Do I need a crossover?

sfbonner

Hello, I am just wondering do I need to purchase an external crossover for Peavey Pro Sub 15 MK1? They are 500W passive subwoofers and I have them connected to a Prosound 1600 amplifier. I use them for DJ'n. They sound ok as they are but there isn't any real oomph out of them, my home cinema subwoofer seems to create a deeper bass and it is only 40W.

Ive looked through google and found nothing about this, it does say though on the link below that the crossover frequency is 160Hz on the subwoofer

www.thomann.de/ie/peaveypeavey_pro_sub_crossover.htm

unclebill98

Well ruling out faulty cables/mixer etc....

The Amp is putting out 250w @8ohms into a cab rated at 8 Ohms, 200 Watt RMS, 400 Watt Programm, 800 Watt Peak. So your amp is not even hitting the RMS levels.

So it depends on how you are running the amp and how you have the entire system wired etc.

sfbonner

The amp is 500W @ 4Ohms
The subs are 250W RMS... also 4Ohms

The subs are wired to the amp using twist n lock speakon cables.

From the amp there are 2 XLR to rca cables running to RCA outputs on a mixer, I also have 2 active tops connected to the mixer through XLR outputs. The mixer is connected to a usb controller by RCA which is then connected to my laptop..

The bass on the mixer is turned up to about 2 o clock (12 o clock is normal level for all)
And the 2 tops have the bass set at 10 o clock.
This is so that the subs recieve a little extra bass.

I don't know anybody in my area that uses a crossover because they do not have as much gear as me, I only know one DJ a d he uses 2 Behringer subs but without a crossover and there is hardly any bass out of them, also the fact of that is his small amp is having to drive 2 subs and 3 tops..

Would it be worth my while buying a second hand crossover to see would it make a difference?

sfbonner

The amp is 500W @ 4Ohms
The subs are 250W RMS... also 4Ohms

The subs are wired to the amp using twist n lock speakon cables.

From the amp there are 2 XLR to rca cables running to RCA outputs on a mixer, I also have 2 active tops connected to the mixer through XLR outputs. The mixer is connected to a usb controller by RCA which is then connected to my laptop..

The bass on the mixer is turned up to about 2 o clock (12 o clock is normal level for all)
And the 2 tops have the bass set at 10 o clock.
This is so that the subs recieve a little extra bass.

I don't know anybody in my area that uses a crossover because they do not have as much gear as me, I only know one DJ a d he uses 2 Behringer subs but without a crossover and there is hardly any bass out of them, also the fact of that is his small amp is having to drive 2 subs and 3 tops..

Would it be worth my while buying a second hand crossover to see would it make a difference?

unclebill98

Are you running one sub on the left channel of the amp and the other of the right? i.e. only box per channel?

If you have no x/over in the chain then you are running the full range of audio into the subs, which is not ideal/good and can result in damage to the subs. Rolling off the signal at 100-150hz would result in just a better signal over all but it will not increase the thump your are looking for.

How to you figure have the tops bass signal turned down = the subs recieve a little extra bass

Running active/passive in the one set up is not the norm but its not un heard of, just takes a little more tweeking to get right.

Is this the Amp? http://www.maplin.co.uk/p/prosound-2-channel-1600w-power-amplifier-n91fn
Are these the subs? http://www.thomann.de/ie/peavey_pv_118_sub.htm

sfbonner

unclebill98 wrote: »

Are you running one sub on the left channel of the amp and the other of the right? i.e. only box per channel?

If you have no x/over in the chain then you are running the full range of audio into the subs, which is not ideal/good and can result in damage to the subs. Rolling off the signal at 100-150hz would result in just a better signal over all but it will not increase the thump your are looking for.

How to you figure have the tops bass signal turned down = the subs recieve a little extra bass

Running active/passive in the one set up is not the norm but its not un heard of, just takes a little more tweeking to get right.

Is this the Amp? http://www.maplin.co.uk/p/prosound-2-channel-1600w-power-amplifier-n91fn
Are these the subs? http://www.thomann.de/ie/peavey_pv_118_sub.htm

Yes each sub has its own channel

Ok. But what does the 160Hz crossover mean that is internally built in?

I turned up the bass on the mixer and the bass down on the tops so that the subs will receive a little extra bass. Its been set like this for about 8 months and have been using them nearly every weekend.

Yes that is the amp, but they arent the subs. I dont think they even sell these subs anymore because the MK2 took over them. I cannot find a website they are on but here is a picture of them.

http://www.ebay.co.uk/itm/281140135644?redirect=mobile

unclebill98

In your current setup the X/over is doing nothing cause you are not using passive tops.

The subs can feed power and a signal to the tops, it will x/over the frq at 160hz, so the sub gets 20-160hz and send 160hz-20khz to the tops.
So you want to be taken 20-160hz away from the tops, which you in a round about way are doing by rolling the bass of the tops.

I am surprised the subs are rated at 4ohms. Does it say this on the back of them?

The lack of a proper x/over setup is not the issue of the lack of thump you are suffering from.

If they are then Its one of the following,

Amp is not giving it the amps rated spec
The subs are damaged
Dodgy Speakon lead

They are old school solid subs. Without hearing it, its hard to say if its just doing its job but you want more. Then your in the "not enough rig for the gig" land.

You could try coupling the subs to make more of just having two subs. You could also try mono bridging the amp and see if that gives it more welly, but and I mean BUT, if the amp specs are to believed you do not want to run it this way for more than a min or so as you will fry the subs. Its just one way to find out if the amp is not up to the job.

sfbonner

Yes it says 4 Ohms on the back of the subs. I dont think I would be able to bridge them because there is no normal output from one sub to another, just a high pass. So I think that would send high frequencies from one sub to another? Not too sure about this though.


http://www.thomann.de/ie/peaveypeavey_pro_sub_crossover.htmay.co.uk/itm/281140135644?redirect=mobile

unclebill98

If the subs have a x/over built in then yes, the output would be useless to another sub.

Know anyone with a better amp?

sfbonner

But wouldn't the internal 160Hz crossover in the subs only give the subwoofer upto 160Hz frequency? Or do tops coming from the high freq output on the subs need to be connected in order for this to work?

Unfortunately I live in a small town and nobody I know of has a amplifier more powerful than mine.

unclebill98

The subs are fine as it would appear there is an x/over in them. The tops are getting the full range. However like I said rolling of the bass lets the subs do most of that work.

Without hearing it its impossible to tell if your getting the best you can get from the subs with the amp you have.

Couple the subs an gain the extra low end.

sfbonner

I always have the subwoofers coupled, I have just realised that there seems to be more bass behind the subwoofers ( where i normally DJ ) than there is when standing facing them, so i can try turning them around. I never tried putting them against a wall either ( I read that putting them next to a solid wall increases the bass ). Thank you for all of the help!

unclebill98

That would be perceived loudness. The wave form would be best at the front. However sub wave forms will have a element of backwards travel where as the tops don't, hence the thinking that they are louder from behind, your just getting less tops.

Same thing when placed against the wall, your must playing around with the bass waves etc.

As with any PA for the mobile DJ, just worry about dance floor coverage. Anything after that is a bonus.

sfbonner

Oh yeah, completely forgot about the tops facing the same way ha so thats why it seems there is more bass.

Thanks for all the help, nobody around here would have been able to give me all that information!

I will play around next time I get a chance and will reply to let you know how I got on.

sfbonner

I completely forgot that i had a Behringer DFX69 in my loft and that has a low pass filter on it.
So i connected it up and the sound is far better. Much more deeper than before.