A DIY solution for latency problems

[Glory_Morris]

I had to move some vocal sessions out of the studio recently and track them mobile. My laptop isn't much up to the task, and all I could borrow was an M-Audio Fast Track Pro. The round trip latency made it impossible to monitor through Pro Tools in Input Monitoring Mode, so I built a box that automatically switches channels and let's me monitor without latency. Anyway, you can read about it here:

http://glorytron.com/2012/12/a-bit-abou ... e-monitor/

[Jim Williams]

An old trick is to monitor the "real time" stuff though a digital delay. Line that up and everything is back in "time", only a little "late-ncy".

Or, use analog stuff like I do. There the latency is about 60% of the speed of light, not a problem.

[Glory_Morris]

I'm typically either working with Pro Tools HD, tape or HD24xr. Latency has never really been a problem for me until I went mobile for overdubs.

This solution worked out really well for me though. The switching is handled by FET mutes and a microcontroller fed HUI commands from Pro Tools. I needed a headphone amp anyway, so I built it all in the same box. Totally a purpose-built, one-off design.

[Jim Williams]

I also use the HD24XR for location recording and dubbing, never a latency problem with that rig. I have even sent PA feeds out after conversion, not even a singing drummer can tell. I found if I stay away from computers I never have those sorts of problems nor that "computer sound" to deal with. Music is more fun and sounds a lot better without a PC around.

Besides, it only takes one time for a laptop to ruin your day. That happend to me once, never again. The HD24 has worked flawlessly for over 10 years now.

[vvv]

Music is more fun and sounds a lot better without a PC around.

I can't afford to subscribe to this, but it would make a great signature!

[Brett Siler]

Pretty cool man! It's crazy that little m-audio interface still has 250ms of latency even in Pro Tools monitor mode. Even my old Digi 001 in monitor mode worked well!

[Snarl 12/8]

Besides, it only takes one time for a laptop to ruin your day. That happend to me once, never again. The HD24 has worked flawlessly for over 10 years now.

I hate to tell you Jim, but the HD24 is a computer. Yeah, it's a purpose built, more-reliable-for-audio computer, but still a computer. I think what you like about it is that it gives you more of the benefits of both worlds than an analog recorder or a pc. (I've got an MX2424, so I agree with you there, if I'm putting the right words in your mouth.)

[Glory_Morris]

I hate to tell you Jim, but the HD24 is a computer.

It's an embedded system, so you're right to point out "purpose built"-- not exactly a Personal Computer. I thoroughly enjoy editing in Pro Tools, and I don't mind recording when I'm in a proper HD facility (2ms latency), but by and large there are far fewer problems when using a purpose built machine like the HD24. Just a preference.

I prefer to not make a career out of clicking in menus and tweaking OS settings.

[Glory_Morris]

Pretty cool man!

Thanks! Took about ten days to design, build and test. But it was just about the only tenable solution, short of buying a bunch of new things (including a new laptop). I couldn't get the latency low enough while maintaining a stable working environment with any amount of tweaking.

We've been tracking for about 5 days and things are going pretty smoothly. I can keep my playback engine where it's happiest, and the tracking experience has been seamless for the artist. As far as they can tell, everything is just right. And that's basically what I was looking for-- getting the technology out of the way so the artist doesn't get frustrated.

[Jim Williams]

The HD24 is ASIC based design, there is no dedicated "processor" chip insides like even a low end Lexicon reverb, which is designed around an Z84 microprocessor chip.

Technically, anything that makes a decision in the digital domain can be called a computer. I just never heard of anyone refer to a LXP-1 Lexicon reverb as a computer before.

If one keeps score, the potential failures attached to a PC based recording system are no match for the 100% success of the HD24 format around here.

That decision was based on the Scotty rule:
"Fool me once, shame on you, fool me twice, shame on me".
Or, as Roger Daltry said, "I won't get fooled again".

If you select live recording gear based on the fact that your career or life depend on it, you will not gamble on PC based systems.

[Glory_Morris]

If you select live recording gear based on the fact that your career or life depend on it, you will not gamble on PC based systems.

I mostly agree here, but I'll reiterate that Pro Tools HD systems are quite stable (at least in OSX) and we have almost no problems. Pro Tools HD is a seamless experience for me, and I can't even begin to put other DAW/Hardware combos in the same class.

[Jim Williams]

"Almost no problems" is what I call "close, but no cigar". From what others have told me, Pro Tools is a necessary evil. I've not heard anyone say that uses it that they love the sound of it.

Several times visiting Pro Tools sessions I've had to "step out" as those DAW generated sounds rip my ears a new one, but I never really tell them why "I have to go". Some folks get conditioned to those sounds, I can't.

I prefer more organic sounds. I'm more concerned with listenability than the process to get there. That usually means avoiding convieniences and taking a harder route than clicking the ol' mouse. The PC is never turned on here while recording, that's an oil and water mix to me. Music and computers require you to use different sides of your brain. I prefer to keep it in the art side while making music. When I do electronic design and pcb layouts, I switch to that other side.

YMWPV.

[chris harris]

I think that the solution you came up with is killer. Good, creative solution.

The rest of the thread is LOL City!

[Glory_Morris]

Well, we've had our share of problems with the HD24xr. Most recently, one of the two synced units changed the sample rate from 96khz on 12 of the tracks back to 48khz. We couldn't reset the sample rate, so all 24 tracks had to be dumped to PC, set to 48khz and loaded back to the HD24.

Not to mention how many calls per week I get to service tape machines.

I'm not a subjectivist about audio quality. I find no measurable or quantifiable problems with the audio quality of an HD system. Most professional full time engineers that I know will never balk at an HD system, and these are men who've been making records since the 80's and 90's, some of whom have close to 1000 records under their belt. I hear no complaints about Pro Tools audio quality from them.

And let's face it: No two tape machines sound alike. You work with what's in the studio-- it's part of your job as an engineer to work what's available. When it comes to engineers who've done hundreds of records, most of them care more about how well a particular tape machine punches than they care about how it "sounds".

I continue to agree with you specifically on the point about dedicated systems, but this is just my personal preference. It's mostly about workflow for me.