Stereo downmixing through an AVR - effective or add a centre channel?

[jim33]

I've been looking at 3700 vs 4700 for some time too. Main differences on the 4700 are Aura3d, hdmi port on front, extra zone output, buttons on the front panel, bit more power, construction is a bit more robust ( in theoy) , an extra setting on the LFE which i can't remember now. I think they were the main highlights. Personally I prefer the look of the 4700. Please report back if you buy one to let us know how you get on.

 

[Propheticus]

Q1. If I understand what I've read on other threads, is it the case, for Denon amps, that 'direct' keeps the cut-off (or crossover, whatever it's called) and the sub in the mix if I set my speakers to 'small', and that if speakers are set to 'large' the sub is also bypassed?

If your input is stereo, it will remain stereo without a sub unless you set LFE+Main mode for the subwoofer.
If your input is multichannel it'll play all channels that are there as they are without any mixing. If an x.1 / LFE channel is there, it'll play it on the sub.
Setting the speakers to small with a crossover set works for the stereo mode, not for the direct modes.

Q2. I'll want to push a single button to switch from 'direct' to using the digital circuitry with Audyssey, i.e. to go from playing a music CD to watching a movie on Netflix. Is that possible?

It'll remember the last sound mode set per source (but also depends on the material received). You can also use the 4 quick select buttons which you can program to store the combination of source+configurations (speaker config, audyssey, etc). Handy when you want to switch between different settings from the same source.
There's also the sound mode buttons, MOVIE/MUSIC/GAME that each remember the last sound mode they were set to. And then the separate 'PURE' button. Pressing PURE for CD playback and pressing MOVIE for ..movie playback could suffice. If you want more settings changed other than sound mode, program yourself a pair of quick select buttons.

Q3. Will speaker presets help in switching between the different modes of use?

Speaker presets are handy when your room changes or you move seating/speakers for different occasions and you need 2 sets of audyssey corrections/eq/distance settings etc. Example: with and without the projector screen deployed. I'd use the quick select or sound mode buttons.

 

[Propheticus]

an extra setting on the LFE which i can't remember now.

I think you're referring to 2ch playback settings. On the 4xxx line you can configure your speaker setup (large/small/ crossover to sub etc) separately for stereo source material. So you can use a sub with multichannel sources even using small+crossover to offload more bass to the sub, while for stereo sources you set LR to large and defeat the sub. Or conversely for multichannel stuff you only feed the sub LFE material and for stereo LFE+main or set small+crossover.

 

[Artsfols]

I've been looking at 3700 vs 4700 for some time too. Main differences on the 4700 are Aura3d, hdmi port on front, extra zone output, buttons on the front panel, bit more power, construction is a bit more robust ( in theoy) , an extra setting on the LFE which i can't remember now. I think they were the main highlights. Personally I prefer the look of the 4700. Please report back if you buy one to let us know how you get on.

If the power boost was 50%, I'd be in on the 4700H. Front panel HDMI is nice, the occasional time the kids come in with a laptop, but I can live without it.

One thing I noticed is that they advertise the 4700H as having "two dual SHARC+ core DSP" chips but just refer to two powerful DSP" chips on the 3700H.
Better, i.e. less noisy, more features, DSP could be sufficient.

 

[Artsfols]

If your input is stereo, it will remain stereo without a sub unless you set LFE+Main mode for the subwoofer.
If your input is multichannel it'll play all channels that are there as they are without any mixing. If an x.1 / LFE channel is there, it'll play it on the sub.
Setting the speakers to small with a crossover set works for the stereo mode, not for the direct modes.

It'll remember the last sound mode set per source (but also depends on the material received). You can also use the 4 quick select buttons which you can program to store the combination of source+configurations (speaker config, audyssey, etc). Handy when you want to switch between different settings from the same source.
There's also the sound mode buttons, MOVIE/MUSIC/GAME that each remember the last sound mode they were set to. And then the separate 'PURE' button. Pressing PURE for CD playback and pressing MOVIE for ..movie playback could suffice. If you want more settings changed other than sound mode, program yourself a pair of quick select buttons.

Speaker presets are handy when your room changes or you move seating/speakers for different occasions and you need 2 sets of audyssey corrections/eq/distance settings etc. Example: with and without the projector screen deployed. I'd use the quick select or sound mode buttons.

Great explanations.

Given the Arro's lack bass, it's not as simple as I hoped it would be, but of course I would need the DSP on to get a subwoofer cross over, which 'direct'isn't going to give me. It sounds like I just leave the sub on without a cut-off on L+R which is what I do now.

 

[Artsfols]

I think you're referring to 2ch playback settings. On the 4xxx line you can configure your speaker setup (large/small/ crossover to sub etc) separately for stereo source material. So you can use a sub with multichannel sources even using small+crossover to offload more bass to the sub, while for stereo sources you set LR to large and defeat the sub. Or conversely for multichannel stuff you only feed the sub LFE material and for stereo LFE+main or set small+crossover.

I definitely want that level of granularity so to me, that's a big plus for the x4700h.

 

[Propheticus]

Of course on a 3700H a combination of the Quick select and Speaker presets could work for that.
Quick select saves whether you use preset 1 or 2.

And those presets save:

“Amp Assign” settings
“Speaker Config.” settings
“Distances” settings
“Levels” settings
“Crossovers” settngs
“Bass” settings
“Front Speaker” settings
“MultEQ® XT32” data
“Graphic EQ” data

 

[Bear123]

I think the simple and highest fidelity solution is to just use the Denon AVR and not worry about analogue/digital/signal chain etc. There is a good chance that the Denon AVR using its internal amps and HDMI is higher fidelity than your external amp........hundreds of two channel amps have been tested and shown to have objectively worse performance than Denon AVR's. Very few actually have better measured performance, but are highly praised and admired in the audiophile 2 channel world. What will cause a huge lack of fidelity is lack of bass management, lack of low frequency eq on your speakers, and lack of eq on sub(s), along with poor placement and integration of sub(s).

Also, as far as center channel, I would avoid a 2 way MTM center channel like the plague if sound quality matters to you. Just look at the 2 way MTM center that was tested here on ASR....they will all suffer the same horrible off axis issues to some degree, which affects sound quality even when sitting on axis....we hear a lot of the off axis reflected sound no matter where we sit.

If you want to keep the budget and size small, I'd look at Emotiva's C1+ 3 way center channel, especially considering how well the corresponding bookshelf just tested here on ASR. If you are willing to accommodate a larger, more capable center, look at their C2+ or the Infinity RC263 that was tested here.

Essentially, proper bass management with eq on everything below 3-400Hz or so will provide orders of magnitude improved sound quality vs using "Pure Direct" in order to use an analogue amp that is highly likely to have lower SINAD than the Denon. Even if it does manage to measure better as a very small handful of 2 channel gear has been shown to do, minute differences in SINAD on paper won't be audible in real life i.e. .003% vs .001% or whatever the difference may be.

For a more specific example....using the Denon's full capabilities over HDMI and internal amps, you are sending a signal to your speakers with .004% SINAD. If you use the pre-outs instead, and have gear that is actually better than the Denon(it's highly likely it isn't), the signal is .001%. If this were played back to back A/B switched level matched etc etc, is there anyone who actually believes they can hear this difference in real life? Its chasing a single grain of sand on the beach but being in a paved parking lot, vs being on the beach with all the sand. What you WILL hear that has a drastic affect on fidelity that you can actually hear is a train wreck response without proper eq.resulting from "Pure Direct", otherwise known as the low fidelity button.

For $75, I would also recommend a Umik-1 mic if you haven't measured, so you can optimize mic placement and see what's actually happening in your room. The Audyssey app, although a bit clunky, can yield excellent results but its a good idea to verify and start with the best baseline, which the Umik and REW allows.

 

[Artsfols]

I think the simple and highest fidelity solution is to just use the Denon AVR and not worry about analogue/digital/signal chain etc. There is a good chance that the Denon AVR using its internal amps and HDMI is higher fidelity than your external amp........hundreds of two channel amps have been tested and shown to have objectively worse performance than Denon AVR's. Very few actually have better measured performance, but are highly praised and admired in the audiophile 2 channel world. What will cause a huge lack of fidelity is lack of bass management, lack of low frequency eq on your speakers, and lack of eq on sub(s), along with poor placement and integration of sub(s).

Also, as far as center channel, I would avoid a 2 way MTM center channel like the plague if sound quality matters to you. Just look at the 2 way MTM center that was tested here on ASR....they will all suffer the same horrible off axis issues to some degree, which affects sound quality even when sitting on axis....we hear a lot of the off axis reflected sound no matter where we sit.

If you want to keep the budget and size small, I'd look at Emotiva's C1+ 3 way center channel, especially considering how well the corresponding bookshelf just tested here on ASR. If you are willing to accommodate a larger, more capable center, look at their C2+ or the Infinity RC263 that was tested here.

Essentially, proper bass management with eq on everything below 3-400Hz or so will provide orders of magnitude improved sound quality vs using "Pure Direct" in order to use an analogue amp that is highly likely to have lower SINAD than the Denon. Even if it does manage to measure better as a very small handful of 2 channel gear has been shown to do, minute differences in SINAD on paper won't be audible in real life i.e. .003% vs .001% or whatever the difference may be.

For a more specific example....using the Denon's full capabilities over HDMI and internal amps, you are sending a signal to your speakers with .004% SINAD. If you use the pre-outs instead, and have gear that is actually better than the Denon(it's highly likely it isn't), the signal is .001%. If this were played back to back A/B switched level matched etc etc, is there anyone who actually believes they can hear this difference in real life? Its chasing a single grain of sand on the beach but being in a paved parking lot, vs being on the beach with all the sand. What you WILL hear that has a drastic affect on fidelity that you can actually hear is a train wreck response without proper eq.resulting from "Pure Direct", otherwise known as the low fidelity button.

For $75, I would also recommend a Umik-1 mic if you haven't measured, so you can optimize mic placement and see what's actually happening in your room. The Audyssey app, although a bit clunky, can yield excellent results but its a good idea to verify and start with the best baseline, which the Umik and REW allows.

There's quite a lot here to think about and thanks for your insight. You're ten steps ahead of me on the centre channel thinking, so all the more reason to defer the center channel for now and focus on the AVR purchase.
I'm onboard with your thinking on S/N ratios and achieving sound purity in an amp. Back in the day, you could really improve your system by spending 50% or more of your budget on speakers and cutting back a bit on the amp, tuner and turntable. So, I'm not really chasing perfection in an amp.
And I'm sold on equalizing everything below the Schroeder frequency with Audyssey. But keep in mind that many of my classical CDs, especially the older recordings, don't even move the subwoofer. (And some of the newer classical recordings turn up the bass beyond what you'd normally hear in the concert hall, unless you're sitting directly below the bass violins - something I did once experience). So, for my foreground music listening all I want to do is preserve the sound I have now.
Now mind you, it will be fun to see just what Audyssey and all this new tech will do with foreground music listening. I'm skeptical that I'll see any improvement over the purist simplicity of my existing set up that I purchased and tuned with my ears.

The reason for moving to an AVR is that it seems to be the only way of dealing with the various streaming sources which increasingly occupy my leisure time. I've coped to this point by front ending my 2.1 analogue system with devices of one sort and another. Here follows a small example of what I'm dealing with. Yesterday I streamed another episode of Parks & Rec which I'm still working through (on Amazon Prime). Immediately the voices were about 10 db below what they should be so I turned up the sound without thinking about it. After a few minutes, background music cuts in and just booms through the speakers at spouse-annoying levels. So, something wasn't getting through to me in the voice department, and I've also noticed Amazon Prime is sourcing more and more audio in 5.1 format. The Apple TV box supposedly mixes to stereo, but sometimes the setting magically changes - but then the TV should down mix to its optical audio out. Given that I also enjoy quite a number of opera and classical concerts as well as folk/ indie material on the Apple TV box or on my multi-media computer ... I need to fix the issues. Running everything through on HDMI into a single AVR box at least gives me a single point of failure to worry about when it does not work.

By the way, have you ever wondered why Apple removed the optical audio out from their Apple TV box? This was a highly annoying move ... Apple is good on annoying its customers, don't even let me begin. But like its position on not supporting Adobe Flash, it's a gutsy move. Apple is saying ... we don't care about compatibility with the market leader, we only do 'quality' here. I read the change on the Apple TV box as a policy move - dropping USB and optical audio in favour of HDMI (or their Apple Airplay - no thanks), and never mind backwards compatibility. I would imagine a lot of customers with older Apple TV boxes using the optical audio out would be quite upset by the move. But Apple's clout is so huge that the industry will have to follow whatever they decide.

I must say that on further reading that the down mixing problem on the X4700H has me quite worried. To my mind it's possible that the X3700H doesn't exhibit the problem; ASR has not tested it for the problem and the DSP chips are different. So right now, because down mixing is so important for my 2.1/3.1 system I feel I'm back to the drawing board on the AVR decision. To whit, I'm not chasing a high S/N ratio, down mixing and configuration capability is key, and Audyssey/ Dirac/ YPAO is a nice bonus. What other options in an AVR might I have? Maybe get the much cheaper new Yamaha as it down mixes cleanly.

 

[Propheticus]

Lost me there, what downmixing issue?

 

[Artsfols]

Lost me there, what downmixing issue?

It's documented in the second X4700H review. The amp malfunctions under certain mismatches between the number of channels supplied by the HDMI input source and the output speaker configuration.
Reader comments range from "these conditions rarely happen" to "serious problem, happens all the time".

 

[Chrispy]

So my original question was just to ensure that I can bypass the AVR DACs, but still split out the sub. Correct me if I'm wrong, but if you don't use a direct or pure direct setting the analog inputs (from my CD player and from my OPPO player will go through the AVR digital signal processing and I don't want them to. They're already analog. I want them amplified and out to the speakers, that's it.



Right now I'm not doing sh*t, I'm just looking at spec sheets and forums and sorting out what to buy. I think I'm going to buy the Denon X3700H although if I could think of a reason I would get the X4700H.

Generally an avr with multi-ch analog inputs will act as just an amplifier if you want "purity" and bypassing processing in the avr. Neither the 3700 or 4700 have that feature set altho generally previous models of that range from Denon did. I just use my Oppo digitally....even tho my Denon does have the multich inputs.....(gave it a shot, preferred having the processing in the avr).

 

[Propheticus]

That's when connected to a pc configured as a 7.1 source and then only sending a stereo signal.
Plus turning off other channels in speaker config. Making it downmix 8 (6 empty) to 2 channels. A normal source playing stereo material will not present itself as a 8 channel source nor do you have to disable speakers in your speaker config to be able to play stereo content 'normally' over LR alone.

Apart from this Windows pc edge case not a real issue IMO.

 

[Artsfols]

That's when connected to a pc configured as a 7.1 source and then only sending a stereo signal.
Plus turning off other channels in speaker config. Making it downmix 8 (6 empty) to 2 channels. A normal source playing stereo material will not present itself as a 8 channel source nor do you have to disable speakers in your speaker config to be able to play stereo content 'normally' over LR alone.

Apart from this Windows pc edge case not a real issue IMO.

I'd like my Apple TV box to send over multi-channel audio and have the AVR do the down mixing. And then later I'll want to pull out the center channel for a 3.1 system.
As long as my use case isn't unusual, and from reading it seems like this is something quite a few listeners do, I believe that Denon would fix any issues through a firmware upgrade.

 

[sritacco]

I think you would benefit from having a center speaker which you could enable or disable when you like.
I have one smaller TV in a room with stereo down mix and it's fine, but I would really miss the center channel in my main room.
Having the dialog right under the TV just seems like where it belongs.
Also, you may find the AVR is able to use the center to enhance the vocals on some recordings. I know it's audiophile blasphemy, don't hate me. ;-)

 

[Artsfols]

I think you would benefit from having a center speaker which you could enable or disable when you like.
I have one smaller TV in a room with stereo down mix and it's fine, but I would really miss the center channel in my main room.
Having the dialog right under the TV just seems like where it belongs.
Also, you may find the AVR is able to use the center to enhance the vocals on some recordings. I know it's audiophile blasphemy, don't hate me. ;-)

Lol. Love the closing comment. I'm only a purist in philosophy; it's not a religion. I have to say though that when I review the buzzword compliance of today's AVRs I wonder about the point of it all. To me the point is to hear the musician. Some of the best classical recordings were made in the 1950s and 1960s, by Philips in Holland, Mercury and RCA in the USA, and Decca at Abbey Road. Multi track recording resulted in a lot of inferior recordings through the 1970s, compared to the earlier days when microphone placement and acoustics were crucial.
So, I do try to remain purpose driven in what I do. But it IS time to make a change.

I like the possibilities suggested in your post, and I need to think of my system upgrade more as a doorway, than a point of arrival.

 

[Chrispy]

I like much of the multich recordings I've collected. Not much classical, not my thing generally, but have a few of those that sound very nice, too. Generally there's much more multich offerings in classical, tho. I know some classical music fans who even upmix their 2.0 stuff....more blasphemy

 

[sritacco]

Lol. Love the closing comment. I'm only a purist in philosophy; it's not a religion. I have to say though that when I review the buzzword compliance of today's AVRs I wonder about the point of it all. To me the point is to hear the musician. Some of the best classical recordings were made in the 1950s and 1960s, by Philips in Holland, Mercury and RCA in the USA, and Decca at Abbey Road. Multi track recording resulted in a lot of inferior recordings through the 1970s, compared to the earlier days when microphone placement and acoustics were crucial.
So, I do try to remain purpose driven in what I do. But it IS time to make a change.

I like the possibilities suggested in your post, and I need to think of my system upgrade more as a doorway, than a point of arrival.

I like much of the multich recordings I've collected. Not much classical, not my thing generally, but have a few of those that sound very nice, too. Generally there's much more multich offerings in classical, tho. I know some classical music fans who even upmix their 2.0 stuff....more blasphemy

My Onkyo AVR has a really nice multi-channel upmix of stereo. I think it's just a mono-blend on center and left and right on back. Truth be told, most of the time when I have music playing and I'm doing other things, that's what's on.

 

[Chrispy]

My Onkyo AVR has a really nice multi-channel upmix of stereo. I think it's just a mono-blend on center and left and right on back. Truth be told, most of the time when I have music playing and I'm doing other things, that's what's on.

You may even have a way to manipulate the content of the center (center spread feature).....think the matrixing for surrounds is based on frequency range but center I think is just summed L/R but could have some frequency limitations, not sure.....

 

[sritacco]

You may even have a way to manipulate the content of the center (center spread feature).....think the matrixing for surrounds is based on frequency range but center I think is just summed L/R but could have some frequency limitations, not sure.....

It probably does. Digging into the menu fore some of those features isn't something I've really done enough of. Just the other day I discovered that it has a delay feature to fix lip-sync on analog inputs. I bought three little digital delay devices to fix that problem. :-(