Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Rick Jones]

Hey guys maybe someone can suggest something.

I do FOH sound for club bands and I have started making multi-track recordings of the shows. I'm using an 8ch. ST Audio sound card (DSP2000 C-Port) to record to hard disk on a PC that was built just for this purpose. The ST Audio system utilizes a PCI sound card and a single rackspace 8ch. AD/DA converter box. My console has 8 subgroups that have direct outs that are 1/4" unbalanced outs. The 8ch. AD/DA box has 8 inputs and 8 outputs that are also 1/4" unbalanced. This allows me to send directly to the sound card from the subgroups. You can install up to 4 of these DSP2000's in 1 PC for a total of 32 inputs. I just want to use 2 units for a total of sixteen channels simultaneous. My problem is how do you split the 16 channels on the snake to go balanced into the console and then unbalanced into the AD/DA converters? I have found some 8ch. mike preamps that have XLR balanced inputs that are 2K ohm loads. My console has 150 ohm inputs. If I use some kind of XLR Y's to split the snake the load on the console would drop to 139.5 ohms if my math is right. Will this make a noticeable difference in the audio quality of the live mix or will it just cause me to have to increase the input gain a little on each channel? Also the 8ch. mic preamps S/N ratio is listed as being greater than 80db. Isn't this kind of low? Isn't signal to noise usually listed as a negative number? I think my sound cards AD/DA box is listed as being around 105. I'm doing this on a budget and these 8ch mic pre's are only $99.00 Does anybody know of any other way to do this?

Thanks in advance,

Rick Jones
rwj1313@knology.net

[Andy Peters]

rwj1313 wrote on Thu, 20 May 2004 07:59

My console has 8 subgroups that have direct outs that are 1/4" unbalanced outs. The 8ch. AD/DA box has 8 inputs and 8 outputs that are also 1/4" unbalanced. This allows me to send directly to the sound card from the subgroups. You can install up to 4 of these DSP2000's in 1 PC for a total of 32 inputs.

Interesting.  I assume that the converter clocks for all channels are synchronous, and that you can slave one box off the other?

Quote:

I just want to use 2 units for a total of sixteen channels simultaneous. My problem is how do you split the 16 channels on the snake to go balanced into the console and then unbalanced into the AD/DA converters? I have found some 8ch. mike preamps that have XLR balanced inputs that are 2K ohm loads.

That's standard.

Quote:

My console has 150 ohm inputs.

No, it doesn't, and I don't even know what kind of console you own.

Quote:

If I use some kind of XLR Y's to split the snake the load on the console would drop to 139.5 ohms if my math is right.

You math may be right but your assumption is wrong.

Quote:

Also the 8ch. mic preamps S/N ratio is listed as being greater than 80db. Isn't this kind of low?

It Is What It Is.  At what gain is S/N specified? Perhaps you're confusing S/N with EIN (Equivalent Input Noise), which is usually something around -126 dB or lower.

Quote:

Isn't signal to noise usually listed as a negative number?

No.  If it was, then the noise would be greater than the signal.  Remember the ratio is signal to noise; when expressed in decibels, if signal is greater than noise then the number is positive.  It's the Power Of Logarithms!

Quote:

I think my sound cards AD/DA box is listed as being around 105.

It may very well be, or may not.

Quote:

I'm doing this on a budget and these 8ch mic pre's are only $99.00 Does anybody know of any other way to do this?

Get a couple of Firewire mic pres.  Get a Pro Tools system with appropriate A/D hardware.  How much do you want to spend?

-a

[Kurt Rivers]

Why not just get a Alesis HD24 for at the gig then take the hard drives home and load all the tracks into your editing program(I think the add on is called fireport)? That would minus the computer unless your using it for sometihng else and give you 24 tracks to use. It's around $1,200-1,500 too so it wont hurt the pockets compared to a Pro Tools HD which start maybe at 8-10k because their "LE" software really isn't that great compared to Nuendo, Logic...

Maybe some type of splitter here would work?
http://www.procosound.com/contractors/micsplit/index.htm

[Andy Peters]

Kurt wrote on Thu, 20 May 2004 13:53

Why not just get a Alesis HD24 for at the gig then take the hard drives home and load all the tracks into your editing program

He'll still need sixteen splitters and sixteen mic preamps.

-a

[Kurt Rivers]

So then why not run direct outs from the FOH for all of them? If he needs all those pre's might as well get a Soundcraft Ghost and hide it some where(or a truck) w/ a person just running it.

[Mark T]

How about using channel inserts?  Depending on the board they are proabbly unbalanced and are after the console preamp.

If any effects are patched on inserts then you can just "Y" the send to the recorder.

The soundcard inputs and the return on the board should be high impedance so driving two shouldn't cause a problem.  The recorder would need to be close to FOH, you don't want long unbalanced runs anywhere.

[Rich Wirz]

Kurt wrote on Fri, 21 May 2004 01:37

So then why not run direct outs from the FOH for all of them? If he needs all those pre's might as well get a Soundcraft Ghost and hide it some where(or a truck) w/ a person just running it.

I use direct outs into an Alesis HD24 and it works great.  When I originally started using this set-up it was with an Allen & Heath GL2200 - the direct outs are all post fader and there were some instances where some signals I was sending to the Alesis were rather low depending on how much was being re-inforced into the house.  I did find, however, that since the HD24 is a 24-bit recorder it worked well even when track signals were in the -25 to -30db range.  I've since solved that problem by getting rid of the 2200 in favor of the GL4000 which has an Aux send that can be switched to a direct out level control.  I do not have the Fireport 1394 since I do all the re-mixing right from the HD24 back through the A&H, but from what I have heard it works well.  All in all, though, I am very happy with the results I get with the HD24.  

[Tim Padrick]

Modify the console so the direct outs are after the mic pre only, so you don't get any EQ or insert on "tape".  A friend did this with his Venice and it works great.

[Rick Jones]

Hi Mark T,

Thanks,

I think I'll try what your talking about. This sounds like the least expensive approach that will get exceptable results. I read a lot of good ideas but I think everyone overlooked the "on a budget" portion of my post. This project is just for my ammusment and not something I'm trying to make money with.

Thanks to all for your ideas,

Rick
rwj1313@knology.net

[Todd Wilcox]

Andy Peters wrote on Fri, 21 May 2004 01:21

Kurt wrote on Thu, 20 May 2004 13:53 Why not just get a Alesis HD24 for at the gig then take the hard drives home and load all the tracks into your editing program He'll still need sixteen splitters and sixteen mic preamps. -a

Well, he could get a Yamaha 01V96 (or 02R96) and patch the direct outs to the ADAT outputs.
Works great for me, but that's a big reinvestment.

Todd Wilcox