Sorry, I am reposting this as my first try ended up in the FS forum
I have a couple of pairs of L-100's in good condition. What is the advisability of using one pair for my sons rook group PA system. It will be driven by an onkyo 100 watt integrated amp and the source signal will be 3 akg microphones through a high end yamaha mixer.
Aside from the sacreligous aspects of this idea, what are the technical merits?
Thanks,
Chris
Not a good idea, in my honest opinion. You see live audio with musicians produces signal far above that from recorded music! Now If you go to a concert and you see the equipment they work with you notice lots of compressors and limiters! A singer screams into the mic, the limiter catches it, and keeps it to a safe level. The bass guitarist hammers the E string, and this signal is considerably stronger than any signal on a record or CD! Its very easy to overdrive your amps with live music to way higher than normal levels and this is why Musical Instrument speakers are made to withstand such abuse!Originally posted by rcpmac
Sorry, I am reposting this as my first try ended up in the FS forum
I have a couple of pairs of L-100's in good condition. What is the advisability of using one pair for my sons rook group PA system. It will be driven by an onkyo 100 watt integrated amp and the source signal will be 3 akg microphones through a high end yamaha mixer.
Aside from the sacreligous aspects of this idea, what are the technical merits?
Thanks,
Chris
The L 100,s are Bookshelf speakers designed to play pre recorded music and are not designed to handle the abuse live music dishes out. Your speakers could be blown quite easily.
Just to clarify, this would be for voice only and not sound reinforcment of the instruments.
Aren't the component drivers originaly those of studio monitors?
Wouldn't they have been subjected to non-compressed signals as well?
Isn't there some output limit provided with the 50w /Channel amp? The amp, (Onykyo A-7040,) has meters that show output in green, with RED leds between 50w and 100w per channel.
I need more information about this proposal. A simple "they are home Hifi speakers, therefore...," even though that may be the case, is too off the cuff to be satisfying.
Thanks,
Chris
What they are trying to tell You is the L100īs are designed for complete musical range, which varies widely in frequency, instead of a closer range such as voice; the drivers of the L100 are not designed for continuous voice, You will burn them to get enough sound.
For SR get some EON15Pīs, if You sell the rest, You will end up with money.
If You want just voice, E120's with 2416's and 2307 horns, 1,200Hz X-over or so; look for "cabaret series" also.
Alex.
Voice is very demanding too! You can get your voice to sound very deep through the mic by proximity effect and bottom out the L 100,s woofers more easily than you ever imagined!
Feedback! Open mics feedback! You hear the shrill screech from your speakers one second, and the next second your tweeters and mid drivers are fried! Instantly! Thats why pro applications require feedback eleiminators on mics in addition to EQing! You happen to have a Sabine feedback controller?
The Onkyo reciever is not up to the task of live voice either! Live voice has wide frequency range, and large amplitude transient signals and makes the amp work at continous high levels of output! You can drive the onkyo to twice its rated output, and the Onkyo will heat up, and shut down! Thermal overload! Consumer recievers have NO limiting features, as limeters are never really used in consumer Hi Fi.
Dropping a mic! It happens! Speakers will protest! With the exception of a very few audiophile recordings and test recordings all music is compressed. Your JBL L 100,s were never designed to handle the extrtemely large dynamic range of Live Voice or Live Instruments!
Studio monitor components are quite different than pro drivers for live and sound reinforcement work! Studio monitors use drivers that have very high accuracy! Sound reinforcement and MI drivers are designed to takes very high levels of power and abuse! And how many Studios blow their monitors on a fairly regular basis? Guys doin a mix in studio A drive the shit out of monitors too!
Voice can be very demanding as I said before! Thats why all the pro speaker manufacturers used Phenolic diaphragms in compression drivers for speech application, unlike the Aluminum or Titanium diaphragm in the driver intended for music!
If you dont feel confident in my words call JBL at 1-800-8-JBL-PRO! Ask for Everett Watts and see what he has to say!
Last edited by scott fitlin; 10-23-2003 at 04:41 PM.
Scott, Thanks for the JBL contact.
You guys are likely correct but I'm looking for the definitive word.
I will check with JBL and report back.
Your idea of using full range home/monitor speakers in a PA application is not all that off-base. The concept of stacking full range speakers has been done with great success (Greatful Dead), but usually the drivers are robust, pro quality units, stacked in large arrays , and driven with tons of power. The things you should probably do to make this work is cut the low frequencies, say below 80 Hz, down significantly, stack at least six L-100s on each side, and use six big, 150 watts per channel stereo amps to drive these.
Tom
Last edited by Tom Loizeaux; 10-23-2003 at 05:29 PM.
Six L100's per side would still be less effective and way more expensive than a better pro system/equipment made for the job.
To the original poster; I have quite a bit of experience with both home and pro gear, and attempted things like you are talking about. Go another route.
Even with mutual coupling the efficiency of the L 100,s and the little integrated amp with 50wpc will be out of gas quickly!
The drivers in the L 100,s are not rugged enough for this kind of use! Especially the mid driver and tweeter units!
Grateful Deads Wall of Sound was amazing! All that top of the line Pro JBL and a million dollars worth of McIntosh! But they had all the neccesary electronics and engineers to run that system properly, and it was JBL Pro drivers, the best of its time, and still good today, too! They blew plenty of speakers, too.
I just dont think the L 100,s are tough enough, nor designed for live application, whether voice or instrument.
That phone call should make Everett"s day!!!!! Oldmics
No doubt!
But Everett will give him an answer! The right one. And if asked he will recommend whats right!
Not yet mentioned, but another reason not to use your L100s for this task is that the early models used minimalist crossovers that will not provide adequate protection for your speakers. With live sound you will easily be clipping your amps and be more likely to burn up your tweeters than you would with a higher powered amp that can better deliver clean high-level transients. The current LSR32 studio monitors use 4th order crossovers. If you don't need the L100s for another room, perhaps you could sell them on ebay and buy some used 2226H, 2426H or 2416H compression driver, and a 2370 horn, or a cheaper clone from PartsExpress, and use the SR4725 crossover, the schematic is available at the prosound archives and I have a copy of the PDF file if you need it. Used Eon 15s, as mentioned above, may also be a less expensive solution. This combination of drivers will be much more robust than your L100s and will also have good resale value if you don't need them in the future. You may still probably want to look for a used pro sound amp. I'm not up on what the current best used pro amps are but QSC and Crown have good reputations for quality construction.
Last edited by TimG; 10-23-2003 at 09:26 PM.
Yeah, since L100's go for around a grand a pair on eBayyou can sell both your pair and buy some pretty damn cool Pro JBL's instead
That's funny.Originally posted by Giskard
Yeah, since L100's go for around a grand a pair on eBay
I'm guessing in fact they might bring $500 or so. One pair stays in my livingroom.
What I can sell for $1000 and more is a pair of perfect Rogers LS3/5a's that I picked uo 3 years ago from the GoodWill thrift store in Seattle for... well you can't imagine how little... I've spent more buying espresso and cocoa's for my family in Starbucks.
Anyway I'm begining to be convinced I shouldn't try this, although your imaginations have gone abit off the mark in picturing the venue. I am talking school gym or church basement.
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