Wanted- help finding amplifiers

[Chris D]

Guys, I need a hand. I need to find some amplifiers that can drive tactile transducers. (bass shakers) Since it's tactile use only, they do NOT need to be clean or have high fidelity. Just cheap power. Here's what I need:

- Total of 6 channels (or multiples, like three 2-channel amps)
- 100-300 Watts per channel
- 4 Ohms
- RCA input jack preferred but not required
- Volume/Gain control for each channel on front face preferred, but not required
- Preferrably quiet for home theater use (no noisy monster cooling fan)

I'm not picky here on brand, looks, etc. I just need raw power cheap. Used would even be okay. I'd use some of my old outdated receivers I have lying around, but they look like they're for 8 Ohm speakers only, not selectable for 4 Ohm devices.

Help? :sos:




CHRIS
Luke: "Hey, I'm not such a bad pilot myself, you know"

[Clive]

Chris Email Rebob

rebob@well.com




CLIVE




HEY!! Why buy movie tickets when you can own a Theater?

[David Meek]

Chris, check out the Furman line of amps. Here's one of their lines that might fit the bill. It's the QSA ICL line. One thing that caught my eye was this:

Unique among distributed sound power amplifiers, the "T" versions will drive 8- or 4-ohm loads and a distributed system on the same channel simultaneously. This enables a contractor to reduce the number of required amplifier channels by allowing a limited number of distributed speakers to be attached to the same amp as is powering the main sound system.

David - HTGuide flunky
Our "Theater"
Our DVDs on DVD Tracker

[Chris D]

Another question for you electronic geeks/gurus-- Can ANY amplifier that runs at 8 Ohms automatically run at 4 Ohms? Or does it have to be specifically designed to operate at 4 Ohms? Do you have to have a selectable switch on the back of the amp, or will it automatically drive at whatever impedance your speakers/devices are rated?




CHRIS
Luke: "Hey, I'm not such a bad pilot myself, you know"

[Clive]

Most amps can handle a 4 ohm load but it is best that you check with the specs first if this is important to you. Some amps I've seen have a manual switch to select 8 or 4 ohms. Don't take it for granted. Read the specs!




CLIVE




HEY!! Why buy movie tickets when you can own a Theater?

[SiliGoose]

Whatever you do don't pay a lot for them.

How about Audiosource? They're usually pretty cheap and I believe their monoblocks can drive a low impedance load.




-Sili

[Chris D]

Sili-

I agree, since they're tactile, not audible, I don't want to pay a whole bunch of money. Funny you should mention Audiosource. Their monoblocks (Amp 5 series) seem to be PERFECT for tactile transducers in design, and I'd love to use them. However, the cost seems to be about $.80-$1.20 per 4 Ohm watt of total power. Since I'm driving 6 different powered seats and need a total of about 1200 Watts of power, it adds up and we're talking big bucks just to drive something that isn't even audible.

If I look at other options, I'm able to find stuff like "American Audio" that brings down the cost to $.60 per 4 ohm watt total power. Don't know if I want to go that route, though.

I was hoping others might have opinions or suggestions.




CHRIS
Luke: "Hey, I'm not such a bad pilot myself, you know"

[Jariten]

8O

1200Watts???

are the seats supposed to levitate and fly around the room o_O

sounds like fun!

^_^

[Andrew Pratt]

Chris do you need them all to be independantly controled for volume? if not just buy a cheap pro amp and then wire three of the TT's together to get an easy load to push. Assuming their 4 ohms each you could wire them so get either a 3 or 6 ohm load on each channel of the pro amp which should be fine...3 ohms is getting a little low but some pro amps can do it.

[Chris D]

Well, each seat has its own dedicated transducer, which requires some serious power to drive the very low subsonic rumbles. (10-20 Hz) Each one needs about 200-250 Watts to run right, for a total of 1200-1500 Watts.

Andrew, I've been wondering about that, but it's been a while since my Electrical Engineering class in college. How would you wire that? If you just twist the input wires together for two transducers, don't the two resistances of 4 Ohms each add to a total of 8 Ohms?

Ideally, yes, I'd like to have volume controls for each seat so each guest can set their own tactile level. But in the interest of saving money, I'm okay with having one level control for 2-4 seats. I'll keep the prime seating for me and the wife dedicated, independant controls.




CHRIS
Luke: "Hey, I'm not such a bad pilot myself, you know"

[Andrew Pratt]

Chris since it would be a stereo amp you'd have two sets of volume control...at least some amps allow for that or you could just add a volume pot to the chairs so you'd shunt the volume after the amp like you do for second zone wall plates.

http://www.adireaudio.com/tech_papers/dvc_wiring.htm]This link is for wiring dual voice coiled speakers but the concept is identical. As you can see mixing series and parallel you can play with the resulting net resistance to give you a manageable load. Most pro amps can generate a lot of power esp into lower ohm's so getting 200-400 watts per channel shouldn't be that difficult and the price would be very reasonable compared to similar wattage consumer amps.