Tech: PA Sub-mixers, Pros-Cons

Subject: Tech: PA Sub-mixers, Pros-Cons
From: DonMeixner
Date: 14 Aug 03 - 11:44 AM

We need to get more use out of our PA. We would like to add a few instruments but haven't the channels. We would like to investigate the sub-mixer option before we buy a bigger board. Any opinions? (Of course there is no end of opinions but I thought I'd be polite.)


Don

Subject: RE: Tech: PA Sub-mixers, Pros-Cons
From: Leadfingers
Date: 14 Aug 03 - 01:40 PM

I often use a Folio four channel mixer to increase the inputs to my H H Five channel mixer amp when in trio mode.I run the vocals through the folio (and the CD or Tape for interval) and plug the two outputs
into one channel,leaving four channels for instruments.Works a treat.

Subject: RE: Tech: PA Sub-mixers, Pros-Cons
From: Richard Bridge
Date: 14 Aug 03 - 07:05 PM

It really depends:   some boards are expandable - new channels straight onto the busses - some not. The latter you are going to have to run the sub-board into either existing channels or onto an aux input. The former you will have two sets of EQ in series. The latter you will probably have to be careful about the gain since most auxes are 100 mv not +4 db. Either way you run two preamps (in effect) after each other and can expect to degrade the sound quality.

So if you do, use the sub-board for the channels you can afford to degrade - line outputs from guitars is a fave, others put all the drums (except kick and snare maybe) onto the sub-board. I would say NEVER put the vocals on the sub, you want them as clean as possible.

Preferred option - bigger board!

Subject: RE: Tech: PA Sub-mixers, Pros-Cons
From: michaelr
Date: 14 Aug 03 - 07:27 PM

I use a Behringer 4-input mini mixer (under $100) to get more mileage out of my Mackie 8-channel head. I generally assign it to one band member, for example the percussionist, or the multi-instrumentalist who'll run his fiddle, mandolin, and vocal mic through it.

It works fine except for the fact that you have to balance the sound at the mini mixer and have no control at the main board over individual inputs. I have noticed no deterioration in sound quality.

Cheers,
Michael

Subject: RE: Tech: PA Sub-mixers, Pros-Cons
From: Bernard
Date: 15 Aug 03 - 11:59 AM

The Behringer mini-mixers are excellent value for money, although the line outputs aren't balanced (the Folio outputs are). A DI box soon gets around that problem, and is still the cheap option.

Alternatively, keep the mini-mixer with the main mixer, though you will need to run more cables!

The Behringer has proper LED ladders, but the Folio just has peak LED's to tell you you've already gone too far! Swings and roundabouts... but you can buy two (or even three) Behringers for the price of a Folio...

It's unlikely that you'd notice the sound degradation if you aren't recording. For PA purposes it's perfectly acceptable practice - just be careful not to overdrive the input stages, though, and beware of earth loops. Try to drive the mini-mixer output hard, and attenuate it at the main mixer - it helps with the signal-to-noise ratio.

Subject: RE: Tech: PA Sub-mixers, Pros-Cons
From: GUEST,Claymore
Date: 15 Aug 03 - 12:28 PM

Actually several of the Behringer mini mixers do have balanced outs, including the MXB1002, $109, the MX1604, $169. and the MX2004A, $249. I use my MXB1002 as a main mixer for a small outdoor system when I need everything to run off of battery power. I set up two Peavey Solo amps on stands (which are battery powered) and run the MXB to them each as left and right balanced lines to their balanced inputs. It works great for situations where you don't need tremendous volumn, and just want to balance the sound out. (We play a hammered dulcimer, harp, flute, guitar and banjo, and use Boss pedal inserts to add reverb and delay for the flute and harp).

But for a few extra bucks, you can overcome the cost of a DI, and following the excellent advice above, get a good sound at a relatively cheap price.

Subject: RE: Tech: PA Sub-mixers, Pros-Cons
From: DonMeixner
Date: 15 Aug 03 - 01:14 PM

Thanks guys, great help, as always.

Don

Subject: RE: Tech: PA Sub-mixers, Pros-Cons
From: JedMarum
Date: 16 Aug 03 - 09:40 AM

I like the Behringer - good value. I use it for small set ups, but for lotsa input channels I "stack" my two folio mixers. Folios do have a ladder LED display; one for the board. You can use it for the mian output or send any channel to it. The "idiot light" LED on each channel is used to set the optimum input gain for each channel.

Folio make great stuff, cheap. These really are top of the line products for moderate cost.

The sub mix can be used effectively, but you'll need some experience managing it. I would put those instruments that don't need to go through the monitor sends into the sub-mix - those instruments that don't need much attention, once their set. The sub mix won't behave like your main mix. You'll have to sepnd some time experimenting with what works for you.