Mixer question.

After the preamplification, and attenuation stages (and sometimes EQ), is a mixer nothing more than a complex "Y" cable?

The reason I ask, is I would like to use two Motu 896HD's together for live mixers, and I need to combine both of their main outs into one signal to go to my processor and then to the powered main speakers. Do I have to have a small mixer for this, or would a "Y" cable do the same thing? Assuming I don't need to attenuate either signal, but merely combine the two. The 896HD's have attenuators on their outputs, so I can use those for setting the levels.

Send the out of 1 into the other inside the PC then take the out of the second to the sound card.

Using a small 4 buss mixer you would have very easy routing.

Buss 1-2 tracks to processor.(DAW)

Buss 3-4 monitors.(or whatever)

Main outs -main speakers or power amp.

Is that what your thinking?

The reason for having a mixer in a live situation is that if you need to increase or decrease the overall volume of your show, then you only have to move 2 faders with a mixer.. but without one, you have to adjust 16, and then your mix is most likely going to change. Unless the motivation is totally financial, I wouldn't do it without a mixer. The mixer also allows you to insert dynamics or effects.

BD

I guess I'm not making myself clear. I have a mixer, two of them. The Motu 896HD has a built in mixer. It is a microprocessor controlled mixer, and is controlled by the software. The software doesn't mix the signals, the Motu hardware does it. The software only tells the hardware what to do. So I do have two mixers, and each of them have a main output attenuator (fader). My question is, in order to use two of those units together, I need to combine each of their stereo outputs into one single output that I can send to my Driverack-PA and then to my main speakers. I know I could buy a small mixer with at least two stereo line-level inputs, and mix them together and take the main output from that little mixer to my speakers. But in doing that, I don't need the mixer's preamps, it's EQ, it's attentuators. All I need it for it to combine two line-level signals into one. So what I'm asking is do I need a mixer for that, or would a "Y" cable do the same thing.

If the motu dsp mixer part is confusing, just pretend have got 16 mics on stage, and instead of having a 16-channel mixer, I've got two 8-channel mixers, and I need to combine their outputs. Do I have to buy a third mixer to do this, or can I just "Y" them together?

To put it simply, I'm asking this. Is there any magical thing involved in a mixer combining signals? Or does it just tie them together in parallel?
And if that's all it's doing, I can do that without a mixer.

What happens when you tie two line-level signals together with a "Y" cable? Is it the end of the world as we know it? Does the signal become so hot that it overdrives my amps? Does it start armageddon? Is there any reason I can't do this, and just use the two main output attenuators in the MOTU's to throttle back the signals if they are too hot?

ORIGINAL: OffAnAirplane

On second thought, I could use cuemix on 896HD-#1 and send all the inputs to the ADAT output, then take the ADAT out from 896HD-#1 and plug it into the ADAT input on 896HD-#2 and then use the analog output from the 896HD-#2 to go to my speakers.

It would be simpler to combine the analog outputs though, but I don't want to have to buy a small mixer to do that. Any thoughts?

Thats how I would do it. This way all 16 tracks will be within 1 cuemix console, whats more simpler than that?

ORIGINAL: ohhey

A mixer is different electronically then a Y cable but does the same job only in a better way. A Y cable causes a dead short between two outputs and that can affect sound quality so a mixer is the "correct" way to combine The other advantage is that you can at least one extra chance to adjust the volume and even add gain if needed.

The Y cable analogy is a good one to describe things like the Aux send on the channel of a mixer, again it's better then just a wire but it just makes an extra "copy" of the signal to drive some other input. Aux returns are just simple extra channels with no features like EQ.

If you need a small mixer with good quality I would suggest the Soundcraft Compact 4.

You say a "Y" connector is a dead short between the two signals. Is a mixer not? With all the attenuators set at 0db, I would think it would also be a dead short. No?

ORIGINAL: ohhey

ORIGINAL: OffAnAirplane

ORIGINAL: ohhey

A mixer is different electronically then a Y cable but does the same job only in a better way. A Y cable causes a dead short between two outputs and that can affect sound quality so a mixer is the "correct" way to combine The other advantage is that you can at least one extra chance to adjust the volume and even add gain if needed.

The Y cable analogy is a good one to describe things like the Aux send on the channel of a mixer, again it's better then just a wire but it just makes an extra "copy" of the signal to drive some other input. Aux returns are just simple extra channels with no features like EQ.

If you need a small mixer with good quality I would suggest the Soundcraft Compact 4.

You say a "Y" connector is a dead short between the two signals. Is a mixer not? With all the attenuators set at 0db, I would think it would also be a dead short. No?

No, there are other electronic components in the path with a real mixer so each one is fooled into acting like it has it's own device of the correct impedance.

I see. Well, I'll probably just do it like I described in my previous post then. I really like how clean and compact this setup will be, and I like being mixer-less.

Does anyone make an extremely compact, two channel mixer? Or just a box that is designed for combining two line-level signals, without all the frills of a mixer that I don't need anyway?

ORIGINAL: ohhey

ORIGINAL: OffAnAirplane

........
I see. Well, I'll probably just do it like I described in my previous post then. I really like how clean and compact this setup will be, and I like being mixer-less.

Does anyone make an extremely compact, two channel mixer? Or just a box that is designed for combining two line-level signals, without all the frills of a mixer that I don't need anyway?

Yes you can get line-level combiners I think Whirlwind makes some, the problem is they cost more then a good mixer and color the sound more then a mixer would, I think they are just transformers and good transformers are very expensive (and cheap ones sound bad) and don't work as well as active electronics.

From what I've just read on the net, I found an article that answers me question in depth. And it basically says that the reason you can't just tie to outputs together is because they will "buck" each other, and it can sound distorted, and even damage the outputs. But a typical mixer just adds resistance to each circuit, and it solves the problem. It didn't show any transformers. Maybe it just depends on what type of mixer you use. But I could probably build a two-channel mixer according to this document.

http://www.epanorama.net/circuits/linesum.html

I don't think I'm going to try and mix the outputs. I think I'm just going to output all the inputs from one through the adat out into the adat in on the other unit. Like Lay in Wait said, that would allow me to control all of them with one cuemix window.

Thanks for the help.

ORIGINAL: bill durham

OAA,

OK, you don't need to mix, you just need to combine the outputs. Here's something that will do that and provide some isolation between the two sources, albeit there is 3dB loss in the combination.

http://www.rdlnet.com/product.php?page=87

You need to use a balanced topography when you do this. If your drive rack doesn't have balanced inputs, you might have problems.

BD

Thanks for the link. The driverack does have balanced inputs, but this just seems like way too much trouble for what I want to do. If I could send all the inputs from the first 896HD to the second one via the ADAT connection, then I won't need to combine the outputs, because all the signals will already be at the output of the second 896HD. I think I will do it that way.

Or better yet, I talked to Motu about this and they recommended instead of purchasing a second 896HD, just buy a Motu 8-Pre. It adds 8 channels of analog inputs much easier than adding a second 896Hd, and much cheaper. And since all I wanted was another 8 analog ins, I think that would be the best, most cost-effective way to get it done.

ORIGINAL: lazarous

If you're ok with building your own y-adaptor, but want to do it right, check out this article from Rane electronics. It gives you the true technical reasons why not to Y, AND it gives you the schematic and parts list to build what you need.

http://www.rane.com/note109.html

Very good ! I would trust me picking 1% matched resistors rather then thinking some bean counting vendor would bother.

Hey man, You already got it figured out. The 8pre was gonna be my next suggestion. I was thinkin of adding one for my laptop. I just dont understand why you sold the digimax's and are now replacing them with Motu pre's. You already had this(pretty much excact) set-up with the 2408mk3 and the 2 LT's, and better pre's to boot. Maybe Im missing something.

edit- Oh ya, scrap the Y-cable idea.

The 2408Mk3 would'nt have worked, because it has a PCI interface. I need something more portable than that. I want to use this in live gigs, so I need a firewire interface I can use with a laptop.

Of coarse I forgot about the pci thing. To keep your rig smaller have you considered going with 2 8pres, thats 16 pres in 2 rack spaces rather than 3 or 4 with the 896HD's. Just a thought.