PA Speakers for gigs

LI Slim

LI Slim

New member
I am looking for a pair of speakers to be used with a powered mixer for small venues. Probably 15" speakers. Mackie, Yamaha, JBL, Carvin -- they all have candidates. Does it matter? Which is best? Also, I came across Avatar speakers, a small company from San Francisco, is anyone familiar with them?

Please help.......
 
The ones you mentioned are pretty much all the same - boxy, boomy, "PA" sound. But, JBL is probably the best choice of the major brands.

I haven't heard them, but Avatar uses Eminence drivers which are typically low end.

You don't even start to approach what I consider to be decent sound until you look at brands like Bag End or Meyers.

barefoot
 
The Bag End ELF (Extended Low Frequency) sub design is outstanding. Rather than a big ported systems whose transient response severely degrades at even moderate power levels, the ELF uses a very small cabinet with active circuitry and powerful amplification to reach the low bass. I use a similar design for my subs.

Meyers has a fairly traditional design approach but uses the highest quality drive units, does perhaps the best engineering of their horns , crossovers, etc., and builds their cabinets like rocks.

I don't keep up on prices, but I know Meyers and Bag End are expensive. Quality never comes cheep.

I'm currently designing my first true sound reinforcement system for a friend's 4000 sq ft (370 sq meter) graphic design studio. I beta tested a more modest satellite system there last week and it sounded spectacular. Fidelity wise they left his JBL SR4731X's in the dust. But, they weren't up to the task of filling the space with sound after the usual 100 or so people show up to his frequent parties. The new system will not have this problem and will be even higher quality.

My design is completely none traditional for sound reinforcement. The distortion levels are so low and the dynamics so wide that you can actually hold a normal conversation while sound is thumping through your bones. There is an amazing sense on space even at very high SPL's. Of course this doesn't come cheap. The cost of materials and components alone is about $6000 and we're still reusing one of his amps . Since he's a good friend and I'm sort of using him as a guinea pig, I'm not charging for my labor or development costs. His brother will build the cabinets and I'll assemble and test everything. If I were to actually go into business again and sell this system, I'd probably wind up charging over $25k when all is said and done - not including installation.

Anyhow, I'm straying off the subject, but that gives you an idea what a very hi-end speaker system can cost for a moderate size club.

barefoot
 
Very interesting.

But let's say we're talking about a 1000 sq. ft. coffeehouse and a performance by a solo acoustic guitarist/singer. Significant difference for the low end of THAT sound? For the high end?

Thanks.
 
Well, that definitely makes things easier spec wise. You don't need very high SPL's and you don't need very low bass. The difficulty is actually finding something high quality in that category.

Something like my "beta" system I just mentioned would be perfect for you. Unfortunately there's really nothing like it on the market that I can recommend (that I know of). Look for small midbass drivers (6" or 8") because they generally have better midrange. Any base extension below 70Hz would be a waste for you.

Unless you use stereo effects, I would place the speakers relatively close together and run your voice and guitar through separate cannels. Preferably place them nearly in front of you (maybe over head?). This will give a nice separation but still make it sound natural, like the sound is really coming from you and the guitar.

I'll get back to you if I see a system that looks promising.

barefoot
 
LI Slim,

I did some figuring. If you can build the cabinets and do some basic wiring, I can give you plans for speakers that will sound incredible compared to the average PA speaker.

A pair will cost about $500, maybe more depending on how fancy you get with the cabinets. The main supplier is in NYC.

They will be medium sized, fairly heavy, medium efficiency, and very limited bass below 70 Hz - but for the cost the sound will be breathtaking. :cool:

Let me know if you're interested.

barefoot
 
Very very interesting, barefoot. Yes I am interested. Tell me more (feel free to e-mail me).

It sounds like if I do end up getting one of the previously-mentioned commercial brands I'd be better off with 12" speakers than 15". Yes?
 
Ok, here's the system.

To save time, money and effort on my part, I just did a variation on a kit available a Zalytron in NYC. http://www.zalytron.com/

It's basically the German 2-Way kit (Budget section) multiplied by 4 and laid out as a line array. These are the same drivers used in the previous version of the Alesis M1.

Why his design?
Most pro speakers use horn loaded compression drivers coupled with large midbass drivers to achieve high SPL's (Sound Pressure Levels) and control directionality. This system works on a different principle. It achieves a narrow vertical directionality (desirable) by putting multiple drivers in a line. Interference cancels sound in the vertical direction rather than squeezing it down with a horn. Since the drivers are relatively small wide horizontal dispersion is maintained (desirable). Multiple drivers and the extra surface area and power handling they provide allows the use of relatively low efficiency hi-fi components (4x7" drivers are about equivalent to 1x12").

Details

Boxes
Rough drawings are attached. They include all of the critical dimensions. The second speaker should be built as a mirror image. Joinery details are left up to you. I drew butt joints, but dados and rabbets are preferred. You can get the driver cutout diameters from the Axon datasheets posted at Zalytron. The tweeter holes are routed rather than cut through. Flush mounting the tweeters in nice but not critical in this case. Small holes will need to be drilled behind the tweeters and between the internal walls to run the wires. They should be caulked afterwards. The chambers should be stuffed with 0.5 lbs/sqft Acoustostuff filling. Terminals are left up to you.

Do not use speaker grills of any kind and do not extend the box sides out beyond the front. The side corners should be rounded. The speakers can be attached face to face with some sort of spacer to protect the drivers during transport. The top and bottom panels of the box can be extended beyond the front to help facilitate this since the line arrays don't radiate vertically at higher frequencies.

Box covering, handles, mounting fixtures are left up to you. Don't put carpet or anything soft on the front. A good source for this stuff is Parts Express http://www.partsexpress.com/

Crossovers
The drivers are wired such that they present to same load to the crossover network as a single driver. The German 2-Way crossover schematic, therefore, is basically unchanged. The only thing I have done is specify higher quantity components and replaced the single resistor with 4 resistors in order to account for the higher power handling capabilities of this system.

Zalytron has a special on the Axon drivers: 10 woofers for $180 and 10 tweeters for $150. Call Elliot there and tell him you are doing this variation on the German 2-Way. You need 8 of each driver, the crossover circuit board, and the upgraded crossover components. It's cheaper to buy 10 drivers than 8, but maybe he can cut you a deal where he keeps the extra drivers in exchange for the circuit board, upgraded crossover parts and maybe some other parts?

Usage
These speakers are fairly specialized for the guitar and vocal range. Not that they can't be used for any music, but they do have a couple "problems".

1. Not a lot of bass extension. The -3dB frequency is about 80Hz. The closed box gives it a shallow -12dB/octave rolloff so they still give good response at 70Hz if you tune down to D.

2. High frequency vertical comb filtering. The separation between the tweeters will cause significant response peaks and dips above 10kHz as you move up or down from the vertical axis. Guitars and vocals don't have a lot of information in the region so it shouldn't be a problem. Even with broader band music it's not overly bothersome, and compression horns also have response problems of their own above 10kHz.

The efficiency of these speakers will be about 95dB/W/m. This is on the low side for sound reinforcement, but they will easily fill up a coffee house or small club. A 100W to 200W amp should work well.

I can give more details if anyone decides to built it.:)

barefoot
 

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Most interesting. Now, whether I actually build this is another question.

Thanks for getting into this!
 
Slim- you might want to look at Yamaha's 4115's. I have a pair that's twenty years old, and they are built like a tank, never even blown a driver! My old ones are only 100 watts, but the new ones (with 15" Drivers) go to 150. We're an acoustic/folk duo and have done quite well with the Yamahas in all sorts of venues.
Beware- they weigh a TON! You're gonna need a handtruck for em.


Bob
 
thanks Bob. I'm looking at the S115 IV's (or the 12-inch version, S112 IV), which I think are today's version of what you have.

It's just hard for me to figure out -- assuming I do not go for the audiophile high-end as barefoor suggests, if it'ss worth it paying for the Yamaha or JBL of Mackie models or whether I'd be getting pretty much the same thing with Carvin, Avatar or one of the other less expensive speakers. They all seem to use basically the same systems and components.
 
You could go with a pair of stand-mounted speakers. You will sacrifice low end, but their height gives them great dispersion in any room. I've got a pair of Yorkvilles on stands for small rooms, and in larger rooms or outdoors I use the Yamahas as well. If you're doing a single, that's what I would do.

Bob
 
LI Slim said:
They all seem to use basically the same systems and components.
Click to expand...
LI Slim,

Looks can be deceiving. Cheaper brands and expensive brands may look similar, but the quality and engineering that goes into them can be vastly different.

Here's and example. I think Carvin uses Eminence drivers. Let's assume they use top of the line (which I doubt). Well, top of the line Eminence Delta P-15A 15" drivers go for about $300 a pair. Top of the line JBL 2242H's go for about $1100 a pair. JBL is slightly over priced because of their "name", so lets say $900 a pair as a fairer price. Still that's a 3x difference, and for good reason. The performance of the JBL's with respect to distortion, compression, power handling, etc., leave the Eminences choking on dust.

Visually from the outside you would hardly notice a difference between the two. Sonically, there's a world of difference - especially at high power levels.

None the less, I still think this basic design of large midbass drivers (10"+) and horn loaded compression drivers is just WRONG for applications like yours - regardless of the quality of the components. Even the best designed speakers of this type sacrifice a great deal of fidelity for the sake of efficiency (high dB's per watt).

Until you've actually heard the difference between my approach and the conventional approach, I know it's difficult to be convinced. The only word I can use to describe it is "space". Conventional systems sound crowded, like each note is struggling for it's own turf. My systems sound open, like both physical space and the frequency spectrum have had the walls torn down - almost like you can reach out and touch each note in it's own place, with lots of lots of room in between to breath and take it all in.

Anyhow, I know those words are cheesy. But it's impossible to really describe sound with words. You just have to hear it.

barefoot
 
What about Bose

Barefoot, Bose seems to have PA speakers with a bunch of little speakers instead of one big one. What do you think of them?
 
The basic 802 layout was developed nearly 40 years ago. It was a bad idea then, and it's still a bad idea. The 402 vetical line array is a little better but the execution is completely wrong. Bose arrays are based on their classic 4 1/2" full range drivers. Using a 4 1/2" speaker as a tweeter is worse than using a 12" speaker as a midrange. When you try to make a single driver do too much it winds up doing nothing well.

Oh, and the "Acoustimass" design is nothing more than a small woofer loaded on both ends with bass-reflex boxes. It's a worse idea even than the normal bandpass (closed/bass-reflex loaded) subs you see everywhere around - muddy, undefined bass with lots of harmonic distortion.

Personally, I hate Bose systems the moment I hear them. It's takes the average listener about 5 minutes before they really start to grind on their nerves. Those 4 1/2" drivers produce gobs of intermodulation distortion, which is harmonically incoherent and particularly fatiguing.

barefoot
 
I'm no electrical engineer like Barefoot, but I agree on the Bose stuff. Garbage.
Slim - check out the JBL EON15G2 System. 300 watts down to 39db (they say), with a powered mixer. Looks like the whole system would fit in a compact car. As for sound quality......Barefoot?


Bob
 
Bob,

Electrical Engineer!?!? Put up your dukes, man! I happen to be of a higher species - p h y s i c i s t.;)

I heard the EON15 G2's at a GC in Portland OR almost a year ago. As I recall, I hated them. I was helping a friend pick out a DJ mixer and having no luck with comparisons because the speakers sounded so bad. They wouldn't take the time to hook the mixers up to some studio monitors, so we left.

Maybe I'm a bad person to ask about all this.:) I hold the vast majority of pro sound reinforcement speakers in such low esteem that when comparing them I'm usually coming from the perspective of which one is 'less bad' rather than which one is better.

After my recent experiments with a larger space system I'm absolutely convinced I have a much better way. But it's a very steep uphill battle. My designs have two big things going against them. They're unconventional and they're relatively expensive. Since I don't have extra cash to build some demos right now it' next to impossible to convince people to invest their money just on my word. I'm going to make it happen though, so keep an eye out for that barefoot logo to your left.:D

barefoot
 
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