Ciao, yesterday it took me a lot of time to find those gadgeds on Partsexpress
The day before I passed another 5 minutes in scrolling 10" woofers
While I was there I took a look at the Clearance sales 😀
So...
The thing I saw was a BMS+battery holder ( 5 batteries 18650 - which are 3.7V) and..ok, let me take a look at the computer's timeline...
Here it is https://www.parts-express.com/Dayton-Audio-LBB-5-5-x-26650-Lithium-Battery-Charger-Board-Module-325-133
And it has some DC-DC converter...as the little battery packs incorporate it in 1 cm2 area, necessary for making the battery chargeable by a 5 V supply ( USBkind) and to supply the necessary 5 V out from 3.7, but maybe I'm mistakin'...
Well, the product is that. Usually BMS cost 10 times less, but you have to engineer the whole pack.
So, you've got to face with three 'sciences': the supply, the amplifing and the transduction thing...well, all you need is 'spreading the sound'
BTW. the Faital Pro woofer at 200$ with the roll surround was the one I saw...of course now that the project has changed, thinking of some '<6" subwoofer' to pair with the MA is another thing, and stickin' with what I originally said holds still in my mind
The day before I passed another 5 minutes in scrolling 10" woofers
While I was there I took a look at the Clearance sales 😀
So...
The thing I saw was a BMS+battery holder ( 5 batteries 18650 - which are 3.7V) and..ok, let me take a look at the computer's timeline...
Here it is https://www.parts-express.com/Dayton-Audio-LBB-5-5-x-26650-Lithium-Battery-Charger-Board-Module-325-133
And it has some DC-DC converter...as the little battery packs incorporate it in 1 cm2 area, necessary for making the battery chargeable by a 5 V supply ( USBkind) and to supply the necessary 5 V out from 3.7, but maybe I'm mistakin'...
Well, the product is that. Usually BMS cost 10 times less, but you have to engineer the whole pack.
So, you've got to face with three 'sciences': the supply, the amplifing and the transduction thing...well, all you need is 'spreading the sound'
BTW. the Faital Pro woofer at 200$ with the roll surround was the one I saw...of course now that the project has changed, thinking of some '<6" subwoofer' to pair with the MA is another thing, and stickin' with what I originally said holds still in my mind
I use B&C DE07 with a ciare woofer. The tweeter has a conical 3" horn and a L-pad after the crossover.
The woofer 'sits' in a cube with open back.
That's it.
The woofer 'sits' in a cube with open back.
That's it.
Pioneer's STK4141 inside with dual 28 VDC supply would guarantee some 30 W ( full distortion) and I made the heatsink add-on 😛
To have the same acoustic output given by the combination of amplifier/speaker system, given a 90-91 dB sensitivity (10" woofer...and efficiency rises by using two specialized speakers) but using e.g. 88 dB drivers woulkd require twice the output of the amplifier
Someone corrects me..! 😱
To have the same acoustic output given by the combination of amplifier/speaker system, given a 90-91 dB sensitivity (10" woofer...and efficiency rises by using two specialized speakers) but using e.g. 88 dB drivers woulkd require twice the output of the amplifier
Someone corrects me..! 😱
The thing I saw was a BMS+battery holder ( 5 batteries 18650 - which are 3.7V) and..ok, let me take a look at the computer's timeline...
Here it is Dayton Audio LBB-5 5 x 26650 Lithium Battery Charger Board / Module
Duh. I looked everywhere except than the same place where I bought the amp board. That sounds like a very interesting solution. Actually the board only needs 12V so this one with this battery should fit the project (unfortunately don't have a 3-pack for higher capacity batteries, but 3350 Ah are compact and should give me a decent life).
BTW. the Faital Pro woofer at 200$ with the roll surround was the one I saw...of course now that the project has changed, thinking of some '<6" subwoofer' to pair with the MA is another thing, and stickin' with what I originally said holds still in my mind
I already spent too much on speakers 🙂 I will try a "boom box" version with two Alpair 6 in one box: two merged cabinets with bass reflex sharing a wall,(<=300x240x180mm); and a "spread out" one with Alpair 7 in two separate cabinets, speaker wires and detached amp box for when better sound quality is needed and I can afford the space. In both cases I would rely on bass reflex for extended low range.
I could not work out a mono design with only one Alpair 7 because it's rated at 15W so even if I could wire the two 15W outputs I would be pushing a single driver instead of two, which I doubt would give more volume than the 2x Alpair 6 configuration.
I used 12 18650s wired 3s4p.
12 volts and 8ish Ah. Plays entirely too loud, for hours and hours.
12 volts and 8ish Ah. Plays entirely too loud, for hours and hours.
Thanks. Just as a starting point, this is what I set up with the last time: it all fit in a camping backpack that fit into a milk crate on a bicycle... sound system, accessories, including a DIY disco light (another story) and a change of clothes for the next day...
Attachments
I originally sat out to do 3s8p, but when I saw how little power the setup drew for normal listening, I cut the battery bank in half.
It's two 6" subs (ported, tuned to 35hz), two 4" mids, and two tweeters. Ran from two TDA7498s. Set to about 40 watts per speaker, max.
So, here it is... I cheated on the speakers' break-in process and tried to turn it up for a few moments. I have to say that the Alpairs, at 86 dB efficiency driven by a 15W/channel amp, are underwhelming. A little bit louder and cleaner than my CA box, but not up to the task.
I believe speaker efficiency is really what makes a difference here. Maybe I can try that single 99 dB Dayton Audio with the two 15W channels strapped together.
I believe speaker efficiency is really what makes a difference here. Maybe I can try that single 99 dB Dayton Audio with the two 15W channels strapped together.
Attachments
T-Amp Tripath TA2024 2 x 15W Audio Digital Amplifier Board
To say it all, the part they sent me was defective. I had to press my finger on the chip to make the right channel go! So I'll take my tests with the benefit of the doubt...
To say it all, the part they sent me was defective. I had to press my finger on the chip to make the right channel go! So I'll take my tests with the benefit of the doubt...
Yes, Imagine that I've two of that size'.
And with open back. In an open space, you don't have the room's walls reflecting the back emission of a speaker.
Nice and professional job you've done, but the physics tells you the basic lines...that also applies for the Dayton you mention...search for Hoffman's law in speakers
And with open back. In an open space, you don't have the room's walls reflecting the back emission of a speaker.
Nice and professional job you've done, but the physics tells you the basic lines...that also applies for the Dayton you mention...search for Hoffman's law in speakers
Thanks. By the way, I noticed your Italian flag. I am leaving for Italy tomorrow and will use this box on the road. Do you know any good supplier of chip amps that ships to/within Italy within a few days? I could try to swap amps on the fly...
Ebay it is then...
Amplificatore audio mono digitale TPA3118 PBTL 60W 8V a 24V 45x3 per auto 392 | eBay This is so dirt cheap that I bought a few just to experiment. A single 60W mono chip (even if the ouput is less at 12V) should be able to feed both speakers handily, with the input channels wired together.
Amplificatore audio mono digitale TPA3118 PBTL 60W 8V a 24V 45x3 per auto 392 | eBay This is so dirt cheap that I bought a few just to experiment. A single 60W mono chip (even if the ouput is less at 12V) should be able to feed both speakers handily, with the input channels wired together.
Is output power proportional to both input power and chip efficiency? Are all class D chips roughly in the same efficiency range or are there significant differences between models?
If they are all in the same efficiency range, it may as well be worth for me to just look at speaker efficiency.