amp power & driver sensitivity in multiamp setup

Hi Al- got it. I really don't think so, although it would help the amplifier to have lower distortion. He would still need either greater power or a more efficient driver.

Ralph, sorry I missed your post. And thanks for chiming in!

Al is right: I was considering using a single 16 ohm driver.

Maybe using specific examples helps. The original 94dB/2.83V driver was a B&W FST. PHL Audio makes high sensitivity drivers, and I was considering some of their 6.5" and 8" midranges as well. For example 2520 is an 8" 4 ohm driver spec'd as 100dB/2.83V and the 2530 is the same but 16 ohm.

Also as example, I'm looking into Yamamoto A-08S (45 SET) and A-011 (2A3). These only have one set of speaker connectors, though. I'm looking into what kind of impedance they were designed for, but so far haven't discovered it.

BTW, what's the impact you would expect if I ran one channel on the 5 ohm tweeter and the other channel on a 16 ohm midrange? Would that tax the amp in any way?

Thank you!

Its probably that if the amp has only one output and no taps, that the 5 ohm load would result in less output than the 16 ohm load.

If you use drivers that are 100 db 1 watt/1 meter (PHY?), then you have a chance with the 2A3 amp but I have my doubts about the type 45 amp- realistically they only make about 0.75 watts.

When you say "if the amp has only one output and no taps", what are you referring to by taps? I initially I thought you meant speaker output connectors, but maybe not.

PHL Audio is a French manufacturer, well regarded in EU.

PHY is a French manufacturer too...

'Taps' are the outputs of an output transformer. A tap is a connection into the winding of the transformer that allows for a different impedance. Usually a tube amp has an output for 4 and 8 ohms, possibly also 16. If there is only one output, its probably for 8 ohms.

The 1040 or 1050 seem the best bet in 6.5" drivers; the 2520 or 2530 in teh 8" drivers. Now I suspect that the specs are not accurate- they may be efficiency specs rather than sensitivity as claimed. The reason for this is that the drivers I have mentioned here have the same sensitivity rating while having two different impedances, and the sensitivity rating does depend on impedance somewhat.

What I am getting at is if these driver selection represent the same driver but in two different impedances, the 16 ohm unit should have had a sensitivity rating of 3 db less. Now they are claiming that the 16 versions are 100db, if that is really true the efficiency would 103 db.

This is because efficiency is 1 watt/1 meter regardless of the impedance, while efficiency is 2.83V/1 meter. 2.83volts into 8 ohms is 1 watt, into 16 ohms its only 1/2 watt- a 3 db difference. You might want to contact them and see if they can shed some light on this.

At any rate if the drivers are 100 db then you have a good chance of using them as midrange drivers with your 2A3 amp.