Making boom box beginner advice

Thread Starter

zazas321

Joined Nov 29, 2015
716
Hello. I have finally decided to make a cool project that I have been thinking about for a while. I would like to make a custom bluetooth speaker ( boom box). I am currently deciding on what components will I need to get and thinking about how everything will be connected together. The plan is:

1. ESP32 as a microcontroller
2. Use external DAC (PCM5102)
https://www.amazon.com/Comimark-Int...hild=1&keywords=PCM5102&qid=1603092096&sr=8-1

3.Use audio amplifier for example:
https://www.ebay.co.uk/itm/WONDOM-2...Board-TAS5630-Module-Stereo-Amp-/350616487361

4. And Im planning to buy coaxial car speakers as such:
https://www.hertzaudiovideo.com/car-audio-coaxials-dieci-dcx87_3/


I would like to get some general advice from someone who has some knowledge about audio. I have some programming and ESP32 experience but my audio knowledge is very limited. I would like to know whether what I am planning to do even makes sense?

What is the most logical way to power everyththing? Ideally I would like to run it on rechargeable batteries
 

bertus

Joined Apr 5, 2008
20,881
Hello,

Do you realize that the given amplifier has a maximum output of 300 Watts?
The shown speaker can only handle 30 Watts.

Bertus
 

Thread Starter

zazas321

Joined Nov 29, 2015
716
Hello,

Do you realize that the given amplifier has a maximum output of 300 Watts?
The shown speaker can only handle 30 Watts.

Bertus
I was under impression that as long as amplifier maximum power is bigger than the speaker power, the amplifier will be able to drive the speaker.


Are you suggesting that for 30W RMS speaker I need 30W or lower amplifier? Also, do I choose my amplifier based on RMS or peak power of the speaker?
 

bertus

Joined Apr 5, 2008
20,881
Hello,

Yes, the 300 Watt amplifier will blow the 30 Watt speaker.
An amplifier of 20 Watt is enough for the 30 Watt speaker.

Bertus
 

Thread Starter

zazas321

Joined Nov 29, 2015
716
Thanks fir all the response! Well as a comparison, i am looking to build a sound quality something simmilar to JBL or beats boom box. What wattage would you recommend? Also, how does one brand soeakers compare to other brands for the same power and ohm ratings?

Il make sure to read that article now
 

Audioguru again

Joined Oct 21, 2019
2,061
The high power amplifier (600W!) you selected has its main IC made by Texas Instruments who says, "Not recommended for new designs". Its minimum voltage is 25V so a huge heavy battery is needed.

The cheap tiny little unknown speakers you selected will produce no bass and will blow up.

I heard JBL and Bose little Bluetooth speakers and I was amazed at their good bass and extremely high prices. They claim an output power of 30W but it is actually only 20W. Their battery is a reasonable size and weight.

What will you need a microcontroller to do?
 

Thread Starter

zazas321

Joined Nov 29, 2015
716
A microcontroller I am planning to use to get bluetooth functionality. And in the future I am planning to also make a sound to light equalizer for my boom box. But for now, I am mainly concerned about building a boom box than everything else.

I will probably try use the coaxial speakers for my first prototype, see the sound quality. If I am not impressed I will to go woofer/tweeter design.
 

Audioguru again

Joined Oct 21, 2019
2,061
All the Chinese 2.1amplifiers with bluetooth are the same. They have no detailed audio spec's like power supply voltage vs output power and amount of distortion vs output power. They also do not say the speaker impedance that produces the rated power.

They all use the same Texas Instruments TPA3116 amplifier ICs that have all the spec's:
12V supply, left and right 14W each into 4 ohm speakers or 8W each into 8 ohm speakers.
12V supply, sub-woofer 28W into 2 ohms or 14W into 4 ohms.
24V supply, left and right 55W into 4 ohms or 30W into 8 ohms.
24V supply, sub-woofer 110W into 2 ohms or 60W into 4 ohms.
A 24V battery will be huge and heavy. A 12.6V to 16.8V Lithium battery will be reasonable and produce enough power.

There are very few 2 ohms woofers available and they are all very large. You will probably use a 4 ohm woofer. Parts Express online have detailed spec's for many speakers.
 

bassbindevil

Joined Jan 23, 2014
110
I'd start with an amp that does about 10 watts RMS per channel, which can be had for about the price of a hamburger. See the TPA3116; there's also chips from Yamaha YDA138, YDA148; Tripath (but those may be fakes since Tripath has been out of business for years) TA2024, TA2020. That's about the same power that "high power" car head units really deliver, yes, the ones that loudly claim 40 watts on the box; read the fine print and it's more like 9 watts per channel at reasonable distortion levels.
Think about investing in more sensitive speakers; efficiency is a better way to get high volume than more power. The speakers in concert PA systems can be 20 dB more efficient than many home speakers; that means they're as loud with 10 watts as the home speaker is with 1000 watts. Drawbacks are size and cost, since there are laws of physics which cannot be broken.
 
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