ACA Speaker short list

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#43
herm said:
Christo - I also investigated Faital. Lots of positive feedback for an inexpensive driver. I was going to go there myself until I learned of the Pluvia. Cheap here in the US!

Cant wait to hear your impressions and opinions on both the Faital and ACA...
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Herm, I'll most certainly post my findings here after I've completed the whole system. The B1 is built and tested. Next will be speakers and then ACA. It might take a while.

Christo
 
#44
Jim Shearer said:
I'm not X, but I did build X's 0.53 Karlsonator w/ two TC9FD per box. I tried running the drivers in parallel & in series. When in series, the inductance of the two voice coils resulted in weak high freqs. When in parallel, the high freqs were quite good. This was the result using my old Sansui 4000 and Yamaha CR-1000 receivers, which aren't bothered by the 4 ohm configuration.

Not sure how other drivers and /or amps would perform, but that's my story.
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Thanks for your input Jim. Much appreciated. I need to make a decision based on what I read in this thread, because I don't have enough experience to do it on my own. Hopefully, people will be forthcoming with dependable information.

Christo
 
#45
xrk971 said:
The parallel gives more sensitivity to the power limited ACA. Let's face it, the ACA with only 14dB of gain and maybe 5w if you push it hard isn't goi g to get loud. But if you have speakers that hit 100dB at 4vrms then that's very listened able.

The ferrite costs way less and has slightly higher Qts for deeper bass I. The Karlsonator design.
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Thank you, X. That makes sense. It will have to be Ferrite's then. The only remaining question then is whether the ACA's will be happy with 4ohm speakers.

Christo
 
#47
X, how did you fit dual 3FE25's in the 0.53x cabinet?

I've drawn it in CAD and they don't fit. The cabinet height inside is 381mm according to the Karlsonator 0.53x for dual TC9FD drawing. Is it ok to increase the height or should I make the driver panel higher? Btw, I'm going to use 12mm MFD. If a cabinet from foam board sounds good, I suppose it's ok to use MFD?
 

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#49
Skylar88 said:
X, how did you fit dual 3FE25's in the 0.53x cabinet?

I've drawn it in CAD and they don't fit. The cabinet height inside is 381mm according to the Karlsonator 0.53x for dual TC9FD drawing. Is it ok to increase the height or should I make the driver panel higher? Btw, I'm going to use 12mm MFD. If a cabinet from foam board sounds good, I suppose it's ok to use MFD?
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I haven't actually tried just assumed it fits because I know TC9FD fits. Thanks for drawing cad picture. Just extend panel that drivers mount to accommodate. That will change the angle of that board a bit but it is of no consequence.
 
#50
xrk971 said:
I haven't actually tried just assumed it fits because I know TC9FD fits. Thanks for drawing cad picture. Just extend panel that drivers mount to accommodate. That will change the angle of that board a bit but it is of no consequence.
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Ok, great. I will do that. Thanks for the prompt answer. If the magnets on the 3FE25 weren't so big, we could've moved them down even more.
 
#51
ACA works fine with 4ohm speaker

I just tested my ACA with an XKi fitted with dual PA130-8's in parallel (4 ohm nominal load). It sounds great - gets quite loud and the single speaker fills the room nicely. I am thinking that this might just be the next combination for my shop speaker. Driven with a Focusrite DAC, it plays very nicely. With an iPhone - can't get as loud but still enough to be very listenable for a 14dB gain amp. Here is a quick sound clip on this special XKi designed as a midrange/top tuned for 80Hz and not much bass (although you can hear it, it was not designed for it). I don't hear any distortion artifacts or clipping, so I think you are good to go. Check out this mp3 sound clip of the ACA driving a 4ohm XKi. Change the .asc extension to .mp3 to listen.

attachment.php


For those of you wondering what the third device mounted on the heatsink is, that is a 7812 with some resistors to slow down a small CPU cooler fan on the backside of that tiny heatsink to allow this amp to work quietly and cool while not needing a big expensive heatsink.
 

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#52
Thinking about it, at the last diyFEST a couple weeks ago the ACA (full kits from diyAudio store) drove the Frugel-Horn Lines with 4Ω Mark Audio Alpair 5.2eN marvellously.People listening were stunned by the (apparent) bass.

The ACA seems to play much louder than one would think for its power rating, likely a sign of how well behaved it is on clipping.

dave
 
#56
xrk971 said:
I just tested my ACA with an XKi fitted with dual PA130-8's in parallel (4 ohm nominal load). It sounds great - gets quite loud and the single speaker fills the room nicely. I am thinking that this might just be the next combination for my shop speaker.
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Thank you X. Now we know that it works and I'll go ahead with the 0.53x build with dual Faital 3FE25's. 😀

And thanks to all who have contributed to this thread. I have decided what speakers to build for the ACA's.


For those of you wondering what the third device mounted on the heatsink is, that is a 7812 with some resistors to slow down a small CPU cooler fan on the backside of that tiny heatsink to allow this amp to work quietly and cool while not needing a big expensive heatsink.
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I may need to do the same since the heatsinks that I've ordered look about the same size as yours.
 
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#57
xrk971 said:
I just tested my ACA with an XKi fitted with dual PA130-8's in parallel (4 ohm nominal load). It sounds great - gets quite loud and the single speaker fills the room nicely.
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Great stuff! Thank you X for real life operation testing.

planet10 said:
Thinking about it, at the last diyFEST a couple weeks ago the ACA (full kits from diyAudio store) drove the Frugel-Horn Lines with 4Ω Mark Audio Alpair 5.2eN marvellously.People listening were stunned by the (apparent) bass.

The ACA seems to play much louder than one would think for its power rating, likely a sign of how well behaved it is on clipping.
Click to expand...

Thank you Dave for that feedback on ACAs.

Good to know that (within the ACA limits) there is no real concern driving 4ohm speakers then. Gives me peace of mind to try the dual TC9FDs, 3FE25s or PA130-8s sometime in the future.
 
#58
I understand Skylar88 has chosen a project. For everyone else in the same situation, I can offer thoughts on the last few years of my DIY path which has involved some of the speaker projects already discussed. I started out with some banana coned Fostex 126en in FH3. Great intro into semi-high efficiency speakers. Worked fine with a few W of SE DHT on delicate music. Then I went to a Karlsonator with a range of 12" and 10" new, vintage, pro, and hifi drivers and also in a couple of econowave set ups. These worked much better on mainstream types of music. They were particularly stars with overdriven guitar stuff. Still fine with low wattage amps. They weren't nearly as refined as the FH3 with the Fostex, but they certainly all had tighter punch. After that, I tried some MA Alpair drivers in the FH3. Huge improvement for most everything over the Fostex except for the sensitivity. They benefitted from more power, stepping up to a PP EL34. Then I tried a range of front horns with all sorts of drivers. Mixed results. Now, I'm entranced by some MLTL with Alpair 12pw run full range with a waveguided compression driver to fill in the highs at 10k Hz with the 12pw run out of steam. Certainly the best I've heard so far. My thoughts anyway. What a fun hobby....
 
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