Aleph3 with Eminent Technology 8b

Hallo, this is from owner's manual of the Eminent Technology lft 8b:

"LFT-8b Impedance:
The LFT-8b impedance generally averages much higher than 8 ohms. This means that the speaker does not require a high current amplifier. Because of the lower than average efficiency (83/84 db 1w/1m) you will still need an amplifier with a fairly high power rating (75 watts per channel or more). If an amplifier clips into the speaker it will probably be due to a voltage
limitation.
The woofer curve shows an impedance minimum at 75Hz (10 ohms) and a steady rise above 100 Hz due to series inductance. The mid-range and tweeter section impedance curves trends down through the frequency range. Without the crossover in place, both the midrangeand tweeter panels have flat impedance curves (the mid-range impedance is 11 ohms and the tweeter impedance is 7.5 ohms).
With the woofer section in parallel with the mid-range/tweeter section, the
impedance curve becomes essentially flat with a minimum of about 7 ohms
occurring around 75 Hz and a maximum of 20 ohms at 50 kHz. The 20-ohm
peak is with the tweeter in its low output position. When the tweeter level is
set to the high position, its impedance will drop to about 10 ohms at very highfrequencies. The speaker should be considered as an “easy” 8-ohm load
having only very small reactive components."

I have two original Aleph 3 to drive the E.T., if I'll find that vertical biamping has not sufficient power:

1) is it a wise move to bridge the two amp as monoblocks?
2) will I lose the beautiful sound of the Alephs (perhaps not any more in class A/s.ended, more distortion)?
3) which kind of wiring to do with preamp (not balanced) and with the speakers (they have separate connectors for low/high)?

Excuse me for my bad English and technical ignorance.

Thanks.
 
with preamp having only RCA outputs , you need custom cables for your purpose of bridging two Aleph channels ;

leave Aleph RCA iinputs unused , make two cable sets as per sketch , one per Aleph ; luckily , Aleph is having XLR - balanced inputs , so we can invert one channel simply by using inverting instead of non-inverting input

as outputs - use two hot ones , with gnd terminals unused
 

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WBS

Member
Paid Member
2007-01-03 12:13 am
Napa Valley
I owned a pair of Eminent Technology LFT-8b and was amazed by their sound and build quality. When I visited CAS last year, I auditioned speakers costing 5 times as much that didn't come close to the transparency and imaging these things offer. Plus, Bruce Thigpen is a great person to deal with. He's happy to answer any questions and provides unsurpassed customer support.

My only problem was the size of my room being too small for them. One big surprise was that they sounded better using the internal crossover instead of bi-amping! :scratch1: On other multi-ways I've used I've experienced vast improvement with bi-amping.

Keep us posted on your progress and let us know how everything sounds once you have your amps set up correctly. It will be interesting to hear your observations. :cool: Have fun and enjoy these!
 
Aleph 3 has not balanced inputs.

bummer

I forgot that , counting that Aleph 3 is same as Aleph 30 regarding that

in that case , you'll need external phase splitter , which will bring opposite signal phases to two inputs

so - either electronical or xformers (with center tapped secondary)
 
I owned a pair of Eminent Technology LFT-8b and was amazed by their sound and build quality. When I visited CAS last year, I auditioned speakers costing 5 times as much that didn't come close to the transparency and imaging these things offer. Plus, Bruce Thigpen is a great person to deal with. He's happy to answer any questions and provides unsurpassed customer support.

My only problem was the size of my room being too small for them. One big surprise was that they sounded better using the internal crossover instead of bi-amping! :scratch1: On other multi-ways I've used I've experienced vast improvement with bi-amping.

Keep us posted on your progress and let us know how everything sounds once you have your amps set up correctly. It will be interesting to hear your observations. :cool: Have fun and enjoy these!

You gave me good news! Thanks God I have a large room.
When I talk about biamping I mean vertical passive biamp (internal crossover). The problem may arise if two Aleph3 are not enough to drive the speakers...
So I answered about bridging them but I fear it is not a simple question.
 

WBS

Member
Paid Member
2007-01-03 12:13 am
Napa Valley
You gave me good news! Thanks God I have a large room.
When I talk about biamping I mean vertical passive biamp (internal crossover). The problem may arise if two Aleph3 are not enough to drive the speakers...
So I answered about bridging them but I fear it is not a simple question.

I read somewhere that bridged, the Aleph3 puts out 60W. I wouldn't bother passive bi-amping. Just try them bridged and if you feel the LFT-8b's need more power, get another amp or two for the bottom end and actively bi-amp using the bridged Alephs for the mid/highs.