How bad is MOTU 828 mkII audio conversion? (Let's find out)
Old 27th December 2010
  #1
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How bad is MOTU 828 mkII audio conversion? (Let's find out)

The MOTU 828 mk II gets a bad rap for its converters, internal clock, and preamp. Since I have been considering using some analog gear for mixing, I had been wondering exactly how much a signal sent out of the 828's D-A converters and back in for another round of A-D might suffer. In order to qualify the suckiness of the MOTU, I put together a little midi sequence of drums and synths in my trial version of ableton live and sent the resulting wav file in and out of the interface for five passes of conversion at 44.1 khz and 88.2 khz sampling rates (24 bit). The results are posted below.


So what do the rest of you slutz think? Are there noticeable differences? What do you see if you compare the original wav file to the converted files on a spectrogram?
Attached Files
Original.mp3 (813.5 KB, 7768 views)
1 pass 44_1.mp3 (868.6 KB, 6258 views)
1 pass882.mp3 (868.6 KB, 6912 views)
2 passes 44_1.mp3 (868.6 KB, 5279 views)
2 passes 882.mp3 (868.6 KB, 6250 views)
3 passes 44_1.mp3 (868.6 KB, 5399 views)
3 passes882.mp3 (868.6 KB, 6323 views)
4 passes 44_1.mp3 (868.6 KB, 5496 views)
4 passes882.mp3 (868.6 KB, 6284 views)
5 passes 44_1.mp3 (868.6 KB, 5952 views)
5 passes882.mp3 (868.6 KB, 7421 views)
100 passes 882.mp3 (868.6 KB, 8242 views)
Old 27th December 2010
  #2
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My thoughts: maybe a little bit of transient definition is lost with repeated cycles of conversion through the 828. However, I definitely don't see too much to get hung up about. 100 cycles of D-A-D conversion gets you into a secret level
Old 27th December 2010
  #3
Fhl
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Nice test! Thanks for posting

It just reinforce my view on the insignificance of converters compared to everything else. I'm sure a lynx (or similar) converter is better than the mk2, but when the difference is so subtle, I'll spend my money elsewhere.

Fred
Old 27th December 2010
  #4
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cdog's Avatar
I did a blind A/B between the original and the 4 passes at 44.1

I think the difference is pretty audible, although its not huge. YMMV
Old 27th December 2010
  #5
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drBill's Avatar
 

Nice test. Goes to show that sometimes reality doesn't match expectation....


HOWEVER


You would no doubt hear a lot more loss of definition in first pass recorded real instruments that still had their transients intact and in place - ac guitar, percussion, real drums, etc. as opposed to loops and synths which are heavily processed already.


I'm not in my studio but at 44.1 on my computers monitors (JBL 25P's) I can hear a degradation at 4-5 loopthru's that I would not be happy with.
Old 27th December 2010
  #6
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828mkII: Mine does NOT suck!

Quote:
Originally Posted by prontold View Post
The MOTU 828 mk II gets a bad rap for its converters, internal clock, and preamp. Since I have been considering using some analog gear for mixing, I had been wondering exactly how much a signal sent out of the 828's D-A converters and back in for another round of A-D might suffer.......................
Thanks for posting this Prontold. I've owned the 828mkII for over six years and simply won't get rid of it due to it's amazing flexibility and price point. It doesn't suck as folks on GS would have you believe either. If one has generally good recording and mixing practices, the A/D stage is virtually unnoticeable. Especially if you have great talent, good instruments and decent arrangements. Listeners will be focused on the music...and not how many times you ran your final mix through the analog inputs on your 828.
Old 27th December 2010
  #7
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How bad is MOTU 828 mkII audio conversion? (Let's find out)

the 828mk2 is 'ok' and I wouldn't overthink about the quality of coverters... as long as you like what you hear.

that said, i sold my motu and got mr816... the difference was very audible. (more solid, transparent)
Old 27th December 2010
  #8
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I really appreciate this info because I am seriously looking at the motu mk3 hybrid (usb/firewire) or the Apogee Ensemble for example (which costs alot more)
Old 27th December 2010
  #9
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If we're doing a test here about the converters---may I ask why these are in MP3 formats as opposed to RAW .WAV files? The other issue, unfortunately, is that one might only hear the true results when listening to the direct converters themselves. And of course, the monitors play a key role. I say this because I've seen and been a part of these shoot-outs that just weren't done properly and it's a false representation of what's going on.

WITH THAT SAID, it is a good starting point :-) The MOTU converters are nice, they offer a very nice sound and good product that is a good value for the money. The new MK3 are improved converters over the MKII series and are clean, plenty of gain, and again a wealth of features and value.
Old 27th December 2010
  #10
Gear Maniac
 

Black Lion Audio does a great mod on these that really made a diference to me. I got a 24 i/o done and it really opened it up.




Just an option if you don't want to switch to another unit.....
Old 27th December 2010
  #11
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Thread Starter
Quote:
Originally Posted by drBill View Post
Nice test. Goes to show that sometimes reality doesn't match expectation....


HOWEVER


You would no doubt hear a lot more loss of definition in first pass recorded real instruments that still had their transients intact and in place - ac guitar, percussion, real drums, etc. as opposed to loops and synths which are heavily processed already.


I'm not in my studio but at 44.1 on my computers monitors (JBL 25P's) I can hear a degradation at 4-5 loopthru's that I would not be happy with.

I'm interested in doing a test on real instruments as well, but have the inherent problem of having the MOTU as my sole A->D. For anything I record, people could say that most of the definition was probably lost just getting the signal into my DAW. Would anybody be willing to provide a suitable wav file?
Old 27th December 2010
  #12
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Quote:
Originally Posted by Eric Pederson View Post
I really appreciate this info because I am seriously looking at the motu mk3 hybrid (usb/firewire) or the Apogee Ensemble for example (which costs alot more)

As Brad Lyons said, the mk3 is supposed to have better conversion than the mk2
Old 27th December 2010
  #13
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Quote:
Originally Posted by BradLyons View Post
If we're doing a test here about the converters---may I ask why these are in MP3 formats as opposed to RAW .WAV files? The other issue, unfortunately, is that one might only hear the true results when listening to the direct converters themselves. And of course, the monitors play a key role. I say this because I've seen and been a part of these shoot-outs that just weren't done properly and it's a false representation of what's going on.

The files are MP3 because when I tried to upload 11 16MB wav files, I got error messages... I guess I could have done them one at a time. If there's enough of a desire for the wav files I might upload them over the next couple of days.

What do you mean 'listening to the direct converters'? Having a feed from the 1/4' jacks on the MOTU's D-A outputs?
Old 27th December 2010
  #14
testing converters with 128kbit mp3?
Old 27th December 2010
  #15
3 + infractions, forum membership suspended.
 

Quote:
Originally Posted by prontold View Post
I'm interested in doing a test on real instruments as well, but have the inherent problem of having the MOTU as my sole A->D. For anything I record, people could say that most of the definition was probably lost just getting the signal into my DAW. Would anybody be willing to provide a suitable wav file?
can send over some stuff recorded on Prism 8-XR if you want?

Probably the best converters going.
Old 27th December 2010
  #16
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Thread Starter
Angry

Quote:
Originally Posted by Aerophone View Post
testing converters with 128kbit mp3?
Fine... Here are some wav files

http://dl.dropbox.com/u/8335661/Test%20Loops.wav (the original wav)

http://dl.dropbox.com/u/8335661/1%20pass882.wav

http://dl.dropbox.com/u/8335661/1%20pass%2044_1.wav

http://dl.dropbox.com/u/8335661/2%20passes%20882.wav

http://dl.dropbox.com/u/8335661/2%20passes%2044_1.wav

http://dl.dropbox.com/u/8335661/3%20passes%20882.wav

http://dl.dropbox.com/u/8335661/3%20passes%2044_1.wav

http://dl.dropbox.com/u/8335661/4%20passes%20882.wav

http://dl.dropbox.com/u/8335661/4%20passes%2044_1.wav

http://dl.dropbox.com/u/8335661/5%20passes%20882.wav

http://dl.dropbox.com/u/8335661/5%20passes%2044_1.wav

http://dl.dropbox.com/u/8335661/100%20passes%20882.wav (just for clarification, this one is a joke. It's been fed through a guitar stomp box envelope filter [subdecay prometheus ] separately for the left and right channels)


Quote:
Originally Posted by therealbigd View Post
can send over some stuff recorded on Prism 8-XR if you want?

Probably the best converters going.
sure, that would be great!
Old 27th December 2010
  #17
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gumby1220's Avatar
much better thank you
Old 27th December 2010
  #18
Two observations from me:

1) On the results... The degradation at 5 passes was about what I, as a 6 year 828mkII owner, would have expected. But then it wasn't like I had a super low opinion of the unit. I bought it (like others) on the features and price point (FW multichannels were still relatively few, particularly under $1000) and the generally decent rep of the company's products. I was coming from a stereo Echo Mia card and, frankly, my impression was not that I had stepped up in sound quality. Actually, I was afraid that I liked the Mia better. (The Mia was then stranded in an old-underpowered desktop when I moved to a then-relatively speedy laptop as primary in 2004 [laptop is still doing fine but it doesn't seem so speedy... that said, it's long overdue for a clean system reinstall]. I keep meaning to do a shootout. Maybe sometime before another 6 years is over... but the MOTU is pretty engrained in my rig. I even use the CueMix dsp mixer for other, non-critical signal routing like everyday audio, video sound and such.)

(Now, there is little question, as with so much else in the trendy, faddish world of record making, that familiarity breeds contempt. Sometimes that is just faddishness but, of course, there's another side: as production runs go on, profits are milked and, sometimes, corners are cut or fundamental flaws that were initially unnoticed and later, never fixed, can quite legitimately undercut a product's rep. But mere ubiquity can be a real factor, as well.)

2) On the test material... To really get a get a handle on high frequency handling, I tend to like to focus on the decay of material with delicate HF content -- room ambience, reverb of various types and sources, and cymbal decay. A good, well-recorded cymbal, in fact, is a great way of focusing on HF handling since with poor HF handling, you can still have what at first sounds like relatively similar HF levels but, on inspection, the lesser devices or processes often remove detail and character and one gets a glassy/glossy sound that may well be pleasing, but doesn't actually reflect the character of the initial sound. I'm with those above that feel like the initial sounds used for this test might have been more valuable had they had more of the subtle but important HF material (and that often comes from excellent recordings of real instruments). When I heard the original here, I was already 'disappointed' in the sense that I knew the choice of sounds would make it difficult for me to make the sort of evaluation one would like in a case like this.
Old 27th December 2010
  #19
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Quote:
Originally Posted by theblue1 View Post
2) On the test material... To really get a get a handle on high frequency handling, I tend to like to focus on the decay of material with delicate HF content -- room ambience, reverb of various types and sources, and cymbal decay. A good, well-recorded cymbal, in fact, is a great way of focusing on HF handling since with poor HF handling, you can still have what at first sounds like relatively similar HF levels but, on inspection, the lesser devices or processes often remove detail and character and one gets a glassy/glossy sound that may well be pleasing, but doesn't actually reflect the character of the initial sound. I'm with those above that feel like the initial sounds used for this test might have been more valuable had they had more of the subtle but important HF material (and that often comes from excellent recordings of real instruments). When I heard the original here, I was already 'disappointed' in the sense that I knew the choice of sounds would make it difficult for me to make the sort of evaluation one would like in a case like this.
It would be awesome if you or somebody else could provide a good wav file of that sort of material. I was not going to work with a recorded instrument because the original would already have to have passed through the MOTU's A->D
Old 27th December 2010
  #20
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Five words...


Last edited by Funny Cat; 27th December 2010 at 08:22 PM.. Reason: corrected start time in linked video
Old 27th December 2010
  #21
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Thread Starter
Actually, I think I'll just lift the Beck example from Norman Nomad's Behringer ADA 8000 vs Lynx thread

Let me know if this is good material or not
Attached Files
Beck - Original.wav (4.65 MB, 3581 views)
Old 27th December 2010
  #22
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Better than your original choice, but it would still be preferable to get a solo instrument / cymbal / etc. that's not mixed, has no compression, verb, delay etc. THATS where you will hear the most differences because you can hear the transients unobscured.
Old 27th December 2010
  #23
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Jose's Avatar
 

This test is flawed. Just kidding.

I had a Motu traveler and now I have a FF400.

Try recording some guitar/audio tracks with both interfaces and then tell me that there is not a difference.

I respect those that try to convince themselves that converters doesn't matter, but for me they matter as much as any other piece of gear in the chain.
Old 27th December 2010
  #24
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Quote:
Originally Posted by drBill View Post
Better than your original choice, but it would still be preferable to get a solo instrument / cymbal / etc. that's not mixed, has no compression, verb, delay etc. THATS where you will hear the most differences because you can hear the transients unobscured.
Any way you could hook me up with something? I'm not sure I have any music on me that really fits the bill
Old 28th December 2010
  #25
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Quote:
Originally Posted by prontold View Post
Any way you could hook me up with something? I'm not sure I have any music on me that really fits the bill
Sure. This will give you a wide variety of source material to choose from. THese clips are from Mic shootouts that I've done here on GS. I chose some variety for a variety of different listening tests. Feel free to download and use them. All clips were straight mics to pre to converters (DigiHD 192 @ 44.1k 24b) All I ask is that you point people to the shootout threads :

https://www.gearslutz.com/board/gear-...c-madness.html ; https://www.gearslutz.com/board/gear-...mparisons.html ; https://www.gearslutz.com/board/gear-...d-madness.html ; https://www.gearslutz.com/board/gear-...-up-km84s.html



First how about some unprocessed Ac Gtrs. Mic to pre to converter only. No EQ or other processing :

Steel Str
http://www.mindseyeprod.com/wp_mic_c...EL-MJNT1aR.wav

Nylon Str
http://www.mindseyeprod.com/wp_mic_c...KM84L-U87R.wav


Second, some drums :

Drum Overheads : 2nd half of clip is OH only - no direct mics - that's why it thins out. Maybe use the first half only.

http://www.mindseyeprod.com/wpdrumsh...SpacedCard.wav

Hi Hats
2nd half of clip adds OH mics for stereo - I'd dump the first half and use the second half for stereo imaging purposes.

http://www.mindseyeprod.com/wp_mic_c...HiHat-451E.wav


Vocals. First is a U87 FET and 2nd a pretty ssshhhy tube mic (modded U47). Listen especially to ssss's after multiple conversions....

http://www.mindseyeprod.com/wpmicmod...1-Acapella.wav

http://www.mindseyeprod.com/wpmicmod...3-Acapella.wav


Here's a piano clip for stereo image collapse. It's an mp3, sorry, but that's all I've got right now.....,
Old 28th December 2010
  #26
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Grrr...Piano clip wouldn't upload. I'm going to convert it (mp3 to WAV). Sorry for the mp3, but it was all I had. It's hi rez though, and should be telling on the stereo image collapse (if in fact there is a collapse, which I suspect there will be fairly early on.....)
Attached Files
bpPianoClip (snippet 1).wav (8.09 MB, 5052 views)
Old 28th December 2010
  #27
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Talking

Thanks Dr. Bill! I got a little impatient and started on an FLAC download of a song off Tone Poems by David Grisman and Tony Rice. Just mandolin, acoustic guitar and room ambience, I'm pretty sure. If I find the time, I might try some of your files in the next few days and post the results.

Here are the latest wav files

http://dl.dropbox.com/u/8335661/Mill...ey%20Waltz.wav

http://dl.dropbox.com/u/8335661/1%20pas%2088_2.wav

http://dl.dropbox.com/u/8335661/1%20pss%2044_1.wav

http://dl.dropbox.com/u/8335661/2%20pases%2088_2.wav

http://dl.dropbox.com/u/8335661/2%20pases%2044_1.wav

http://dl.dropbox.com/u/8335661/3%20pases%2088_2.wav

http://dl.dropbox.com/u/8335661/3%20pases%2044_1.wav

http://dl.dropbox.com/u/8335661/4%20pases%2088_2.wav

http://dl.dropbox.com/u/8335661/4%20pases%2044_1.wav

http://dl.dropbox.com/u/8335661/5%20pases%2088_2.wav

http://dl.dropbox.com/u/8335661/5%20pases%2044_1.wav

http://dl.dropbox.com/u/8335661/100%20pases%2088_2.wav

http://dl.dropbox.com/u/8335661/10%2...ses%2088_2.wav




and the MP3s are attached



I hired a local teenager to do passes out to 10,000. Needless to say, at that level of conversion and reconversion, the quality and propriety of the recording suffered dramatically.
Attached Files
Mill Valley Waltz.mp3 (657.1 KB, 3814 views)
1 pass 88_2.mp3 (657.1 KB, 3501 views)
1 pass 44_1.mp3 (657.1 KB, 3305 views)
2 passes 88_2.mp3 (657.1 KB, 3282 views)
2 passes 44_1.mp3 (657.1 KB, 3213 views)
3 passes 88_2.mp3 (657.1 KB, 3233 views)
3 passes 44_1.mp3 (657.1 KB, 3514 views)
4 passes 88_2.mp3 (657.1 KB, 3181 views)
4 passes 44_1.mp3 (657.1 KB, 3239 views)
5 passes 88_2.mp3 (657.1 KB, 3897 views)
5 passes 44_1.mp3 (657.1 KB, 3442 views)
100 passes 88_2.mp3 (657.1 KB, 4083 views)
10,000 passes 88_2.mp3 (563.7 KB, 3719 views)
Old 28th December 2010
  #28
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Thread Starter
Once again, I don't hear much if any difference... Maybe I would with a better monitoring setup. My take away from this, though, is that I really don't need to worry about converters at all until I've got my room, monitoring, mic, preamp, and musicianship situations squared away, and have a thousand dollars burning a hole in my pocket, which might be in about 40 years...
Old 28th December 2010
  #29
Gear nut
 

I don´t think you have to worry at all.
The converters works fine.

However I would make sure that the local teenager got some help after doing this test, it obviously must have been a nightmare to run the file 10000 times and listening to the changes over time...
Old 28th December 2010
  #30
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this is great, i love this stuff. i can't believe how strange 100 passes sounds...i was expecting degradation, but that envelop-filtering distortion is wild! anyone with some knowledge care to explain why that happens?
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