Advise On Active Subwoofer

[carloos 0]

Hi all,

I have just bought an active subwoofer and i'm not sure what the best way of hooking it up to my PA.

My PA consists of a studiomaster powered mixer and two PV pasive impulse speakers.the subwoofer is (the box cl115). Any help here would be great.

kind regards,

Carloos.

[dj will 0]

As far as I can see it seems to be a bit of a catch 22 but I would need to know the model name/number of the mixer to be sure. Whilst you could use the speakers as normal and plug the sub into the mixer (hopefully there is a standard output as well as a powered output), you would end up with bass coming out of your full range speakers, which you do not want when you have a subwoofer. What you would do in most cases would be to use an active crossover but this wouldn't work using a powered mixer as you would effectively have to have an unpowered output going in to the active crossover, which the sub would connect to, but then you would have to go back into the mixer and out to the powered speakers. You cannot go back into the mixer like this - it will not work!

 

As far as I can see the solutions are:

 

If the mixer has an unpowered output then you will need to buy an amplifier and an active crossover and not use the powered feature of the mixer. You would plug the unpowered output of the mixer into the active crossover and from there into the sub and into the amplifier, you would then plug the amplifier into the full range speakers.

 

If the mixer doesn't then you will need to buy a new mixer and an active crossover and possibly even an amplifier. You would plug from the new mixer into the active crossover, from the active crossover into the sub and into the amplifier, from the amplifier into the full range speakers (or you could plug from the active crossover into channel 1 of the old mixer and then out to the full range speakers)

 

I think the real problem is that powered dj mixers are rare and these tend to be used by bands or singers.

[carloos 0]

 

Hi dj Will,

Thanks a million for the advise. I was thinking as much that i would have to buy a amplifier. The mixer has a line output so i would be bypassing the built in amplifier on the mixer. And you were right about the powered mixer been used by bands because i use to sing and play guitar using this set-up but seem to need that extra bass thump for dj-ing

[superstardeejay 0]

If the mixer has an unpowered output then you will need to buy an amplifier and an active crossover

 

What?

 

Its ok you dont need to buy another amplifier. Use the impulse speakers as before, ie run off the main outputs of the studiomaster, (you've used them like this before so carry on) then use one of the line-out jacks at the back of the studiomaster (I guess its a powerhouse or similar?) to drive the powered bass bin. This is fairly standard practice, and there's not much point taking the amp that's inside the mixer out of action just to buy another external one to do the same job. Even if you wanted an active crossover, the Studiomaster will accept it as an insert (send/return channel)..all Studiomasters have at least 2 inserts..so again no reason AT ALL to buy a second amplifier. You'll be wasting money.

 

If you're not sure which output jack to use for the bin then just tell us more about which model Stud you have and I'll look at the manual.

Edited March 12, 2009 by superstardeejay

[djgorey 0]

you would end up with bass coming out of your full range speakers, which you do not want when you have a subwoofer.

 

If they are full range speakers, then why shouldn't he make use of the bass capabilities of those speakers.

[Dukesy 0]

I've got some lovely full range speakers. The bass is great and I ditched the subs last year.

If ever I need subs, I can always hire or borrow!

[djgorey 0]

I've got some lovely full range speakers. The bass is great and I ditched the subs last year.

If ever I need subs, I can always hire or borrow!

 

My full range go down to 45hz and are stunning. My bins go down to 40Hz so it is only for some gigs that I bother to take the bins (they're also very very heavy and very big).

 

The problem I have is that the only processing/LMS I have is a dbx crossover which means that I am not making the best of the capabilities of the speakers. The LMS unit designed for the speakers has a variable LP filter for the bins and then a 60Hz HP filter for the full range so you can take a little bit of the bottom end off if you want. They are designed though so that you send the bins what it can nicely reproduce (say up to about 100Hz) but then the full range speakers get full range.

[carloos 0]

What?

 

Its ok you dont need to buy another amplifier. Use the impulse speakers as before, ie run off the main outputs of the studiomaster, (you've used them like this before so carry on) then use one of the line-out jacks at the back of the studiomaster (I guess its a powerhouse or similar?) to drive the powered bass bin. This is fairly standard practice, and there's not much point taking the amp that's inside the mixer out of action just to buy another external one to do the same job. Even if you wanted an active crossover, the Studiomaster will accept it as an insert (send/return channel)..all Studiomasters have at least 2 inserts..so again no reason AT ALL to buy a second amplifier. You'll be wasting money.

 

If you're not sure which output jack to use for the bin then just tell us more about which model Stud you have and I'll look at the manual.

 

Hi all,

thanks for all the advise. you asked me "what kind of mixer i have" and you were right it's the studiomaster powerhouse 300. thats 300 watts a side.it's got two line outputs left and right and at the back it has inserts left send and return and right send and return.don't know anything about inserts.I tried the bass bin with the two line outs as the bin has left and right inputs and left and right outputs and used the impulses as normal and the sound was'nt bad.I was told i could use the monitor out to the bass bin and use the monitor volume slider to adjust the volume to the bass bin.This actually gives me great controll once i have the levels set on the bass bin.what to you think and any info on inserts.

cheers.

[superstardeejay 0]

The amp inserts are twin stereo jack sockets that are used to 'insert' an external unit in the signal path between the mixer stage and the amplifier stage. The sockets are wired the same for left and right inserts and you can plug something like a crossover, graphic EQ, digital reverb, feedback eliminator, compressor-limiter, etc etc into these sockets. When the jacks are plugged in here, they operate a switch that interrups the normal signal and routes it through the jack leads. Hence if you were just to plug a couple of empty plugs into the sockets, the sound would be cut off to the amp section.

 

You can use these sockets as mix sends to your sub woofer. Take a stereo jack plug, open it up, solder a link between tip and ring, (to enable the internal amp to continue to operate as before) and then connect a screened cable to the sleeve (screen) and the inner core to the two linked terminals tip+ring. On the other end, attach a suitable plug for your sub woofer and plug it in, then the master fader on the Studiomaster will fade the subwoofer up and down in sync with the main built-in amp.

 

I'd prefer to do it this way because using the monitor bus means the master fader hasn't got ultimate control over both speaker sets; only the top cabs...therefore it isnt a 'master' fader at all!

 

 

 

 

[carloos 0]

You can use these sockets as mix sends to your sub woofer. Take a stereo jack plug, open it up, solder a link between tip and ring, (to enable the internal amp to continue to operate as before) and then connect a screened cable to the sleeve (screen) and the inner core to the two linked terminals tip+ring. On the other end, attach a suitable plug for your sub woofer and plug it in, then the master fader on the Studiomaster will fade the subwoofer up and down in sync with the main built-in amp.

 

I'd prefer to do it this way because using the monitor bus means the master fader hasn't got ultimate control over both speaker sets; only the top cabs...therefore it isnt a 'master' fader at all!

 

 

 

Thank a million for your expert advise.I got a guy to make me up two leads just like you said,it's the bizz.

kind regards,

carloos.