Pa advice

[Triumphman]

Help required.
In our band we use a beheringer pmp3000 powered mixer.
We have 2 passive speaker cabs (2 x 12) which are connected to the 2 "speaker outputs" on the back.
We now have an active alto tssub15 sub which we'd like to use.
We are not a loud rock band, more a sixties beat group playing mid size venues. We normally use the pa for vocals only but by adding the sub or possibly two we want to be able to put the bass and bass drum through the pa to throw it further in the room.
We don't really want bass and bass drum in the main speakers, just in the sub.
How would we seperate the outputs?
Anyone done this?
Advice welcome

[skidder652003]

we do this in our band but I don't know how! The drummer owns the desk and knows how it works, but I think it's something to do with active or passive crossovers? Im sure someone who knows what they're talking about will be along soon to help.

[bonzodog]

I am not an expert either but I do know it is not a good idea to mix passive and active speakers. If you went all active you would run everything into a none powered mixer then feed that into your alto sub (preferably you would want two so you have one either side of the stage). Then on the back of your alto sub you will have a high pass output which you connect to ACTIVE tops which will only send high freqs, thus keeping the low freqs like the bass and kick in the subs.
If you went all passive then you would run everything into a POWERED mixer then use a crossover to split the signals into passive tops and passive subs.
The fact that you are trying to use a passive tops set up with an active sub makes it a lot harder to set up

[Huge Hands]

I've just had a look at an image of that mixer. I think you will struggle to do two separate mixes on it using the faders because I presume the monitor sends are permanently "post fade". If you can set them to pre-fade somehow, then it is a lot easier.

The only way I can think of doing it is that you use "Mon 1" for your normal mix, and "Mon 2" for your sub mix. You would then have to make a y-split patch lead that went from the "mon 1 send" to the amplifier L and R inserts. It would make the FOH PA tops mono, but that probably doesn't matter one bit in small venues.

It would mean that you would have to mix everything on the Mon 1 or Mon 2 knobs on each channel (not the faders - they would just need to be up). This is the only way I can see of doing it without having to replace your mixer.

I hope that makes sense!

Edited May 15, 2015 by Huge Hands

[Triumphman]

Thanks for all this.
I'm assuming 2 mixes is the best way to go but I'm no expert.
The manual for the sub says, connect 2 xlrs from the main out puts on the mixer to the sub inputs. Then connect the passive (or active) speakers to the outputs on the sub.
This wouldn't use the speaker outputs on the mixer at all?
Would this by default limit the amount of bass going to the more delicate top speakers?

[Triumphman]

The sub has a hi pass filter switch, does this come into play?

[Dad3353]

The User Manual...

[url="http://www.behringer.com/assets/pmp1000_p0566_m_en.pdf"]PMP3000 ...[/url]

...tells us (page 9...) that there's a 'Mono Out', specifically for sending signal to an external sub amp/cab, which will obey the Sub Filter frequency knob. You don't really need 2 subs, but I suppose you could 'daisy chain' their i/ps, and mono is fine for subs. That should solve your problem, no..?
Hope this helps...

[Huge Hands]

[quote name='Triumphman' timestamp='1431695879' post='2774071']
Thanks for all this.
I'm assuming 2 mixes is the best way to go but I'm no expert.
The manual for the sub says, connect 2 xlrs from the main out puts on the mixer to the sub inputs. Then connect the passive (or active) speakers to the outputs on the sub.
This wouldn't use the speaker outputs on the mixer at all?
Would this by default limit the amount of bass going to the more delicate top speakers?
[/quote]

That reads to me that the sub and tops are from the same manufacturer and are designed to run that like so that the sub acts as a crossover, splitting the high and low frequency content between the speakers. This would also dsay to me that the amplifier inside the sub is powerful enough to run the sub and passive top speakers?

What I was suggesting with the two mixes was so you could totally separate kick drum and bass guitar from the main mix, which is what I thought you were asking in your OP.

Having a crossover and just one mix is probably the better way to do it, so you get full range kick and snare through all speakers.

EDIT :... or what Dad says above probably makes sense too....

Edited May 15, 2015 by Huge Hands

[leftybassman392]

It's a bit of a compromise, but in simple terms you connect the main speakers to the speaker O/Ps on the mixer, any onstage monitoring goes through mon1, and take an O/P to the sub from mon2. Don't forget to set the mon1 level for the kick to zero. You'll have to send some of the bass guitar signal through the main O/P because if you just send it to the mon2 send you'll get a *[i]really[/i]* boomy sound with no character at all (active subs normally cut off at around 120Hz, give or take). Anything else is going to be very difficult to manage in an onstage environment.

Also if the sub has an XLR I/P you'll need to get a special lead made up as it looks like the send on the mixer is a jack.

Edit: to add: monitor sends should always be pre-fade, and you should have mon level knobs on the channel strips.

Edited May 15, 2015 by leftybassman392

[leftybassman392]

You can't power passive speakers from an active sub. The signal is split at the I/P to the sub, i.e. before it reaches the power amp. The high pass O/P from the sub will send a line level signal, which won't work with your passive speakers.

Edited May 15, 2015 by leftybassman392

[Huge Hands]

[quote name='leftybassman392' timestamp='1431697914' post='2774093']

Edit: to add: monitor sends should always be pre-fade, and you should have mon level knobs on the channel strips.
[/quote]

I agree, that is what you would want, but I've just read through the manual and I can't see it specified anywhere as to whether they are or not (nor does it say it is post for the FX). I would never assume with a "budget" desk, as I'm thinking this is. If they are pre-fade, great, if not, then the wired bodge I metioned would be needed to totally separate the mixes and still use the internal amp for the tops.

[Triumphman]

Thanks all.
It's beginning to make sense.

Why would mon1 level for the kick need to be zero?

This might be a stupid question but how will I leave the kick out of the mon2 mix (to the sub)
And similarly, how will I mix only a little bit of bass into the top speakers, with most going in the sub?

[Dad3353]

The 'normal' set-up for this type of PA/venue is to connect the sub using the dedicated 'Mono Out', adjusting the filter frequency, and send kick and bass into the system exactly as any other signal, such as voice. Adjust the levels of each to get the reinforcing that you're looking for; it won't need much at all. It's not much use sending kick and/or bass solely to subs; you'll hear/feel only 'mush'. That's not how subs are used. I wouldn't worry about having too much kick or bass in the vocal tops. If they're too 'present', you're feeding too much in. Try it first the 'normal' way and see how it works out before looking for more exotic solutions, maybe, especially as you already have everything you need to do it..? Report back if there are any issues, but that's how most of us do things, and it works for most of us.
Just sayin'.

Edited May 15, 2015 by Dad3353

[Triumphman]

Thanks all.
We'll try the simple set up that dad suggests at tomorrow's gig and see how we get on.
I was a little reluctant to put bass and drums through our 2 x 12's as we asked the chap who built them to make them specifically for vocals and to suit our mixer.
They've got 2 eminence 12's in each so I'm sure they won't be damaged by a little bass and kick.

[leftybassman392]

[quote name='Triumphman' timestamp='1431699427' post='2774109']
Why would mon1 level for the kick need to be zero?

[/quote]

It's not strictly necessary, but if you're sending just the vocals through the onstage monitors (as you must have been up to now), having the kick sound there as well can confuse the issue a bit. If you're playing the kind of gigs you seem to be then the drummer (and the bass player while we're at it) is likely to provide all the reinforcement you need from a few feet behind you. Dad3353 can speak to this from the drummer's perspective; it's just how I would do it in your situation. This all assumes you have monitoring in the first place of course, but do you really want a monitor mix consisting of vocals, bass and kick drum?

Dad also reinforced and developed my point about how the subs work. All they should be doing is adding a bit of 'weight' to the sound - if they're set up correctly most people won't really notice them. Please take this in the spirit in which it's offered, but trying to use them in the way you seem to want to is to slightly misunderstand what they're there for.

Edited May 15, 2015 by leftybassman392

[Triumphman]

Understood.
Thanks for the advice.
Once I find a funky jack to male xlr cable then we'll give it a go

[Dad3353]

[quote name='leftybassman392' timestamp='1431714789' post='2774330']... Dad3353 can speak to this from the drummer's perspective; it's just how I would do it in your situation. This all assumes you have monitoring in the first place of course, but do you really want a monitor mix consisting of vocals, bass and kick drum?...
[/quote]

You won't be wanting bass or kick in the monitors until you're either...

1 - playing very big stages

or

2 - all playing too darned loud.

Sometimes others like just a touch of kick, so as to stay 'locked in' to the beat, but the drum itself should be quite enough acoustically to provide that. Wait until you're playing O2 before going down that route, I'd say.

[mike257]

I'd agree with the comment about not keeping kick and bass exclusively in the subs. The sub you have rolls off above 125Hz, the good stuff that gives a bass guitar its definition and clarity is above that in the mids. Same applies for kick, you'll get the very low end welly, but all the attack and the beater click is (depending on the tuning of the drum, type of beater, playing technique etc) will be up in the high mids between around 3kHz and 7kHz somewhere. Subs will give you the low end extension missing from the current setup, but they don't give a full range representation of bass instruments.

In most PA systems, you would use a crossover or system processor to make sure only the relevant bits of the frequency spectrum were sent to each set of speakers, so (for example) you don't overwork the hi/mids by trying to make them reproduce sub bass frequencies outside of their capability. Looking at the kit you've got, you can actually achieve this by using the "Power Amp Insert" points on the mixer. From what I can gather looking at the manual, they're post master fader so you could pick up a couple of TRS to XLR insert leads and connect them from the insert point with the "Send" going to the inputs of your sub and the "Return" coming from the outputs. This will make the sub work as part of your complete system with no extra buggering about with monitor sends etc and have the added bonus of using the crossover built in to the sub to filter the extreme low end out of the signal being sent to your tops, so both the power amp in your mixing desk and your main PA speakers aren't being worked as hard.

Hopefully that makes sense! It's late and I'm tired so it's very likely I'm excessively waffling!

Edited May 16, 2015 by mike257

[Dad3353]

[quote name='mike257' timestamp='1431731409' post='2774549']...Looking at the kit you've got, you can actually achieve this by using the "Power Amp Insert" points on the mixer. From what I can gather looking at the manual, they're post master fader so you could pick up a couple of TRS to XLR insert leads and connect them from the insert point with the "Send" going to the inputs of your sub and the "Return" coming from the outputs. This will make the sub work as part of your complete system with no extra buggering about with monitor sends etc and have the added bonus of using the crossover built in to the sub to filter the extreme low end out of the signal being sent to your tops, so both the power amp in your mixing desk and your main PA speakers aren't being worked as hard...
[/quote]

This looks good to me (yes, it makes sense..!) and is worth a try. You'll need a pair of subs, however, to keep the stereo image in the tops. As mentioned before, only one sub is really necessary, but if you've the logistics for a pair, this method would work well, I'd say.

[mike257]

[quote name='Dad3353' timestamp='1431733643' post='2774562']
This looks good to me (yes, it makes sense..!) and is worth a try. You'll need a pair of subs, however, to keep the stereo image in the tops. As mentioned before, only one sub is really necessary, but if you've the logistics for a pair, this method would work well, I'd say.
[/quote]

Wouldn't need a pair of subs as the single Alto TS sub they already own has Left and Right ins and outs so can work as a mono sub under a stereo pair of tops. To be honest, in most small setups there's an argument for a single sub being a better solution than a spaced pair - less issues with phase etc. They're fairly omnidirectional once you get right down low anyway.

[Dad3353]

[quote name='mike257' timestamp='1431735949' post='2774572']
Wouldn't need a pair of subs as the single Alto TS sub they already own has Left and Right ins and outs so can work as a mono sub under a stereo pair of tops. To be honest, in most small setups there's an argument for a single sub being a better solution than a spaced pair - less issues with phase etc. They're fairly omnidirectional once you get right down low anyway.
[/quote]

So much the better (I'm not familiar with the exact sub discussed, but it sounds just right...). A single sub does not necessarily have to be placed in the centre of the FOH; it can be tucked away in any reasonable space, as it will diffuse pretty much omnidirectionally. We'll find out, I hope, how the OP gets on with trials; should be interesting.

Edited May 16, 2015 by Dad3353

[Triumphman]

That sounds a good way to try also. I'm just gonna have to wait until that lead arrives.

[leftybassman392]

[quote name='mike257' timestamp='1431731409' post='2774549']
Looking at the kit you've got, you can actually achieve this by using the "Power Amp Insert" points on the mixer. From what I can gather looking at the manual, they're post master fader so you could pick up a couple of TRS to XLR insert leads and connect them from the insert point with the "Send" going to the inputs of your sub and the "Return" coming from the outputs. This will make the sub work as part of your complete system with no extra buggering about with monitor sends etc and have the added bonus of using the crossover built in to the sub to filter the extreme low end out of the signal being sent to your tops, so both the power amp in your mixing desk and your main PA speakers aren't being worked as hard.
[/quote]

Yup, that would do it too. Using the X-over built into the sub will definitely get the best from it. Hadn't noticed the power amp sends and inserts - sorry!

I'd agree that the insert looks post master fader - despite it not being explicitly stated in the manual it would be a bit weird if it wasn't given it's intended function. A circuit diagram would have helped...

@OP If you decide to go this route you'll have a number of cabling solutions for the sub. Probably best not to give too much detail here, but if you have long cable runs it could get a bit messy - one option would be to use a cable snake: it would most likely have to be custom made (not hard but a bit fiddly unless you're handy with a soldering iron), but would be much the neatest way to do it.

Long story short, any of the above would work although mike257's suggestion looks the most elegant.

Edited May 16, 2015 by leftybassman392

[Triumphman]

Thanks chaps