Rack setup vs. the live sound problem...

[troll]

All preferences and arguments aside, I have a bit of an issue that has been ongoing, that I'd like to finally correct.

I have what appears to be a slightly unusual setup, which mainly is centered around my preamp. An Ampeg SVP-BSP.

As many of you know, this has two channels. A dirty and a clean, both of which I use to an extent. These of course are on their own separate DI's. Trying to explain this to sound guys that if they want direct, I need two lines, simply gets a *** look. And if I ask to be mic'd then, 'oh I don't have any extra'.

The problem also exists in that I wire it all a little silly. I run the one 1/4" 'mixed' output to a Maxcom compressor, then out to the power amp (PLX 1602). I'd much rather get that already compressed, mixed and eq'd signal to the board if possible. Obviously a Mic easily takes care of this, and have considered just getting one of my own to tote around.

I tried to put in a mic splitter box (between compressor and amp), but this completely sucks all the life out of the sound on the other side. Including what gets sent to the power amp. It just sounds like a dry clean signal right from the bass. Am I doing something wrong?

I've read plenty of threads concerning Mic VS DI and so on, but nothing really hits home on my specific application.

I'm half tempted just to ditch the pre and compressor and get a MM SWR Preamp and use it's boost channels instead, it seems to have a decent built in compressor (best I've seen in any other preamps I've liked).

Any thoughts?

[JimmyM]

Now I understand why this preamp never caught on. Two XLR outs that can't be combined? Silliness.

I think you have two choices....ditch the BSP or buy a mic and stand and carry it with you and insist that they use it instead of a DI. Channels on cheap club PA's are hard to come by. Billy can get as many channels as he wants, but apparently he and Ampeg forgot that others may not have that option. Big mistake to design a preamp like that and expect it to sell to us regular folk.

[bongomania]

Originally Posted by troll

I run the one 1/4" 'mixed' output to a Maxcom compressor, then out to the power amp (PLX 1602). I'd much rather get that already compressed, mixed and eq'd signal to the board if possible...
I tried to put in a mic splitter box (between compressor and amp), but this completely sucks all the life out of the sound on the other side. Including what gets sent to the power amp. It just sounds like a dry clean signal right from the bass.

If the mic splitter is transformer or buffer isolated then it shouldn't be sucking the life out of the signal, and I'd be curious to test that further. If it's not xfo or buffer isolated then the problem is excess loading on the signal paths. I guess one alternate potential problem to explore is phase cancellation when the two signal paths are amplified simultaneously, with speakers pointed/positioned in such a way as to interfere with each other. That can certainly cause a "lifeless" sound quality.

Another potential issue is mixing unbalanced and balanced connections. It sounds like the 1/4" output of the preamp might be unbalanced, and you're asking the MaxCom to balance it, which AFAIK it won't do. Use only all-balanced or all-unbalanced connections.

One option:
Clean balanced output of preamp --> MaxCom ch. 1 --> power amp ch. 1 --> speaker cab 1
Dirty balanced out of preamp --> Maxcom ch. 2 --> power amp ch. 2 --> speaker cab 2

In this way there is no mixing except "in the air", and you can regulate interference by re-positioning the two speakers. Bring your own mic, mic clip/stand, and simple DI box to get this tone to the PA.

[troll]

Originally Posted by bongomania

If the mic splitter is transformer or buffer isolated then it shouldn't be sucking the life out of the signal, and I'd be curious to test that further. If it's not xfo or buffer isolated then the problem is excess loading on the signal paths. I guess one alternate potential problem to explore is phase cancellation when the two signal paths are amplified simultaneously, with speakers pointed/positioned in such a way as to interfere with each other. That can certainly cause a "lifeless" sound quality.

Another potential issue is mixing unbalanced and balanced connections. It sounds like the 1/4" output of the preamp might be unbalanced, and you're asking the MaxCom to balance it, which AFAIK it won't do. Use only all-balanced or all-unbalanced connections.

You know, I wondered if that is part of what was going on. It's been so long since I really played around in there. I am using the balanced out of the compressor to the power amp, but indeed the mixed out being a 1/4 is likely unbalanced. I could swear I remember putting a balanced 1/4 cable in there though. I'll have to check it out next week after the extended weekend. Don't even know if we'll load back in and practice Monday like normal with the holiday.

The mic splitter is a transformer. Samson S-split

I wonder if I should just use a combiner box and just combine the two DI's into one.

Honestly, I only ever got the BSP because I couldn't find a SVP-PRO at the time (for a reasonable price), but I've come to like having both channels and use it for solo parts as a boost, which the Marcus pre can accommodate as well.

I actually do use the maximizer section of the compressor to round out the lows to supplement the lack of variable frequencies on the BSP

[MaceTheBass]

Why don't you put the compressor in the effects loop?

Push the 'combine' button to combine both the clean and dirty channel, and select the 'post eq' position.

The DI of the combined channel will send your eq-ed, compressed and overdriven signal to the board.

Good luck!

[TimmyP]

If it's the same splitter I used (I think it was a Whirlwind), it's an impedance problem. I tried to use it in a line level application in a pinch, and the device could not drive it. Presumably it works fine on dynamic mics. WW and Radial make splitters that are specifically for line level applications.

One can combine any two sources - see Rane Note 109.

I'd feed the sum of the comp outputs into a good external DI (Pro 48 or ProDI) and feed that to the board. Or get a J48 DI - it has the ability to sum the L and R inputs with the push of a button.

However if the distortion tone is a big part of what you do, I'd want the clean and dirty on separate channels on my console, as the distortion will likely need different EQ tweaks than the clean (it will likely need more very low end, and less top end).