Morel MDT37 for live pa?

[milobender]

Hello,

I wonder if any of you can tell me if the Morel MDT-37 is robust enough for 3 Way PA speaker used for live music? I'm having a hard time deciding on a tweeters for these (Eminence Delta Pro 12" on bottom, and Eminenece Alpha 6A 6" mid or B&C 6MD38 6" mid)... I don't want to use horns, at least from what I've heard, I'd like a smoother sound. And of course, money is a problem. Any help would be greatly appreciated.

Thanks,

Brian

[Dirk]

If you decide that they are robust enough, I have a pair that I'd sell. Been kept boxed, never mounted, never received more than a quick test signal with a series cap.

[milobender]

Hello Dirk,

What caused you not to use them? Any thoughts on tweeters for live situations?

[Dirk]

I planned on using them for a set of very large, very efficient WMTMW floorstanders. And then we moved and I lost the perfect listening room to put them in. Cest la vie.

I've also got a set of (4) Peerless CSX 5.5" woofers that were to be used as the mids in the same project, though I think I'll hang onto those.

Anyway, they've got high sensitivity for a dome and wicked amounts of power handling. I don't see why they wouldn't work, though since I'm trying to unload a pair I wouldn't blame you for calling my intentions suspect.

[milobender]

Suspect intentions aren't the end of the world I just haven't made up my mind yet.

I can't see why they wouldn't work either... but they're not technically "Pro Audio" and I'm a total newb with this stuff... I've seen mention of comb filtering with multiple tweeters too. I don't guess I see a way around that if multiple drivers of any sort are used? Just a different "focal" point depending on how far apart the drivers are. Am I understanding this? I was thinking of 1-12", 2-6", and 2 tweeters (per side). Each with their own boxes, and a graphic eq for each section for crossovers. With an eye to doubling everything at some point.


Brian

[andreweckhardt]

Partsexpress.com is down right now so I can't look, but if that's the little horn loaded job I used them for a theater project in a "barn". I used a pair of the Morel 2" domes and the Dayton series II 10" woofer for each satellite speaker. The system is all active crossover with 24dB slope. The worst part of the project is we had to use Peavey amplfiers due to cost constraints. The customer blew out every single tweeter within the first 2 months. He's kind of a meathead even though he's a doctor and in spite of quickly training him as to what clipping distortion sounds like I doubt he could tell after he got drunk partying with his buddies. Anyway, one of the reasons I selected the Peavey amps is the option to engage their little built in soft clipping circuit. I decided to start out with it off and see if the drivers survived and turn it on if necessary. Went around and turned all 18 of them on . Its been a few months now and no more burnouts. The tweeter coils are connected directly to PV900's.That doesn't say much really, because that amp can not output very high voltages, but it plays very loud. I measured the sound pressure before clipping with differnt sources but I forget the value. They're not very forgiving tweeters and I would suggest leaning toward higher fidelity power amps. After all, if you're not really into higher fidelity you can spend a little more money and get some compression drivers and horns that will play several dB louder with less distortion at such SPL and last a lifetime in the right hands anyway. If I had it to do over I would have used compression drivers for the tweeter. So yeah, it's been done. Technically not the same as live sound but the way this guy plays the system it may as well be live. Off hand I think I measured 105dB or something in before serious clipping. If you decide to go for it just don't feed them any square waves.

[wg_ski]

Depend on what you mean by "live PA". If it's fairly tame music and venues, it will likely work. Amplified acoustics, vocals, etc. in an intimate setting - go for it. Try to do a school dance with it and expect burnt tweeters. MDT37 works really well with the Alpha 6 - but I'm using the setup in a car with subs. The box works well for tailgate parties, but won't do the whole parking lot without stress.

[Hackomatic]

The system is all active crossover with 24dB slope. The worst part of the project is we had to use Peavey amplfiers due to cost constraints. The customer blew out every single tweeter within the first 2 months. He's kind of a meathead even though he's a doctor and in spite of quickly training him as to what clipping distortion sounds like I doubt he could tell after he got drunk partying with his buddies.

Is it possible the "Meathead" had the amps on then powered up the crossover or mixer spiking the tweets?

A series cap might be good insurance . . .

[billfitzmaurice]

Hello,

I wonder if any of you can tell me if the Morel MDT-37 is robust enough for 3 Way PA speaker used for live music?

They're 10dB shy of the requisite sensitivity.

[Paul O]

They're 10dB shy of the requisite sensitivity.

Exactly... so why not use something like the Selenium slot tweeter if you're building a 3-way...
http://www.partsexpress.com/pe/showd...number=264-360

Also... should be no need for 2 mids.

P.S. I have a big set of 3-way PA cabs with a 15" low, 8" mid, and 1" bullet tweeter which have seen years of abuse with absolutely zero driver failures. The bullets are crossed at about 5khz at 12db/oct and are 50wrms drivers.

[subsonic]

with pa stuff, its not the normal use that blows stuff, its the drunken
screaming into mics and cords being unplugged and the unexpected
stuff, thats why I would not do it, but if its a dj thing and you cross
them above 3k at 24db per octive you may be ok, but they will
have some power compression above 105-110db...
that said, I am amazed
how loud atc mains with seas tweets will play.

[milobender]

Thanks everyone, for taking the time to help.

Paul:

I've been thinking about the possibility of bullet tweeters also...

P.S. I have a big set of 3-way PA cabs with a 15" low, 8" mid, and 1" bullet tweeter which have seen years of abuse with absolutely zero driver failures. The bullets are crossed at about 5khz at 12db/oct and are 50wrms drivers.

How is the sound quality of the bullets compared to soft-domes? Were/are you happy with the sound you got with that combination?

The Selenium Slot tweeter caught my eye also... but I thought the power rating was too low. Am I mistaken here? I'm familiar with my guitar speakers and their subjective loudness levels per watt, but I have no idea how the tweeters will subjectively sound with similar wattages applied...

How does the sound quality of the Slot tweeter compare to the other two possibilitys mentioned above?

I'd like highs as "smooth" as possible, but having said that, I realize I don't really know what causes the "harshness"... like the nasty tone from cheap horns

[andreweckhardt]

with pa stuff, its not the normal use that blows stuff, its the drunken
screaming into mics and cords being unplugged and the unexpected
stuff, thats why I would not do it, but if its a dj thing and you cross
them above 3k at 24db per octive you may be ok, but they will
have some power compression above 105-110db...
that said, I am amazed
how loud atc mains with seas tweets will play.

Just to note when I did the barn theater system I crossed at around 6k /24dB oct.

[andreweckhardt]

Is it possible the "Meathead" had the amps on then powered up the crossover or mixer spiking the tweets?

A series cap might be good insurance . . .

I built a powering sequencer circuit and everything is powered through relays. I wish we could have just bought one but the budget was too tight. If that sounds all backward you have decent horse sense. I wont do it again. I wasn't the money man on the project but next time I will demand that either a system has to be much more simple or the customer is going to pay. The sound didn't come out quite as good as I hoped just because the crossovers and amps were not of high enough quality. The Dayton 10's had a resonance problem at the upper crossover point that was very hard to deal with too, but the driver was able to handle the most power for the money. Done deal.