Hi there,
I am learning active crossover on a budget, and want to add some subwoofers to the mix. The idea is to have multiple identical Class D boards for tweeter, mid, woofer and maybe subwoofer. Idea of the build is described here: https://www.diyaudio.com/community/...th-active-x-over-8ch-total-4-x-stereo.405605/
As the sub will be most power hungry I want to run it on both channels: for example the board is rated for 2 x 15W, I want to squeeze full 30W to 1 channel.
I still haven't got the boards, but thinking about one of these:
https://www.audiophonics.fr/en/ampl...ifier-module-tda7498-2x50w-8-ohm-p-12224.html
https://www.audiophonics.fr/en/ampl...-amplifier-20-class-d-2x25w-8ohm-p-12144.html
https://www.audiophonics.fr/en/ampl...plifier-module-t-amp-ta2024-2x15w-p-7371.html
Do I need common ground boards? How can I know if they are common ground boards? I checked my Topping MX3 amp at home - it has 0 Ohm resistance between left and right channel grounds when off and the same when playing music. I think it has TDA7498 chip inside, does it mean that it has common ground between channels and all the boards with this chip will be suitable?
Thanks for info
I am learning active crossover on a budget, and want to add some subwoofers to the mix. The idea is to have multiple identical Class D boards for tweeter, mid, woofer and maybe subwoofer. Idea of the build is described here: https://www.diyaudio.com/community/...th-active-x-over-8ch-total-4-x-stereo.405605/
As the sub will be most power hungry I want to run it on both channels: for example the board is rated for 2 x 15W, I want to squeeze full 30W to 1 channel.
I still haven't got the boards, but thinking about one of these:
https://www.audiophonics.fr/en/ampl...ifier-module-tda7498-2x50w-8-ohm-p-12224.html
https://www.audiophonics.fr/en/ampl...-amplifier-20-class-d-2x25w-8ohm-p-12144.html
https://www.audiophonics.fr/en/ampl...plifier-module-t-amp-ta2024-2x15w-p-7371.html
Do I need common ground boards? How can I know if they are common ground boards? I checked my Topping MX3 amp at home - it has 0 Ohm resistance between left and right channel grounds when off and the same when playing music. I think it has TDA7498 chip inside, does it mean that it has common ground between channels and all the boards with this chip will be suitable?
Thanks for info
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Yes, common speaker return and not 'already bridged'. However, it is better to look out for the 'bridgeable' feature, as there could be thermal and reliability limitations when it comes to simply bridging any amp. In other words, the amplifier should be capable of more current source/sink than is currently being used.
If I have a budget for lets say up to 15 EUR/USD for single stereo board, which from your experience, are bridgeable? Ballpark is 10W of power per single channel at 12V
No idea, things here do not work in dollars, which is maybe why. But why would you want to bridge at such itsy-bitsy power levels like 10W, 20W etc. ? Aren't non-bridged / already bridged amplifiers enough ?
Remember that bridging only extends the usefulness of your existing resources by using two amps in place of one but doesn't save you any money.
Remember that bridging only extends the usefulness of your existing resources by using two amps in place of one but doesn't save you any money.
Well the listening levels will be 1-5W, that is for midranges, midwoofers and tweeters, but as my experience says you need at couple several times of that for reserve and if I add to the mix at least simple 4-5 inch woofer with low sensitivity, power requirement jumps even higher.
Besides:
Budget is limited
I want to have IDENTICAL boards for all 4 x 2 = 8 channels
I don't need 50W+ boards. Just don't need, see the "Budget" line
If the bridging functionality is there, why not to use? Yes, in the worst case scenario can use single channel
Besides:
Budget is limited
I want to have IDENTICAL boards for all 4 x 2 = 8 channels
I don't need 50W+ boards. Just don't need, see the "Budget" line
If the bridging functionality is there, why not to use? Yes, in the worst case scenario can use single channel
Maybe you understood me wrong: I want to use both channels of stereo board for mono channel. Yes, It saves money, because I want identical boards for all the speaker drivers in this way I will not need to buy multiple powerful and expensive boards
1-2W normal listening x10 is exactly 10-20W I am aiming for.
Purifi monoblocks are for better times
All the amp modules you mention in the first post are already bridged (btl) amps. You cannot bridge them for more power. You could (eventually) run them in parallel with a 2 ohm speaker for higher power (pbtl).
or even better: run two amps and two subwoofers in parallel.
For running amps in parallel you would need to check data sheets/manufacturer user manuals.
Well unless you are building four/five-way speakers I don't see the need for more than six channels, but your original use-case isn't fully clear?
My point was just that you can buy "low-power" boards like TPA3221 that still sound good, and then when you need more power you can add a board that is designed for it like a TPA3255. Even a basic TPA3255-board isn't much more than 15 USD/channel from Aliexpress, and it is would probably be cheaper than two TPA3221s.
Also, if your 10 EUR/channel is a hard limit I'd consider it too low for getting anything that is usable in the long term - remember the "buy cheap, buy twice" rule, because that also applies here.
My point was just that you can buy "low-power" boards like TPA3221 that still sound good, and then when you need more power you can add a board that is designed for it like a TPA3255. Even a basic TPA3255-board isn't much more than 15 USD/channel from Aliexpress, and it is would probably be cheaper than two TPA3221s.
Also, if your 10 EUR/channel is a hard limit I'd consider it too low for getting anything that is usable in the long term - remember the "buy cheap, buy twice" rule, because that also applies here.
Thank you, stv, for an answer,
It is a sad news
Now I am more confused than before first post: for example I have stereo board with 10W x 2 at 8Ohm or around 15 to 20W x 2 at 4Ohm, I want to have 20W x 1 at 8Ohm by using both channels to drive single subwoofer. I don't want to bridge double boards (4 channels total) info 1 speaker (subwoofer in this case).
Or I just get not 20W x 1 at 8Ohm but 20W x 1 at 4Ohm, which is more or less the same as using the single board channel?
Anyway - my task is to have subwoofer play LOUDER from using both channels of amp.
Can I kindly ask, which use case you described?
Then you also need to remember that doubling the power your deliver to a speaker is only going to deliver a marginal increase in SPL - if that is your use-case then I think you need to read a bit more on how speakers and acoustics work. You also need to understand a bit about gain and gain structure to ensure that you can actually drive an amp to be "louder".
Suggestion: Forget about power levels specs and bridging for now - build something that works within your budget and then look at what you want to improve. If you don't want to do that and treat it as a learning exercise (for time or budget reasons) then I can only recommend that you buy something ready-made from a dealer where you can return it if you are not happy.
DIY is usually a series of experiments, so if that doesn't appeal to you then save yourself the headache right now.
Suggestion: Forget about power levels specs and bridging for now - build something that works within your budget and then look at what you want to improve. If you don't want to do that and treat it as a learning exercise (for time or budget reasons) then I can only recommend that you buy something ready-made from a dealer where you can return it if you are not happy.
DIY is usually a series of experiments, so if that doesn't appeal to you then save yourself the headache right now.
Yes, 6 channels for stereo 3-ways + 2 subwoofers. That is 4 stereo boards. I thought if I can use both channels for single subwoofer - that is 5 boards total.
Use case is to play and practice with software xovers before soldering and buying expensive stuff.
I understand your idea. But the thing is that I want have identical boards to avoid music coloration between different drivers. Yes, I am very close to "golden ears" and can hear difference between TPA3118 and TDA7498 amps I have at home. Even different 3116/3118 implementations (I think I have 3 different cheap amps models) sound different one from another. Of course, when speaking about cheap stuff you will never know how much potential is revealed in cheap several $ board - sound can be just bad because of cheap components or variation between units and so on. It is Aliexpress level of stuff after all. I somehow hope, that bigger distributors have their own channels and a little more quality control than buying form Ali directly.
I am leaning towards 3116 atm
You are right again. This is a compromise. It is a hobby and it gets out of control quickly. 10EUR/channel for bare board are decent money, as I expect to get the same performance as barebones Wondom, Aiyma or similar small amps. I just don't need case and volume control knob. Besides - I do not see something with better quality control for 20EUR/channel or 30EUR/channel. It is the same Ali stuff just with different chip of bigger in physical size capacitors.