Need help with homemade speaker project

[vascobrissos14]

Hello everyone, my mom asked me to make her a speaker, a small one but with good sound and after searching on ebay I found some parts that may be good for what I want.

The parts are:

Amplifier: http/www.ebay.com/itm/172146398353
I think 20W (with both drivers) is a good setup for a good and loud sound and this has bluetooth integrated which is good.

Drivers:
http/www.ebay.com/itm/121799694960

Im not sure if these are good for what I want but I couldn't find any better one (thats mostlt where I need help). My budget for them is max

"PSU": http/www.ebay.com/itm/311552007557

I will be putting 4 li ion batteries is series and lowering their voltage to the amplifier needs.

Well, I think thats it! Hope someone can help me so I can help my mom

Thank you

 

[americanaudiophile]

I think you are on the right track but I would suggest posting your question on the speaker building forum on http/www.parts-express.com/
They sell good quality parts and the forum can be quite helpful.

 

[Alabalcho]

You might also visit a hobby site like Instructables, where you will find step-by-step instructions.
On your build: If you want to make the build portable, Li-Ion batteries are good choice, but you will have to provide for their charging as well, and this lead to catastrophic (read: explosion) events if done improperly. Sealed 12VDC lead battery is much better choice for starters, and is much easier to recharge.

For a starter - find out good 12VDC power adapter, and skip on "PSU" board (you would likely don't need it anyway even with batteries).

 

[vascobrissos14]

Ye I was thinking on 12v batteries, what would you recommend (budget)?

And are the speakers I chose good?

Thank you

 

[vascobrissos14]

And do you think I need tweeters? Thank you

 

[Alabalcho]

Don't start with (very) high expectations. You have two goals in front of you:
- to make that amplifier (with BT built-in) working. To do that, you need speakers, that amplifier, and power source (that power brick I've mentioned)
- once you do that, you need to make it "presentable", that is - build an actual speaker box. You will need much more knowledge and help here (speaker dimensions, material, soundproofing etc), and you should check tutorials about building speakers. For your tests, probably you will have to do just the basics.

ABout the speakers: The seller does not publish any specs, and based on price, I don't expect you will get something which will make Hi-Fi addicts to droll. So, get them, play with them, make some box, you'll gain experience. Ditto for the battery.

 

[vascobrissos14]

Hey again, I have made 2 speakers alredy but 5W only, and after thinking abou this a lot I got to a conclusion ad alredy ordered the items.

The 2 10W speakers
The 10Wx2 amplifier with BT integrated
Power supply being 2 tablet batterys (around 6-8A of capacity in paralell) being boosted to 9V and then 12V. I did all the math and the amperage is enough to run the amplifier.
A charger controller for the batteries (5v)
And a voltage meter.
For insulation or whatevs I have some foam other speaker builds.
For the box I was thinking on MDF and painting it black and white.

Thats it

What do you think?

(I only camr here to check if my project was good or if it could be improved )
Sorry if I bothered you for not saying I have a good experience on building these earlier.

 

[Alabalcho]

The only weak point I can see is with the batteries. "Boosting" the voltage (even doing it twice) is coming wit losses, and reducing power, there is no "magic" here - if your amp needs 12V @5Amps (that is, 60VA), you will need power solution which can provide these 60VA (not counting the losses at these "boosters"). If your batteries can only give 7.2VDC, this means that they should be able to provide almost nine amps. Do the math.

Use the occasion to make this as an instructable - document your progress, post some pictures here. It would be useful for others with similar questions.

 

[vascobrissos14]

How did you get to 60W? The amplifier needs 12V 2A minimum and thats 24W minimum. The batteries go to 2 5V TO 9V which give 4 amps on 9v whixh gives 36W and then 9V to 12V which will be able ti provide atleast 2.5A to 3A in the end so I have atleast 10W spare. I will do a schematic later so you can undertand it better! Thank you so far

 

[vascobrissos14]

http/prntscr.com/cckc7h

 

[vascobrissos14]

You can see the schematic on that link

 

[Alabalcho]

Again - you will gain nothing (and create yourself a host of problems) by using two low-voltage batteries and double-boosting them (with boosters also in parallel) to get 12VDC.
- If your amps draws 1A @12V, you need 12VDC. Bring this down to 3.7V, and you're asking for excess of 3A (providing that these booseters are 100% efficient) from both batteries, or 1.5A per battery. With their rated capacity of 4000mAh, you will see two-and-half hours on battery operation.
- connecting these boosters in parallel is asking for troubles

If you insist of using "cheap" 3.7V batteries - get a handful of them, connect them in series (four will get you about 14VDC, and your amp will be happy with that). You will see 4hours of runtime (at least), you will save hassles of these voltage boosters, and you will have much cleaner schematic.

Again - think how you will charge these batteries. Charging them incorrectly can (and will) make them explode (you remember these exploding hoverboards, don't you?)

 

[vascobrissos14]

I have more batteries if needed, and I want to charge it with 5V.
Ill try this way, if it doesnt work Ill change it