Building a set of PA speakers, any help appreciated.

[Bull]

I'd say the Eminence Delta 10 would give better [vocal midrange] than the Delta pro 12 which would give more low mid.
And use the Eminence Kappa 15LF or Kappa pro 15LF for the bass.And the Fane CD140 1 inch titanium compression driver with Fane FH323 polyamide horn flare.

[sreten]

No, just an angled 4 x 4.

I've been thinking some more about the possibilities.

With 100W per channel I reckon your into the bass extension
cabinet volume efficiency trade off applied to all speakers and
118dB single channel over 120dB both will be plenty.

The Eminence APT150 seems to suit well and is a good price here (£24) :

http://www.bkelec.com/

Is basically a 4"x 8" horn loaded tweeter and you can ignore the
power ratings once you've padded it down to ~ 100dB. You can
also ignore Maplins warning you must use a 6KHz crossover.

TBH one per side is all that really needed crossed over at the
classic hifi ~ 3.5 KHz. Fit it with a L-pad of course after the c/o.

Now a 4 x 8 with the tweeter as shown in one of your diagrams
will be equivalent to the 1x15 + tweeter they currently use and
would probably manage a lot more bass output.

The problem with most PA loudspeakers is they do have
earsplitting output capabability in the midrange / treble
and thats about it as far at it goes.

If you go the Audax route more because because it would look right
and be flexible I'd suggest three 2x8 horizontal cabinets per side.

One horizontal cabinet would have the tweeter mounted midway
above the two 8" units. When stacked with another cabinet its
inverted to effectively form the 4 x 8 you show. Adding in the
final cabinet will give you a 2 x 8 , tweeter, 2 x 8, 2 x 8.

The 2 x 8 + tweeter could have a c/o on the 8" units but I
suggest the other two 2x8 cabinets are simply run full range,
or knocked back a little with an inductor.

So for your 100w per channel powered PA you have a
choice of 12, 6 or 4 ohm loading and sensitivity of your
"stack", 92dB, 98dB or 100.5dB.

Bass alignment of the cabs I'll leave up to you.
Also how you deal with BSC but line level only.

The tweeter pad would be marked for the 3 versions of use.

Some compromises made, but the midrange should be good.

Only one "top hat" mounting per cabinet is needed, and
you could use locking plastic corner protectors for stacking.

Spruce* ply cabinets, finish carpet or scuff proof textured
paint applied with a dirt cheap foam roller will do the job.

(*spruce ply is far cheaper than birch and finish is poor,
bit its a not as dense as birch so if you use a thicker
section it will still be lighter and stronger than birch ply)

sreten.

[5th element]

OK well I and he have lots to choose from now. I think he already uses two 15" cabs when he borrows it off a mate of his when he needs equipment. With regards to SPL Im just concered etc that it wont be enough in some cases. But I will have a better idea when he tells me what he already uses. It may turn out that the cabs he uses now go plenty loud enough and they go louder then they require anyway.

Depending on how much money he wants to spend, I think its quite a bit TBH so budget components are not really needed. So depending how much to spend and SPL I had another idea for a speaker.A compression driver say the fane CD140, two Audax PR170ZO in an MTM and two Cres12MB per cabinet. This would give an average SPL of about 98-99 SPL after BSC. This is quite a bit more expensive but the audax mids are meant to sound fantastic which I think it the primary goal along with SPL.

If it turns out the 15" cab he uses is way more then enough then I would simply use one fane CD140 one audax PR170ZO and a suitable 15" bass driver, giving about 93dB sens. The fane bass drivers are good because they have a reasonable one way xmax. The audax will need to be crossed at about 300hz, audax say its range covers 500 up but it actually goes lower. I could use it at 300 with steep slopes. 0.5mm xmax aint alot but my W15's crossed at 150 dont move a mm so at 300 I think excursion will be fine. The Colossus 15B-600 looks like a nice candidate for bass. Infact the fane drivers typically look much better then the eminence ones anyway.

What d'ya think of that idea?

[sreten]

It sounds good. And probably the best option.

But its not scaleable for use in various contexts.

I've got used to the fact if someone asks " whats the best
.......... for .......... I've got a ........ budget they do really
want to spend that budget, even if they don't need to.

I still think what would make then happy is valve amps.

sreten.

[5th element]

With regards to budget I think its whatever it will cost, obviously within reason I cant go buying super dupa JBL units that will make it many pennies too much!

Yes this wouldnt be scaleable I dont think that would really be an issue as the speaker wouldnt be humongous in size anyway which is the main factor, can i fit it in my car, if it can, then it doesnt matter if its a bit overkill for one venue. Im not going to be there to set it up either and I know the simpler to set up is better. If its one set up everytime then there is less chance for it to go wrong.

OK well cheers for all your help it looks like ive got a nice cadidate to tell him about. Im also pleased that it uses a nice quality mid for jazz stuff, I did have my reservations about PA stuff for this in the first place.


Cheers Matt

[sreten]

Just checked the Audax unit and its 96dB in the flat
part of the midrange, so your SPL's are a little off.

I've checked excursion limits, 100w at 600 Hz, but
only 10W at 300Hz, it does not go below 500Hz
with 100W driving it, it is 50W at 500Hz.


My final thought on the Audax 8" :

You could make a 12 ohm 92dB vertical pole mounting
MTM with the Eminence tweeter for the two guitar only
gigs, but with no BSC, just tonally tweaked at the desk.
Then add a 4 x 8 reflex bass cabinet crossed over 1st
order at the BSC frequency, 92dB/W 6 ohm with full BSC,
(still 12 ohm mid/treble - BSC again)

Certainly compared to most "PA's" max midrange and
treble levels would be modest, c'est la vie for BSC.

I'd say 150w to 225w per channel would be about right here.

If mid/ treble levels become an issue add another MTM.

sreten.

[5th element]

Posting a reply a coupla months on! anyway this is really for sreten. Instead of the Audax PR170ZO unit do you think that the focal 7K6411 would be a better choice, obviously the price is something to think about. But this driver has 4 times xmax of the audax and can handle more power. Simulating with the ZO shows that your very limited with the design whereas the 7k would add greater flexability.