12 volt subwoofer amp?

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Not sure if this is the right forum, but class d is all about efficiency right? Well, I'm all about efficiency too. I live in an off-grid cabin in Alaska with a 12 volt battery bank and solar array. I listen to my stereo alot (no tv or internet), so it needs to be efficient so as to not overly tax my batteries. I'm really enjoying my super t and fostex 167 t-lines, but I want a subwoofer to help out the bottom end. I need an amp that will run off 12 volts DC and provide maybe 50-100 clean watts. All the high wattage 41hz amps need higher voltage. Car audio amps seem logical, but I don't know how to separate the cheap crap from the "I want to make my ears bleed with loud bass" crap from the ones I might actually enjoy. I plan to drive a t-line sub with a moderately efficient driver (don't know which one yet) crossed over at 65 hz and extending down to 25 hz or so. I listen to mostly acoustic folk and classical music. Edgar Meyer is pretty much my motivation for building this thing. Hit me with your suggestions. Thanks!
 
Ex-Moderator
Joined 2005
If you only want the amp to run off of a 12V rail then I'd recommend looking for a driver or combination of drivers that gives you a 2 ohm load and an amp that can deliver a lot of current while working off of a low voltage supply. Otherwise, you could build a switch mode power supply to step the 12V up to higher voltages which opens up a lot more options.
 
Indeed you need a higher voltage in order to obtain the requested power (50..100W) with conventional 8 or 4 ohm drivers. For 8 ohms you need +/-32V for 50W and +/-45V for 100W. That's why I would consider building a step-up SMPS and using some commecial class D module if I was you. Furthermore, you can use the same SMPS to fed various modules and end up with a very efficient full class D system. The next step in efficiency would be to replace t-lines by horns, but that's another story.
 
If you want higher voltage, instead of building a supply you can find a car amp that has bad output devices and rob the supply out of it. Or buy one thats cheap and just disregard its amp section and use your own.

I'm in the middle of adding two 41hz.com AMP1-B boards to a car amp supply that has +-35v rails and is probably good for around 400 watts.
 
Administrator
Joined 2004
Paid Member
Bump.

Did you ever figure out someting on this? You know, Alaska and solar power, especially this time of year, don't seem to go together. :) But it would be cool if you can get it to work.

What the heck are you doing way up in the north woods anyway? Are you a trapper or just a park ranger?
 
I'm also interested in how this works out -- I'm based in India where power is dirty, unstable and expensive (only the other night I tested 290v coming out of the mains), so am moving the entire music system over to SLA batteries but am still interested in stereo subs.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.