Model 19's and subs

[bigjunglejim]

I have 5 Model 19's I plan to use for home theater. I need subs for the 19's and for the added sub channel. I was thinking about using one sub for each model 19 and the following for the seperated sub channel:

I have 4 Servodrive subs that were custom made for Verizon. Each cabinet has three motors with a total of 6 15" cone/baskets. The low inertia servo motors in mine are not what they used in other applications. These motors were the same ones used for turning the tape reels in the old IBM computers. Only these motors were custom wound for this one application.

I talked with two of the people at Servodrive and was told the following: Servodrive made 20 of these boxes for Verizon. Verizon used 9 at a time firing down through the open bottom of the cabinets, through the concrete floor, into a concrete chamber. Verizon's test equipment was pegged at 160 dB and couldn't get a true reading so, there's no way of telling how high the SPL really was. The frequency response was flat to 5 Hz (five). Verizon was doing some kind of bio/psych testing and simulating close proximity thunder.

When I talked with the people at Servodrive, they were upset that I had these boxes. These subs weren't supposed to be sold to the public due to the dangers with high SPL at extreme low frequencies. I discussed with them my plans of using them for sound reinforcement and high passing at 20Hz etc. and that I was aware of the dangers of misusing them. They said it sounded like I knew what I was doing but, they still didn't like the fact that I have them.

What's really a kick, I've never heard them. I've never so much as attached an amp to them. I bought them untried, brought them home and they've been sitting untouched ever since. I wanted more information about these speakers but, the folks at Servodrive weren't really helpful other than what I've just told you. They wanted me to give them the numbers off the motors before they'd give me any more information.

I've often wondered if Verizon was doing "defense" research with these. I've heard about the Nazis aiming super subs at towns in Europe as weapons but, they stopped because the ultra high SPL super subs were killing the operators.... True or urban legend?

Any way, I have four boxes with a total 12 motors, 24 15" baskets and no real idea how to use them to their fullest potential...

When I asked the guys at Servodrive for their advice, they told me to find a good speaker designer. By the way, each box is a column with two opposing sides having 3 15" baskets in a vertical row. The bottoms of the boxes are open with a shoulder attached around the bottom with rubber gaskets and holes to bolt them to the floor. Remember, these were designed to fire down through the floor.

I'm not sure what to do with them because I haven't done sound reinforcement for quite some time. I need subs for my home. I had thoughts about using all four, placed equally around my living room and running them all off the same signal. That aught to give some real good vibes to anyone in the center.

Oh yeah, I was thinking about setting each upon a horn set up so they can work as designed, the drivers firing into the box and out the bottom. Any thoughts? I've very open to suggestions. I've been thinking of digging them out and taking some pictures.

When I tell this story, most people think I'm full of "it" and just telling a story. I may be full of it but, the story is true.

[email protected]

<font color="#FFFFFF" size="1">[ January 13, 2007 10:38 AM: Message edited by: Todd W. White ]</font>

[Tom Brennan]

Huh?

[sfogg]

Seek out Tom Danley and he could certainly give you the scoop on them. Try the High Efficency forum on AA for example.

I've had a CB for about 10 years now. What you have sounds completely nuts! From the setup it sounds like they were intended for an infinite baffle setup.

Shawn

[Tom Brennan]

There's a prosound website that Tom Danley frequents, no doubt he can tell you everything you want to know about your CBs.

I was at Tom's house a few times and his running just a couple of normal CBs in the house could be, well, overwhelming.

[bigjunglejim]

Hi Shawn
Nuts? Perhaps but, if I get these subs running in my home system, I'm sure to have the best bass on the block... perhaps in LA? Who knows where this will lead. Did you see Bass Pigg's video showing the carpet flapping? I'm wondering, could low end drivers do such a thing? I wonder what I can do with these servodrive units... Perhaps it's me that's nuts? LOL. AT this point, all I have is bragging rights of owning some very unusual equipment with unbelievable specs. Jim

[sfogg]

"Nuts? Perhaps but,"

Didn't mean it in a bad way. After all I have a CB and 4 JBL Sub1500s in a 1000 cubic foot room.

The only thing I'd be a little worried about with your units if you used them as an infinite baffle would be hearing brush noise at low levels from having the box basically being open. The way around that might be sort of reversing the IB. Have the sub itself in the room and have the box vent into the baffle outside of the room.

Shawn

[bigjunglejim]

Hi Shawn
I don't want to cut into any of my walls, floors or ceiling. The only other way I could do it would be to remove my sliding glass door and build something into that space. Unless I get other ideas, I'll build a box open on one side and let them fire through the bottom into the box and then out the open side. OR, just put the speakers on a riser and let them pump the air righ out the bottom and let it disperse naturally. Having subs fire down is nothing new. I think the SPL coming out the bottom will be about 6 times greater than the six woofer pumping into the room directly (since all the energy of the six woofers would be combined into a smaller space rather than radiating into the room. So, it should kick pretty good. I imagine pushing a battle ship side ways in the water. A lot of water may be moved but, the pressure wouldn't be nearly as great as the same energy redirected into a shorter length. Like pushing water with your hands. It would hit it's target with more effect. I guese the best way to say it would be pressure vs volume (mass). Check out the following link: http://www.danleysoundlabs.com/DANLEY_dts20.htm Big numbers using only one 12 inch woofer.

[bigjunglejim]

I still haven't figured out what to do for subs... I just picked up four 816-V's loaded with 421-8LF's. Nice vinal covered cabs but, I bought them for the 421's. Now I don't know if I'll use the 421's or keep them loaded in the 816's to use in a small SR system. Perhaps I can use them for mobile DJ work? I got the four 816's plus a couple non-Altec two way's along with a Soundcraftsman 5002 amp that looks (like the one in the picture I?ll attach only the one I bought is flat black and has different handles) and Fender stereo Amps. I have pictures of the speakers I bought with the seller standing in front of the speakers.

[just me now]

maybe you could build "scoop type" extensions, and mount your boxes on that?

[bigjunglejim]

louped garouv
You wrote, *maybe you could build "scoop type" extensions, and mount your boxes on that?*
Were you thinking of mounting the model 19's or 421-8LF loaded 816-V's on the scoops?
I think the 816's sitting on subs with horn on top would be great for mobil DJ or small SR.