Using bass cab as PA Sub?

[pendergasta]

Edit: See my next post below for more detailed info on this---

I have a 15" bass cab that I use with my Ashdown Combo. (Shown below)
Could I (or, should I) use my cab as a subwoofer for my band's PA system? It would be at reasonably low volumes, just classic rock and oldies. Am I wasting my time or putting my speaker at risk? It's a Celestion 15" 300W. The PA system right now is a Yamaha StagePas 300 (150w per side)
Any advice or thoughts would be greatly appreciated.

We are booking some of our first gigs after new years and I'm trying to make sure that we have enough live sound gear in order.

 

[4Mal]

That thing is pretty limited - the Stage PAS I mean. You've only got the Monitor out to play with for a sub which of course means no monitor unless you split or run 1 speak for main and 1 for monitor or you play quietly enough that you don't need monitors. Truly that system is designed for a couple of guys and their acoustic guitars playing at a level where they don't need monitors ...

If you can live with out monitor's then you can use the Monitor out to drive an amp and a sub using an electronic crossover with a mono sub out.

If I were going to do that - which I probably wouldn't - the amp would be a QSC RMX - that one has a selectable 50 hz hi pass filter on it - that's going to help protect the sub. The issue with your concept for me is that by adding the sub, you're aiming at playing louder than you probably can run without monitors - and singing 'blind' sucks ...

My advice would be save your sheckles and get a real PA down the road somewhere, leave this one in the rehersal space - don't laugh too hard - it's pretty sweet being able to walk in and reherse without dinking with PA crap ...

 

[GregShadoan]

While it is certainly possible, there are a few things you need to consider.
1. Is anything you are using in the PA going to need a sub.
2. You will need two things to make this work.
2.a a way to Low pass the unit into the correct freq area - LPF=Low pass filter
2.b an amplifier to drive the sub box.
(2.a)You can use either a passive LPF inside the box itself, or some kind of external active crossover.
(2.b) an amp capable of at least 300 watts, being driven via the LPF device off a signal from the board.
If you are using the Yammy for a music playback system, I would think it would benefit from having an extra speaker setup as a sub. 100 hertz on down or so.
If you are using the yammy for a vocal only system, I see no real benefit.

 

[pendergasta]

Thanks for the info so far guys. I guess I didn't give you the whole story in my original post, so here's the rest:
I have $800 in gift certificates that must be spent at Carvin, and I want to make the best investment possible.

Here is the config that I'm thinking to utilize the StagePas 300 and make it more usable.

-Buy 2 Link Removed.
-Buy 1 Link Removed
-Buy a used Peavey VSX crossover locally
-Run the monitor out through 1 channel of the DCM2000 to the LM15's in series. This would be the mains, and would be running at 700W at 4ohms.
-Use the second channel to run through the crossover and then to my bass cab, which would be 425W at 8ohms.
-Use the StagePas speakers as Monitors. (basically using the mains channel for monitors and the monitors channel for mains)

With this setup, I'm thinking I could probably just play through the PA at gigs, and maybe run the guitarist through it as well.

Obviously, owning the power amp would give me lots of flexibility in the form of bass, monitor, or main amplification down the road with other bands.

Does it feel like I'm on the right track, or would you guys do something totally different?

 

[GregShadoan]

Yes. Sounds like you ARE on the right track. You are still lacking channel inputs. But it sounds like you have a clue.