Need Recommendations for 2-way PA Tweeter

[Droidipihle]

Hello all ! I am modernizing some old Altec Lansing PA cabs from the 80's. The woofer of choice is the Eminence Delta 12LFA (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-416&FTR=Eminence%20Delta-12LFA) (8 ohm version). This woofer is a near perfect match for the box/port volumes, plus in theory should have far improved bass response. It is as close to a drop-in replacement as I can find. Checking online chat with Chris, he stated I could cross these at 2.5K no problem.

The stumbling block for me is the tweeter selection. Currently, the high frequency drivers are Fostex/Foster horns about twice the physical size of the ones offered by PE. The ongoing problem with those is that at PA power levels, the voice coils blow out with regularity. It was an accepted evil for those of us who used them. Consequently, fixing the power handling issues is one of my redesign goals.

My current idea is to use Pyle Pro PDBT18 (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=272-110) of Podzuma fame. Part of the problem is the impedance mismatch between the 8 ohm woofer and the cryptically defined 4-8 ohm tweeter. Another consideration is that the woofer may reach up to 2.5K, but Dareen states "The tweeter is the limiting factor and cannot play much below 5 kHz", even though the stated response is down to 2K.

Sensitivity wise, the PDBT18 is a better match for the woofer than the existing Fostex horns (98dB). Sound and dispersion seem to be on a par or better than the Fostex horns. The power rating is just what I'm looking for. Also, I can live some non-linearity as the Fostex horns, the Kings of Cheap, are no where near linear down to 2.5K, but any improvement would be welcomed.

Please comment on the feasibility and/or lunacy of this driver combo. Please make any tweeter recommendations you feel would be better.

Lastly, assuming I chose with the PDBT18, do I consider it to be a 4 ohm load, and what other crossover magic do I need to consider for a XO point of 2.5K???

Thanks folks !!!

[donprice]

If you have room for it, the Dayton 6x12 waveguide and the screw-on Selenium D220Ti works great. Lots of info for this combination in the "econowave" threads here and on AudioKarma. In fact, this link will take you right to a parts list for a crossover specifically for the Delta 12LFA and D220Ti/Dayton 6512 combo. http://www.audiokarma.org/forums/showthread.php?p=4575859&highlight=12lfa#post4575859

Of course it will cost a good bit more than the pyle bullet tweeters.

[billfitzmaurice]

I would not run the D12LF higher than 1.5kHz. The on-axis chart may indicate it can go higher, but off-axis is what counts. But for that matter I wouldn't run any twelve much higher than that, for the same reason. Crossing over too high is one of the main flaws of most two-way PA cabs. As for the blowing of Foster diaphragms, that's usually the result of inadequate filtering, usually only second order, often even first order. With a good fourth order filter they work just fine.
I'd avoid anything Pyle.

[Droidipihle]

If you have room for it, the Dayton 6x12 waveguide and the screw-on Selenium D220Ti works great. Lots of info for this combination in the "econowave" threads here and on AudioKarma. In fact, this link will take you right to a parts list for a crossover specifically for the Delta 12LFA and D220Ti/Dayton 6512 combo. http://www.audiokarma.org/forums/showthread.php?p=4575859&highlight=12lfa#post4575859

Of course it will cost a good bit more than the pyle bullet tweeters.
Thanks for the link and info! The parts list is excellent, but is there an associated schematic ? I suppose I could guess, but it would be a lot safer to follow a schematic.

[Droidipihle]

I would not run the D12LF higher than 1.5kHz. The on-axis chart may indicate it can go higher, but off-axis is what counts. But for that matter I wouldn't run any twelve much higher than that, for the same reason. Crossing over too high is one of the main flaws of most two-way PA cabs. As for the blowing of Foster diaphragms, that's usually the result of inadequate filtering, usually only second order, often even first order. With a good fourth order filter they work just fine.
I'd avoid anything Pyle.
Thanks for the info ! You have hit the nail on the head. There is a stock 1st order XO in the Altec cabs.

[donprice]

The crossover is very similar to the standard version except for the zobel (zoebel?) circuit (cap and resister in series) across the woofer. The crossover point will be around 1.6kHz.

http://www.audiokarma.org/forums/attachment.php?attachmentid=151281&d=1242968714

The crossover parts for the pair will cost about the same as a cheap (used?) electronic crossover so consider that if you have a spare amp in the rack.

[Whitneyville1]

Don's right. Bi-amp the things and don't look back. Run a four conductor Speakon connector to the back of each box to make them stupid-proof. Please, please never buy anything from Pyle or Peavey. Personally, I LOVE Mackie equipment. If it quits, for ANY reason, call them ,and your have a return authoriazation # for your's and a loner is on the plane to you. I've had 3 hour delivery from So Cal from them to Tulsa, OK more than once. It's not the cheapest on the market, but I've seen a soft drink spilled into a 2000 watt per channel amp and it just tripped the breaker, and after drying out a half hour it was working again.

[tom_s]

Don's right. Bi-amp the things and don't look back. Run a four conductor Speakon connector to the back of each box to make them stupid-proof. Please, please never buy anything from Pyle or Peavey. Personally, I LOVE Mackie equipment. If it quits, for ANY reason, call them ,and your have a return authoriazation # for your's and a loner is on the plane to you. I've had 3 hour delivery from So Cal from them to Tulsa, OK more than once. It's not the cheapest on the market, but I've seen a soft drink spilled into a 2000 watt per channel amp and it just tripped the breaker, and after drying out a half hour it was working again.

This goes to show that everybody has their favorites and leading the MI sector is often all about marketing. I mixed a friend's band this past summer using his little Yamaha subs and a pair of Peavey SP2x tops with no FOH EQ. I remembered the original SP2s, so I was not looking forward to it. I thought these boxes are way too light to be taken seriously..and come on, they're just Peavey! I was very surprised (stunned is more like it!) by how good they sounded! I hear their line arrays & associated subs sound great, but many touring companies just won't buy them because Peavey isn't rider friendly gear, no matter how good it sounds. Speaking of mixing, I never met a Mackie mixer that I liked. Allen & Heath or Yamaha seemed to feel & respond better for me...but that's kind of a Ford vs. Chevy thing.