looking for an efficient 100wrms 2ohm 10'' sub

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#9
Googling your zoudio, it looks like you're chasing the impossible. While the chip amps are capable of 2 ohms per channel in stereo, they run into a thermal wall when bridged at about 65 to 70 watts RMS. TI doesn't rate them at 2 ohms bridged, and at 3 ohms they start leaving the thd graph around 70 watts. Bridged at 4 ohms, the climb starts at about 55 watts. So if you are running the thing at a lower input voltage, say 18 volts, you can run a 3 ohm load and peak out at near 100w at 10% thd and maybe not thermal shutdown. If you're feeding the full 24 volts, the 4 ohm load hits the same scenario about 10 or 15 watts behind. The 3 ohm load hits the thermal wall early, so the chip runs out of power before it can develop full rail voltage.

So there you have it. Given the trade-off, I would have no problem sacrificing 10 watts to find a 4 ohm, super efficient, affordable subwoofer.
 
#10
Oh man. Thanks for looking that up Jeff !! I had trouble deciphering the data for that amp board.

So basicly I need the most efficient 4ohm subwoofer I can find? lol

I think I'll look at some better amp and DSP options out there 🙂
 
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#11
jeff5may said:
........find a 4 ohm, super efficient, affordable subwoofer.
Click to expand...

This is an oxymoron IME, especially if it has to fit in a 1 ft^3 box, so 'chasing the impossible' is apt. 🙁

Per the sealed chart, a 1 ft^3 cab @ 20 Hz can only be 0.1% [0.001] efficient = ~ 112 dB + 10 log (0.001) = ~ 82 dB.

GM
 

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#12
Hahahaha no.

I'd put the amp dsp head into something like the triangle speakers you just got. 2 channel stereo in the bedroom. Dsp up the room eq wizards (auto eq computer flavor) in it like guy in the other thread advocated. Consider it like a sonos, only better, cheaper, more productive.

Everybody and their brother is raving about one or two new class D amp chips. One is the chip in your all in one board. It's the "smart" version of the tpa3118. Your board has 2 of them in it.

Other one is the TPA 3255. Not as "deluxe" as your chip, but more powerful. There are a lot of cheaper chinese versions and the masses love them. Just Google tpa3255 bluetooth shootout. The consensus on diyaudio is the 3e audio gear is about the bottom of the pack.

Here's the 2 channel board:
https://m.aliexpress.com/item/10000...0n.store_home.smartJustForYou_1000021629297.0

DrMordor, 360 customs, and xrk audio are some high end, not super expensive 3255 boards. There are also single channel monoblock amp boards for close to the same prices.

Above the power level of the 3255, most people are going with discrete output transistor amps, rather than single package chip amps.
 
#13
so I'm looking at 2 different TPA3255 boards with bluetooth. I read on the Texas instruments website that the chipset can support different outputs options. My question is, If I get this one with 150wx2 +300 for the Sub If I don't hook up the sub, do the 2 stereo speakers get the FULL 300w x2 ???

https://www.amazon.com/gazechimp-TP...words=TPA3255+bluetooth&qid=1606796252&sr=8-2

or should I get THIS one with only 1 knob 😛

https://www.amazon.com/gp/product/B082V4J9N7/ref=ox_sc_act_title_1?smid=A2HIRA0BE7P4NT&psc=1
 
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#14
illnastyimpreza said:
If I get this one with 150wx2 +300 for the Sub If I don't hook up the sub, do the 2 stereo speakers get the FULL 300w x2 ???

or should I get THIS one with only 1 knob 😛
Click to expand...
Assuming you have a 48volt (actually 51VDC) supply that can provide about 700 watts, and the little DC plug does not melt, and you don't mind 10% distortion, the TPA3255 amp can provide about 600 watts total at 4ohms.
In the L/R/Bass configuration, not using the bass output won't allow any more output from the L/R, they each can do only 120 watts at 1% distortion in to 4 ohms.

The "1 knob" unit can provide two channels with double the power, 240 watts at 1% distortion at four ohms.

What power supplies are you considering?

Art
 

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#15
Awesome thanks thats just what I thought! I ended up grabbing the 2 channel model, and a meanwhile 48v 7.5amp power supply for 28 bucks 🙂 7.5amps x 48v will still get me some decent power for short money!

And yeah, let's hope that little plug can handle it! ....speaking of, I need to find one lol
 
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#16
I'm tellin ya, even the nobsound 2 channel little plastic boxes, the size of a few slices of toast, are pretty loud. Sound quality, that really depends on what you would usually get for the price. Compared to some Target bluetooth player, they win. Compared to a 1000 dollar class a anchor, nope the anchor is king.

The ones I previously mentioned cost somewhat more, but the difference is worth it if you're chasing fidelity. Choosing the anchor over it for 800 bucks extra isn't easy.
 
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#17
The speakers I bought it for are the HIVI DIY 2.1A , which are $250 speakers. If I like the amp I will definitely keep those you listed as an option in the future. What do you think makes the ones you listed better than the ones on amazon??

also, is an Anchor going to sound better than a high end Marantz $1000 receiver?
 
#18
Hahahaha! Life or death situation: would the marantz be heavy enough to keep you and your kayak from going down river into the waterfall, if tied securely to the end of a 2 ton proof chain? For the scientific, assume 6 knots river speed and 100kg captain and kayak, minor lateral acceleration from paddling.
 
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