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Yamaha DSPZ9 i Link Bass Management

2340 Views 36 Replies 8 Participants Last post by  Tom Edge
Hi


I am about to buy one of the new Yamaha Z9s but have a concern over sacd / dvd audio bass management if the i Link input is used.


I am correct in thinking that in it's purest mode, the Z9 does not allow any bass management of the signal from the iLink input on DSD?


If this is (or isn't) the case, then what players with iLink will allow BM at source in the player ? Or do they all turn the DSD signal into PCM first ?


Many thanks


Tom.
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I beleive the Z9's bass management and any other DSP can be applied to the i-link. Room eq, size, x-over cut-offs, etc are all done digitally when the signal is fed in through the i-link.
If you want the "cleanest" signal via the i-link, then the Z9 should only be using one step in D/A conversion. The only way to bypass any digital processing would be the analog inputs, but you lose all the nifty customization.
I may be wrong, but I tought that if you pipe DSD down the iLink into the Z9, you have to select Pure Direct which means no bass Management etc.


I hope I am wrong though. Do you have maybe 2 options:


1. Keep it in DSD and no Bass Management etc.


2. Convert from DSD-PCM and get Bass Management.



Tom.
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I'd be very suprised if you couldn't apply BM and TA over i.Link it should be treated just like any other digital connection. The Pioneer receivers with i.Link can apply BM and TA over i.Link so I think the Z9 would.


Daniel Smith
If you look at Page 97 of the Z9 instruction manual, it describes how you assign iLink components. You then press "PURE DIRECT" to complete the process.


"PURE DIRECT" however "bypasses all of the unit's decoders and digital circuitry".


So, where is the BM applied ?


Tom.
 http://www.yamaha.co.jp/english/product/av/index.html


Click on the picture of the Z9 over on the right hand side. Next, click on the first category labeled "Highest Sound Qaulity". Scroll down the page a bit to see the diagram of signal flow and enlarge it. The i-link can either get "processed" or go directly to the DAC's.
Hi


Yes, you're correct, but doesn't this slightly contradict the manual unless I've misread it ?


Maybe someone with a Z9 could tell us ?


Tom.
The signal flowchart in the manual (page 125) shows DSD signals going straight to the DAC. If this is correct, it means there is no option to convert to PCM for bass management, time alignment, YPAO or DPL2x. I would hope it's incorrect but that's what the manual shows. The only possible ray of sunshine is if the signal block labeled "i.Link Interface" is capable of translating DSD to PCM. Maybe someone who owns one can settle this for us.
I may be alone on this one, but I've always thought i-link was implemented for the express purpose of Bass Management and simpicity in wiring. I find it hard to believe that with the advancement of i-link, that BM or other DSP processing can't take place. If we were discussing the analog inputs and there were disputing charts at play, then I see how the confusion and curiosity would exist.


Yes, I guess we'll just have to see what an owner of this unit has to say, or until one of us get to play with one first hand.
The problem isn't i.Link per say. It's DSD. DSD is very very hard to do bass management on without first converting it to PCM. It would negate any advantage you had with DSD in the first place. (That is if you had any.)


~D
Catapult,

I just looked at the users manual for the Z9 that you were referring to. After a quick glance, your questions should be answered. The block diagram in the users manual is much more extensive than the one I linked to, but in no way do they contradict each other. The one on page 125 should put all this confusion to rest. In that diagram, it shows an "i-link interface" that actually splits the signal into PCM and DSD. You may want to take another quick glance at the manual regarding this matter. I guess that after looking into the manual, I have no doubt that the Z9 can indeed do BM via its i-link.
I think catapult is right and the diagram does not have an answer. It will do BM for PCM signals but I can't find any indication anywhere to say if it can convert DSD to PCM


Cheers

Tom
There's an easy way to find out...


Tell the Z9 you have no subwoofer.


Run a DSD stream with a bass signal. Feel the cone, and see what happens.
Thack,

First off, I have to ask if you looked at the diagram Catapult brought forth. Did you see the splitter labled "i-link interface"? From this splitter, the signal is split between DSD and PCM. Am I imagining this?


Has everyone taken a glance at pg. 125 yet?


If I am shown the light, then I'll accept it. However, no stronger evidence has been offered and I think the block diagram speaks for itself.
Hi Cougar,


p125: There is a box that is called iLink interface and the outputs PCM & DSD as it will have to for DVD-A (PCM) & SACD (DSD). But nowhere does it mention it will convert a DSD signal into a PCM signal.


Cheers

Tom
I talked to some Yamaha engineer from Japan at CEDIA 2003. He answered that they use NPC DSD/PCM converter for DSD with some post-processing. I am very sure that Z9 can do either straight DSD or conversion to PCM and ANY post-processing.
Tom,

"But nowhere does it mention it will convert a DSD signal into a PCM signal."


I think you're missing my point here. In the diagram it shows two signals branching off the "i-link interface", one is DSD, and the other is PCM. Once that PCM signal path branches off the "i-link interface", why would it need to be re-converted back to DSD? Once it is converted to PCM thats it. That signal then goes in through the bowels of the unit to receive digital signal processing.


In your prior post you state that it does indeed convert to PCM.


"There is a box that is called iLink interface and the outputs PCM"


It doesn't matter whether or not its DD, DTS, DVD-A, or whatever. If the firewire signal is converted to PCM, then it only needs to occur once on this input to do its job.


If you follow the PCM signal after its been split (converted) from the "i-link interface", it passes the A/D converters and goes up into a block labled "SEL". From then it passes through the decoder section, the DSP section, and finally through the YPAO.


On the other hand, one could use the PCM signal in "direct" mode and only output 2 channels. Also, the DSD signal can be output in "direct" 5.1 with only 6 channels active.


I'm not quite sure where the confusion lies?
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Cougar,


I understand your point about the PCM post processing. It is nowhere mentioned however that a conversion will take place. Outputting PCM does not equal conversion. jheoaustin's post is the only clue that it may indeed do so but how would you know from reading the manual?


Cheers

Tom
"It is nowhere mentioned however that a conversion will take place. Outputting PCM does not equal conversion."


I still don't understand why there is a roadblock regarding this point in the thread. On one side of the (i-link interface) we see one single incoming firewire signal. On the other side we see the interface outputing PCM and DSD signals. Why would you not interpret that as a conversion step? Its taking a signal in, and splitting it up for the diff. signal paths. If that's not conversion, then what do you call it?
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