Late fall of last year (05), I had the idea to build my own pro-audio setup. A few hundred hours and a several hundred dollars, I ended up with a sound system that IMO sounded as good as anything I've heard on the water. (note, I've never heard Wetsounds gear and have only briefly heard NVS) While beached the system is clean, clear and LOUD. At 80' underway, it sounds ok..maybe a 7 on a scale of 1-10. The idea came from a friend who ran a basic 150 watt single 2" throat horn and 10" midbass, he leaned quite heavily on the HLCD and the mid-bass lacked, though in terms of SPL it is good for over a mile (~850hz+) on the river. Other than he and I there are no other Pro-audio setups in this community.
I ultimately abandoned the system in favor of Rubicon 450s. (well, I'm not sure favor is the right word) The reason I did this is because my system had a few short comings.
1) Weight, projected 120lbs finished. (i have to lower my tower every use)
2) box complexity (I'll elaborate on this further)
As you see some of my design decisions you may think, "why did he do that?" Well, suffice to say, I'd do things differently the second time around.
The Design:
Without a clear picture in my mind of the desired end result, I purchased a set of JBL 2425H's with Altec Lancing Constant Directivity horns. Then a pair of JBL 2012h.
The 2425's are a 1" Compression Driver from JBL. They are 8 ohm and 110db SPL (1w1m.) Freq response: 800hz-20khz. 100w continuous program power above 1.2khz. Weight 15 lbs ea. I chose the constant directivity horns in an attempt to achieve strong 'throw' back to the rider, leaving the boat at a comfortable volume level. (This was acomplished, comfortable SPL in the boat while decent throw.
(
http://www.jblpro.com/pub/obsolete/2425hj.pdf)
The 2012h's are a 10" mid-bass driver also from JBL. They are 100db SPL (1w1m) 300W Continuous power capacity. 75hz - 7khz. Weight 20 lbs ea.
(
http://www.jblpro.com/pages/pub/components/2012h.pdf)
(btw: I love these drivers, warm sound, CLEAN, and LOUD)
For you guys who are really up on this stuff, I'll bet you can see some problems emerging.
At this point I had to figure out how to power these things. Having never built cross-over networks before, I decided this project was big enough and so I decided to bi-amp the setup.
Let's start at the head unit:
I went with a PG active crossover. I chose this crossover because it has a resistor network that can be replaced to achive any cross-over point. This way I can change the 90hz cross-over point with a 1200hz point. Or 3500hz, or 2000hz. I bought a bunch with the intention of playing around with different cross over points. This cross over also has a Mono switch which I used.
(
ftp://208.187.38.55/Phoenix_Gold/Manuals/Processors/Crossovers/AX204A.pdf)
Now I need a way to match the HLCDs at 110db to the 100db MidBass. Here I selected a Phoenix gold EQ215. This is a 2/3's Octave 'trunk mount' EQ that provides individual control over the right and left channels. Out of the x-over I merged the High's into one RCA channel, and ran that into the Right channel of the EQ. The lows were also merged and run to the Left channel. Then with individual control of left and right I was able to attenuate the HF to more closely match the mid-bass.
(
ftp://208.187.38.55/Phoenix_Gold/Manuals/Processors/EQ_DEQ/EQ215.PDF)
A Phoenix Gold Titanium 600 was selected to drive the Mid-bass. 600w bridged at 4ohm. enough said there.
(
ftp://208.187.38.55/Phoenix_Gold/Manuals/Amplifiers/Titanium/Ti600_2Ti400_2manual.pdf)
The HF was driven by a PG Xenon x200.2, 200watts bridged at 4ohm. Overkill, but it worked.
(
ftp://208.187.38.55/Phoenix_Gold/Manuals/Amplifiers/XENON/xenonampmanual.pdf)
Enough with the electronics, now on to the tower box. The box ended up being where the short-comings of the design were at. The ultimate goal was a fiberglass box. I was already getting concerned about weight with 70 lbs of JBL drivers. I used 5/8" MDF for the frame. Tons of engineering thought went into how to safely secure 70lbs with 5/8" MDF over peoples head on a wakeboard tower that's always bouncing around.
At last:
The Mock Up, taking measurements:
Rings for the MID-BASS are mounted
Here I'm bending acrylic so that the compression driver will fit in once the box is fiberglass wrapped. The
Somewhere along the line I stopped taking pictures.. Here we can see the enclosures for the mid-bass drivers. The enclosures were a point of frustration as I knew I needed something substantial, but could not figure out what would do it and not tack on weight, right now the box loaded with drivers is closing in on 90lbs. So, at last, I found that 5 gallon buckets were the right size and close to the right volume. So I fiberglassed them in. I knew if everything worked right I would have to fiberglass reinforce them to get their performance up.
An attempt to strengthen the back of the buck:
Aluminum plates and thread-all for strength:
Final Mock Up.
BatWinged Ribs:
This spring I ended up traveling quite extensively for work. About 4th of July I was attempting to wrap it in fleece and had two of the acrylic ribs break when I flipped it over while resin'ing it. so I had to pull the resined fleece back off. I wanted to use the box so I racked it up. At that point I had pretty much decided to abandon the project primarily because of weight. About that time I decided to order the Rubicon 450s since Wakeside indicates they weight 22lbs each. Well, Wakeside is wrong, they weight 44lbs each. So I saved 2lbs.
This is the only picture that was taken of it racked up:
So, I'll leave it at that. feel free to ask questions as there was logic behind every decision. Some of the logic may have been flawed, but it was there.
Also, I'd like to thank Wakeworld as I spent countless hours digging through archived threads about pro-audio. And those who posted pictures of their projects which gave me a number of ideas. Those of you who answered my in-depth, or anal, questions: Grant & Clay, Mikeski, Adam Curtis, Rod McInis... and others..
(Message edited by yosquire on October 10, 2006)
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