Ayre DX-5 bluray player - Page 4

Thanks for the explanation Charles. The C-5xeMP is an awesome sounding universal player in a dedicated 2 channel audio system and I bet that the DX-5 will be both incredible with video and audio in a full-blown home theater.

Hi Charles,
I use 3 preamps,2 tube and Proceed AVP for sub vol,and distance control only.With 4 amps,Audio Research REF 600mkIII monoblocs front left,front right(BEST HT AMPs),Krell Theatre Standard Amplifier mono for centre only,Bat vk-500 for rear left,rear right with 4 subs,2 x revel b15 fronts,2 x genesis 900 rears with Martin Logan,Prodigy,s,logos and Request for rears and I do want all channels to be Very High Quality the difference is easy to notice.
HDMI sound quality as you know is lacking and SSP using it are very sub standard,maybe someone will solve this digital problem.You have far more Knowledge about this subject than myself,but the source(bluray player) is important as it can only degrade signal ,once of the disc.
So maybe your Bluray wil be our only choice?
cheers Victor.

WOW! That is quite some system!

If everyone were that dedicated to good sound, there wouldn't be such an abomination as Dolby Digital -- essentially just 5 channels of 96 kbs MP3. But now we have Blu-Ray, and at least the chance for better sound.


There are a lot of problems with surround-sound processors, generally speaking. The single biggest one is the volume controls. A good volume control is expensive and takes up a lot of PCB space. I don't know of a single SSP that doesn't use the single-chip IC's from Crystal or Burr-Brown that have internal op-amps in the signal path. While the Burr-Browns are better than the Crystals, they are far from competitive with even a lowly rotary potentiometer from the standpoint of sound quality.

The next problem is that a good two-channel preamp costs between $3,000 and $20,000. Yet most people are unwilling to pay that much for an eight (or more) channel SSP that has a multitude of additional DSP features. So it becomes a classic case of quantity versus quality.

Finally, since DSP has become so essential to so many of the functions of today's modern SSP, it is important to send it a digital signal. But the only standard that has emerged is HDMI. It will never be adopted by the specialty manufacturers due to the exorbitant licensing fees, and the inherent amount of jitter is orders of magnitude worse than even the flawed S/PDIF format.

This latter point is addressed in some proprietary solutions from Pioneer (PQLS) and Sony (HATS). But HDMI 1.3a allows for a generic, industry-wide standard. We will incorporate this into our Blu-Ray player, but it won't do any good until someone makes an SSP that also supports this feature.

And even then, they still need to include a good analog volume control. So the only other solution is an all-analog one. In theory, we could make a multi-channel HDMI D/A converter. Then you could feed the outputs of these into a bank of slaved AyreLink preamps (we should have some coming in the future that will be less than $18,500 each!). But then you still wouldn't have any way to do bass management or time delays....

We could build a great SSP, but it would take at least two years of development time and sell for at least $20,000. I think it would be a great way to bankrupt our company. Kind of like what happened with Proceed and the PMDT DVD player....

The only other possibility would be to do what we are doing with Oppo. Find an SSP from a mainstream manufacturer that could serve as the "engine" for improved analog supporting circuitry. This could reduce both the development time and the selling price. But I wouldn't hold my breath waiting for such a beast....

Sorry!

I posted before I was fully awake. I don't drink coffee, but maybe I should start....

I suppose the simplest solution would be to add a single extra D/A converter for the subwoofer output. Then there would be three channels of analog output. If there were a great three-channel preamp, you would be all set.

I think it's too late at this point to try and include such a feature. But the other problem is where to stop? If we add another output for the LFE, should we add more analog outputs? I think that is something of a dead-end road.

Let me noodle on it some more.

How many people are there that are really interested in an HT 2.1 system?

Or I suppose another way to put it would be, what if we could mix the LFE into the main analog outputs and then you could just have an HT 2.0 system with all of the bass in place? This might not actually be all that hard, come to think of it. And although it would violate Dolby rules, we never completed all of the paperwork for our Dolby license....

Give me some feedback on this idea, please.

Charles,

So how would YOU implement a state of the art 5/7.1-HT + 2-CH system using Ayre products? I assume you would suggest one of your preamps with processor pass thru, timbre matched (if not identical) speakers all around with Ayre amplification around as well... this along with the DX-5 sounds like a formidable system.

I've heard this exact system as described above (sans DX-5, was a DX-1 at the time...) with an McIntosh processor and B&W speakers years ago at Nicholson's in Nashville. They are no longer dealers but...

At the risk of stepping on toes, are there any companies processors you have head that sound "right" with Ayre equipment? I would imagine that Arcam might be a good match but I've never heard them mated.

Also, which companies' speakers does Ayre typically demo with at the shows?

PS. Still cycling? Glad you recovered btw...

I know you have hinted about Ayre are not technically bound to anything, because you OEM the OPPO, and that is one of the reasons I brought up the matter.
It would be great to also have a secret feature that would mix the LFE into the mains (and we all know the other secret feature will be the one you're not commenting on..)
But there is no free lunch after all. You will have to digitally attenuate the mains 10db to have enough headroom to properly reproduce the LFE channel properly. Not that big of a problem with a 24bit path, but it still would possibly be a compromise.

I don't think there is a need for an analog out for the LFE and the DX-5. Who is using a 3 channel preamp anyways? (And then you'd have to find a way to make use of the subwoofer when you play CD's /USB and other strictly 2 channel sources, everythings possible but I'm all for KISS)

As for my own setup, I'm using a SSP as a preamp and I COULD just connect a subwoofer to the LFE output. I'm not as critical as when it comes to SQ from movies.

The point is that I have big enough mains already and I don't really want to add a big subwoofer as I don't have the room for it. My speakers don't go all the way down in terms of hz but certainly can handle the added LFE without much trouble.
But what about this scenario: I buy the DX-5, and I swap out the SSP for a KX-R. I don't want nor have the space for a full blown HT. Would it not be sweet to NOT having to rely on the SSP for LFE reproduction? I mean, that IS an extra box, and of course the subwoofer itself would cost a lot to match the quality (you could get quantity for less but what is the point of that?) of the mains. If I paid 10000usd for a Blu-Ray player my wish would be that I also could use it for movies. *With* explosions and not having to rely on the SSP for LFE, which also would degrade the SQ of the mains compared to the state-of-the-art analog output from the DX-5 into a KX-R.
(I realise I could use the audio only HDMI into a SSP, and then adjust the volume manually but..I think you are getting my point!)

It's kinda ironic that a 1000usd HTIB gets to reproduce low frequency sounds than I am nowhere of getting, only because it includes a ****** subwoofer with a ****** 8" driver..

PS! I got the MX-R and QB-9. Thanks Charles. I know it's a sin to use a SSP for a preamp. But it will have to do until the KX-R is within reach.
Maybe some beautiful day I could have 7 MX-R, 7 TAD R1, an Ayre 8ch HDMI DAC, and 4 Ayrelinked KX-R. There would be no need for bass, delay or SPL management. One can certainly dream.

(Of course the DAC could have basic bass and delay management and the Ayrelinked KX-R could the the SPL-management if the setup wasn't symmetrical. Just a thought)

This paragraph has Anthem written all over it

There are several:

1) The Mark Levinson N40, that I use. With digital sources, it's better than most 2 channel dedicated pre-amps.

Here it what they say about it:


2) Their new 502 model, which offers a 120dB range.

3) The Goldmund processors: they are digital in/digital out only processors, and process the volume digitally.

That's so good that when competing with analog pre-amps, even though an analog signal has to be first digitized, they are on top. I compared the entry level Goldmund SR8 processor against a Mark Levinson 32 using a phono stage as the source, and they were close, it was a draw. It's way better than the ML40 for music, but lacks HDMI.

That implies of course using a good DAC (like the ones inside my amps) to convert the processor digital output.

4) Very likely the Tact processor, since it also outputs volume controlled digital signals.

For two-channel playback I think that a good preamp with a processor pass-through mode is essential. I just have never heard an SSP that sounds as good as a two-channel preamp. The other problem is that connecting your video and audio systems together can result in ground loops and other sonic degradation unless you are *extremely* careful.

All of our video players have the video and audio outputs completely isolated from each other, including galvanically isolated grounds. But connecting any other video source will short those two isolated grounds back together. That's why all of our preamps (and integrated amps) since 2001 switch the *ground* connection also when selecting inputs. This completely disconnects all unused sources and minimizes this problem.

Video systems (like computer systems) tend to be big sources of RFI, both conducted into the AC power mains (largely from switching power supplies) and radiated (you would be surprised how much junk a big flat screen display "sprays" out into your listening room). The best way to deal with that is to put all of your video equipment on a switched power strip and turn it off when you are listening to audio-only sources.


As far as an SSP, I think it all depends on how much of your time is spent listening to music versus watching movies. If you only watch an occasional movie, then it's simply not worth spending a ton of money on a fancy SSP. The visual element tends to dominate your senses, and with two good front speakers (and a phantom center, assuming that you don't have chairs all the way to the side so they are in-line with the speakers), you probably won't notice the differences in the surrounds as readily.

I would probably tend to put more money into the subs, however. I am pretty intolerant of boomy, muddy, or distorted bass, even when it just for explosions!


We try to mix it up. At the forthcoming CES we will have an HT 2.0 display with a 50" Pioneer Kuro and the new Vandersteen 7's. At the recent RMAF we had one room with Wilson Sasha WP's and another room with Avalon Aspects. Last CES we used the Sonus Faber Stradivari Homage. Before that we used the TAD R1's and before that we used the JBL K-2 9800's. There are a lot of great choices!

Since my accident, I've been paralyzed and working from home in a wheelchair. There is a researcher who has a cure working for spinal cord injuries in rats. You can read more about this research at:

http://www.telegraph.co.uk/science/s...-injuries.html

He need additional funding to get the therapy out of the lab and into hospitals. You can make tax deductible contributions at:

http://www.cufund.org/giving-opportu...ption/?id=3485

100% of all funds go directly to his lab. Even the credit-card charges are paid by the CU Foundation. His work will first be applied to spinal cord injuries, but later will have applications with all kinds of damage to the central nervous system, including stroke, Alzheimer's, Parkinson's, and even traumatic brain injury.

Now is the time to be thinking about your charitable contributions for tax planning. This is a truly great and important cause. I'm sure that Dr. Davies will one day win a Nobel prize for this work, but in the meantime he can use all the financial support that he can get. Thanks for your generosity!

Charles, I am particularly interested in being able to put all channels from a DVD/BRay into a two channel output. That way I can use my current Wilsons:

http://www.avsforum.com/avs-vb/showthread.php?t=1154494

The Levinson stuff is all gone now and replaced with the Ayre amps and preamp per Audio Advice. You are lending me a cx-7? cd player until I can be delivered the DX-5.

aehaas

This seems to be the most parsimonious route. Folks with big full-range speakers would get the LFE. Folks with good subs could implement bass-management in various ways including using external crossovers or the ones built into many subs. Of course, those with weeny speakers need not apply unless you include a defeat switch.

Holy crap
These restrictions come from the childhood of surround sound and still stand. And the most part, maybe rightly so. I think Dolby/DTS should allow the mixing of LFE into the mains for special applications, for this very reason. . I just can't understand that certain software DVD players always have had this feature, but no hardware SSP/sources have it.

Just as Apple first allowed the Wadia iPod Dock to tap into the digital output of the iPod. And now we see that feature all from Pioneer surround receivers to the new Naim Dac and the B&W Zeppelin Mini.

One more thing. I don't know if it is a standard feature of the OPPO already, but it should also be possible to mix in the surrounds out of phase of eachother in a 2 channel mixdown. Just to have this quasisurround/Dolby Prologic 2x compatible output. Some DVD players I have stumbled upon in the past had this feature.

This would be relatively easy to implement. As you note, it would require attenuating the main channels, but I'm not sure the full amount. The LFE channel is supposed to be boosted 10 dB *if* it is being reproduced by a single sub-woofer. But if you are running into *two* speakers (which is what we are talking about, then Dolby has created an empirically derived formula that says it only needs to be boosted by 5.5 dB.

Now we are withing spitting distance of 6 dB, which is just shifting everything over by one bit. (I don't think being 0.5 dB off in the LFE level is critical, especially since their "compensation formula" was just made up on the basis of listening tests in the first place.) The only thing we would have to do is make sure that when we mixed the signals together that they didn't ever clip. We'll have to look at the math (and the Dolby manual), but I'm guessing that probably you would want to attenuate the main signal by 9 dB and the LFE signal by 3 dB so that the sum would never overflow.

If we are clever, we could even actuate the feature by pressing a button sequence on the remote that lights up an indicator on the front panel. Then you would know what mode you were in.

I don't think we have room on the audio PCB to add relays to change the analog gain to compensate, but we *could* send AyreLink commands so that an AyreLink preamplifier would automatically adjust the volume when the mode of the player was changed.


If you get the DX-5, you can sell the QB-9 as we will have an audio USB input on the unit also. That will help pay for the KX-R!


That would be a nice system!

I think that by the time we put some bass and time delay management in the DAC, we might as well go all the way and make an SSP...

Of course the readers here know more about other products than I do!

The hybrid digital/analog scheme makes a lot of sense to me. If we ever made a digital disc player or a DAC with a built-in volume control, that is what we would do. In a way it is just an automatic version of Wadia's method of setting the maximum output level with internal jumpers and then attenuating digitally, but even better as you never need more than (say) 6 dB of digital attenuation.

The big caveat here is that it assumes that you only have digital sources. With a scheme like this, analog sources would need to be digitized. Most people that still have analog sources cringe at the thought of digitizing their analog source components! That makes the other all-digital attenuation schemes seem even more problematic.

I'm sure that the reason that the Goldmund lacks HDMI is that the license fees are $30,000 per year. Very few specialty manufacturers can sell in numbers large enough to justify the expense.

Hi Kal,

I think a defeat switch would be mandatory. The only cost effective way to do this would be in the digital domain. (Adding an extra DAC and analog stage just for the LFE, and then having a switchable way to mix that in with the main two channels would bump the cost up significantly.) That means that we are losing 10 dB (roughly) of information. With a 24-bit signal path (capable of 144 dB!) that is not so bad.

But still I would want to be able to have full resolution when listening to music and then only reduce the resolution (slightly) when mixing in the LFE channels.

This is all strictly prohibited according to the Dolby Manual, but then so is putting a master volume control on a source component! So either they have changed the rules or else they are looking the other way on the Oppo...

If I weren't in this wheelchair, I would trade you the Enzo for a nice system....

I just got off a conference call with the other engineers and I think we can figure out a way to add a remote control command to put in a mode to mix the LFE into the two main channels. No promises, but it looks do-able.

It is strictly forbidden by the Dolby spec. The problem was that when they first added the LFE soundtrack (as an analog magnetic strip on 70 mm film), it was easier and cheaper to boost the gain 10 dB. But that has come back to haunt them, as it causes all kinds of problems now.


This *is* something that is allowed in the Dolby spec. Basically there are two different stereo mixdowns that are possible. One has everything in phase and is good for stereo and/or headphone listening. The other puts the surrounds out of phase in one channel. The purpose of this is to make a signal that would be decoded by a subsequent ProLogic processor.

But the Oppo doesn't do that. I can't imagine the need for that in this day and age. If you are going to get a surround system, you may as well get a full-blown one instead of cobbling together a ProLogic version. Although the guy who invented ProLogic made an all-tube, pure analog decoder for a while, so I guess if you were a hard-core tube + analog guy you could hunt for one of those on the used market....

I guess you are right Charles. If it only needs to be boosted 5.5 (or 6db), then you would actually have to attenuate the mains approx 13.5/14db instead of 10DB. But I guess the best solution would be to attenuate the LFE channel by 13.5/14db instead. Then you would keep the resolution of the mains channels and still get proper LFE support and then you won't have to resort to any Ayrelink volume tricks that would be proprietary for Ayre preamps. Hopefully I am not wrong in this assertion.

I'm really happy with the QB-9, even though a DX-5 would be even nicer.
But my mind it settled on the KX-R, and then possibly wait for your reference DAC thingy.. For movies, the PS3 with a cheap S/Pdif DAC will have to do for now. Priorities..

I just like the idea of Ayre one upping the competition when it comes to a dedicated Blu-ray player. I can't even begin to describe the various systems I've had thoughout the years, and the piece of mind when I finally found the one brand that made the hifi-swapping-virus go away.
I guess this just a little OT, but speaking of one upping the competition: why not talk to Gordon and tell him to make the USB Audio 2.0 firmware in the forthcoming revision of the QB-9 (and DX-5) to not only support 24/192 but also 24/384 for true DXD support. (I read he has 32/192 working)

As for for Pro Logic II option. I don't literally mean that one should use that as a basis for "true" surround. But the rear speakers out of phase will give the 2 channel mixdown as played back in a 2 channel sound kind of "spacier". But it is not worth implementing if not already implemented in the OPPO.

I'm not sure that I'm following you. Dolby screwed up when they introduced the entire LFE concept. I guess they figured that if you were going to go to all the trouble of putting a dedicated subwoofer system into a real movie theater (at a cost of over $100,000 per screen), that it better be *damned* spectacular!

To get the bass to be stupidly loud, they had two choices -- either reduce the level of the main soundtrack and then turn the volume of everything up, or else boost the gain of the LFE channel. The first choice would have reduced the S/N ratio (of what was essentially analog magnetic tape back then). So they chose to boost the gain of the LFE channel instead.

As long as you are duplicating their system, this isn't a problem. But that means a third independent output, with its own DAC, current-to-voltage converter, analog reconstruction filter, a three-channel preamp (at least!), a separate power amp, and a separate subwoofer. That a lot of baggage just to rattle your windows during explosions....

So for someone sane who wants a simple system, or as you have pointed out, someone simply wanting to correct the mixing errors of the idiots who put all of the low frequencies into the LFE channel, the only solution is to mix the LFE channel into the two stereo mixdowns. As noted previously, Dolby expressly forbids this!

There are two ways we could do it in a player. One would be to do it in the analog domain. This would be almost as complex as the entire chain noted above and would increase the price of the player significantly. The only way to do it that makes sense is in the digital domain, as this will essentially cost almost nothing except for a couple of days of writing code.

The penalty is that the only way to match the levels is to reduce the level of the main channels by at least 6 dB and probably more like 9 dB. This causes two problems. The first problem is that the S/N ratio will be reduced. But with a 24-bit signal path, this is not an issue. We have already established that with listening tests at the factory during the development of the QB-9. That unit uses the "little brother" DAC chip with lower output current that reduces the S/N by 6 dB, but while the difference is measurable, it was completely inaudible during listening comparisons.

The other problem is that if you want to disable the LFE mixing system, then the output of the player will jump up by ~10 dB or so. This is not enough to blow speakers or anything, but it is enough to be un-nerving if you are not expecting it. So in an ideal world we would put some sort of automatic gain adjustment into the analog chain somewhere. I literally don't think we have even a few square inches of PCB space that this would require, plus it would delay the entire project for several weeks while we re-laid out the analog PCB.

I think that this feature won't be used by most people, so I don't want to spend a lot of time and/or money solving an obscure problem. I think what we will do is have a red LED on the front panel that indicates when it is in this mode. That will attract your attention and remind you to turn the volume down when going back to normal mode. We can also easily (well another couple of days of programming!) include commands that would automatically adjust the gain of an AyreLink equipped preamp or integrated amp so that you wouldn't have to remember. But even if you forgot, 10 dB isn't the end of the world. It might make you reach for the volume control quickly, but it's not going to blow your speakers or amps or anything. If we were talking 20 or 30 dB, that would be a different story.


Yep! Step-by-step...


Yep! At home I have a QB-9 USB D/A converter running into our AX-7e integrated amp, with everything (computer and monitor included) plugged into our L-5xe AC power filter. I have virtually no incentive to upgrade the system, even though I know I could. It is very satisfying, and I spend more time now just buying new music.


The big change will be replacing the current USB 1.1 receiver chip with a USB 2.0 receiver chip. At that point we can do just about anything via simple firmware upgrades. I don't think there is any point to spend time on 384 kHz decoding at the present, simply because there is zero content available at that resolution. But if it ever becomes a reality, it will only require some programming work on Gordon's part and a firmware upgrade.


It's not in the Oppo. Theoretically we could do it ourselves, as we could take all of the other 7.1 channels and make any mixdown we wanted to. The problem would be how to access the feature. We would need an extra button on the front panel, plus some sort of indicator light. Then the entire thing would have to be explained in the owner's manual. "If you want to hear a different mixdown of the original multi-channel soundtrack, blah, blah, blah..."

It really goes against our "simpler is better" approach. That's why we don't include an absolute polarity switch on our equipment. We want our customers to spend their time listening to music, not fiddling with their system. We can't be all things to all people. If I had my way, I would actually strip a *whole* bunch of "features" out of the Oppo. But we would have to buy 100x times as many players as we can possibly sell before Oppo could justify making a custom version of the firmware for us without certain menu selections....

Sorry Charles. I actually (kinda)know this stuff, bur tried to be clever and confused myself. Too many drinks yesterday, and the morning came too early..

The only way is to attenuate the mains. And you are just about right with -3/-9db.

The Prism/DAD stuff can record in DXD 24/352|384. That is what 2L recordings of Norway are using. If you go to 2l.no you can download DXD samples. Good to know that it is just a simple firmware update away, but I don't see any reason that DXD support should not be implemented right away. Maybe you could then use DXD files at the next CES to show what your gear REALLY is capable of. It would certainly be an industry first.

CH,

Did I read or misread that you replace the DACs in the OPPO?


Regards,
Mike

Hi Charles,

Thanks for participating in this thread. It has been very educational.

This statement of yours caught my eye:


It is a small thing but isn't the HDMI video connection balanced?

I still regularly use by DX-7e (SDI) for DVDs. I have it connected directly to my external DAC as well as a Meridian 568 (for which I use the same external DAC). I was impressed to find that for 2-channel or mono the sound is better going from the Ayre directly to the DAC, leaving the Meridian out of the chain, particularly in the higher frequecies. I don't use a center channel so the DX-7e ability to decode DD into 2-channel is ideal for me.

I hope you don't mind me going OT for a question on DD. With a 5.1 DD/DTS DVD does the Ayre just reproduce the front three channels with the center channel folded into the left and right or are the rears folded in also?

Many thanks.

Hello,
I'm new to this forum and have the Ayre CD5 player and MXR monoblocks as part of my system. I have ordered the new Ayre D5 BD player but am now concerned that there isn't a digital output other than HDMI as I have an older, but high quality processor that doesn't have HDMI, namely a Simaudio Moon Attraction. Also, the cabling running through my walls to my projector ( about to be replaced with a Sony VPL-VW85 ) is a high quality component type.
I realize that my processor is outdated ( doesn't have the latest surround sound matrices ) but there is nothing out there that has a combination of quality and features as a suitable replacement. Is the new Ayre BD player compatible ( I can run an HDMI instead of the component cabling if need be ) ?
Thanks,

Dolby only requires basic functionality. Special applications are fine. I only know that because I worked there for a while.

So you answered your own question, since the S/N would have been hurt (among other issues), the LFE channel was defined without changing the main channels. How is that a screwup? It's dealing with the reality of evolving theatrical sound standards in an ongoing industry with established practices and an installed base. Would it have been done differently with a clean sheet approach? Definitely. So would color TV, FM stereo radio...


The idiots only mix some of the bass into the LFE channel. A good deal of the soundtrack's bass is carried in the main L/C/R channels.

I was there 25 years and never saw Dolby forbid this. Maybe you didn't ask the right question, or make a compelling case? And if there are software players doing it, as others allege, how could that be so if Dolby forbids it? And how could LFE be mixed into L/R for Dolby Headphone?


The bass management built into AVR DSPs includes the ability to mix LFE into main L/R, and the products using that option handle the analog gain shifts in the programmable volume controls. These same DSPs also know how to downmix 5.1 into stereo without clipping or compression. So the heavy lifting is already available "off the shelf."

BTW, the LFE on/off jump would only be about 5 dB, not 10. When LFE is shared by two outputs, the level needs to be reduced to maintain the same effect. THX and Dolby empirically found that a 4.5 dB attenuation was about right in typical consumer rooms. So the LFE is normally mixed into L/R at +5.5 dB.

Almost everything is replaced. We use the transport, the main PCB with Blu-Ray/MPEG decoder/main processor and ABT scaler chip, the display VFD, and the remote handset.

There are many modifications to the main PCB, largely pertaining to improving the power supplies. Both the main PS board and the audio board are completely replaced, and we add two boards -- one is an audio-only USB input for use as a music server, the other and audio-only HDMI output.

Our audio PCB is much more complex than the original one and there is only room for two channels in place of the original ten (!). The DAC chip used is the DSD1792A from Burr-Brown. We only use current-output DAC chips, as we find that the current-to-voltage conversion stage has a huge impact on the sound quality, and this allows us to use discrete fully-balanced, zero-feedback circuitry after the conversion to analog.

So, in a word, "yes"...

You're welcome! I must say that I have enjoyed this thread quite a bit. I haven't been to the AVS forum for years (literally!). I used to come here back when Greg Rogers posted a lot, as I learned a tremendous amount about video from him. But when we introduced our DVD player, it seemed to draw nothing but wrath and ire. Ten years ago it seemed that most of the participants refused to believe their own eyes or ears...


Yes, kind of. (How's that for a definitive answer?)

There are 4 high-speed signal pairs (actually triads, with positive, negative, and ground) that carry the three color channels plus the pixel clock. That accounts for 12 of the 19 pins. There is a no-connect, and that leaves six more pins that carry single-ended grounds, power, hot-plug-detect, CEC, and DDC information.

With a true-fully balanced connection (such as is used for the analog signals in professional recording studios), the internal circuitry can be made relatively immune to problems with external hum and/or noise. The measure of this is called the Common-Mode Rejection Ratio (CMRR).

With HDMI, the complete connector is not fully balanced. Even if it were, the higher the frequency, the more difficult it is to achieve a high CMRR. It isn't too hard to get 80 dB or more at audio frequencies, meaning that unwanted signals are attenuated by a factor of 10,000x. But by the time you get to a few hundred MHz, the best CMRR I have seen for balanced circuitry is only on the order of 10 dB, which is a factor of ~3.3x.

The bottom line is that the best performance is achieved when the video and audio systems are completely isolated. This is an easy task if you use one of our video players as your only source. But as your system becomes more complex and adds more sources, you need to take extra steps to achieve the maximum performance that is possible.


The digital audio output on the DX-7e is as good as we could possibly make it. The master clock for the entire unit is the audio clock, and it is located right at the digital audio output where it re-clocks the outgoing S/PDIF signal for the cleanest waveform and lowest jitter possible. It doesn't surprise me that putting *anything* else in the signal path would degrade the sound quality.


Dolby specifies the mixdown coefficients that must be used. All 5 channels are mixed in according to the following formula:

L' = L + clev*C + slev*Ls
R' = R + clev*C + slev*Rs

where "clev" and "slev" stand for "center level" and "surround level" and are coefficients chosen by the mastering engineer and encoded in the Dolby Digital stream. I believe that the default values are 0.707 and that it is probably rare to find a disc where somebody bothered to change them.

The LFE channel is NOT mixed in. This is forbidden by the Dolby spec, largely due to the legacy they created when they first made "tacked-on" systems to retrofit into movie theaters and specified a different gain level.

There are a couple of questions you are asking. I'll try to answer them, but please let me know if I misunderstood your questions.

1) There are actually three ways to get audio out of the Ayre DX-5. The first is via HDMI, either the main output or the audio-only output. This will output all of the channels from any encoding method on any disc. The second is with an S/PDIF digital audio connection. This has a limited data transfer rate, so can only output traditional Dolby Digital, traditional DTS, and up to two channels of high-data rate PCM. It cannot play multi-channel PCM soundtracks, or the new lossless multi-channel formats from Dolby and DTS, nor mixdowns from those formats. The third way is with the stereo analog audio outputs. These contain a mixdown of all of the channels from any format, and as we are discussing on this board, possibly will also include the LFE channels mixed in as an option.

2) The only video outputs are the HDMI and the composite video. The composite video is retained *solely* for troubleshooting purposes, in case that there are compatibility problems between the player and display and the on-screen menus become unusable with the digital video connection.

We omitted the component video signals because these have two problems. First is that they are limited to a maximum of 1080i (and possibly even lower by the disc itself). Second is that they are of much lower quality than the HDMI signal.

The HDMI output is generated by the ABT2010 deinterlacer/scaler chip. This chip provides state-of-the-art performance that is unsurpassed. In contrast, the deinterlacing, scaling, and D/A conversion of the component video signals is performed by the main Blu-Ray/MPEG decoding chip. The performance level of this output simply isn't up to our standards.

If you have an older display without an HDMI input the best thing to do at the present time is purchase an HDFury 2, which will convert the HDMI signal to component video. The performance is very good and the price is very low.

If there is enough demand, we may make an over-the-top outboard video D/A converter. That by itself would be a fairly straightforward project, but I don't know that we would sell enough of them to be worthwhile. The other possibility is that we could make an outboard deinterlacer/scaler with multiple inputs and state-of-the-art analog outputs (perhaps as an option). That would be a bigger project, but would probably sell more units. We will wait for feedback from our dealers and customers after the DX-5 is released.

Uh-oh....

I think I am about to be caught with a large foot in my mouth...

Roger Dressler was one of the "founding fathers" of Dolby Digital and largely responsible for creating not only the format, but also making it into the world-wide standard that it has become for both theaters and home use.

I tend to say things I shouldn't. I never figured that somebody from Dolby would be reading this forum. I should have known better...