[luisxd]

Turns out my old boombox (one of those huge black boxes) decided to die out of nowhere, so instead of buying a new one (which would me cost around 100-200 USD) decided to make one by myself, which would be a much less cheaper (still studying so my second name is cheap)

Been working on it for the past week and wanted to hear some advices as i'm not an audio expert (or anything close to it lol)

This was the main idea, but it got some changes through the process

Electronics:

Amplifier: 1x TDA7492P 50w+50w (2 outputs, 50w per output, bluetooth receiver included).
Drivers/ Speakers: 2 x random ~200w 8ohm (bought them from my neighbor for 15USD)
Crossover: 1x JBL GTIX6-01 (came bundled with the speakers, pretty old afaik, couldnt fin any tech spec on google

)

This is how everything is connected:


Photos:
















Th sound is amazing and pretty loud, it can be easily heard from 10 meters away.

Things to do:
-Add power input female plug
-Add ON/OFF switch

PD: If this kind of post are not allowed in this sections please fell free to tell me so i can remove it.

 

[CJRhoades]

Are those woofers full range units? I don't see any tweeters.

 

[luisxd]

Quote:

Originally Posted by CJRhoades

Are those woofers full range units? I don't see any tweeters.

Yes they are. About the tweeters i couldn't find any of them locally (i cant buy anything online for the moment), only some chinese models but rather not to waste my money on them

.

 

[CJRhoades]

Ah ok. I gotta say it looks really nice. Much better than the boombox I cooked up... though mine has more features.

 

[Nukemaster]

With full range do you even need the crossover?

Does it not just separate the high and low frequencies for dual speaker setups(I know you have 2, but I am guessing you are running stereo)?

It looks good What is your power source.

 

[luisxd]

Quote:

Originally Posted by Nukemaster

With full range do you even need the crossover?

Does it not just separate the high and low frequencies for dual speaker setups(I know you have 2, but I am guessing you are running stereo)?

It looks good What is your power source.

I wanted a dedicated "woofer" so the bass would sound better, also i might add a tweeter whenever i find one locally =) ,currently im using a duracell adapter 12v 1.8A

 

[CJRhoades]

Oh, so it's not stereo. I guess it doesn't really matter with the drivers being so close together. What frequency are they crossed over at? How high does the HF driver play?

 

[luisxd]

Quote:

Originally Posted by CJRhoades

Ah ok. I gotta say it looks really nice. Much better than the boombox I cooked up... though mine has more features.

Im currently trying to figure how to add a 3.5mm plug as the amp doesn't comes with it, but theres a a variant of the same amp that comes with it, so it might be possible, also a potentiometer for volume =)

Thanks!

 

[luisxd]

Quote:

Originally Posted by CJRhoades

Oh, so it's not stereo. I guess it doesn't really matter with the drivers being so close together. What frequency are they crossed over at? How high does the HF driver play?

what do you mean by being stereo? the amp?. I can't tell at what frequency the're crossed at since i couldn't find any tech specs about the crossover :/

 

[CJRhoades]

Quote:

Originally Posted by luisxd

what do you mean by being stereo? the amp?. I can't tell at what frequency the're crossed at since i couldn't find any tech specs about the crossover :/

No, the boombox.

 

[Nukemaster]

the BT is an addon, You may have to find a datasheet for it to see if you can track where the outputs are to follow them to the amplifier.

I am sure you could bypass it to add a 3.5 and volume control. or even mix the 2 of them thru 10k resistors(ok that is most likely too much) or something(buffer use an opamp to sum the 2 inputs if you want to get more fancy.). That would invert the signal, but you can just wire the speakers backwards

Volume dial should not be hard (per side you have 3 legs top to your input bottom to the ground and the middle[wiper] out to your amplifier). You should go high enough to not load the device being connected. 100k should work.
Quote:

Originally Posted by CJRhoades

No, the boombox.

Since the BT audio is an addon, I am guessing the amp is getting stereo. I would just remove the crossover. I let those speakers will deal with full range fine.

 

[luisxd]

Quote:

Originally Posted by CJRhoades

No, the boombox.

Quote:

Originally Posted by Nukemaster

the BT is an addon, You may have to find a datasheet for it to see if you can track where the outputs are to follow them to the amplifier.

I am sure you could bypass it to add a 3.5 and volume control. or even mix the 2 of them thru 10k resistors(ok that is most likely too much) or something(buffer use an opamp to sum the 2 inputs if you want to get more fancy.). That would invert the signal, but you can just wire the speakers backwards

Volume dial should not be hard (per side you have 3 legs top to your input bottom to the ground and the middle[wiper] out to your amplifier). You should go high enough to not load the device being connected. 100k should work.
Since the BT audio is an addon, I am guessing the amp is getting stereo. I would just remove the crossover. I let those speakers will deal with full range fine.

The bluetooth input is stereo, acoording to what i found the 3.5mm plug in the variant models is only mono, so if i find a diagram to wire the 3.5mm plug it will be mono.

So the crossovers are useless with full range's?

 

[CJRhoades]

If the drivers are identical, theres no reason to cross one over into another.

 

[Nukemaster]

It has 2 amplifiers on a chip(well 4, but they are BTL), I do not see why it would be mono. It is very strange. Can we see the board up close?

Keep the crossover for when you get some smaller mid/tweeters, but not with the current setup.

 

[luisxd]

Quote:

Originally Posted by CJRhoades

If the drivers are identical, theres no reason to cross one over into another.

I didn't know that, i just removed it, gonna try to see how it sounds now. Thanks!

 

[luisxd]

This is the exact same board. Acoording to what i found the 3.5mm plug on those variants also works as a microphone input.

 

[Nukemaster]

Well that image looks better, the other one had 3 x 300 and 1 x 100 for the coils(the 330's I think are good for 8 ohm speakers).

That little blue board is the BT portion. It connects to all the buttons and may have its own regulator on your main board.

If I had to guess the n5532 may be a buffer or gain stage before the amplifier, This may be the place to get an input, but again it could load the BT module(adding multiple inputs can had odd side effects.). By the same right it could do any number of things.

Here is the datasheet on the amplifier chip. You may be able to trace the inputs.
http://www2.st.com/content/ccc/resource/technical/document/datasheet/35/01/97/6b/20/ce/40/6f/CD00211320.pdf/files/CD00211320.pdf/jcr:content/translations/en.CD00211320.pdf