12V Computer speakers in CUCV?

[wired1000]

I just got a job with a 40-min commute (1 way). So, it's time to think about some audio for my M1009.

An idea I'd been kicking around for years was to use an old set of computer speakers (Boston Acoustics BA635). The AC adapter for these states that it adapts 120V AC to 12V 2Amp DC.

My question is: can I slice the AC adapter off and wire the power cable into the 12V system on my CUCV?

I know that the CUCV alternators are probably making the actual voltage closer to 14V +/- in that system. I have not tested what kind of amperage is being put out. I'm also not sure how most electric components work... there are certainly items on the CUCV that would burn out if they were supplied with the full amperage. Is there an easy way to step down the amperage to suit the speakers? Maybe an existing circuit that's around 2A I could tap into?

Appreciate your advice in advance.

 

[mistaken1]

The speaker will draw amperage based on the voltage supplied and the inherent resistance of the speaker power supply/amplifier.

At 12V they will draw a normal amount of power (amperage). At 24V they would draw twice the amount of power (amperage).

Assuming 24V does not overcome the dielectric or overdrive the amplifier (instant smoke) the increased current draw and attendant heat will cause the power supply/amplifier to burn out in short order.

Will the 13.2V of an auto power system be too much for them?

Depends on the design parameters. There is probably listed somewhere in the world the minimum and maximum voltages the speaker power supply/amplifier can use without short-term or long-term damage. Might google it.

If you do cut the cord make sure you get the DC polarity correct and I would highly recommend an inline fuse rated at no more than 10A. That will not protect the speakers but it will protect the supply wire from becoming a welding lead (a small welding lead but a welding lead nonetheless) or worse yet a toaster heating element!

 

[rogersn67]

If you wire this in directly you will fry the speaker system. Go onto Amazon and get yourself a voltage convertor, type in the search 24 volt to 12 volt. then tap into that. It is like $40 and it has sufficient power to run your speakers, or even a regular car stereo.

 

[wired1000]

The CUCV has a 24V system to power the starter and glow plugs, but a 12V system that powers most everything else in the vehicle. I'd run the speakers off the 12V system, but it too might be slightly more than 12V (13 or 14?)

Thanks mistaken1, this is pretty much exactly the info I was looking for. I'll give it a shot and let you all know how it works out!

 

[rogersn67]

If you do cut the cord make sure you get the DC polarity correct and I would highly recommend an inline fuse rated at no more than 10A. That will not protect the speakers but it will protect the supply wire from becoming a welding lead (a small welding lead but a welding lead nonetheless) or worse yet a toaster heating element!

Anything electrical should be fused at least, or circut breaker protected at best. The fuse should be inline as close to the power source as possible.

 

[rogersn67]

You really should try to regulate the power to 12 volts before you hook this up. There are plenty of places you can get a regulator for 12 volts, check out any of the car pc type sites. I would ahte to see you fry a good pair of speakers for no reason.

 

[wired1000]

Great! I am tracking down a DC - DC converter that has those output specs. Thanks so much for your help

 

[mistaken1]

This place says the power transformer they offer as a replacement unit for the BA635 speakers provides 12AC.

12V AC adapter for boston acoustics BA635 BA735 speaker - LCDPayless.com

This manual labels the power supply as a transformer. Transformers convert AC voltages. No detailed specs though.

http://ec1.images-amazon.com/media/i3d/01/A/man-migrate/MANUAL000010448.pdf

This picture indicates the power supply is 12V AC.

Boston Acoustics AC Adapter DK1201A5-1AN 12V 1500mA | eBay

Not questioning your ability to read but I was doing a quick search for specs on the power supply and based on what I found want to verify that your speakers are using a DC power input before suggesting you connect them to your CUCV DC power system.

 

[wired1000]

This place says the power transformer they offer as a replacement unit for the BA635 speakers provides 12AC.

&^%$... back to square one :-/

 

[wired1000]

I saw 12V and got excited about skipping all the hassle of installing a radio.

 

[Midnight Rider]

It seems to me like you would have more of a hassle trying to install these speakers than just installing the radio.

Why not just get a DC to AC convertor, then you can power your speakers? There are plenty of spaces in the CUCV to tap for 12V to run a convertor.

 

[rogersn67]

At this point it may be the easiest way to do it. Keep in mind the cheap ac inverters are all modified sign wave, but it probably wont make a whole lot of difference with what you are doing. Home depot probably has a cheap one for like $20

 

[Warthog]

How about something like this instead.

http://www.steelsoldiers.com/cucv/56441-12-cucv-amp-solution.html

 

[Stalwart]

Not to clog up the discussion too much but audio amplifiers actually run on DC voltage. The transformer gives you the stepped down AC but the AC is often rectified into DC inside the device, and then used by the amplifier, rather than in the transformer unit itself.

Just sayin' . . .

 

[wired1000]

Hmm... so... 12V X 2A = 24W, right? So I could get one of the super-cheapo inverters and be OK.

Actually, now that I've been looking at inverters... I'm probably gonna get a bigger one so I could run minor power tools from it.

Nice to have 120V AC power in the vehicle

 

[wired1000]

Hmm... so... 12V X 2A = 24W, right? So I could get one of the super-cheapo inverters and be OK.

BUUUUUUUT:

I think instead I'm gonna buy a much larger (~500W?) 24V DC - 120V AC inverter and hook it up to the 24V hookups on the Passenger side near the rear seat. I'll mount it on the wall nearby and maybe make some kind of cover... paint it with lightning bolts and hazard signs. Cool....

 

[mistaken1]

Sounds good, just be sure to fuse at least the positive lead from the radio bus behind the passenger seat to the inverter.