Re-Record vocals/guitars at 24bit?

[soul]

Guys,

Q: Will I benefit from recording 24 bit audio in PTHD, using 18 bit ADAT converters as my input?

I have to combine two sessions to assemble a song. One of the sessions (drums/bass) is 24 bit. The other session (vocals/guitar) is 16 bit.

It was suggested to re-record the vocal and guitar at 24 bit. i use an HD96 I/O interface with an ADAT as the analog input. The ADAT converters are only 18 bit.

Will I benefit from recording 24 bit PT files? Or should I just upconvert the 16 bit files?

[albee1952]

I would for the theoretical extra headroom, BUT(great big but) what is going on that you think you need to re-record? FWIW, I always work at 24 bit and 48K. why? because recording at 24 bit gives you more headroom in the DAW, and any audio that is destined for video may need to be 48K(so why not start there). In the early days of digital, conversion(between sample rates) was not so good, but these days it has gotten plenty good. Having said all this, a well-recorded 16 bit track will probably sound better than a poorly-recorded 24 bit track. If you lay out the typical chain(source>mic>cable>preamp>gain staging>converter), you can see there are several places for the quality to be affected...

[Bob Olhsson]

My experience has been that truncating from 18 to 16 increases "crunch."

[Rich Breen]

Yes, you should record at 24 bits - you'll at least get the most you can out of the (very questionable) ADAT converters, and you'll gain (theoretically) 12dB of noise improvement over 16. Plus, as Bob says, if you recorded at 16bit, you'd be truncating the ADAT outputs increasing distortion.

[soul]

Ideally everything would be 24. But Ive always stuck to 16 bit because my PTHD2 rig is limited on resources, and I use ADAT converters into 96 Digital I/O which are only 18 bit.

The tracks are well recorded... nice input chain SM7/Neve/1176

The question is... will I get the 24 bit benefits if I record through 18 bit ADAT converters?

If so, I think Im going to buy another Accel card and start doing everything 24 bit. But If it wont make a difference since the input is 18 bit, then I'll probably just upconvert the files.

thanks for your comments/suggestions.

[Darryl Ramm]

Your PT HD2 system's workload should not be significantly affected by stuff here. The DSP hardware is always operating at 24/48 bit for example.

But for input and audio file dynamic range reasons most people would not be working at 16 bits.

Is it worth rerecord stuff? That is up to you. Are you not happy with the current recordings? Try rerecordibg something at different bit depths and see if you can hear any difference playing back that one track.

[soul]

Think Im going the 24/48 route, thanks for the advice. The tracks I have now are good, but I can redo them no prob.

My Digi 96IO interface has 8 channels of 24 bit analog in. Now Im wondering why I never used it.??? Ive just been using the ADAT llghtpipe input for so long... I think its because its easy to monitor the adat analog outs to my board channels and send the lightpipe to PT.

Not sure how I will setup monitoring routing using just the 8 ins and outs on the 96IO.... Does it do any internal routing? I guess I can set that up in PT IL COnfig, right?

[Darryl Ramm]

Originally Posted by soulsystem

Not sure how I will setup monitoring routing using just the 8 ins and outs on the 96IO.... Does it do any internal routing? I guess I can set that up in PT IL COnfig, right?

No internal routing. It is just an interface. And routing is controlled by the mixers/sends/bussing in Pro Tools not the IO setup per se. You have HD TDM so low latency, so why not just monitor through Pro Tools (back through your console if needed if that is driving headphone outs etc.).

[soul]

Good point. I guess Im just used to having the additional monitoring in my console from the ADAT analog out. I usually listen to it along with the PT outs when I track. But I can change. I should have been recording 24 bit for years. Now's the time.