• JBL Installations

My personal experience came on a small scale some years ago; I had music playing outdoors at a small festival through some older JBL horn loaded cabinets (4560BKA) which are fully horn loaded for the woofer at 200Hz and above.

The old literature stated that 4560's were for use in listening distances of 80 feet and beyond. I walked down a street and up a hill where go-kart races were taking place, and was really suprised what kind of presence and volume these two simple cabinets had at about 450-500 feet distance. Much different than a non-horn box at any volume level. I listen to them in my workshop area and the response below 200hz suffers since the horn is only so long.

My 4560's never fail at outdoor parties to impress people, particularly when they realize I'm only running a watt or so average much of the time.........Lucking into these cabinets some years ago is what made me a (very) amateur JBL pro gear fan.

Now, give me reasonably near-field listening and I'm plenty happy with a non-horn woofer arrangement. I've hired a guy for years to do a smaller outdoor festival, 200 feet wide, 400 feet deep, 1000-2000 people, and he uses McCauley cabinets. Not as efficient, obviously, but they are fine.

Again, however, check out what Turbosound or JBL uses for the long-throw situations..........geez, am I wearing this out, or what?

If there is a forum for "people who like using good pro audio stuff at home because it is fun and loud and built like a rock", then we're in luck. Otherwise, Mr. Johnson might as well go to the pro audio forum and start pickin' their brains.........

Still, as an utter neophyte to these forums et al, I have to say that Pi speakers are interesting to me because they seem to promise what I have come to love about pro audio boxes........ efficiency, dynamic range, high SPL capability, heavy duty drivers. I've always said that I would rather hear a big box loafin' than a small box workin' hard.......... think of the irony of those guys who love the really expensive, high tech small speakers, with 5.5-6.5 inch woofs, etc. I understand and appreciate what it is that they like, but keep coming back to "the big sound".

I design loudspeakers because the choices I would make aren't found anywhere else. The components I use are sometimes value-priced, but more often than not are higher quality parts, occasionally price-no-object. I tend to prefer high efficiency speakers with controlled directivity at a fairly wide radiating angle that isn't very tall. Good on-axis response is important, as is a uniform reverberent field. To make this happen, I pay careful attention to driver spacing and crossover topology. I also like the cabinet to be attractive as furniture. Pi Speakers do well at all of these things; It's important to me that these criteria be met.

I spend a lot of time perfecting the designs, and even though I do it just for my own use, I find it better not to keep the designs to myself. It would be gross underutilization to spend dozens, sometimes hundreds of hours on a design, and to have the loudspeaker only used by one person or a single family. So by publishing the designs and supporting them here on this forum, they benefit others as well. It is very gratifying to see my loudspeakers proliferated across the globe, enjoyed in homes and small businesses everywhere.

The fact that only the audience is targeted means you need less power than a system that scatters everywhere. A football field stadium with an audience of up to 70,000 people expecting up to 125 dB in most positions can be had from an all horn loaded system using around 40,000 watts. I have worked and mixed on non horn loaded systems in these same venues with systems of over 150,000 watts and not got as high an SPL at distance, and a far less intelligible sound. The 150 Kw system with all its amps takes three 32-ton trucks, 18 crew and 2 days to assemble. The 40 Kw system will fit in one 32-ton truck, needs only 6 crew and an afternoon to setup. Need I say more.

Best wishes,

Rog.

There are several horn flares that are designed specifically for dispersion control. Most designers are more concerned with directional control than they are with acoustic loading purely for efficiency's sake. That is definitely the current trend, the focus of modern loudspeaker design.

About loudspeaker arrays, when there are multiple point sources - which is what it takes to fill a 70,000 seat stadium - then directivity control and efficiency are your friends. One helps convert electrical power to acoustic power, and the other helps you put it where you want it without comb filtering and other anomalies.

• X array info page