- Thread Starter
- #101
We are a team Don. Without you all showing interest, nothing would happen.
Agreed! And by "we", I mean "you" and measurements like these! Go Amir!
I would love to see AVR/AVP manufacturers step up their game and deliver much higher performance. OTOH comparing a full-blown AVR/AVP to a small stand-alone DAC or whatever is not fair IMO. Trying to provide all the functionality demanded by consumers in a relatively small form factor for a relatively low price means corners will be cut. And in some cases the cuts are things like shielding and reducing the number of circuit boards so noise coupling is much greater than a stand-alone dongle. I am surprised we don't see more DACs in AVRs enclosed in shielding boxes but that would drive up costs and potentially cause thermal management problems. Designing something like an AVR or AVP with all of its internal noise sources strikes me as a major technical challenge with no easy solution. That said I do wonder when I look inside some of these and see basic tenets of EMC compliance guidelines violated, whether lack of a shield between boards or around noisy components, or simply not orienting boards and components inside to maximize isolation.
I wonder what the market would be for a two-piece AVP with all the DSP (including video) in one box and all the mixed-signal (ADC/DAC/analog) circuits in a second box. You could design a custom digital link or use one of the standards, maybe even go to a wideband optical connection between boxes (I can get 100G Ethernet over an optical link -- not TOSLINK!) Probably nil or not enough since they aren't around now.
With no push from marketing and sales organization, what comes out of these AV gear is whatever an engineer thought was good enough. I am confident if sales/marketing pushed them, far better performance can be had. In desktop and 2-channel systems, there is some pressure from sales/marketing. There is none in AVR market. Hopefully we can change that and get better products.
The XMC and the RMC are not meant for the useries (or bas-x series). They are meant for the X series amps (XPA amps). The older gen XPA amps are indeed discontinued to my dissapointment. However they do still have current gen 3 XPA amps for purchase.Emotiva made great low cost amps (UPA series), but their processors have been major disappointing.
The high end Amps were discontinued more like they were orphaned.
The current amps, the lower end are RCA inputs, their XMC-2, RMC-1L and RMC-1 are all XLR outputs. So you now have to go out and get XLR to RCA cables, not a problem.
The UPA amps had a compatibility issue with the XMC triggers, but they looked after clients if the asked they were given a trigger box, which was a nice gesture.
I have lived the UMC-1, UMC-200 and XMC- issues and have found the honest lacking, though Emotiva keeps trying.
The company seems to try, but they are definitely their own worst enemy followed by those that believe Emotiva can do no wrong.
I am waiting to see how the RMC-1L and RMC-1 resolutions and manuals, Dirac etc all work out before I sink more money down.
Bottom line, because of all the signal manipulation going on in an AVP/AVR, it will never equal that of a simple DAC.
Lonnie
In my opinion, comparing any AVR/ AVP to a simple DAC is not a good comparison. AVR/AVPs cannot and will never perform at that level and I will tell you why. For a DAC the SPDIF signal comes in and goes straight to the DAC. After the DAC it goes through an I/V converter and out. Pretty straightforward, no post processing going on so nothing to degrade the performance. Now lets look at an AVP for comparison. Bitstream comes in and goes to the DSP. The DSP decodes and renders the various channels. The output of that then goes through a bass manager where crossovers are applied, the bass is summed and redirected. The dedicated LFE channel is also put into the mix where it gets summed as well. After that it all goes to EQs, Room correction, time delays and finally sent to the DACs. Don't be fooled into thinking that all this happening in the digital realm is any different from what would happen in the analog realm. DSP algorithms are just mathematical expressions of an analog circuit and since a DSP cannot operate above 0dbfs a lot has to be done to prevent it from clipping. You can't sum 16 channels of bass without lowering the level down quite a bit, which means you have to lower everything to match. Add in EQs, you can't boost a signal in a DSP, so what you are doing is actually cutting everything around the center frequency to allow the chosen frequency to appear boosted. Room correction works the same way as an EQ. I feel confident that most here are aware that when you lower a signal in the digital realm, you loose resolution. EQs and room correction add phase issues as does time delays. So all this summing, crossovers, EQs and delays mean a lot of signal manipulation before it ever ends up at the DACs. If you were to do everything being done in a DSP in the analog realm, you might be surprised at how bad your performance actually would be.
Bottom line, because of all the signal manipulation going on in an AVP/AVR, it will never equal that of a simple DAC.
Lonnie
In tests performed here a lot of that signal manipulation just isn't happening. In fact analog in->analog out is tested (no digital).
You'd think the basic digital to analog conversion and output would measure a bit better in a product proclaiming superior sound quality.
And what's going on with the -90db muting?
First, welcome to the forum. I don't know about your product but many AVRs/Processors have a pure-direct type of mode that is supposed to bypass the entire DSP pipeline. That is the mode I try to use and there, I expect and like to see pass through as stated by them.Bottom line, because of all the signal manipulation going on in an AVP/AVR, it will never equal that of a simple DAC.
**I should preface this by confirming you are with Emotiva, correct? If so welcome.**If you set the XMC-1, RMC-1, XMC-2 or RMC-1L to reference stereo mode, then it is truly analog in, analog out and the performance is quite impressive in my personal opinion.
Not sure what is going on with -90db muting. I would have to do some digging.
Lonnie
First, welcome to the forum. I don't know about your product but many AVRs/Processors have a pure-direct type of mode that is supposed to bypass the entire DSP pipeline. That is the mode I try to use and there, I expect and like to see pass through as stated by them.
**I should preface this by confirming you are with Emotiva, correct? If so welcome.**
Hi Lonnie,
Thanks for joining the forum. I sent this discontinued unit in to test because of my interest in the XMC2 and the XMC2 does not yet have any published measurements. Both Nick and Keith from the Emotiva forum have mentioned they will be posted in the Specs section soon.
1-Any idea on when these will be posted?
2-Possible to get an XMC2 to Amir for testing?
Also, see post above for the -90db muting issue I quoted from KeithL.
Thanks
Darin
Thank you for the Welcome and thank you for site, you have done a great job with it.
With all due respect, I'm sorry to say that I do not know of any processors whose Pure Direct mode actually bypasses the DSP. What Pure Direct does, at least for the various manufactures that I know, is simply this. The signal still has to go through the DSP to be decoded and rendered. Depending on the manufacturer, bass manager is sometimes dis-engaged and sometimes not. EQs are set to 0, and depending on the manufacturer, room EQ will or will not be dis-engaged. Time delays will still be retained through.
Pure Direct mode for most manufacturers (Including us) will retain bass management and time delays and turn off EQs, Room Correction and things like that.
Now there is one scenario where the DSP is completely bypassed and that is DSD. DSD gets sent directly to the DACs because of how it's structured.
Lonnie
@Lonnie Welcome to the forum.
If I've captured the gist of your first post correctly, it seems that you feel that subjecting AVRs to instrumented testing is unfair due to the unique way they operate. Setting aside the excellent point made by @amirm about pass through and pure direct modes of operation, may I offer the following?
If AVR manufacturers wish to be exempt from independent scrutiny on whether they meet hifi standards, perhaps they should stop advertising their units as high fidelity, SOTA, high performance, transparent, etc. Furthermore, they should post clear and complete specifications, using standards established by relevant authorities (such as AES, FTC) so that consumers can make informed decisions about where products lie in the grand scheme of things.
It is at times like this when I wonder if manufacturers and consumers speak the same language (i.e. English), as the words "pure" and "direct" seem to be far less ambiguous then they actually are when used in conjunction with each other.
Oh no, let me clarify here. I have no objection to AVR/ AVP being tested. In fact I welcome it. I will put my gear up against any AVR/AVP out there. I am simply saying that I do not believe a comparison of an AVR to a simple DAC is viable. Comparing AVRs and AVPs against each other has some real relevance in my opinion.
AFAIK a number of AVR/AVP units have some sort of "pure direct", "reference" or similar mode that is the equivalent of an all-analog signal chain. Of course it only works on analog inputs, and bypasses all DSP functions, bass management, and all that jazz. And different manufacturers use different terms, some overlapping, so it can be really confusing. One's "direct" is another's "pure direct" etc. And not all "direct" modes bypass everything. But, I have had several that do bypass all digital processing for a pure analog chain in to out (again, from analog inputs), and I think the XMC-1's "reference stereo" mode does as well. At least this is the description from the manual (note the bullet on stereo analog inputs):
Reference Stereo ModeReference Stereo Mode provides the purest listening experience, with the fewest options forprocessing or modifying the signal.In Reference Stereo Mode:• The output is always TWO CHANNEL STEREO.• There is NO bass management, and NOTHING is sent to the subwoofer.• You CANNOT use the Loudness Control, or the Tone Presets, or the Tone Trims.• You CANNOT use Dirac Live or the manual Parametric EQ Presets.• Level Trims, which operate in the analog domain, are still available.• Speaker Distance adjustments are active for digital inputs but not for analog inputs.• Stereo analog input signals are passed straight to the Volume Control and the outputs.• Stereo digital input signals are converted to analog then sent to the Volume Control.• Surround sound digital signals are decoded, mixed down to stereo (the Center Channel andLFE signals, if present, are mixed into the stereo output), and converted to analog.
This is fairly typical of what I have seen on previous units. I've never really played with it, don't really care, as one of the reasons I got the processor was for Dirac Live to correct some room issues and to provide bass management. I am very pro-crossover and pro-bass-managed speakers. I have yet to understand the aversion to room correction and need to switch off all processing for music. My room does not change going from movies to music, same issues are still there, and I like having my subs for the music that needs it without mucking up the mains.
I am already on record saying the comparing AVR/AVP uits to stand-alone DACs is not fair for numerous reasons, component density, features, and cost among them.
FWIWFM - Don