Sub woofer w/ built in amp

[MrD]

I was thinking of adding this to my jukebox for deep bass.  It has it's own built in amplifier.

http://www.geeks.com/details.asp?invtid=6015&cat=SPK

Assuming I can get the 12vdc to handle it, does anyone have any thoughts on it?

Thanks

[Silver]

Looks cheap and chearful, but I'm sure it will add some base. Its quite small, so the mount of air is actually gonna move is limited - but if its going inside a cab that will probably act as a resonater anyway...

Note that its designed for use in a car, and is such is expecting an engine and/or a car battery to power it. So if its anyway near its claimed 200Watts, it could pull 16amps on your 12V supply. This is probably seriously beyond what a PC powersupply can give on its 12V rail, even it has "500W" stamped on the side.

I would reccommend a completely seperate supply (ie a seperate AC->DC transformer) for it.

Having said all that, I may be being over cautious!

[Bumblebounces]

I would be skeptical of the "200W" in the printed material.  There are a lot of interpretaions of what this means.  There is a meaningless scale called "music power" and the more meaningful RMS.  If it was 200W RMS, that would be a hugly powerful sub that would probably be way too much for a jukebox.  As it stands, the 200W music power (porabably) will still deviver quite a kick in your juke cab.

I totally agree with Silver.  DO NOT attempt to power this with a PC power supply.  You'll kill it with the first beat.  To power something like this without the car and huge capacity battery that is constantly being charged by the engine/alternator would require a very large power supply.  I am thinking it would have to be in the 10-15 amp at 12VDC range.  That's a pretty massive power supplu and transformer setup.  In fact, it may be cost prohibitive to attempt.  I would look for an adequate powersupply and it's costs and factor that into the purchase if I were you.

Hope this advice isn't too late...

Good luck

Bumble

[MrD]

Nope not too late.   I started another thread about a power supply but it's applicable here.

look at this power supply.  650 Watts with 34 Amps on the 12vdc side.

http://www.chiefmax.com/psu/cm650.php

I'm not necessarilly going to buy this sub, but I know I need a power supply to handle any kind of amp, etc.   Even if this one can't do 34Amps 12v,  It would at least appear to be a lot more then some of the 8-10amp models.  I'm not going to run off the same power supply as my pc.   I'm thinking of using it independently.

[Bumblebounces]

As big as it is (and it is a big PC power supply), this is still a switching power supply.  This would still be a poor choice of supply for powering something meant to be in a car.  It simply cannot supply the kind of current a car audio amplifier will be demanding constantly.

What you would need is something more like this or even larger if you can find it:

http://store.yahoo.com/allcable/alsmpowsup7.html

Basically, beware of any power supply that does not include a hefty (meaning very large and very heavy) transformer.  If you have a surround sound receiver that puts out 75 to 100 watts per channel, take a look through the vent grill on the case.  Chances are, you'll find one of these humongus transformers I am talking about.  Anything without a large transormer is probably a switching power supply that can only deliver the rated output for very short bursts.  A PC power supply falls into this catagory.

I have found that for the most part, making things designed for a car work without the car is not always a fruitful endeavour.  Speakers are the exception as though they are 4 ohms and the standard home speakers are 8 ohms, most current day, higher technology amplifiers are capable of driving the smaller loads (ever see a car amp ad that says "2 ohm stable"?).

Hope this helps

Bumble

[whammoed]

Yeah, I don't know that I would trust the rating on that supply.  I would go with something a little more industrial where you can trust its rating such as:
http://www.power-factor-1st.com/shop/enclosed-switching-power-supplies/pfc-series/sp-320.html
A switching supply will work fine and be lighter...look for PFC like this one has to ensure low noise.  Just put a fuse inline with the amp at the power supply rating so you know you aren't pushing it too hard.  Its definitely possible to run car audio without a car since they do it at the audio stores to demo the merchandise.  You may want to choose a 13.5 volt version since thats actually closer to what it would be getting in a car with the car running.

After its all said and done though, you may be better off and end up spending less on a nice set of surround sound pc speakers like the Klipsch promedia series.