Help Connecting M-Audio Kit to Computer Workstation

Hi guys,

I’d like some advice on the best way to connect the monitors and sub I have to my computer workstation. I should start off by saying that I have little knowledge on the subject of sound! Through the years I have gained some bits through trail and error but not a lot else

I have two active M-audio BX5 D2’s and an active M-audio sub - AV32.1. I have tried to connect the BX5s to the sub via the outputs on the sub. I brought cables that go from XLR to exposed ends. I then connected to the computer using a Behringer UMC22 audio interface using TRS cables to the back of the sub. I get sound come through but only at high volumes. I’m guessing that because the sub has an amp and the BX5s do too, that something is amiss. It also sounds rubbish. Am I right in thinking that the signal needs to be split so that only the low end goes to the sub? Would an amp in between the audio interface and the sub do this? I did have it set up years ago with it going through a mixer - Behringer Xenyx 802. This sounded okay but I still had in the back of my mind that it wasn’t the right set-up. I still have the mixer but have lost the power brick and trying to find another one is proving difficult.

I’m aware I’m doing something fundamentally wrong here and thought I’d get some advice from people that actually know what they are doing instead of just trying to buy bits to try and make it work, a little knowledge is dangerous after all If pictures or more information would help please let me know.

Thanks in advance.

 

Looking at the various bits of equipment you have, the sub is intended to drive passive main loudspeakers as it includes three power amps, and the crossover between sub and mains. This way, the mains get bass cut-off which the sub reproduces, and the sub only gets the bass which the mains don't, if you see what I mean.

What I think you need to do is to send the output of the UMC22 to the sub, then take the L&R outputs to the BX5s. What I can't tell is whether the various sockets on the back of the sub are all inputs (except for the bare wire connections) or whether they're also outputs to mains. The Sub manual may tell you.

What you then have to do is to balance the output level from the sub with the input level of the mains. You may find that you have to use the bare wires high-level (passive) loudspeaker outputs, and that will give you all sorts of problems with excessive level, so you may need to wire in some attenuators.

I('m pretty sure your BX5s are much better than the passive 'speakers that come with the AV32.1 sub, so worth keeping.

S.

 

Hey, thanks for the reply. Yes, I think I understand. So the sub has three power amps; one for itself and then two for the passive speakers that are meant to be connected? I was wondering if there was a crossover in the sub so that clears that up - thanks.

I have connected it up the way you have suggested, and you're right - it sounds messy. The RCA and TRS connections are inputs on the sub, so the only outputs are the wired connections. So attenuators will reduce the amplification from the sub before the signal gets to the mains where it should be amplified? Are there any sort you could recommend, I haven't used such bits of kit before.

I replaced the passive speakers that came with the sub because I wasn't happy with them so I'll defo be keeping the BX5s. It would just be nice to have the sub included. Is there any merit to my idea of having the output from the UMC22 going into a mixer and then having separate channels going to the sub and mains?

 

As the only outputs from the sub are the wired connections, using a mixer would be a lot safer than attenuating the wired outputs. There aren't attenuators for this function ready made, you would have to make something yourself, and there's a risk of damaging the power amps in the subs if you get it wrong.

Using a mixer means that you would set up the mains/sub balance in the mixer, then the main volume control would be the UMC, and you would leave the mixer fixed. The only problem with this I can think of is that the mains would get the full frequency range signal, so reducing their power handling. If they go loud enough with low distortion without the sub, you're OK, and the sub can just fill in the bottom end.

S

 

Great, I'll do this then. Could you put crossovers in between the mixer and the mains? In my head (perhaps incorrectly) crossovers here would block the low end going to the mains?

Having a quick look online, would a unit like this take the place of the mixer and filter the signal to the sub and mains correctly?

 

Yes, that would do it nicely!
S.

 

Great, I'll give that a go instead of the mixer then. Thanks for all your help - greatly appreciated.

 

One last question if I may. What would be the recommended method of changing the input source on this setup, i.e. to a games console. Is it possible to hook everything up so that multiple sources can be connected without having to change cables?

 

As you have a mixer, you could use that as a source selector, then take the output of the mixer to the crossover and on to the 'speakers. I did pretty much that in my study system.

S