Where do I find 16 ohm woofers for my Altec A4 cabinets?

[Cal Weldon]

Thought#1

I am interested in updating the Pyramid WX 15 woofers in the big boxes. I would like to parallel 16's rather than series 4 ohm auto woofers like I have now. I would like to keep it at 8 ohms.

Thought #2

I am using a Carver cube mono bridged (L+R) on each box now. Could I just run an 8 ohm woofer off each channel of each amp instead of mono bridging it? This would mean running two sets of speaker wires to each box.

This is new to me so if thought #2 works, it's easy I'll just pick up four more of the woofers.

Here's what I'm using

woofers

[sreten]

Don't quite understand your post.

Your amplifier in unbridged mode (assuming 8 ohm bridged)
should be able to drive 2 ohms per channel. Then again its
usual that such an amplifier is best with 4 ohm per channel.

Theoretically 2 ohm per channel = 8 ohm bridged, but its
usual that 8 ohm bridged is barely more than 4 ohm per
channel, which is another way of saying output into 2 ohm
per channel is barely more than 4 ohm per channel.

Which the astute will infer is that 16 ohm is best for bridging.

Simple fact is its impossible to make an amplifier that works
well in both modes, the only good bridged amplifiers are
designed as such from the outset, with low rail voltages.

Single channel output is limited into normal loads but
they handle low impedance loads with relative impunity.

Bridged amplifiers cannot handle low impedance loads.

sreten.

[Cal Weldon]

Hi sreten,

I guess when I said I wanted 8 ohm load I wasn't taking into consideration the fact that when you bridge you are effectively looking at a using a 16 ohm load if you want the amp to read 8 ohms.

My thought #2 is if I run two sets of speaker wires (from each amp to the two drivers}, I will end up with the 8 ohm load I was lookng for. If I bridge it with an 8 ohm load, in effect the amp will read it as a 4 ohm load?

I guess what I'm asking is if I run only left channel or only right channel into one of the amps (split with a Y connector) and run two sets of speaker wires, ie: left channel to one of the woofers and right channel to the other woofer in the same box, is there any concerns with that?

It seems I will end up with the 8 ohm load. No?

I hope this clarifies things

Cal

[sreten]

No,

A 8 ohm amplifier cannot be bridged sensibly.

A 4 ohm amplifier can be bridged for 16 ohm.

A 2 ohm amplifier can be bridged for 8 ohm.

A 1 ohm (ha!) can be bridged for 4 ohm.

sreten.

[Roscoe Primrose]

Originally posted by sreten
No,

A 8 ohm amplifier cannot be bridged sensibly.

Don't tell all the pro-audio manufacturers, that's how they spec most of their amps...

Cal, Eminence makes 16ohm & 4ohm versions of most of thier woofers, but most of the discount vendors like Parts Express don't list the 16ohm versions in the catalogs. You may need to find an 8ohm driver you like the price & specs on and make a call to see if you can get a 16ohm or 4ohm version.

Peace

[Cal Weldon]

OK, another thought:

Right now, the set up is this:

Master pre-amp to slave pre-amp to Carver cubes to big woofers
and
Same master pre-amp to Hafler to full range

I am using the slave pre-amp in the system so I have a variable attenuator (I guess I mean volume control) to balance between the big woofs and the full range. Right now I have to back off on the woofs even with the Pyramid woofers

So if I run each cube mono bridged woofer set up at 16 ohms, the amp will read it the same as two 8 ohm drivers, which is what I want.

If I run the two 8 ohms in series (16 ohm), I'm losing...what...3dB versus 8 ohm? This doesn't seem to be that much considering I have to back off on them anyways.

Am I on the right track here or are the drugs taking effect too early?

[sreten]

Seems I've got myself confused :

8 ohm bridged = 16 ohm load.
4 ohm bridged = 8 ohm load.
2 ohm bridged = 4 ohm load.

So running a amplifer bridged into two series 8 ohm units
is the same as running each channel with 8 ohm units.

Your current arrangement is the same as running each
channel with 4 ohm units.

sreten.