custom Class D for subwoofer

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Hi,

Right now I am using my Behringer Nu3000DSP to power my dual sealed Dayton Ultimax 15". As I am aiming on a near silent setup, I replaced the fan with a Noctua, for a more silent work. In the near future I would like to upgrade it. I might have the chance to upgrade it to a NX6000DSP and then replace both fans with Noctuas.

Other alternative would be to build a "custom" amplifier with ICEpower modules from PE, which I think might offer a much better SQ. I'm thinking on these 2x1000W class D amps:

-. 1000W amp + PS:
ICEpower 1000ASP Class D Audio Amplifier with Power Supply Module 1 x 1000W

-. 1000W module:
ICEpower 1000A Class D Audio Amplifier Module 1 x 1000W

I think I also need:

-. wiring harness kit
-. aluminium chassis
-. bigger noctua fans (140mm or 120mm)
-. binding posts
-. power button and IEC connector (I've red these need to be of high quality)

Price for everything would be around USD$800 or so...

What do you think? Is it worth it? Or should I stay with Behringer or any other "good" PA amplifier? I am aiming for a silent setup, and hopefully an amplifier that can run unbalanced input.

Also, I know that with the ICE Power modules i lost DSP features, but I probably also get a MiniDSP NanoAVR-HDA or even use my PC as only source and DSP.

Thanks in advance!
 
Out of sheer curiosity, i don't suppose you've, say, simulated those woofers in the enclosures you have, to see how much power you need to reach their xmax, have you?

And on an unrelated note, i'm not all that sure one could be talking about "sound quality" (as such) when it comes strictly to subwoofers, but i may well be wrong on that one. One might argue the placement of the subs, as well as the listening position and the room itself will influence things infinitely more than amplifier choice.
 
Out of sheer curiosity, i don't suppose you've, say, simulated those woofers in the enclosures you have, to see how much power you need to reach their xmax, have you?

And on an unrelated note, i'm not all that sure one could be talking about "sound quality" (as such) when it comes strictly to subwoofers, but i may well be wrong on that one. One might argue the placement of the subs, as well as the listening position and the room itself will influence things infinitely more than amplifier choice.

Yes, I modeled my subwoofers on WinISD. They are 3.5cu. ft. (net volume). According to simulations xmax is reached at 500W, but people always say it's better to have some "room", more so if you plan to use Linkswitz-Transform to get better response below 25hz.

Also... the difference in $$$ between ICEpower 500W and ICEpower 1000W is minimal.

I agree with you, placement and probably sound treatment are very important, but I am really "hand cuffed" there... the subs are in a room that has limited location and almost no treatment available.

hypex class d

I am a completely noob regarding custom power amplifiers, I only checked ICEpower and Sure Electronics modules, because they seem the more straight up and easy to connect.

I don't know which power supply is good/enough for the Hypex modules I can get from: DIYclassd.com

You would recommend Hypex over ICEpower?
 
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Using a Linkwitz Transform will eat up the available xmax that much quicker, especially down low. You can easily add that in WinISD as well, and see the results. Both that, and whatever low-pass filtering you'll be using.

And then comes the question, whether you actually really NEED the max SPL those monsters are capable of... :D

To your question... no, not really.

You would suggest aiming for lower wattage?
 
Well, it would certainly open up your options a fair bit (not to mention, fit into a lower budget, to boot).

If you've got a minute, go ahead and add a Linkwitz Transform in the WinISD sim for one of those woofer boxes, and see where / when you reach xmax. And then check the SPL graph, to see how loud they'll be at that point ;)

Well It certainly @ 500W with LT I hit xmax very soon.
 
... And the resulting SPL at that point is...?

Of course, it'd be that much more interesting to (be able to) measure the frequency response at your usual listening position, in that room.

One can only wonder what manner of peaks and troughs / dips would be revealed, that may very well render a "flat" response of the subs themselves, pretty much moot...
 
... And the resulting SPL at that point is...?

Of course, it'd be that much more interesting to (be able to) measure the frequency response at your usual listening position, in that room.

One can only wonder what manner of peaks and troughs / dips would be revealed, that may very well render a "flat" response of the subs themselves, pretty much moot...

Well, I get your point... I don't need 1000W per channel to drive these subwoofers...

You would suggest dual 500W? less? The target it's get s "silent" amp for the subwoofers.
 
The sensitivity of the drivers is quoted at 86dB @ 2W (that's what 2.83Vrms into 4 ohms works out to).

89dB @ 4W
92dB @ 8W
95dB @ 16W
98dB @ 32W
101dB @ 64W

Sound pressure - Wikipedia

That list of examples says a jackhammer from 1m (~3ft) away is around 100dB. Yes, there's also the Fletcher-Munson curves that come into play, but still, 100dB's gonna be noticeably loud.

Especially if you happen to live in an apartment building, that's well within the "pi**ing your neighbours off"-area, especially if we're talking bass :rolleyes:

Hell, a few years ago, the next door neighbour had to knock on my door to tell me to turn it down.
I was only using two HiVi B3N 3" fullrange drivers, with a couple of ~30w-ish LM3886 amps driving them :D
And i didn't even have my first (utterly crappy) subwoofer yet, at that point.
 
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I think ICEpower modules are cheaper than Hypex.

Parts Express have 500W with power supply for USD$311 and the additional module (w/o PSU) is USD$101.

Other alternative is Sure Electronics modules, but their power ratings are kind of difficult to understand to someone like me, as they are rated (mostly) @ 2ohm with a THD of 1%, so to get 500W of clean power @ 4ohm I think I need at least a 2000W module, which are close to USD$200 w/o power supply.

HypeX UcD700HG with HxR is €180 w/o psu, which is another €180 (SMPS1200A700). So USD$400 for 700W and USD$600 for another 700W (psu should power 2 ucd700 modules, right?)

IDK, now that I look the numbers maybe Icepower and HypeX they are the same price watt per dollar...

What about the UcD700 modules, is it good/easy to work? Does it accept unbalanced input, coming form an AVR's LFE output? or do I need an input buffer also?
 
I just ordered a few amp. modules. I know they might not be enough for my subwoofers, but it's a start.

HYPEX UCD180LP and ICEpower 50ASX2SE. Both are cheap on ebay.

I've read the HypeX need and input buffer, which it's not necesarry on the ICEpower. Recommendations point to Amplifiers | theslowdiyer

But there are only designs, I preffer to buy an assembled one due to my limited knowledge.

Would this be OK?
HIFI NE5534 DC Buffer Stereo OP-AMP Preamplifier Preamp Board support OPA627 699991670646 | eBay

Also, will this modules accept unbalanced input? or only balanced?

Finally, the HypeX needs a power supply, rated around 48V I think. Any recommendation?

Thanks in advance.
 
I will reply to some of my own questions...

1-. input buffer are not strictly necessary for neither module

2-. the input buffer sold on ebay would work, but it's not the best design nor the best opamp. According to the listing you can replace the NE5534 OPAMP with the OPA627 which offers better performance.

3-. Both modules are designed for balanced input, so... either I convert signal from unbalanced to balanced or use it as is, which won't offer the best performance/gain.

4-. For the HypeX the recommended power supply is the SMPS1200A180 or the SMPS400A180 but any other switching power supply with 48V will reasonably work.

I will buy a Mean Well Lrs-150-48 for starters. It should be enough for one HypeX module and it's reasonably priced, and best of all, can get it locally.
 
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