Denon 1507 Zone 2 and Multichannel problems

[ajinkya]

Does anyone know whether the Zone 2 functionality on the Denon series has limitations with playing multichannel music?
The setup is an Oppo 980H passing audio through its 5.1 analog outputs to the 5.1 analog inputs on the Denon 1507. The front speakers are biamped used the Denon's zone 2 facility for the tweeters and main zone amp for the woofers.
Everything works fine if you play sources connected 'normally' to the Denon i.e using either the stereo RCA inputs or coaxial inputs. (E.g. A CD played via the CD inputs plays fine over the front speakers and any Dolby source plays fine over the coaxial, outputting to all 5 speakers as expected.)

The problem occurs when I try to play via the Oppo, using the 5.1 analog connection. For some reason, the Denon refuses to output anything to the front speakers for any multichannel coded music. For stereo CDs via the Oppo, the Denon only plays the Main zone sound, even though Zone2 is switched on and volume is same. This results in only the front woofers outputting any sound at all! The treble section is not audible. This is not a problem with the Oppo player since it was tested with other equipment and it works.

Does anyone know whether this is an inherent limitation of the Denon, where it can only play over the Zone2 via 'normal' inputs? It seems to me that if I connect via the 5.1 external inputs, the Zone2 is shut off and errors result. I have gone through the Denon 1507 manual in detail but cannot find any explicit mention of this limitation. Maybe I've missed it somewhere. Can someone on this forum help me debug or understand what's going on?

Thanks in advance,

Ajinkya.

 

[venkatcr]

Ajinkya:

At the outset, I am not sure the 1507 can be bi-amped at all. It does not say so anywhere in the manual.

What the 1507 uses for Zone 2 are the Surround Back channels. When you switch the Zone 2 'On', what the 1507 must be doing is duplicating the Front L&R to the Surround Back speakers. What I would suggest is the following experiment.

1. Keep the Oppo connected to the AVR through the 6 channel analog RCA cables.

2. In the AVR set all connections to 'No' excepting for the 6 channel analogue.

3. Disconnect the biamping, and reconnect the metal straps in the loudspeaker.

4. Set the 1507 to normal mode. Set it to normal 5.1 and play a 5.1 sound from a DVD. Make sure you are getting sound from all the speakers. You can also use the test signal to confirm this. Also play a normal Redbook CD and ensure you are getting full sound from the Front L&R speakers.

5. Connect a pair of speakers to the Surround Back L&R. What you can do is use the front speakers temporarily. Jusr reroute the cables from the Surround Bck to the Front L&R Speakers.

6. Set the Zone 2 active in your AVR.

7. First play a Redbook CD, and heck whether you are getting stereo music in your Zone 2.

If all this works, then your AVR is working properly.

Let us know what happens and then we can workout what to do next.

Cheers.

 

[ajinkya]

Venkat,

First of all, thanks for the quick response. Now to answer your post stepwise:

The Denon does biamp, in the sense it outputs the full frequency range of the front L/R channels to the SurroundBack(SB) L/R channels, if the AVR is put into zone2 mode. This is what your post concurs with as well. So if I connect the tweeters of the speakers to the SB and the woofers to the Front channels (after removing the shorting bar on the speaker terminals), we do indeed have a situation where there is a separate amplifier powering each driver set of each loudspeaker. The crossover inside the speaker will take care of filtering the tweeter or woofer frequencies as required. I agree that this is a bit different from first isolating the low and high frequencies at the source itself and then feeding them to the separate amplifier sections, which then go to the tweeters and woofer. But it is still a biamp configuration in the sense that separate amps are driving the two sections.

Having said that, I have tried out what you have suggested. The 5.1 works as given, so does Zone2. In fact, we are using the Denon in the 'biamped' mode, with stereo music and it plays without a hitch i.e woofers and tweeters are controlled via separate main and Zone2 volumes and the full frequency spectrum is output from the front L/R. Ditto for Dolby PLII formats.

The problem occurs when I try to play true multichannel sound from this setup. In this case, the front tweeters do not output anything at all. The woofers still output sound, since they are connected to the main zone output. However, it seems the Denon switches off Zone2 capability when playing anything that is given externally as multichannel, whether 5.1 analog from DVD or coaxial raw Dolby Digital data to process. (I have to amend my earlier post which said that coax plays fine...that was my friend's data and he was mixing coax and RCA). So the bottom line is that the Denon cannot output multichannel music (Coax or analog 5.1) from the zone2 speakers. However, any source connected to the RCA stereo inputs (CD,DVD, TV etc.) all work fine with stereo and all the inherent surround modes, with the Denon biamping the speakers.

So it seems that there is some setting I am missing to switch this on for multichannel or Denon has this idiotic mode where Zone2 is only active for stereo reproduction. But since I found no mention of this in the manual, I was looking for help on whether I was missing something obvious.

Thanks in advance for your debugging help,

Ajinkya.

 

[ajinkya]

Venkat et al,

Found this on the Amazon review site for the 1707, which is the bigger brother of the 1507:
Amazon.com: Customer Reviews: Denon AVR-1707 7.1 CH/5.1+2 CH Independent Zone Home Theater Receiver

"I had planned to replace my old Panasonic with this unit and use it to drive my home theater (5.1) and my two outdoor speakers on the patio. However, I didn't realize that the zone 2 speakers will only recognize analog sources, not digital. I have a couple of items (one being a Roku device) that only have digital outputs, so I ended up keeping the Pansonic in play to drive the speakers on the patio and rewiring my home theater for the Denon."

Looks like I'm out of luck. I'll have to ask my friend to go back to only biwiring the speakers if he wants to use the surround sound on the Denon. Which Denon engineer came up with this idiotic lacuna? Why is digital so hard to output to Zone 2? Dammit!

I'm still open to suggestions from members before I begin dismantling the current setup.
Edit:...why is the analog 5.1 inputs not working? That is Ext In for the Denon and should not have this caveat???

Thanks,
Ajinkya.

 

[venkatcr]

Ajinkya:

As far as I am aware, (I could be wrong), Zone 2 in all AVRs is a replication of the Front L&R into a different room.

In any case, I am glad your AVR is fully functional. I am sure with a little bit of tweaking, you can solve this issue. Your need may be a unique case that will not be mentioned in the manual. Let me also read carefull through the manual tomorrow and see if I can get some 'vision'.

Cheers

 

[ajinkya]

Ajinkya:
As far as I am aware, (I could be wrong), Zone 2 in all AVRs is a replication of the Front L&R into a different room.
Cheers

Venkat,
I agree with your statement. That is why I am connecting the Zone2 L/R channels into the tweeter section of my front L/R speakers. The woofers of the front L/R speakers are connected to the Main/Front L/R channels of the Denon. So each speaker has two amp channels separately powering the woofer and tweeter sections, which implies a biamping configuration. I assume the filters before each voice coil will send the right frequency range to each driver/coil and hence there is no danger in this setup. So I am presumably biamping the front L/R speakers of my 5.1 setup. Am I missing something in the very definition of what biamping means?

Thanks,
Ajinkya.