ADATs - what would you do?

TroutMask

just transferred 3 lots of 24 track ADATs into Nuendo for a remixing/remastering project. They came in at 48 kHz sampling rate (the ADAT blackface standard). My question is this: should I change the sample rate to 44.1 kHz now (like as in each individual track?) or wait till the end and change the final mix bounce to 44.1 kHz?

Thanks in advance

as an aside - i've got to say that the blackface tracks sound really good - Alesis were really ahead of their time when they created the ADAT machine

GTE

TroutMask wrote: »

just transferred 3 lots of 24 track ADATs into Nuendo for a remixing/remastering project. They came in at 48 kHz sampling rate (the ADAT blackface standard). My question is this: should I change the sample rate to 44.1 kHz now (like as in each individual track?) or wait till the end and change the final mix bounce to 44.1 kHz?

Thanks in advance

as an aside - i've got to say that the blackface tracks sound really good - Alesis were really ahead of their time when they created the ADAT machine

Wait till the end. Mixing in a higher resolution of sample rate will let your reverb fades and and things like that get processed in a nicer way compared to 44kHz. I would also have a higher bitrate. I always record at at least 48kHz and 24 bit and bring it down to 44 at the final mixdown. Check out articles about Dithering for more information.

44.1 is a video reference rather than audio. Back in the day of video tapes were used to record audio (computers lacked the storage needed) Sony developed something called a PCM adapter which transferred audio into a fake video signal. Long story short, the complicated maths meant that 44100 samples was the best to use in terms of being compatible with various picture standards of the day.

Quite a tangent there but main point is, 44.1kHz in my opinion is not really very audio orientated as we think. 44.1 wasnt designed with the Nyquist in mind as such. It wasnt decided that we need 40kHz sample rate plus a bit when 44.1 was decided as such. The extra 4100 samples were purely from the video tape storage side of things.

TroutMask

bbk wrote: »

Wait till the end. Mixing in a higher resolution of sample rate will let your reverb fades and and things like that get processed in a nicer way compared to 44kHz. I would also have a higher bitrate. I always record at at least 48kHz and 24 bit and bring it down to 44 at the final mixdown. Check out articles about Dithering for more information.

44.1 is a video reference rather than audio. Back in the day of video tapes were used to record audio (computers lacked the storage needed) Sony developed something called a PCM adapter which transferred audio into a fake video signal. Long story short, the complicated maths meant that 44100 samples was the best to use in terms of being compatible with various picture standards of the day.

Quite a tangent there but main point is, 44.1kHz in my opinion is not really very audio orientated as we think. 44.1 wasnt designed with the Nyquist in mind as such. It wasnt decided that we need 40kHz sample rate plus a bit when 44.1 was decided as such. The extra 4100 samples were purely from the video tape storage side of things.

Thanks - I'm mixing in Nuendo native so that's 32 bit internally. The ADAT takes are 16-bit so no getting around that. I always understood the extra headroom over 2x the Nyquist frequency to be a strategy to counteract non-linearities or leakage in the anti-aliasing filters. Not that it matters that much to me - i'd hold that things like jitter are much more a cause of audio problems than the sample rate.

studiorat

TroutMask wrote: »

I always understood the extra headroom over 2x the Nyquist frequency to be a strategy to counteract non-linearities or leakage in the anti-aliasing filters. Not that it matters that much to me - i'd hold that things like jitter are much more a cause of audio problems than the sample rate.

It was, it was designed to operate on video players of the day so Sony and Philips could use existing machinery for their products. 44.1kHz gives a mix of a relatively wide transition band above 20kHz as you said to counteract filter problems and fits as a multiple with which to fit 3 samples into every line of the raster scan on a PAL or NTSC video machine. It is an actual audio reference, designed to work with video transports and heads.

The video reference of 48kHz was designed to be able to use the drop frame standard used for colour TV in the states.

The blackfaces were good sound machines especially compared to the other digital standards of the day. And they did give us the ADAT ****epipe interface which has out lasted nearly all of the tape based digital media.

TroutMask

Cool - I must read up more on this video angle - it's very interesting. Re the Blackfaces - I'm astonished at how clean and clear the takes are - how well the ADCs preserved the upper harmonics on cymbals etc. The lightpipe is definitely useful too Funny thing about my ADAT machine is - it won't work properly if when turned on, but if it's left on overnight - it works perfectly all day! Since I only use it for transfers (and this happens rarely) - i've never really bothered having it serviced, I just turn it on the day before a transfer!

GTE

TroutMask wrote: »

Thanks - I'm mixing in Nuendo native so that's 32 bit internally.

A 32 bit program or are the project settings set to 32bit?

TroutMask

bbk wrote: »

A 32 bit program or are the project settings set to 32bit?

Both AFAIK

madtheory

Ya I've a bunch of stuff recorded to ADAT albeit via an 02R. All sounds great. Mainly because the room was good, we had nice mics, and I monitored on NS10s. Try saying that on Gearslutz. You'll get flamed.

TroutMask

madtheory wrote: »

Ya I've a bunch of stuff recorded to ADAT albeit via an 02R. All sounds great. Mainly because the room was good, we had nice mics, and I monitored on NS10s. Try saying that on Gearslutz. You'll get flamed.

Well. it's not that good - Pretty good for its time and amazing for the price. There were problems with the ADATs: channels saying they were recording when they were not; eating tapes; tapes disliking machines other than the ones that they were recorded on; BRC sync problems; interminable errors.......

I could go on all day

madtheory

Tell me about it! I was the maintenance guy too. NoFo was my trigger word! But we put up with it because the sound was better than smelly old analogue.

TroutMask

I was fonder of the analogue meself - I was spoiled though as we had a 2" 16 track machine - you could hit that thing very hard indeed! A most pleasing sound. Aligning it was fun - that was like my morning crossword - aligning the cranky 16 track

Used to do a bit of maintenance/tech also - still do, but only for myself and my friends.