Full Digital Speaker

[KOON3876]

Hey any positive reaction?
like "Yes go for break it! I want to look you screwed up!"

I have no interest about practical or not. Just want to DIY something freak

Now finished schematic, attached is BOM. Not so expensive than I thought.

 

[TheShaman]

I have attached a picture of an early prototype...
They are still working on it, of course, but its sound is pretty decent. Promising work.

Koon, go for it mate! It certainly is an interesting project.

 

[lne937s]

dominate

I would love to see this work.

Maybe using something like this for drivers....

http://www.getmad.com/mad_a8.html

 

[Pano]

By all means go for it!

We are just trying to tell you it's a lot harder than you think. If it weren't, these things would be all over the place.

But do build one, it's such a cool idea. I tried and failed, but that doesn't mean that you will.

 

[KOON3876]

Thank you!
If it's easy, no value to DIY.
60 drivers arrived. OMG...

 

[KOON3876]

One block (2 bit in and out) of board. 2x1.4 inch.
I have to copy this 26 times.

From left,
Analog switch and LPF R&C
Differencial Amplifier Rs
OpAmps, Top Differencial Amp & driver, for 1bit, mid 2 LPF, Bottom other bit.
Power Capacitors,
TR and bias Diodes, Rs.

 

[luka]

Hi

Only 26 tmes ?

 

[KOON3876]

Finished board layout.
too huge..
http://koonlab.com/DigiSP.html

 

[KOON3876]

I wrote board but too complicated, too large. It should be more simple.

Let's make 5V single supply circuit.
amplifier section will use TPA311, TI's small amplifier.

I need voltage reference, and positive/negative side driving voltage.
Attached circuit can make 1/2Vdd adjusted positive/negative driving signal. (one switch will supply driving signal to each bit section).

Then each bit section can be driven single 5V power supply.
(switch selects between 1/2Vdd and driving signal)

 

[KOON3876]

Here is ver.02 schematic.

http://koonlab.com/DigiSP/DSP_SCH02.pdf

Now all circuits work on 5V single supply, amplifier section was changed to TPA2005, TI's small Class D amplifier.

 

[jackpipe]

I know this is only vaguely related, and I don't know if such a think exists, but is it not possible to produce a direct digital speaker driver, by having multiple coils? Eg for a 16 bit speaker, you'd have 16 coils, with 1 turn, 2 turns, 4 turns, 8 turns, etc. Or simply have identical coils, but drive them with successively larger voltages/current?

 

[phase_accurate]

In the January/February 09 issue of JAES is an article about such a system.

Regards

Charles

 

[jackpipe]

There goes my chance to "invent" something then. Drat. Surely this isn't a new idea, is the JAES paper focusing more on the signals required to get good quality from such a system, rather than the idea itself being novel (ie a single cone with multiple coils).