Please help! XLR vs TRS??

[narked]

Hello,
I have a motu 828 firewire interface, it has 2 XLR inputs and 6 TRS (plug) inputs. All that I have read says that only the XLR inputs are for mics. and the other inputs are suitable for things like pluging a keyboard etc.

I need to use ALL the inputs for mics because Im recording a drum with 8 mics... so my question is WHY the TRS inputs are not suitable for mics?? if a mic needs phantom power then its obious I need to plug it in the XLR input but if the other mics dont need phantom power isn't the same plug it in the XLR or in the TRS? is there better sound quality in the XLR? please help.

Edit: I read somewhere that the problem is that those inputs does not have preamps. why I need a preamp to plug a mic? preamp = phantom power? is there any "preamp hardware" to fix the problem and be able to connect my mics to the TRS inputs?

 

[Massive Master]

You need preamps for microphones. That's all there is to it. The TRS inputs are line level - A mic preamp brings a microphone TO line level.

 

[bennychico11]

yes, the preamps in your unit bring the signal up to line level, which is the level you want to work with all your audio at. and yes, the phantom power is only on the XLRs.

there are external preamp units that you can buy where you run the microphone into it and then a 1/4" out into your MOTU 1/4" in. search around at sweetwater.com or other sites for preamps and you'll find alternative ones to buy. however, the MOTU will let you use XLR or 1/4" for that channel. You can't do both at the same time. so if there are only 8 analog inputs you have to decide whether to make them all XLR, 1/4" or mix and match. I think you have the option for optical inputs though, too...right?

 

[narked]

yes, the preamps in your unit bring the signal up to line level, which is the level you want to work with all your audio at.

Ok, so what happens if the audio is below the line level. can you just turn up the volume in the software based mixer? or maybe a preamp software plug-in?

and yes, the phantom power is only on the XLRs.

So.. if you plug a dinamic microphone using XLR with phantom power turned off. is that microphone preamplified?

there are external preamp units that you can buy where you run the microphone into it and then a 1/4" out into your MOTU 1/4" in. search around at sweetwater.com

Im not sure if I searched the correct thing but I came out eith really expensive items of $1,000 or more.

however, the MOTU will let you use XLR or 1/4" for that channel. You can't do both at the same time. so if there are only 8 analog inputs you have to decide whether to make them all XLR, 1/4" or mix and match. I think you have the option for optical inputs though, too...right?

My MOTU has only 2 XLR (that can be used as 1/4 instead. but the other 6 inputs are 1/4" only. What Im trying to do is using the those 6 inputs to connect microphones because I need 8 simultaneous microphones. but I want to solve the issue that those inputs are not preamplified. I want to know the disadvantages of working this way and if there is someway it could be solved. the motu has one optical input but I dont have any optical mixer and they are pretty expensive.

http://www.awave.com.au/images/motu828.jpg

 

[Massive Master]

The line ins won't have enough gain, and phantom is a must for condensers.

There isn't exactly a way around this... You can't drive a car without a motor, you can't bring mics to line level without mic preamps.

I *think* Behringer, Nady, etc., might have some "cheapie" 8-channel units that might get you by for a while if you need it.

 

[bennychico11]

Ok, so what happens if the audio is below the line level. can you just turn up the volume in the software based mixer? or maybe a preamp software plug-in?

there is no preamp plugin available. you need to turn up the volume in the physical, electrical world first. turning the volume up in the digital world (either using a gain plugin or nomalizing) will just create problems....for example turning up the noise floor and making your music very very noisy.

So.. if you plug a dinamic microphone using XLR with phantom power turned off. is that microphone preamplified?

the microphone is only amplified if there is a amplifying circuit in the hardware. not all XLRs mean they are preamp in them, but for your unit....yes, if you plug the dynamic in the XLR inputs and turn up the volume....your microphone will be amplified. The electrical signal a microphone produces is very tiny. This is where the amplifier comes in.

Im not sure if I searched the correct thing but I came out eith really expensive items of $1,000 or more.
My MOTU has only 2 XLR (that can be used as 1/4 instead. but the other 6 inputs are 1/4" only. What Im trying to do is using the those 6 inputs to connect microphones because I need 8 simultaneous microphones. but I want to solve the issue that those inputs are not preamplified. I want to know the disadvantages of working this way and if there is someway it could be solved. the motu has one optical input but I dont have any optical mixer and they are pretty expensive.

http://www.awave.com.au/images/motu828.jpg[/QUOTE]

so you have an older 828 huh? take a look at the left hand side of your unit, that is your optical in which will also be able to handle 8 more tracks of digital. So not only do you get 8 analog, but 8 digital as well. You might even have more than that, but I can't read what the other inputs are on the unit in that pic.
a cheap preamp you can look at is the Behringer ADA8000. You can plug it in via the optical connection. and there are other choices out there too. You can even buy a small mixer as well that has XLR ins on it.