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Emotiva RMC-1 AV Processor Review

doodlebro

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Amazing. When you think no one is paying attention vs when slothful decisions are exposed and a company actually has to put nose to grindstone and earn their rep. Now if only Amir's review had enough influence to get Marantz to actually try instead of knocking out good enough feature laden models.

Give it a year. Eventually we can start charging manufacturers ;)
 

Francis Vaughan

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How is that bug even possible?

Doesn't Dolby require certification that their codecs function correctly before letting a company put double-Ds on a product?
They do. But as I noted earlier, their test suite is only available to licencees, and we have no idea what standards they require. Given the generally poor state of HT offerings one can only assume that the standards are depressingly low, and geared towards selling lots of licenses. If their test suite was available, things might change. But Dolby (and DTS) have a vested interest in making the standards only just “good enough”. Despite their marketing.
 
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amirm

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How is that bug even possible?

Doesn't Dolby require certification that their codecs function correctly before letting a company put double-Ds on a product?
No Dolby code is needed for my tests as I am feeding the unit uncompressed PCM. The Dolby Upmixer (for 2 channel to multi) was in the pipeline but told to not do anything since I was using Reference Stereo. Turns out the code was screwing with the bits even though it was configured to do otherwise. The fix was to bypass the module completely.
 
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amirm

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My guess is that the upmixer has a crappy sample rate converter. When you tell it to pass through, it still goes through the sample rate converters but doesn't produce more channels. And hence the artifacts that we saw.

Naturally this does not confidence to the Dolby upmixer code in general.
 

TimoJ

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My guess is that the upmixer has a crappy sample rate converter. When you tell it to pass through, it still goes through the sample rate converters but doesn't produce more channels. And hence the artifacts that we saw.
You should somehow also test AV-gear with surround processing/room correction enabled. I mean, most of the use is with those enabled and a perfect score in direct/pure mode doesn't tell what the actual performance is in regular everyday usage.
 
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amirm

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Dolby does not provide a sample rate converter for its upmixer, or for anything.
The internal algorithm could choose to do whatever it wants. It can separate the incoming stream into separate bands (at different sample rates), process and output.
 
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amirm

amirm

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You should somehow also test AV-gear with surround processing/room correction enabled. I mean, most of the use is with those enabled and a perfect score in direct/pure mode doesn't tell what the actual performance is in regular everyday usage.
I hear you but there is no easy pass through mode here to test. How would you get every EQ system to be active but produce a flat response so different equipment can be tested using the same correction?
 

TimoJ

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I hear you but there is no easy pass through mode here to test. How would you get every EQ system to be active but produce a flat response so different equipment can be tested using the same correction?
I don't know... Maybe just feed Dolby or DTS encoded multichannel test signal and measure how it looks, at least that would tell if it's OK. But that would still leave EQ/Room Correction out.
I have read many messages how some unit has much better multichannel audio performance/quality/dynamics etc. than another unit (while normal measurements may not show much difference) and it makes me wonder what is going on. Some of it probably is just imagination, but is there also something else..?
 

Francis Vaughan

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I hear you but there is no easy pass through mode here to test. How would you get every EQ system to be active but produce a flat response so different equipment can be tested using the same correction?
Flatness of the response is probably the least of the ills. Doing such a test would very likely uncover more nasties related to resampling in all its guises. It didn't exactly take long to turn up one such nasty. I will bet there are many more buried bodies to be found.
 

jhaider

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It's amazing what can be done with firmware/software updates. I lost my ability to be surprised after Tesla improved the braking performance of their cars with an OTA update.

Note that I cleaned up the above graph, taking out the 2.7 volt output of the HTP-1 as that was not a fair comparison against likes of RMC-1 which produce 4 volt output.

Didn't Monoprice also release an update after your tests to enable the volume control to be set such that it outputs 4V or something like that?
 

database

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Did you ever produce a SINAD vs Measured Level chart for the HTP-1? Apologies if I missed it. I'm just curious as to where its "peak performance" area is (since it seems to have tested better at 2.7Vrms than at 4Vrms).

I also wonder if it would look any different now that they've released a firmware update for the issue, although they still have a jitter issue to figure out.

Monoprice stated that peak performance is at 1.8V output. Their published numbers for SINAD:

4.0V: 97 dB
2.3V: 105 dB
1.8V: 106 dB

Third party verification would be nice to have, but Monoprice's numbers do match ASR's at 4.0V.
 
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kernelpanic

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Wow, kudos to both Amir and Emotiva! Despite some of the initial back and forth, it seems like this is a win for everyone. Two questions:

1. Did measurements for Direct mode change at all?
2. I wonder what the implications are for the Dolby upmixer in general. Do we think it has the same limitations across all AVR's and Pre/Pro's? I wonder if Dolby would be interested in also improving based on these results. It's making me second guess using Pro Logic on a lot of my stereo sources now....
 

SOWK

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@ amirm


Can you please tell me what the main volume control was when the output was at 3 volts?
 

digicidal

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How is that bug even possible?
Doesn't Dolby require certification that their codecs function correctly before letting a company put double-Ds on a product?
As far as I was able to determine from the mass of various posts on their forums it was a problem of the Dolby processing occurring even when it wasn't supposed to be present (like in the reference or direct mode) which was increasing noise. It wasn't all that clearly stated or maybe my brain had already gone soft from the previous 20 or so pages of posts I read, but that's what it seemed Lonnie (I think) was saying they'd found.

On a lighter note... your post made me think of this advertisement for some reason: :cool:
22971218192_f73c444216_b.jpg
 

anmpr1

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If I was an owner I'd be happy with the fix. But I'd have to ask about a company that releases a substandard (I won't call it defective, but some could) product at this high-end price point. Let's face it, 5K direct is not exactly chump change. But a product that can be corrected with a software fix. If I was an owner I'd want to know whether the company aware of these problems all along? Or was the fix done specific to this review? If so, who is in charge of QC over there? Or is it just the old 'we'll let the consumer be our beta-tester' mentality, and hope no one notices?

If the fix was done subsequent to the ASR review, every owner ought to send in an ASR contribution. Just to say, "thanks" for the effort.

Going to their 'info hub' and scrolling through the Steve Guttenberg reviews to find the fixes, we see how prior Firmware 1.7 was released six months ago. Didn't see a 1.8. I guess consumers are at the point with hardware now dependent upon software that we should expect updates on a regular cycle.

Oh well, at least these updates fix some things. And they are free. You don't have to lug your preamp to a dealer like your old ARC SP-3 for the numerous updates they used to come out with in order to extend the life of their product. So we've made progress. LOL
 
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