Active Pa Bass Subs

[Kevin Dean]

I'm looking at getting a new 15" or 18" active sub , both are the same make "Alto" & same wattage but not sure what benifit the 18" would give me for the extra money if any?

[JTUK]

I think subs are a bit more critical than tops in some ways. We tried some pretty flabby and unfocused units
and they just sound like mush.
Depends how you want to use it... a reasonable sub with good tops might just add a bit of depth and seperation
which could be all you need for a pub or small venue.
Subs are hard to demo but I'd be thinking 18" over 15" if weight and size wasn't an issue, but you still need to hear one.

We brought a Mackie Thump on spec and it was a pile of poo... so we had to buy again... Not good.

[Kevin Dean]

At the moment I use Peavey Ul 12 tops & active cross over using 1 x 15 UL subs . but at the weekend one of the subs blew .Having said that we didn;t notice . I like the idea of having an active sub making setting up nice & simple , we use an electric kit & keyboards by the way.

[JTUK]

I don't know those tops, but you might try just the one sub to see how you get on.
Taking 2 subs is a bit of a pain for the gain on some gigs..i,e the smaller ones,
but you'd hope the low end extention of a decent sub would enable lesser tops
to sound better, just because they didn't have the bass going thru them.
We roll off 120hz off the tops and so they could theoretically be pushed harder
but it isn't so much about volume, it is about the seperation of the sound.
We think our new Yamaha 12 top and one sub will outperform QSCKW12 tops with no subs
and the signs are good.
Our choice was getting a decent sounding 12 sub that was quite small and light-ish... just to add
a tad down below, rather than carry a very capable 18..
We felt we could justify the carry and set-up of the 12" on every gig rather dance thru hoops
and then consider leaving the 18" at home.
So, our default rig is 2 12" tops and 1 12" sub which is as easy a carry as we could find and the sound is
worth it, from our use so far.
We have reasonable expectations of how large a gig we can go with it. It certainly hasn't ruled out hiring
a P.A and I doubt it will upscale much beyond a 250 people hall...and that is with another 12" sub.

EV and Yamaha do 12" subs that are regarded well, IMO. If they aren't good enough you are looking at RCF 18"'s
and probably close to £1k each..???

There is a pro argument..and it is valid, IMO, that heavy loud subs and active amps being rumbled about inside is not really a good idea..??

[bertbass]

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[cameltoe]

Can only comment on my specific experiences- first we used Mackie SWA1501. Weighed a ton, but gave great punch, in not a lot of thick low end. Seemed to easily cope with the level of the SRM450's and to balance the tops only had to be set halfway. Around £300 each second hand.

Now using JBL EON 518s- very different. Light, big, loads of thick low end. Lacked a bit of clarity and punch at first, but have paired with an old-skool BBE Sonic Maximiser which has tightened them right up. Much more spread to the bass than with the 15's, will fill a room with bass easy. Need to be driven a bit to keep up with the SRM450's though. I think around £800 each new?

Best sub we have used was an 18" QSC. That really kicked, and we only used the one.

Edited August 12, 2014 by cameltoe

[Kevin Dean]

I've just ordered the Alto 15" active sub at 600 Rms & 1200 max ,weighs only 60lbs rrp £349 ..... from GAK including 4 sets of bass strings & a capo £347 I already use 2 x Alto monitors & for me they have been very good value for money .

[mrtcat]

I generally prefer 15's when talking active subs for a band. The 18's are better for djs who need extension down to 35hz but the weight of a kick drum is around 60hz and any decent 15 should excel at that frequency.

[cameltoe]

[quote name='mrtcat' timestamp='1407924076' post='2525327']
I generally prefer 15's when talking active subs for a band. The 18's are better for djs who need extension down to 35hz but the weight of a kick drum is around 60hz and any decent 15 should excel at that frequency.
[/quote]
Yes that was my experience with the Mackie vs JBL- the 18's really benefitted from the sonic maximiser to get that thump.

[goblin]

For band work I prefer 15s. I've got a pair of HK Actors which are 15". I've only been using one with a 1500 watt vocal PA, and it just takes a bit of pressure off the tops (EV SXs) and adds a lot more depth.

You do need a good system controller / crossover though. Otherwise you're just giving a sub a full range signal, and they tend not to like that...

[Skinnyman]

[quote name='goblin' timestamp='1408298130' post='2528770']
For band work I prefer 15s. I've got a pair of HK Actors which are 15". I've only been using one with a 1500 watt vocal PA, and it just takes a bit of pressure off the tops (EV SXs) and adds a lot more depth.

You do need a good system controller / crossover though. Otherwise you're just giving a sub a full range signal, and they tend not to like that...
[/quote]
Ok, dumb question....

How do I prevent the bass signal getting through to the mains? We have a Yamaha PA with a main stereo line out and a separate sub out (which actually gets the full signal so would need an external crossover to feed a pair of subs). Which is fine - but how do I stop the bass going to the mains? Another crossover?

[stubass]

Interesting, our guitarist is a sound engineer and is looking for thumps as he reckons they're the best. Not sure if I agree. I have a couple of 15" passive subs and a 500w crown amp that have served me well. Sounds crisp to me and the drummer loves them too. I hope he keeps the receipt!

[JTUK]

We sold our Thump as soon as we could... big, heavy and flabby.

Now, I don't expect 2 tops and 2 subs to do too much. That sort of rig will do a
pub very well and a small hall, but not much further.
Having said that... there is something to be said for the P.A that runs out of steam before it hits the bar area
as that is where people can get away from the sound.

[stubass]

[quote name='JTUK' timestamp='1408344821' post='2529073']


Now, I don't expect 2 tops and 2 subs to do too much. That sort of rig will do a
pub very well and a small hall, but not much further.
Having said that... there is something to be said for the P.A that runs out of steam before it hits the bar area
as that is where people can get away from the sound.
[/quote]

That's always been my philosophy. Play to a sweet spot. We play weddings mainly so you don't want to be loud to the point it puts people off. We have an extra set of tops if required along with our wedges, never needed anything more for a medium sized hall with a crowd of 100-150.

[Kevin Dean]

For me it's about quality , We only play pubs /clubs .but a cross over & subs I can get that stadium sound with the thump of the bass drum coming through & a nice mix ,plus with an Electric kit we can be as loud or as quite as the landlord likes & that helps us get gigs where volume is becoming more of an issue for the pubs down here .

[cameltoe]

[quote name='Skinnyman' timestamp='1408300311' post='2528809']

Ok, dumb question....

How do I prevent the bass signal getting through to the mains? We have a Yamaha PA with a main stereo line out and a separate sub out (which actually gets the full signal so would need an external crossover to feed a pair of subs). Which is fine - but how do I stop the bass going to the mains? Another crossover?
[/quote]

Not sure exactly what you mean here. You would normally just take the main LR stereo out into the crossover, which would then spilt between High freq LR and low freq LR. Low going to the subs obviously, and the exact crossover frequency can usually be adjusted to optimum performance for your cabinets.

The Sub out on a desk usually refers to sub mix and doesn't need to be used in live applications.

Hopefully this is what you mean and clears it up?

[Skinnyman]

[quote name='cameltoe' timestamp='1408741325' post='2533202']


Not sure exactly what you mean here. You would normally just take the main LR stereo out into the crossover, which would then spilt between High freq LR and low freq LR. Low going to the subs obviously, and the exact crossover frequency can usually be adjusted to optimum performance for your cabinets.

The Sub out on a desk usually refers to sub mix and doesn't need to be used in live applications.

Hopefully this is what you mean and clears it up?
[/quote]
Doh!

Obvious when it's explained like that. Thank you. I feel very stupid. But better informed at least!

Cheers

[goblin]

Yeah that's a common way to do it. Depending on which PA I'm using for a gig, I don't always need a crossover. If I'm using the smaller rig with a little desk and 1000watt rack amp, I'll use the EV system controller, which is basically EV's own crossover.

The inputs are simple left and right from the desk, and then there's a left and right output for the tops, and then 2 mono outputs for the sub (so if going active you can send to a pair, or to different power amps if ising passive subs).

The big desk (soundcraft powerstation 1200) has a dedicated sub out with a sub filter, with that I just feed the tops with the desk and then use the sub out to a single sub.

The best thing to do is check the instructions. They'll tell you whether your desk has a send for a sub or a sub mix.

[mrtcat]

Most decent powered subs will have an lp filter built in and a full range through to send to tops. Some tops will have an hp filter which then negates the need for a separate crossover.

[cameltoe]

[quote name='mrtcat' timestamp='1408880904' post='2534256']
Most decent powered subs will have an lp filter built in and a full range through to send to tops. Some tops will have an hp filter which then negates the need for a separate crossover.
[/quote]

This. We run active JBL 18's with an inbuilt filter which negates the need for an external crossover. Sounds good enough. I'm sure with a decent crossover we could get a bit better results, but it's just another bit of gear to lug around then, and no-one listens anyway.

[Kevin Dean]

I use a Peavey XR 1212 , this has a built in active cross over & the auto EQ ..that a lot of my friends don't seem to know about is very handy .

[Kevin Dean]

I have now done a few gigs using the Alto 15 " powered Sub & the whole band have been very impressed great value for money .

[bassintheface]

Although not the cheapest, we use a JBL PRX set up.
Active 15" mid high cabs and 18" XLF subs.

That speaker set up paired with the X32 is brilliant.