PAT from ART posts here a fair bit... or used to, not sure any more
Missed this thread when it was active. Hope no one minds jumping in after it has cooled off.
Good for subwoofer only? Well, to be honest, I think that applies to 2 of the 3 power level modules. I have futzed with these things, for way too long, trying to solve that problem. At the present, I am building a set for a customer, that we are also doing a electronic crossover for. I finally threw my hands up, about a week ago, and said "Screw it!!!!!!!!!! It won't see anything above 400 Hz, so who cares about what the damn output filter does, above 10 kHz?"
Back in the day, when we were perhaps only one of three companies who sold amps using these modules, I cautioned everyone about their frequency response "problems". Some folks called me every dirty word in the book. Which, I did not understand. Potentially, I was costing us sales, by 'fessing up to their shortcomings. So, who was I hurting, by doing so. Some guy who plunked down $$$$$$$$$$$$$ on Jeff Rowland's version? (No, it was some guy who bought an amp from the 4th or 5th outfit to make an amp with these modules.)
OK, in summation, and as is our policy to be up-front with our customers, I seriously would not advise using the 500W or most definitely the 1000W versions for full-range amps. Yes, I know other companies (some of whom are buddies of mine) sell amps, that way. If that is what you desire in a full-range amp, then continue to buy their fine products. If you want full-range, from us, you are only going to get the 100W (8 ohm) one.
Now..........on top of that.............having heard all the different ones, many times, over many years, I stand by my initial judgement:
1.) The 100W is the smoothest of the 3. Not only just in frequency response, but also it just sounds cleaner.
2.)The 500W, and obviously the 1000W, can drive the hell out of any LF driver. The 1000W more so than the 500W. In the development stage, we ran the 500W at a lower voltage, to see how much the rail voltage was part of the reason why it was better on the bottom than the 100W.
Q= 0.5*C*V^2.
Yep, the voltage is the reason. The 500W sounded a lot closer to the 100W, as we ran the rail down.
3.) If you look at their published specs, the 1000W ASP is rated for "20 to 20" service. But, the stand-alone 1000W "hanger" module is only rated to 1 kHz.
HUH??
What is different? Well, to me: nothing. Except if you factor in these modules were in all likelihood developed for powered loudspeaker applications. If the big amp was only for the LF driver, who cares what it does (or doesn't do) at 20 kHz? Even if the 500W has a droop, it can be corrected! But, when you try to make a "one size fits all" stand-alone amp, you get problems.
4.) They still..........for some odd reason.............sound best on planar speakers. Such as the Maggies. Perhaps it is because the Maggies really need that punch in the bottom, to make them sound right. Or the Maggies don't expose the potential flaws, the modules have. Or maybe it is just because the modules exhibit their best FR into 5-6 ohm loads.
Or, all of the above.
Mind you, they do work with other speakers. We recently did a local audio show, with Van Zyl:
http://www.vanzylaudio.com/It was a good match. The Van Zyls do not have a choke, in series with the woofer, and the control of the ICEpower modules came through. While I have not measured their impedance, it must have been a good match, as the FR sounded right.
(Or, it could be it also had a ribbon tweeter. Nice, smooth Z.)
So, there you have the latest inside scoop. Those of you who have been waiting 5 years or so on the upgrade(s) now know I really have been working on them. Just still frustrated as hell. If all goes well, on the set we are working on, we should be ready to announce the upgrades are ready, in the near future. They are quite extensive, but will not require any new PCBs. Haven't listened to it yet, as they are not anywhere near ready to do that. Stay tuned.
Pat
