Cool find inside my laptop: world's smallest subwoofer

[OscarS]

Doing some laptop repair, I found this little bugger in there, part of the integrated Harmon-kardon 2.1 system:




Get this, it's even ported! LOL




Naturally it's not a real "subwoofer", but it's still pretty cool. Poor little bugger is tuned to 144 Hz, lol.

[freax]

I would be really interested in finding something around the 2 inch range, in a non-plastic design to go inside of a 2U rackmount case.

Oh btw have you seen this?: Stylish Portable USB Powered Laptop/PC Speaker (USB Jack) - Free Shipping - DealExtreme

These little puppies have a passive driver in the middle and two "stereo" drivers on each end, though It doesn't produce much if any stereo seperation, it does produce a nice sound, which is probably coming from the paper "panel" on either end.

I've always wondered what a pair of these puppies would sound like for 1 channel.

I can't seem to get the thing open bar from undoing 6 screws, 3 on each end, and it feels like it could handle more power above 500hz but the tiny amp inside (or the usb interface) just can't cut it.

And it sounds distorted when generating frequencies below about 120Hz, which is to be expected.

Woof woof.

[picowallspeaker]

I have found something similar in a LCD monitor, and I use them as tweeters ( + waveguide)

@ Freaxs - I have also found something similar : look if the voice coil is oval ?!! Same from Sony a
double cone but one piece, but with two motors...New frontiers !!!!

[OscarS]

that USB speaker thing is cool. This laptop has 6 built-in USB ports.

[Don Hills]

Those long skinny drivers do indeed have long, oval voice coils. The voice coil gaps in the magnet assembly are straight, and the curved ends of the voice coil are out in free air. (I have a set of TDK speakers with the same style of driver.) If you think that's odd, take some cell phones apart.. they have some very odd shaped voice coils and diaphragms. A lot of the cutting edge research into driver design is taking place for cellphone use - how to get loud, low distortion sound from tiny drivers and spaces. They run them right on their limits for excursion and voice coil temperature.

[picowallspeaker]

Thx Don. I did put in use the little oval ( 4 Ω-3W-rubber surround ) and it sounds...
good! Preceded by a 33 uF cap and with the aid of a woofer...well, the typical FAST, with about 3-4 mH inductor. Also the woofers came from dumping diving...a big fat sony Tv
with subwoofers inside! The double/one cone 2 motors from the same Tv don't sound
as good ( guess.. )

[peace brainerd]

Those long skinny drivers do indeed have long, oval voice coils. The voice coil gaps in the magnet assembly are straight, and the curved ends of the voice coil are out in free air. (I have a set of TDK speakers with the same style of driver.) If you think that's odd, take some cell phones apart.. they have some very odd shaped voice coils and diaphragms. A lot of the cutting edge research into driver design is taking place for cellphone use - how to get loud, low distortion sound from tiny drivers and spaces. They run them right on their limits for excursion and voice coil temperature.

You're right about that. Being a bit of a speaker tinkerer my ears prick up at things around me that others take for granted.. and I have notice what you mention about cell phones. Standing in line next to someone and hearing Beethoven's “Ode to Joy” in their pocket sounding way too good to possibly be coming from their pocket left me a bit awestruck.

If anyone is interested in playing with USB audio there is a nice little bit of open source freeware called Foobar. I use it to listen to online radio streams and audio files on my PC.
Dedicated USB sound devices like the little soundbar linked to above come packaged with software for some form of GUI for making adjustments. That can range from very simple to very useful. Just in case anyone here is unfamiliar with USB audio, it bypasses the PC's soundcard. The laptop's/soundcard's DAC feeds analog to the headphone jack but the output at the USB jacks is digital. So plug in devices have to either have their own onboard DAC or
one has to be inserted inline between the USB jacks and the device.

With Foobar, regardless of what level of control you are provided by the USB sound device's software/GUI, you have a much fuller gamut of audio control on your desktop between the audio source and the USB jacks.

I'm really not that well versed in this stuff, there may be even better commercial (expensive) options out there. But I had presented this question about controlling output to the USB jacks to a pretty knowledgeable crowd over at gearslutz.com and Foobar was recommended more than once.

All of the utilities in the screenshots below can be used to control either the PC's soundcard or you can select an option for the software to insert itself between the audio source and the USB jacks. Pretty cool really.

[OscarS]

that's pretty cool. B&Ws desktop/computer speakers also use the USB digital stream to feed their speakers, which in turn have built-in DACs.