My Subwoofer Plate Amp - Comments?

[soundNERD]

Hi Everybody,

I just finished my subwoofer plate amp based on the LM3886TF chip. It is all done except for the crossover which I am working on now.

What does everybody think?

Heres a picture of the box

[soundNERD]

and of the amp...

[soundNERD]

and finally another pic of the amp

[SlaitH]

Lookin good!!

what kind of driver are we talking about?? 10 inch or more.

I would really like a comment on the sound later if it's sturdy enough for bass work

But nice design

[unitgain]

I'm planning to build a subwoofer amp, but use four LM3886 chips with a Shiva driver.

[Hybrid fourdoor]

impressive.



You should look at building a Linkwitz transform into it, since its custom.

[soundNERD]

Thanks everybody!!!

Its actually an 8" only. The sound is pretty good, but since I don't have the crossover done, I just have it connected to the headphone of my stereo. I do find it a little thuddy sounding though, like its responding to the higher frequency bass notes better than the deep notes. I am still playing around with port size and stuff.

Maybe just adding a crossover and blocking those high frequencies will help it. Other than that it hits pretty hard.

About the Linkwitz crossover, I am trying to build a variable with an lm837 chip. but I will look into the linkwitz.

And unitgain, I am working on one of those too, but not for this.

thanks again for the comments!
-Mike

[soundNERD]

It sounds great. Especialy with only an 8" speaker. It really adds some punch to music, and haven't tried it with a movie yet since the stereo i have it connected to doesn't have a dvd player.

And i don't even have a good crossover on it yet, just a temporary resistor/capacitor filter.

Right now, the amp rattles a lot, so I have to open it up and tighten everything in it.

Finally, it has been running just listening to the radio for a little over an hour and the heatsink isn't that hot nor is any protection things turning on.

I found that the best sound quality is achieved with a 4" long piece of 2" PVC as a port and an open 2" hole in the case. With two 4" ports, the sound is deeper and tighter, but the volume is cut in about half. With just one PVC port, it made a whistling sound.

Thanks again for all of the nice comments!!

-Mike

[soundNERD]

Originally posted by SlaitH
Lookin good!!

what kind of driver are we talking about?? 10 inch or more.

I would really like a comment on the sound later if it's sturdy enough for bass work

But nice design

Yes, definately powerful enough.


oops, forgot to say before, the box is a bandpass with the speaker mounted in the middle

[leadbelly]

First of all, nice work

Originally posted by soundNERD
Finally, it has been running just listening to the radio for a little over an hour and the heatsink isn't that hot nor is any protection things turning on.

Keep an eye on this. I personally would have drilled a hole through the plate and bolted the chip directly to the heatsink, rather than made a chip-plate-heatsink sandwich. Anyway, as you use the amp more and more, it will become obvious if you have enough heat transfer without needing to investigate.

Enjoy