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Hypex FA253 for 3 way DIY speakers

shandit66

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Dec 30, 2020
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I've been building speakers for about 15 years - this combines my love for audio and woodworking. :)
These have all been 2 way desktop and small MTM configurations.

About 7 years ago I set out to build a large set of 3 ways. (or 2 way with subs)
Unfortunately things got in the way: moving 3 times, switch careers and now a very demanding 5 year old son.... you know, the usual curve balls that constitue life.

The parts are all still here waiting to be rebuilt after a few less successful attempts
Tweeters: Heil AMT1 - the ESS website shows the SPL at 96 db, but other sites show as high as 107
Mids: 4 Scanspeak 18W/8545 - 88 db
Subs: 4 Scanspeak 23W/4557t02 - these are very inefficient at 83 db

The tops were built as MTM, which is a bit challenging with the AMT-1. So they look like this.
MTM.jpeg


The current attempt is tri-amped with a Behringer active crossover, Crown D-75 amps.
(the sub module is in storage with a Crown K1 amp)

The challenge has always been matching the levels between the tweeters and sub.
Once I get the amps and crossover hooked up, there always hissing in the tweeter.
And admittedly, the Behringer is not a great unit - and it likely the culpret.

Input is my old Mac Pro, from 2012, which acts as a music server in my house.
I would like go digital out, direct to an DAC/XO solution and keep the whole path digital until the amps.
Currently, the Emotiva XDA-2 is the DAC (and remote), so analog out, to the Beringer crossover (so converted back to digital, the analog again) and as far as I have worked out is responsible for the hiss.

So I have been researching the Hypex FA lineup.
And this morning read the other thread here reviewing the newest amp with great interest.

Seems like the FA253 would be a great solution.

1 - digital all the way.
2 - enough power
3 - built in crossover w an external PC interface (I "think" I still have a PC around somewhere....)
4 - remote capable
5 - a compact packaging solution - its all in the speaker and I can get rid of the stack of amps & stuff.

The only issue I see is that a Mac's dont have an output for TOSLink or S/SDIF - so I would need some interface.
The Emotiva unfortunately does not have a digital out.

Does this seem like a reasonable plan?
Would I need to consider anything else?

Thanks for any feedback
 
OP
S

shandit66

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Is digital a requirement? Otherwise this amp will be just fine with analog input as well.
Its a soft requirement.
I'd test out the setup, using the Emotiva as a DAC.

But it doesnt make a lot of sense to me to have. Digital -> Analog -> digital -> analog.
And in terms of packaging, it would be nice to get rid of all the rack gear, just Mac -> speakers, with a remote

Of course, I see you have WAY more experience than I do, and especially with these units, so I'm happy for any suggestions.
 

617

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I wouldn't be too concerned about DADA, a lot of the music you listen to is ADADADA.

I think those Fusion amps are the best thing going for DIY speakers. The minidsp ones are okay but no 3 ways.
 

sigbergaudio

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Its a soft requirement.
I'd test out the setup, using the Emotiva as a DAC.

But it doesnt make a lot of sense to me to have. Digital -> Analog -> digital -> analog.
And in terms of packaging, it would be nice to get rid of all the rack gear, just Mac -> speakers, with a remote

Of course, I see you have WAY more experience than I do, and especially with these units, so I'm happy for any suggestions.

The internal AD/DA is transparent, so for the sake of argument I would suggest you forget the fact that the AD/DA in the amp exists, and then choose what makes most sense for you regardless of that.

You could connect directly with a mac analog too? Also you have the middle ground between "just Mac" and "lots of rack gear": There are several very small footprint preamps/DACs with volume control, which would be all you need in addition to the Mac.
 

somebodyelse

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You should be able to run the Hypex software in a virtual machine with USB passthrough to do the configuration - at least that's how I've done it on linux for their older DSP.
 

ncbassplayer

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Regarding the tweeter hiss issue, don't expect that to go away with a change of amps. There is an easy solution you might try with your current setup, which is to create an L-pad for each tweeter. It's super simple... one resistor in parallel (put it between the + and - of the tweeter) and one in series on the + side. Just google "L-Pad calculator." The resistor values are calculated based on the Re of the driver and the desired attenuation.

I had the same issue with my active speakers and I'd assume it is a common problem with active speakers due to tweeter sensitivity and having nothing between the tweeter and amp. I ended up with an L-pad that reduced the tweeter sensitivity by about 12db which eliminated the hiss and brought it in line with the woofer I am using.

Just for reference, I am using a Minidsp 4x10HD for EQ/Crossover duties running into VTV Purifi amps. The tweeter is the Satori TW29BN which has a sensitivity rating of 95db. The VTV amps by themselves are dead silent, but the Minidsp puts out enough noise that I had audible hiss from my listening position. Adding the L-pad completely eliminated the hiss unless I put my ear right up to the tweeter.

With the drivers you are using, I'd probably go for about 8-14 db of attenuation on the tweeter to match it closer to the midrange driver. This depends on how you are doing the baffle step comp (if any) on the mid. This should eliminate the hiss and get it closer to the level of your mid. You should then be able to use the Behringer to fine-tune the gain on each driver.
 
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DonFizzle

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Cool thread, exactly the topic I was looking for, although it seems to have lost steam!

Love the look of your DIY speakers with the Heill AMT, I'd love to know a bit more about them too. Have you got a thread following the build?
 
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