HD Audio. Player vs AVP decoding.

viperirl

nereid wrote: »

We should probably start a new thread for this discussion, but I also respectfully disagree with your DAC/ADC conversions because the better place to do DAC is in a non noisy dedicated place (eg BD or SACD player) and then pass the analog stream to a dedicated multi in, which can then be passed through dedicated analog bypass circuits direct to the amplifiers _without_ applying processing to them, because the stream has been decoded as it was encoded. This is the primary way in which SACD is "supposed" to work.

What you are suggesting is correct though, that to apply post processing to a stream in this way does involve extra DA conversions, the question in my mind is if this is required and even necessary.

Maybe we should start a new thread on HDMI 1.1 vs HDMI 1.3 (Player decoding vs Processor decoding) which is essentially what we are heading towards but there are loads of them on other forums which provide some very interesting debates ...

Player decoding would be my prefered method also cos as u say its less 'noisy', no big power amps in the unit. But the question is whether the DAC's in todays players are as good as those in the AVPs. Theoretically there is no reason why they shouldnt be but I reckon BD players at the moment are comprimised in the DAC section.

You mentioned above to use the multi-in analog bypass in the AVP without applying processing, ie processor bypass. In this case you DO need the player to do the speaker setup, Room EQ etc and as I mentioned before I dont think BD players excel at this. I

The cleanest way in theory I suppose is to get the player to decode the HD audio and send the 7.1 analog signals to a dedicated HD processor(using multi in analog bypass) and from there onto dedicated power amps. (Kinda raises the question though: is there really a need for the HD processor apart from source switching and volume control? A simple mulit channel preamp would do here I suppose)

I know that HDMI is very jittery. Its jitter is quite often worse than that in SPDIF(optical/coax). Its a poor protocol for audio transmission and the reciever requires some smart clock recovery schemes to elimate jitter.

I reckon that a good BD player with a top end DAC section would blow away any system utilizing a player -> HDMI -> HD receiver. I'm only theorising at the moment as I havent heard such a comparison yet. Dont think we're there yet but Denon have released a new player recently. Havent read the specs yet though.

Slaphead07

viperirl wrote: »

I reckon that a good BD player with a top end DAC section would blow away any system utilizing a player -> HDMI -> HD receiver.

Now I know SFA about this level of AV stuff but I do know Hifi and certainly the above would be true in high end audio terms (which is essentially what we're talking about) and makes complete sense to me. Although I do use a HD amp (the Onkyo 606) I do find it odd that the amp is doing the processing when I have a supposedly perfectly good BluRay source there anyway.

Off yis go... knowing at least one other poster is following this!

The Ritz

This is more like it !


I've recently moved from an SD AV system to HD sources and an Onkyo 606. For a brief while I was routing audio from a Toshiba HD A1 HD DVD player to a fairly bog standard Sony AV reciever using audio interconnects. the tosh was doing the decoding and the Sony in Multichannel mode was just amplifying the result, although it's setup (speaker distances etc) were still operative (this kit was pre- built-in setup, I did it myself using a sound meter and sweeps and tones from an Avia disc). I was pretty happy with the improvent in clarity etc on material where I was able to do direct comparisons between the same material on HD DVD and DVDs which I was very used to hearing.

Moving over to the Onkyo, I have it setup to route all sources via HDMI, the only odd one out audio-wise is my pc which is passing spdif as usual, but video via HDMI. I have to say I haven't noticed a great difference in the audio side on the HD DVD, but then, I'm probably less discriminating that someone used to two channel audio systems, but I'll have a further play over the next few days and see.

I will say though that I was fairly pleasantly surprised by the Audessey setup on the 606 - I was skeptical initially and ran it a few times to see how uniform its results would be - it was near enough each time, and I was impressed at how "wide" the soundstage appeared after it had run. I thought it had the sub muted a bit and restored my "room EQ" to my own taste in the settings and corrected an imbalance in the rears - I reckon that the less than scientific placement of the mic probably didn't do me any favours ! My room is also quite narrow, so setting it up for three positions across the room is somewhat redundant.

Bluray is handled using a PS3, so the option of passing a Hd audio signal for the amp to decode does not arise.

Maybe with kit a bit further up the food-chain, the issue of which piece of kit to do the decoding might become more relevant, and I'm interested to read more..................


Ritz.

Idleater

The Ritz wrote: »

This is more like it !


I've recently moved from an SD AV system to HD sources and an Onkyo 606

Maybe with kit a bit further up the food-chain, the issue of which piece of kit to do the decoding might become more relevant, and I'm interested to read more..................

Seems like PS3 -> 606 is the favoured hardware combination in this neck of the woods.

I have gone down the Pre/Pro route myself as I wanted to create a direct bypass circuit for CD (and 2 channel DVD-A/SACD LPCM).

However, as I also wanted to get the benefit of HDAudio from BR, I have a processor that can decode the LPCM stream (HDMI 1.1). Again, I find it interesting that we are somewhat in agreement in stating that the Player is the better place to do this decoding. Fortunately like already said, the ps3 can only internally decode.

I have also read some interesting posts on AVForums where there are inconsistencies on how BD players (particularly low end ones) implement the 1.1 (player decoding) for the different HD tracks. Some were only decoding DTS HD (not MA) as Plain DTS which is why comparisons between player decoding and processor decoding showed a bias towards processor decoding (and also a bias towards dolby above dts). That and of course consumers paying for (eg) TRUEHD decoding, and therefore wanting the TRUEHD light to ignite on the amp display.

Player decoding (1.1) also allows the player to insert extra streams from BD extras (such as directors commentary) into the stream, where as processor decoding (1.3) cannot facilitate this unless the entire stream is separately encoded on the disk which takes up space from other bonus features.

viperirl wrote:

is there really a need for the HD processor apart from source switching and volume control?

Now you raise another interesting point. As my Rotel doesn't provide room equalisation I cannot comment on this and I have heard mixed reports on it's results.

Ritz's extra spatial sound is interesting, as I was reading in a book I got recently on audio, that adding processing (such as "Theatre" "Hall" etc) to audio channels requires upwards of 14million calculations (per channel) per second. Perhaps this is why some processors (like mine) opt for seperate simple delays per channel for room calibration as this does not affect the audio signal path.

There is of course the standalone DPL, DTS and DD processing chips for the SD audio tracks, but these route the signals on a separate path to the High Quality path.

The Ritz

Ritz's extra spatial sound is interesting, as I was reading in a book I got recently on audio, that adding processing (such as "Theatre" "Hall" etc) to audio channels requires upwards of 14million calculations (per channel) per second. Perhaps this is why some processors (like mine) opt for seperate simple delays per channel for room calibration as this does not affect the audio signal path.

Just to clarify, I wasn't referring to additional processing using the 606 in "DSP" mode, I was referring to using the Audessey equalisation to set the speaker levels, distances and cut-offs. The Audessey is supposed to be dynamic and change with the volume levels etc. so I reckon it is doing some additional processing, but I can't detect any diminuition of quality using it, quite the contrary.

My interest has been spiked by this thread and I'm going to do a bit more research and playing around with the HD DVD player and the 606 to see how I get on with the differences.

Things were a lot simpler with my previous setup - spdif, the blue light came on and it was all good !! But sure there's nothing like a bit of experimentation to get the brain cells moving......


Ritz.

viperirl

Some interesting and important points raised so far in the above posts. As far as I'm aware though, any Room EQ can only be done in the digital domain as a processor is needed for the huge number of calculations. Ritz, even though u mentioned before that u were getting your Tosh player to internally decode, u also mentioned that your receivers were setting things up for speaker distance etc. I'm pretty sure that your receiver was digitizing those 7.1 analog inputs to do this. All of this(Room EQ, speaker setup) is controlled on the fly by the digital processing.
I suspect that there will be a slight loss in quality in re-digitizing the signals again however the Room EQ would have given you a nice balance to the sound to suit your room so the 'loss' probably isnt noticable.
With a player doing the decoding and DA conversion, ideally you dont want anything more to potientally 'corrupt' or alter the signal any further. The DA conversion should the last step before going to the power amps.


I had 3 Onkyo receivers on loan last year to try out but I wasnt satisfied with the sound so didnt go ahead with the purchase. I found them overly harsh at times but great dynamics I have to admit. I have an old Myryad preamp processor which cost 4K Punts back in its day and even though it can only do DD and DTS, I thought it sounded better than any of the Onkyo's being fed HD audio. I honestly think that entry level receivers are too noisy environments to reap the full benefites of high-res HD audio.

Recently on a trip to the UK, I heard an Audiolab 8000AP which is a HD preamp processor. It can take LPCM over HDMI, so requiring the player to decode or unpack the DTS HD, TrueHD before tranmission over the HDMI link. The unit itself just passes on the video (without processing) to your display. Its a very clean environment for audio and it certainly sounded the business too when with good power amp separates in tow!

For the moment though, 2 channel audio is more important to me but I'll be keeping an eye on the upcoming BD players/HD processors for sure.

Idleater

viperirl wrote: »

Recently on a trip to the UK, I heard an Audiolab 8000AP which is a HD preamp processor.

I was almost going to go for the 8000AP/8000M combo but went with the rotel instead. I listened to them at the Bristol Show last feb and thought they were the best sounding multichannel equipment on show.

The Rotel offers the exact same functionality as the AP but I decided I needed the component inputs for video as well as HDMI.

I also went for the class D power amps as I am rack mounting the equipment in a cupboard so warmth is an issue.

The 8000 performs very well for two channel audio so I would certainly have little hesitation going for it, and of course it is a very neat set of boxes.

I agree with you on the Onkyo front, but I have heard the 806 powering some Dynaudio's which was not too bad, so I am guessing that it is down to a bit more fussy speaker selection (and auditioning in the home environment) to get the best out of them.

Feature wise, they are hard to beat though, which, let's face it is what most people want and look for primarily.

Speaking of DAC's though, since we are all running video through AVP's how do you folks find the delay setup for different sources?

My AVP routes all video through the scaler apart from HDMI which is video bypass so I seem to end up doing a lot of lip sync adjustment.
My NTL connection seems to need different adjustments depending on which channel I am watching.

Thanks to the HDMI video pass through, 720p games need different adjustment to 1080p BR which is a little annoying.

Seems to me that Audio is more easily adjusted than video, probably because display manufacturers don't give you easy enough access to internal processing.

viperirl

nereid wrote: »

Speaking of DAC's though, since we are all running video through AVP's how do you folks find the delay setup for different sources?

My AVP routes all video through the scaler apart from HDMI which is video bypass so I seem to end up doing a lot of lip sync adjustment.
My NTL connection seems to need different adjustments depending on which channel I am watching.

Thanks to the HDMI video pass through, 720p games need different adjustment to 1080p BR which is a little annoying.

Seems to me that Audio is more easily adjusted than video, probably because display manufacturers don't give you easy enough access to internal processing.

Is it absolutely necessary for you to route your SD video sources through your AVP? Why not go straight to your TV/projector and let it do the upscaling? (Maybe you dont have the required number of connections on your TV????) This might well eliminate some of your lip sync problems unless they are an NTL problem to begin with.

Strange that u also have lip sync problems with HD games and BR? I think HDMI1.3 has the provision to compensate for this?????

As I touched on earlier I had 3 Onkyo's, a Yamaha AVP and a Sony BDP500 BD player on loan at various stages last year but I wasnt happy with the sound or the connectivity/setup so I sent them back and will wait for the newer players/AVP's although the Audiolab 8000AP is tempting. My speakers and amps are 'high-end' so I dont think they are the weak link.

So for now I'm stuck with bog standard DD and DTS.

The Ritz

Well, I'm prepared to blush with this post guys.............

After making changes in the setup, rooting in the manual, repeated re-starts, head-scratching etc, i resorted to the web and realised that the AI won't pass bitstream for the Onkyo to decode. I had been passing bitstream to the Onkyo as before, and that's the way it will stay - I don't have any issues with it in any event. I also have a HD E1, but that's in the same boat as the A1, so there's no point in swapping them. The E1 is a deal faster and less "clunkier" than the A1, and is also multi-region for dvd and a tremendous upscaler, ery pleased with it.

Back to the topic in hand, I have a recently acquired Sony S350 and might give that a head-to-head on audio and video with the PS3 for comparison sake, but at this level I don't really expect "night and day" differences.



Ritz.

Idleater

The Ritz wrote: »

I have a recently acquired Sony S350 and might give that a head-to-head on audio and video with the PS3 for comparison sake, but at this level I don't really expect "night and day" differences.

That would be an interesting comparison.

I see from the 350 specs it does DTSMA bitstreaming (but not onboard decoding) so if you wanted to, you could report on the difference between the 350 bitstreaming DTSMA to your 606 for it to decode, and using the PS3 to decode the DTSMA internally and send the audio as LPCM to the 606.

This would show the difference between player vs avp decoding if it is audible to your ears using your equipment. And of course, this is personal opinion as to which sounds better because everybody prefers to hear sound differently so what you like, I might find dull, or bright, or too spatial or whatever.

viperirl wrote: »

Is it absolutely necessary for you to route your SD video sources through your AVP? Why not go straight to your TV/projector and let it do the upscaling?

Strange that u also have lip sync problems with HD games and BR? I think HDMI1.3 has the provision to compensate for this?????

My speakers and amps are 'high-end' so I dont think they are the weak link.

The lip sync issues in this case are due to the fact that the screen is 1080p native, and because the avp bypasses the internal scaler when using hdmi, it is sending games as 720p (which require scaling in the TV) and BD as 1080p requiring no scaling.

I have the screen set as "unscaled" so it should be just displaying as raw an image as possible, and I have not got many of the image processing features active, but it still is noticable sometimes. Not really an issue, but I do just have to add 10- 15 ms to the delay in the avp.

I could run each source (eg ntl) direct to the tv for video, but I have all the equipment on one side of the room and the display on the other linked by a nice long HDMI cable, so I like the convenience of not having to run 5m of HDMI, Component, SCART etc.

If I could set the AVP to just transcode the signals to HDMI rather than scaling and transcoding then that would be great, but such are the compromises one must make!


Also you mention your speakers, I just upgraded my fronts to a pair of B&W XT2's from a budget set that I got 7-8 years ago recently and I have to admit I am quite overjoyed with how good "good" speakers make the music sound. I also agree though that the expense of upgrading everything together could be quite costly.

My only recommendation is, if you can afford it, is to go down the pre/pro route rather than AVReciever, as with the changing sound/video formats upgrading in future is easier. What amps do you have at present?

Wolff

Hi Ritz

Woould be interested to see how you get on with the 350 vs the Ps3

Want to get a PS3 for other reasons and get rid of the 350

Does the PS3 send the DTS-HD MA to the amp over HDMI and let the AMP decode ?

viperirl

nereid wrote: »

Also you mention your speakers, I just upgraded my fronts to a pair of B&W XT2's from a budget set that I got 7-8 years ago recently and I have to admit I am quite overjoyed with how good "good" speakers make the music sound. I also agree though that the expense of upgrading everything together could be quite costly.

My only recommendation is, if you can afford it, is to go down the pre/pro route rather than AVReciever, as with the changing sound/video formats upgrading in future is easier. What amps do you have at present?

At the moment I have a Krell amp driving a pair of Usher Audio CP8571 speakers. (Those are marginally better in my opinion than B&W803D's). At the rears I have B&W804 and Monitor Audio4i driven by Myryad power amps. Also have Myryad MDP500 G6 pre/pro for the surround sound processing.

On the issue of player vs AVP decoding, I'm sure u realise that there is technically no reason why one method should be superior to the other. The unpacking of the lossless formats are simply done in either the player or amp. What we are seeing in todays implementations is that sometimes this process is handled by the amp better or in other cases, the player. Its simply a case of deciding which method is yielding the better results for your own equipment.

I think though that better results(at least in theory) can come from using the players 7.1 analog outputs(if good DACs are used) going straight to a preamp or power amps. In other words not using the HDMI link for audio, just for video obviously. Audio quailty can be very sensitive to jitter and I know jitter is particulary bad in HDMI. Denon in their latest HD player/AVP stack have the option to use their own proprietery digital link called DenonLink4. This digital link has measured jitter levels far less than that of HDMI.
Regardless though, great audio results can still be achieved over HDMI, IF the AVP deals with the jitter issue properly. But these units, in particular AV receivers, are noisy environments with all those power amps and DSP's, and so require more effort on the designers part to keep the audio clean.

Ritz, let us know how u get on with the Sony S350 and Onkyo testing.

viperirl

Wolff wrote: »

Hi Ritz

Does the PS3 send the DTS-HD MA to the amp over HDMI and let the AMP decode ?

As far as I'm aware the PS3 can only internally decode or unpack the DTS-HD MA to LPCM and then this is sent over the HDMI link. So by using the PS3, you wont be getting the DTS-HD MA light on your amp. You're still getting the DTS-HD MA soundtrack though.
DTS-HD MA or Dolby True HD are just different lossless compression techniques used on the original uncompressed LPCM track.

Idleater

viperirl wrote: »

At the moment I have a Krell amp driving a pair of Usher Audio CP8571 speakers.

Holy moly! Saw/listened to the pair of those in Cloney Audio when I was picking up my equipment and was amazed at them. Not a hope of (being allowed to even consider) getting them for my house! Love the 800 series too though, just again not enough space to justify them. Very happy with the XT2's anyway.

I can also see why you are having doubts about the 8000AP/M combo. not sure if the 7x100w will power them enough. or are they monoblocked themselves?

You might be best just getting a decent BD player that can handle all the audio decoding and feeding the myryad using the analog connections.

Unless you want the BD player with the games console attached, in which case you would need something like the AP to decode the LPCM.

I do realise that my test above should achieve a 0 result exactly because of what you are saying of course. And this is why I suggested the separate thread for Hdmi1.1 vs 1.3. The net gain for 1.3 in my eyes is like you say to have the DTS-MA light show "on" on the AVR.

Have to admit though, that I watched Kill Bill last night which is encoded in raw PCM audio (4.6mbit/s average [wall-e dts-ma 4mbit/s average]) and was blown away by the detail. The soundtrack does lend itself to great listening though.

viperirl

nereid wrote: »

I can also see why you are having doubts about the 8000AP/M combo. not sure if the 7x100w will power them enough. or are they monoblocked themselves?

You might be best just getting a decent BD player that can handle all the audio decoding and feeding the myryad using the analog connections.

I wouldnt even attempt to drive such speakers with a multichannel amp. They need and deserve something more 'pure' and transparent. The Krell I have is a 2 channel amp which also has a HT bypass mode allowing the Myryad pre/pro to control it for movie sound. So the Krell is always driving the main front speakers in both movie surround sound or 2 channel playback from CD's. At some stage this year I might try some high end valve amps and see what they are like.


As you said above, yes I think I'd prefer to wait for a very good BD player that does everything on board and just feed it to my existing pre/pro. However this is only worth it if the on board DAC's are good enough. If not, the Audiolab AP pre/pro is a nice solution for audio freaks! :-D


Having said all of this, movie soundtracks are generally all about slam, bam and big impact sound. It usually doesnt have the sutilties or nuances of say very well recorded music on CD's or vinyl so perhaps striving for a clean audio environment for HD movie soundtracks is not advantageous as say for 2 channel music.

Wolff

thanks for that - I thought as much viperirl


I have the 350 and a Marantz Sr7002 so Im getting the DTS HD MA display

I also have a toshiba E30 as well and it seems to do the decoding and sends True HD to the amp which just displays Multi Channel

Id like the ps3 for mkv file conversions to blu ray - its supposed to be more forgiving than the 350 - these only have dts so no problem there

But id be interested to hear what Ritz has to say comparing the two

The Ritz

Ok spent a couple of hours this afternoon (day off today) swapping between the PS3 sending PCM and the S350 sending bitstream. I was using the Fifth Element on Bluray as comparison material - it has a wide range of "sound scenes" and I'm pretty familiar with the movie so wasn't going to get absorbed in it.

My system has the Onkyo 606, Mordaunt Short 402 and 404 (Genie) for the front, four Eltax bipolars for the side and back surrounds and a homemade sub. The system is crossed over to the Sub at 80hz, uses the Audessey dynamic EQ in the 606. This is clearly simpler and further down the food chain from some of the kit mentioned by viperirl and neried.

Result ? No greatly discernable difference, I was swapping over the disc between the players so there was obviously some interruption between comparisons, but I would find it difficult to put my finger on anything that I could identify as a defining difference.

As a further experiment, I ran the S350 in PCM and in Bitstream mode for comaparisons purposes. Again I didn't find anything I could put my finger on, even with repeated listening to the same selections.

Now I'd be the first to volunteer that I don't have "magic ears", I'm not a devotee of two-channel hifi which probably makes people more critical of the shortcomings, real or perceived, in their systems. I've always been more concerned with achieving better image quality and have been happy to let the sound system do it's thing. I have been careful enough to set it up properly though as a well balanced sound system (with a well integrated sub) is integral to the home cinema experience imo.

So there are a couple of possible conclusions from my point of view. The level of these pieces of kit in the hierarchy of things could well mean that they aren't sufficiently revealing to show up the potential differences. An alternate conclusion could be that I'm not sufficiently discerning to tell in any event.

However, I will say that the HD audio tracks definitely expose more detail and have a wider dynamic range than the regular DD track on DVD - I did run a copy of the same disc on dvd just for fun and there was no mistaking the difference from my point of view.

This was just an interesting experiment and I wouldn't be too keen to place any great emphasis on it. Given that this kit is fairly popular, it would be interesting to hear other observations from people doing a similar comparison, even with the S350 and 606 alone.


Ritz.

Idleater

The Ritz wrote: »

Result ? No greatly discernable difference

Good stuff, and an afternoon well spent!

The other thing to note from your results, is exactly as Viperirl has pointed out, that in fact there is no difference between the audio stream under the two conditions, so you not determining a difference is actually a positive result.

Some inferences that one could make from your testing, is that quite rightly, at the equipment level you are talking about, there is actually no difference between players, decoders amps and speakers - they are, in their own right, matched to each other and there is no discernible weak point in the system.

Secondly, this highlights the marketing spin that is put into motion by equipment manufacturers and cable manufacturers, and to a certain extent "hollywood", because 'their' main aim is to get people to buy more and more equipment, licence newer technologies and generally buy into redundancy.

This is clearly evident from the test that you have demonstrated (essentially the HDMI 1.1 vs 1.3) debate. It is in the interest of manufacturers to claim that since 1.3 is bigger than 1.1, you are getting more features (eg DTSMA light) and your old HDMI 1.1 cable needs to be upgraded to a 1.3 cable.

When quite clearly the fact remains that player decoding results in as good an audio stream (identical by definition) so spending an extra €200 for the newer amp, €50 for a new cable and of course a HDMI1.3 capable BD player because the ps3 is only 1.1 is not necessary.

Of course, if the same test were to be carried out on Viperirl's equipment, we might get differing opinions, but it would not be in the audio content from the disk, but in the decoding of the stream by either endpoint of the chain.

Idleater

viperirl wrote: »

Strange that u also have lip sync problems with HD games and BR? I think HDMI1.3 has the provision to compensate for this?????

Just to follow up on this, I have been doing some (albeit brief) research into this, after I spent the afternoon yesterday adjusting my input delays for Kill Bill.

HDMI 1.3 does indeed provide for communication between the components to adjust for lipsync.

The only problem is that the PS3 is 1.3 for deep colour only and the rest is 1.1/1.2 so I can't test for this.

I guess this is where a proper DBP with 1.3 and the input correction that you were mentioning comes into effect.

And this of course raises the question, where in the chain do you allow this processing to occur - the player which has negotiated with the screen whatever timings need to be discussed, or the AVP which is designed to do such things.

The Ritz

Ìn terms of being "hyped" into getting new gear, I wouldn't disagree generally. However, I'm really pleased with the 606 for a number of reasons. I had 5.1 analogue inputs on its predecessor and was happy enough with the sound, but there is a definite step up in the sound from the 606 and the ability to switch 4 HDMI sources and take PCM or Bitstream simplifies things brilliantly. I have a PS3, HD DVD player, DVD player and HCPC connected by HDMI so switching through to the projector is seamless and a lot easier than having to have a HDMI switch in the equation.

I've already referred to the Audessey equalisation so all in all I feel that it's been a very worthwhile upgrade.

It also impresses me that a very effective AV sound system can be built comparatively cheaply - I knw everyone operates to different standards and budgets but you can get a fairly big "bang for your buck" with well chosen entry level equipment these days.



Ritz.

viperirl

Nice review Ritz. As pointed out before, there should be no difference between decoding in the player or decoding in the reciever as the mathematical process of the decoding is identical in both cases. Only the differing physical implementations in the equipment can possibly impact on this. The fact that Ritz found no real tangible difference in both methods points to him having a good all round balanced system.

There is also another issue in why audible differences can exist in HD soundtracks, even on the same disc. Some discs give u the ability to select between a PCM track or say for example, TrueHD. Now we know that both of these should be the same. One is the raw uncompressed data, while the other is simply a losslessly compressed version. However, on the copy of 'Ghost Rider' with both TrueHD and PCM on the same disc, the TrueHD track is encoded at 20-bit resolution, while the PCM track is encoded at 16-bits. Even though it's the same movie soundtrack, and technically both audio formats are "bit-for-bit identical" to their respective sources, in this case the 'bright minds' in the studio chose to use a lower bit rate for the PCM track, which may affect the final audible outcome in TrueHD's favor.

You can imagine a senario where the above situation is reversed, i.e the studio mixed the PCM track @ 20-bit and the TrueHD @ 16-bit.
In evaluating your new equipment, at first you choose the PCM track, listen to the results and then later choose the TrueHD track. You could end up coming to a false conclusion that your player is not very good at decoding the TrueHD when in actual fact it was the studios actions with the track mixing that is the real reason behind any audible differences.

Bottom line here is that PCM, TrueHD or DTS-HD MA are just 'containers' for audio. They dont guarantee quality. That ultimately depends on the studio.

slavetothegrind

I am sorry to butt in to a very interesting thread but am curious about the ritz' homemade sub.
Was it a kit or a self design and build?

Have been reading on the subject of speaker building and am about to take the plunge!

Maybe move this to it's own thread as it is a bit off track here.Thanks.

Slaphead07

joeclif wrote: »

I am sorry to butt in to a very interesting thread but am curious about the ritz' homemade sub.
Was it a kit or a self design and build?

Have been reading on the subject of speaker building and am about to take the plunge!

Maybe move this to it's own thread as it is a bit off track here.Thanks.

Speaker building is quite complex and really, given you can pick up really good second hand subs these days for very little money, it's not a route to go down looking for bargains. It's a great hobby though but from experience (mainly other peoples!) you'll build 4 before you get one you're really happy with.

ie, here's a REL for €150.http://www.cloneyaudio.com/pre-owned.shtml You couldn't build a sub of that quality for any less.

slavetothegrind

Appreciate that Slaphead, 'tis the challenge i relish!
Not so worried about the cost or value for money.
I have been reading extensively and am aware of the physics and maths involved in design.
I want to build a pair of floorstanding speakers, large, with an active crossover.

My query was just out of interest, did he stop at the sub?

If i go into Cloney i get a lemming like urge to spend lots of money. I get a rush that Junkies would understand!!!!:)

The Ritz

Joeclif,

I built the sub well over 4 years ago !

The sub build was based broadly on the REL Q100e, the supplier of the parts (BKELEC) were the original source of the compnents for REL.

There were a few of us on avforums who built "clone" subs at the time, you can read a detailed thread here: http://www.avforums.com/forums/home-cinema-diy/111293-project-relax-12-subwoofer.html, a detailed set of pictures of the build of Matt's sub can be found here: http://matthew.augier.info/?level=album&id=11

You can read some of the background to my own build here: http://www.avforums.com/forums/home-cinema-diy/138338-diy-sub-advice-needed-please.html

and more here on a subsequent driver upgrade: http://www.avforums.com/forums/home-cinema-diy/143101-mother-driver.html

For resources I'd recomend the diyaudio forums, also parts are available from Bkelec - http://www.bkelec.com/ or IPL: http://www.iplacoustics.co.uk/ - the latter do pretty good sub kits.


If you're lucky enough to find a decent sub secondhand you can save your self a lot of messing around, often for less money, but i was interested in this and more than capable diy-wise and it was great fun.

I would say though that the key to success with a sub is integration with the rest of the speakers and room equalisation if necessary - it's not all about raw power, although that's no harm for action movies !


Ritz.

Wolff

I tested the following on my sony 350 and Marantz 7002

I used Master and Commander with has the full DTS HD master soundtrack and switch between the direct output option on the 350 and the mix option which I presume (maybe incorrectly) switches between the decoding on the 350 and not

My amp shows up DTS HD Ma on the direct option and multi channel on the Mix option

There seems to be a definite improvement in sound when the amp decodes rather than the 350

has anyone else found something like this ?