most powerful class D for car without inverter

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probably 4 dvc woofers in parallel.

I'm not saying it makes a lot of sense, just that it's doable.

From 12v you're going to have to choose between not enough power into one speaker, or not enough power into 4 speakers.

It's probably as cheap to buy 2 speakers and build an inverter to drive them properly.
 
Hi

What he means is tha all dual coil speaker that can be wired to 1ohme are way more powerfull, but you try to drive them with 50w. It would be waste of money. Your head unit can drive 4x 4ohme channels with ~22Wrms, which is pretty close for what you are going for :smash:. If you would buy 6" by 3" ones, they would be pretty loud
 
luka said:
Hi

What he means is tha all dual coil speaker that can be wired to 1ohme are way more powerfull, but you try to drive them with 50w. It would be waste of money. Your head unit can drive 4x 4ohme channels with ~22Wrms, which is pretty close for what you are going for :smash:. If you would buy 6" by 3" ones, they would be pretty loud

Exactly. you would probably get better performance for the less money by buying one woofer, and a cheap storebought amplifier.

It would be interresting to see, but I think it's just not enough power to justify 2 good subwoofers.

-Nick
 
If we also assume that those speaker could have an impedance dip to around 3 Ohms on each voice coil, the total impedance would be around 0.75 in some places. I'm sure that any well designed amplifier would start to kick in the short circuit protection around that point.
 
Saturnus said:
If we also assume that those speaker could have an impedance dip to around 3 Ohms on each voice coil, the total impedance would be around 0.75 in some places. I'm sure that any well designed amplifier would start to kick in the short circuit protection around that point.

Well, if he's planning on designing direct switched from the batt, he's obviously not going to have a short circuit protection that touchy.
 
Saturnus said:
In any event I do hope he's planning extremely short and thick cables. And with that low impedance you most definately have to calculate the cable loss into the speaker design.

Yes, though he's not going to be pushing a huge amount of current, really. A lot more than would be expected for a 100W amp, but still probably only a dozen or so amps.

I would suggest designing the amp to handle a much higher voltage. Then you can try it from 12V and if it's not enough power, you can just upgrade the supply with no need to change other parts. You'll likely find the switching devices are already rated much higher than you need for 12V, so it'll probably just mean getting higher voltage caps.

-Nick
 
Hi

I've listened for years a big 12" Ciare dvc subwoofer in my car, driven by 2 bridge amplifier at 12V (one for each voice coil) delivering 2X20Wrms of amazing power :hot:

I think it's possible to drive dvc speaker with a ampli without inverter, if you don't need a lot of power (i.e.: normal listening)

You have to consider some good factor of that configuration:

- ampli is smaller
- ampli is simpler for diy
- ampli si probably cheaper for diy
- less components to burn
:smash:
- less heat production (considering an ampli in an active box)


For short circuit protection, a normal fuse at +12V (and another in series to speaker/s) can save your car from burning...

So, in the worst case, you have to replace some power transistors/mosfets..


IMHO, jaya000 is trying to deliver an interesting diy project...



:angel:
 
acid_k2 said:
IMHO, jaya000 is trying to deliver an interesting diy project...

I'm not saying it's not interesting but with the amount of current were talking about a practical implementation of a single output 1 Ohms amp could well be more expensive than the 41hz amp9, I suggested to start with. At €59 it's tough to beat when you take into account the versatility (and quality) of it.

Specifically I would use 1 channel of it on each 4 Ohms VC, which would provide the same output power as all 4 channels paralleled into 4 paralleled 4 Ohms VC's but with much less problems. With 2 Ohms VC's I would just parallel 2 channels. It would still provide the same output.

I think that most people overlook the biggest advantage of a direct connected amp; effeciency. It's practically impossible to construct a SM or inverter at these voltages with an effeciency higher than 80%, and often lower than that.
 
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