Alesis HD24 - Connecting to a computer.

[fingerace]

Hello guys, I would appreciate any input you have on this.

I don't have the recorder yet, just to make clear.

I will use it with an analog console, (I am clear on how that part is done) but I want digital data to go in and out of a computer to be used with any audio processing softwate.

Here's an example that shows what I mean: Getting the guitar channel dry from the console, into the HD24, into the computer, running it though some software and returning it to the console to be monitored real time but with the added effects.

It can be done right? I suspect that I must use the "ADAT optical" ins and outs, right?

What hardware should I need for the computer?

I just want to add effects, I don't want to mix using the computer, I just want to use the software as signal a processor. - The thing is, I want to be able to do it in real time. Running the dry signal through the computer and then playing it back afterwards is not exactly what I want.

Sorry if I sound as a total noobie. I am... Please correct me if I seem to have the wrong picture.

Thanks a lot

[Bigduggieface]

Originally Posted by fingerace

I just want to add effects, I don't want to mix using the computer, I just want to use the software as signal a processor.

Hoo boy, this is a convoluted wiring and conversion scheme! But I don't see any reason why this wouldn't work as long as your physical cabling is connected properly and your software is configured properly.

Let's examine the signal flow. For simplicity's sake I'll assume for now that the computer will only be needed at the mixing stage and not the tracking stage (ie live recording) and that you're only effecting ONE mono signal.

The mics enter the mixer and the signal is routed to the HD24's analog inputs. Once the digital data is recorded to the HD24, you'll need to mix. Here is where things get damn complex.

For instance, if you'd like to use the computer to apply effects to 1 of your say,15 tracks, you'll need to send a digital signal from the HD24 to the computer via an ADAT lightpipe optical cable.

You'll need to then open a new project in your computer DAW and create a new track with the appropriate effect on this virtual track. You'll then need to assign your DAW's input buses to route the particular HD24 digital channel to your newly created virtual track. Are you with me so far? The trick here is that you'll be feeding the computer with many ADAT lightpipe tracks, but you must tell your computer software to recognize the one that you would like to effect.

Next, once your software is set up to recognize the particular digital input signal that you would like to effect, you will then need to connect the output of your DAW back to your mixer so that you can hear the newly effected signal. I assume that you're using an analog mixer, so the connection from your computer back to the mixer would be on an analog cable.

Whew! This is an extremely abbreviated summary, but I hope it helps you conceptualize the signal flow at a basic level.

Since the signal flow to your computer is digital, I don't think that there would be any latency (ie delay) issues, but I could be wrong about this. I'm sure that other forum members will chime in to elaborate on this scheme you propose.

As far as hardware, you would need a computer interface which accepts at least one ADAT lightpipe digital input, and a set of analog 1/4", RCA, or XLR outputs in order to route back to your analog mixer. It would also be advisable to use a computer interface with a BNC connector. Along with the ADAT lightpipe cable, also connect a BNC cable in order to help keep the digital signal in synchronization so that you don't experience any digital dropouts.

The HD24's ADAT lightpipe outs are configured to output 8 channels each. You would need an interface with an ADAT lightpipe in which accepts 8 channels. Some ADAT inputs accept only 2 channels. These 2-channel inputs will not work. You would need 8 inputs in order for your computer to communicate with the HD24.

That's enough outta me. Good luck, and let us know if you need clarification!

[fingerace]

As I read this for the third time to try and understand it, let me ask this: Is there a simpler way to do this? - like running the computer in the FX loop of the console? the same way you would run a multi effects unit.

[Bigduggieface]

If you choose to bypass the HD24's optical digital outputs and use an aux send from your mixer, little will change.

You'd need to connect a cable from your mixer's FX send to the input of your computer's interface. Open your DAW and start a new session. Create a new input track and insert your effect of choice. Make sure your DAW's input / output scheme is routed properly. Finally, route a cable (2 for stereo) back to your mixer to hear the effects.

This is basically the same scenario I described in my earlier post, but this is an analog connection, not digital.

The only bitch is getting the computer's DAW set up correctly. It sounds like a lot of steps, but each only takes a second once you understand the in/out scheme. It really is like connecting an effects unit as far as connections go, whether its digital or analog.