Solved! Reusing speakers from old TV (NXT)

Oct 20, 2018
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Hey Techies.
I have an old tv Philips 32pf9830.
I want to salvage the speakers and put them to use again for my PC.

The speakers are not commonly used and as far as I know the only TV ever to have them.
They are NXT with a backside woofer.
I can deal with dismantling the tv and creating new boxes for them. My concern is about connection and crossover.

I think I know what part of the tv is the crossover. What makes me doubt is all the extra cables and components on the same print. But I reckon that available space and resource saving can play a part.
But lets just say I'm right. it dosn't feel manageable implanting that piece of print in the new speakers.
Is there with our new technology a kind of universal crossover that can be used?

Connection or using the speakers is my next thought. I'm a guessing a kind of preamp or other hardware is needed, to get away from the split video/audio signal.

Had this been regular speakers I probably would have felt way more confident.


This may be a stupid dream, considering prices of stereo speakers for pc. I already have a very nice setup, so I dont "NEED" speakers. But that tv delivered some exceptionally good audio and sadly the hdmiport is broken and the LCD is just old. If I can get this to work, they will be a perfect fit for my desktop. A bit angled on each side of the monitor.


Have you got pointers and tips on what I can do to make it work?

Do I lack some info, please let me know and I will provide what I can.

Thanks in advance, have a good day.



 
Solution
There are generic crossovers but not "universal" ones.
The NXT speakers are not anything like conventional speakers so you do want the original crossover. They have 180 degree dispersion, sound decent, and are thin so they may be worth messing around with.
If the crossover is on a pc board you may be able to figure out the crossover circuit and duplicate it without the entire board. I doubt it would be elaborate for cost reasons if nothing else so 6db/oct is most likely. As i remember the Wharfedale NXT speakers didn't crossover the NXT panels just the conventional cone woofer so try them without any crossover.
The amp linked to above is way more powerful than the one in the TV and doesn't have a way to adjust the crossover frequency...
I think mounting these speakers will be critical, seems to be made with some "acoustic" box in mind, if u want to preserve what u like about its sound.

Again, the built-in crossover is "dialed" for it, so if can't re-use, then u will have to figure out what its parameters: crossover frequency, 2-3-4 order filtering? difficult if u don't know your electronics, don't own a frequency analyzer.

All these stuff is audio, am no sure why u throwing in video. Ya is TV but speakers have nothing to do with the TV video.
 
Oct 13, 2018
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The crossover frequency wouldn't be that critical on that small of a setup.
 
There are generic crossovers but not "universal" ones.
The NXT speakers are not anything like conventional speakers so you do want the original crossover. They have 180 degree dispersion, sound decent, and are thin so they may be worth messing around with.
If the crossover is on a pc board you may be able to figure out the crossover circuit and duplicate it without the entire board. I doubt it would be elaborate for cost reasons if nothing else so 6db/oct is most likely. As i remember the Wharfedale NXT speakers didn't crossover the NXT panels just the conventional cone woofer so try them without any crossover.
The amp linked to above is way more powerful than the one in the TV and doesn't have a way to adjust the crossover frequency. You probably would have too much power with 10 watts x 3.
 
Solution
Oct 13, 2018
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originally, its a 15W/ch amp inside the monitor.
class D is not the same wattage scale as the other audio amps used for audio, and the rating is approximately 1/8 when used for audio.
so 50W x2 plus 100W on a class D is 6.25W x2 plus a channel of 12.5W. technically, the amp should be 3db or more over the speakers, or 30+ watts per channel of audio class power. In pro audio, we run amps 3-4 times the rms rating for clean headroom, but this isn't really needed in his application.
 
Oct 20, 2018
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Wow. didn't expect this amount of feedback already, thanks to all of you.

I was concerned about the audio/video thing because I can't point out the exact crossover/filter, which made me think it perhaps was done the same place where the two signals where filtered from the input to the TV.

The speakers do have a very (imo) well build acoustic box. The tv is big and heavy, but the design kinda need to be. My plan was to use the speakers and already build box, just in a new cover/box.

I have a friend who will help me with the final installation of the electronics, I just want to research as much as possible before I invest in anything.
Had this been conventional speakers, I'm guessing he wouldn't have any questions.

The part I'm most confused about is the crossover part. Some of you leans to that it wont be that big a deal, but I had the feeling it would weigh much more, since the NXT is so delicate in its area. (lots of high/mid, no low).
 
Oct 13, 2018
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Distortion destroys speakers, not power. So if you have the volume too high to where the speakers distort, then they will get damaged.

Just remember class D is 1/8 of the peak duty cycle power rating.

This is different ratings you are used to. Here is the technical amendment ruling from the FTC:
https://www.ftc.gov/sites/default/files/documents/federal_register_notices/trade-regulation-rule-relating-power-output-claims-amplifiers-utilized-home-entertainment-products/100126homeentertainment.pdf