Aleph J illustrated build guide

Hi all,

Ive found some focal aria 948 speakers for a banger deal.

But the only thing holding me back is that ive rad that they can be quit hard to drive due to a large impedance dip down to about 2.5ohms in the frequency range of 70-110hz.

do you think the aleph j will be fine for these?
 
Impedance is futile

On the topic of difficult impedance, while possibly not matched that well with my DBR-62 I am still enjoying my Aleph-J's attributes. I'm primarily a soundstage / space chaser so its working out for me so far. Maybe a different amp would do better with these, or a better choice of speaker would fit this one. Nothing for it but to explore those options.

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I'm thinking a number of speaker manufacturers would call that one a "nominal 8 ohm load." Typically, anything north of 6 ohms gets lumped into the 8R category. This speaker only dips below 6 ohms from 150-300Hz (a small range of frequencies). Sure, at 125Hz we get the double whammy of 60 degree phase angle plus lower impedance, but the box tuning lies at 50Hz with a corresponding phase angle that is pretty close to zero degrees. Most "reasonably" robust amps will be pretty happy with this load.
 
Well I'm going to price up the f4, ba3 as I already have the preamp board and jfets and maybe an f5t build. Quite keen on these focals as they're half price atm.
I'm. Open to suggestions on any other diy amps for these speakers if anyone has an idea
🙂
 
@BenE123
FWIW I drive a pair of 1028BE with one ACA at times and it works fine for me. Not sure how they compare to the Aria 948 on paper.

The Aleph J would have roughly the same output into 4 ohms as an ACA? Yes?

I’ll be building an Aleph J next…okay not next, but the one after that.
 
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OK so I'm unable to find a graph with the 948 measurements. But they supposedly measure very similar to these aria 936.
936 is slightly easier to drive. But not by much from what I've read
I'm unsure what the aca puts out into 4ohms. But aleph j is about 12.5 watts
 

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