo config. I then run the L/R signals to my preamp, after which the signal splits to my amp/speakers and to stereo subs (Rythmiks). I have the sub crossovers set to around 80hz.

I think the BDP is supposed to downmix, but will all the LFE information come through? Is dynamic range compression involved in downmixing? Are the new HD codecs able to be downmixed?

I am wondering if I need to have the player configured for an LFE channel and then somehow route that to the subs as well...but then I'd still have a problem with how to set the crossover on the sub amps perhaps switching between movies and my 2channel. I don't think I want to apply an active outboard crossover or anything, but that is probably what it would take?

And if all the LFE is sent to my speakers, should I implement high pass filters (I have some handy)? Is the LFE bass capable of damaging speakers that aren't truly full range?

Thanks for any answers/help you guys can provide.

[JP78]

I am using the new Oppo BDP-83 for movies using the analog L/R outs. I programmed it to know I run a stereo config. I then run the L/R signals to my preamp, after which the signal splits to my amp/speakers and to stereo subs (Rythmiks). I have the sub crossovers set to around 80hz.

so long as you've ensured you have subwoofer set to 'off' and left & right main set to 'large' you should be fine. make sure the downmixing option is set to 'stereo' (not 'lt/rt'). also make sure that you have the system hooked up the the stereo left and right output, not the left and right multichannel output. i'm sorry if this sounds like common sense, but i'm just trying to be complete.

I think the BDP is supposed to downmix, but will all the LFE information come through? Is dynamic range compression involved in downmixing? Are the new HD codecs able to be downmixed?

dynamic range compression is not involved in downmixing; usually there is a separate automatic volume limiter setting for compression. all dolby digital and dts codecs support downmixing to two channel.

I am wondering if I need to have the player configured for an LFE channel and then somehow route that to the subs as well...but then I'd still have a problem with how to set the crossover on the sub amps perhaps switching between movies and my 2channel. I don't think I want to apply an active outboard crossover or anything, but that is probably what it would take?

checking page 63 of the bdp manual implies that the subwoofer is rerouting in downmixing, but it doesn't explicitly say so.
http://download.oppodigital.com/BDP83/BDP-83_English_Manual.pdf
a quick test to see if the oppo is rerouting the bass channel:
- turn the amps to your mains off
- play a passage with deep bass from a movie, and listen to the bass volume out your subwoofers.
- go back to the oppo, turn the subwoofer setting to 'on',
- run an analog rca from the lfe channel into a free preamplifier input
- switch to that input, and replay the same passage

if the bass is almost as strong or as strong, then we can confirm the lfe channel is rerouting. if the bass is much stronger, then we know the lfe is not being rerouted, and we can address this issue with some custom interconnects.

And if all the LFE is sent to my speakers, should I implement high pass filters (I have some handy)? Is the LFE bass capable of damaging speakers that aren't truly full range?
Thanks for any answers/help you guys can provide.

if the lfe channel is being rerouted by the oppo, then you may want to utilize the high pass filter in your subwoofers to connect to your mains as a permanent setup (as opposed to splitting the signal straight out your preamplifier). what mains do you have?

ok, well reply back when you find some time, and we can take it from there.

best,

[keenween]

Thanks for the detailed response JP! I've been trying to find the time to test the reroute...no luck yet. I will post back after I have it tested though!

[JP78]

great . let us know!

[keenween]

Well, I finally had a good chance to test things out. I am not getting the LFE channel downmixed into the stereo signal.

The only "easy" solution I can think of is to configure the players setting to run the speakers as small and turn the subwoofer on. Then possibly I can split the subwoofer out signal and combine it with the Front Left and Front Right signals before the preamp...therefore creating a full range signal. If this was possible, I can just use high pas filters for the speakers and then the onboard subwoofer crossovers.

I have never heard of anyone combining two signals by cabling before though. Perhaps its not wise to try this.

Any thoughts?

I would like to avoid an outboard crossover like an ICBM.

[JP78]

keenween - you should also try the converse of what i recommended above; which is to say try the following:

- plug into l/r of multichannel
- set center channel to off
- set surrounds to off
- set lfe to lfe + main (this will give you quasi-stereo lfe)

if you split the lfe output now, you should be in good shape. just make sure your two channel listening isn't suffering. ok, well try this one out and then we can run through your crossover options .