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phmosele 19th December 2012 05:05 PM

Crossover point?
This probably comes under the category "use your ears," but I have a pair of PAS 18s in slot-ported enclosures and I want to cross them electronically into a pair of EV S-1503 top boxes.
I am toying with crossover points (this is still on the drawing board, so no ears yet) and I am torn between getting the most bang out of the PAS (a higher point) and getting the most clarity from the EVs (a lower point).
I'm still not entirely sure what this guy wants to do with this PA, but it for sure does not include techno basses or Metallica covers. Last I heard he wanted to be able to play his drums along with Karaoke crooners. That's a new app to me!

Last time I used Eminence 18s with JBL 3-way tops I crossed em at 150Hz but that was a fairly arbitrary pick.

GordonW 28th December 2012 05:45 PM

IME, I find, most of the time, that the extra "bang" is because the 18s are "peaking up" a bit in response in that midbass region- which makes them sound louder, but if you measure it,it's not flat at all.

IME, you may need a little more power on the EVs, if they're not already getting at least a good 300w/ch @ 8 ohms. They don't need much more than that, but they do seem to work better, with about that amount. Those S-1503s can "chest punch" pretty good, with good power.


phmosele 29th December 2012 04:15 AM

It appears from poking around the EV "vintage gear" specs that there are two of these cabs that seem to be exactly the same except one has 200 watt handling and one has 300 watt. The plates on the back of these are the 200 watt version.
It's all mono, so they will be driven by one side of a PowerBase 3, which is about 700 watts into 4-Ohms (the equivalent of about 10 watts per ton, if my calcs are right).

It's going to be interesting to see how these two PAS 18" (which I believe to be a high-quality unit, given how PAS mostly makes a living in concert systems) with 1000 watts between them are going to mate with these EVs with that Crown. I've heard the EVs briefly, and they do sound good, but I'm sure something relatively inexpensive has come along in the last 40 years that would sound just as good, weigh 1/3 less and handle twice the power. For around the 300 bucks point I like the Yamaha 2-ways (I forget the model name) but it's his dime and he loves the EVs. We'll see how much he loves getting them out of a crowded bar at 2am now he's in his 50s instead of his 20s:-)

I was planning on pole-mounting the EVs which will help the dispersion situation enormously. And frankly, given the size of the bars and clubs that make up the entertainment circuit in New Hampshire and northern Massachusetts, once he starts trying to whomp these bass units, even thought there is nothing below 50Hz he's going to have some management in his face pretty quickly.

But there are a few bigger places around that he thinks he can get into (although it's still not clear to me exactly WHAT it is he wants to do if he gets these rooms). He actually has four of these old EVs and although I know it's going to be serious overkill for 90%plus of anywhere he is going to get into without being in a band already established on the bigger stage circuit I have considered just tossing a pair a side on top of these PAS bottoms. It would be heavy enough to fall right through the stage (where there is actually a stage that doesn't also double as the floor) but I don't have to hump it; I just have to make a lot of music come out of it. From what I can gather he wants to essentially play canned music and live drum along with it, plus a Karaoke singer of some sort which is essentially stuff I have read about in histories of the NYC disco scene of the early to mid 70s, so while it's unusual, it's not exactly groundbreaking.

But aside from the weight, it would probably make a fairly impressive amd pretty damn loud and clean little PA system. When I think back to when I was a kid DJ in the late 70s I was playing places the same size he's playing and all I had was a home-made 120 watt amp and a pair of 2x12 guitar speakers, and nobody asked me to turn it up. Had it been any louder I'm sure it would have interfered with either the sale of booze or the volume required for gold-encrusted beaux to deliver the pickup lines. He's probably going to meet the same problem in the same-sized rooms; I reckon four of these EVs alone would be enough to blow the windows out of most of the spaces around here.

I realize there is more experimentation required when I actually finish wiring this thing up, but in your opinion where do you think I should start looking to cross over from the bass units please? They aren't horns; they are basic boxes of maybe 8 cu ft with a slot port. From what I think I know about his aspirations, there isn't going to be anything lower than a kickdrum and IIRC that's centered around 80Hz or so, and there will definitely be a 50Hz filter on the amp.

Also, I am concerned that if I DO run serious power through these PAS units (and I'm sure they will handle their rated 500 watts each and they are well broken-in) I could be looking at "only" 400 watts of mids into two of these EVs and I'm not sure if that's enough to keep up with the potential of 1000 watts of bass, although I certainly do understand the difference between trying to produce a lot of bass vs producing a lot of mid, and these EVs certainly appear to be efficient. Apart from heaving about a half-ton of speakers, what would you think of trying 2 EVs + 1 PAS per side? I figure now the mids are going to sprint away from the bass (or at least be able to try). It would cost me the other side of the Crown to run the other pair of EVs, and I was planning on that for driving monitors, but I don't think this guy cares too much about monitors no matter how slowly and clearly I talk about this stuff. Plus monitor amps are cheap and plentiful.

I appreciate your taking the time to read all this guff, and I value your opinions as a pro.

dangus 1st January 2013 10:32 PM

It sounds like the bass bins may be overkill if not unnecessary. I'm tempted to suggest building a cabinet for a single PAS 18" and using that to fill in the bottom end.

phmosele 1st January 2013 10:36 PM

Well, I need em as stands if nothing else. I'm sure they will end up getting whomped at some time. I need to have the capacity for them to be whomped coz this guy doesn't really know what he wants to do with this yet; whether they ever will be is another matter

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