Can the A21 drive 2 ohm loads?

[MarkAR9LS]

Hi,

I've been lurking for a while now and thought it was time to step out of the shadows.

I was wondering if the Halo A21 amp could realistically drive a 2 ohm load.

I have a pair of AR-9LS speakers (4 way 5 drivers) that I plan to tri-amp (via a DEQX Calibrated 2.6P processor) with one A21 and two A23s. The recommendation from DEQX, to achieve the best results, is to by-pass the passive crossover in the speakers. I plan to do this for the bass and mid. My concern with the AR-9LSs is if I do this for the dual bass drivers it will present a 2 ohm load to the bass amp which will be the A21.

The manual says the A21 will cut out on a 1 ohm load which doesn't leave much headroom.

Any advice or guidance on this matter would be most appreciated.

TIA
Mark

[Peter Nielsen]

Hi Mark,

I strongly advice against using the A21 for a 2 ohm load. It is designed for 4 ohms or more.

If you can rewire the dual bass drivers, check these possibilities:
-Drive the dual drivers with two channels (4 ohm). (Of course you need another A21 or alternatively two A23s)
-Connect the dual drivers in series (8 ohms). This should let any amp drive it without trouble.

If that does not work out, then you probably should get an amplifier designed for the task of driving a 2 ohm impedance.

Have you already got your DEQX? (I'm still waiting for mine that I ordered in early January...)

Peter

[MarkAR9LS]

Hi Peter,

re: DEQX
I just ordered my DEQX tonight. According to DEQX it should only be a few weeks until I get it. Of course, I am local - in Australia.

re: A21
thanks for the advice. I'm not sure how the drivers will react to being in series. Ultimately, I think two A23s is the way to go which means I would have FOUR A23s powering the AR-9LSs. That's more grunt than two JC1s but at less than half the cost!

I might go with the third option and leave the passive crossover in place on the bass drivers for the short to mid term.

Mark

[Chris D]

Oh, hey, Mark, welcome to the Guide and Club Parasound! :banana:

[Peter Nielsen]

I just ordered my DEQX tonight. According to DEQX it should only be a few weeks until I get it. Of course, I am local - in Australia.

Mark, any luck with getting the DEQX?

I ordered my DEQX in early January and I still have not received it... (DEQX keeps telling me 3-4 weeks every time I've contacted them).

Peter

[nicholtl]

Mark, any luck with getting the DEQX?

I ordered my DEQX in early January and I still have not received it... (DEQX keeps telling me 3-4 weeks every time I've contacted them).

Peter

Slackers.

[MarkAR9LS]

Hi Peter,

sorry to hear you are still waiting for your DEQX. However, so am I!

Mine was due mid June but apparently there was a delay in production. Currently mine is in testing and is due to be delivered to me later this week.

[Peter Nielsen]

Well, it seems like they've finally solved their production problems. My unit is finally in the hands of Fedex, so now all I can do is wait :T

Peter

[MarkAR9LS]

Hi Peter,

do you have your DEQX yet?

I have had mine for a week now and the improvement in sound is simply stunning. It took a day and half to get everything set!

First, I had to rip out most of the speaker (AR 9LS) crossover. I had to leave the HF part (upper mid to tweeter) of the crossover in place as the DEQX was limited to three bands per channel (triamping). However, I did recap what was leftover with Auricap capacitors.

Next, I added two pairs of binding posts for the woofers (12" and 10") to run quad wiring. I decided to go with your suggestion and use two A21s (one per speaker) to get around the 2 ohm load problem. This was cheaper than going with two JC1s to drive a 2 ohm load.

So in total I have an A21 (bass) and an A23 (mid and tweeter) per Ar 9LS speaker. All amps are controlled by the DEQX unit.

Although this amplification setup has cost me a bit more than two JC1s I have no doubt that the end result with the DEQX is vastly superior.

I expect your experience will be just as good (or better with the JC1s!).

Hope to hear from you in the DEQX users forum.

[Peter Nielsen]

do you have your DEQX yet?

No... It's supposed to be here on Thursday... I hope they got it right though. According to FedEx tracking the package weighs only 3 lbs. Seems kind of low for the DEQX...

BTW, I got the reference package with the Earthworks microphone instead of the default Behringer mic.

Peter

[Chris D]

:banana:

[Peter Nielsen]

No... It's supposed to be here on Thursday... I hope they got it right though. According to FedEx tracking the package weighs only 3 lbs. Seems kind of low for the DEQX...

BTW, I got the reference package with the Earthworks microphone instead of the default Behringer mic.

Peter

Ahhh! Good news. For some weird reason, they shipped the reference mic package as a totally separate shipment. My dealer just got me the second tracking # for a 17 lbs package. I should receive everything on Thursday 6th. Great! I know what I'll be doing this weekend :B :T

Peter