Tri-amping 3.6R's; what amp for the ribbons?


I currently use a active bi-amp setup w/my 3.6R's. The pre-amp/crossover is a DEQX unit, into a pair of 1000ASP ICEPower amps for the bass panels, and a pair of Bel Canto REF500M's for the mid+ribbon. The crossover is at 200hz, 96db/octave. I'm thinking about moving to a tri-amp setup. Anyone tried this with 3.6R's? Any advice?

What amp for the ribbon, assuming I keep the current amps for the bass & mid? I'm thinking a nice Class A tube amp for the ribbons, but that's just my first instinct.

BTW, I like to crank these speakers LOUD -- as loud as you can go before the panels start farting. I guess ribbons don't require much power, but how low can I go?

Also, I'm concerned about blowing a ribbon -- I have to bypass the fuses, right?
mikeand1

Showing 5 responses by magfan

Given the low crossover of 200hz, I'd say the upper freqs are under powered, especially for someone who like to crank 'em until just short of farting....however loud THAT is!
The 50:50 power point is around 350hz for 'average' music. Right now, I'd suggest your REF500s are running into the wall sooner than the 1000s.

It's not that the ribbons are more sensitive and not needing 'much' power, but that the music above the crossover contains less and less energy, meaning you don't need mondo amps to run it, just electrical compatibility.

Another ICE amp would work for tri-amping....just keep the power to frequency spread within reason for the crossover. IOW, if you cross to the ribbon at 10khz, you may only need the 125 watt module. At that point, the 500 for the mids would drop back into line.

If I had your level of bad habit, I'd think seriously about with Pass amps. If you insist on sticking with the bi-amp setup, a selection of 'a' amps would work fine.

Happy Electric Bill.
I was just floating the idea that power needed is related to the crossover frequency. 10k was an extreme example and used to illustrate how little power is needed above very high crossover frequencies.
If you had the perfect amount of power per 'way', they'd all redline about the same loudness.

I'd generally stick to the stock crossover points. The folks in WhiteBear Lake spend a bunch of time getting that part right.

You say you like 'd'amps. I have one, too. So, I've got to ask, what do you NOT like about your current setup? Why do you think tubes are the 'cure'?

Several higher power tube amps may do. ARC would be on the short list, since many panel owners use and like them.
Yes, I believe in the biamp setup, that the 500 is underpowered relative to the 1kw, with the crossover at 200hz.
For 'average' music, the 50:50 point is about 350hz. So, with an even lower crossover it may be 45:55 or perhaps worse.
I'd start by using same amps on the 2 sections....

Now, I'd also measure power output to the panels, even as crude as a DVM. I think the power rails in those amps is what.....80 or 85 volts?
Have you popped a fuse.....yet?

The noise you hear is mylar slap, basically the panel 'bottoming out'. Not recommended, as a general rule.

I don't know that 20.1s play much/any louder. Just move more air and so can couple to a larger room. The NEW 3.7s may have better frequency balance or sound better to whats left of your ears.

If you got the loot to just toss out that you may 'need to upgrade to the 20.1s.....' I'd suggest taking the cash and up-amping to a brace of Pass amps. Don't get me wrong, I, too, have a 'd' amp. And while I'd love to have the pass INT-150, I'm sticking where I'm at and will do room tuning before turning to the bottomless pit of bi/tri amping with the thousands of adjustments.

Keep us posted on your progress.
The reason I bring up relative amp power is that for someone like yourself, for which too loud is NEVER loud enough, you theoretically want both amps to redline at the same time. You can always turn the 'louder' amp down, but did you turn it down because it was too loud relative to the other freqs or distorting...ran out of juice? or the panel is at redline? You may end up needing an SPL meter and a calibrated disk, like the one from RIves Audio, which is a match for my RadioShackup analogue meter.

Extreme example. Your kilowatt amp on the lows. coupled with say.....100 watts on the highs. Kilowatt amp doesn't get out of first gear while the 100 watter is off scale. You're looking for the highest peak power without clipping.

Now, something you might NOT know about ASP modules and 'd' in general. They rate power for SHORT TIME PERIODS.

http://www.icepower.bang-olufsen.com/en/solutions/speaker/ASP_SERIES

Go to link an poke around in the data sheets. you'll find the kilowatt amp is that lofty 1000 watts....for 30 seconds. The 500? Time limit is 60 seconds. Both are limited by cooling. Run 'em upside down in some LN2 (liquid nitrogen) and you could get away with it for far longer.

I think that amp amps is sort of a red herring, but may be wrong, if someone can tell me why. It would seem that in order to keep from running the power devices out of the save operating range, you'd have to run that high an amperage at some very low voltage. After all, 40 amps at 50 volts is 2000 watts. My 1.6s have a 4 amp fuse and crossover about 600hz. If thats near the 50:50 point (it's a little high) I'd have to call the entire panel 8 amps MAXIMUM. I'm not going to do the math. My head is killing me from a long day, but you can work out the power. If you don't know off the 'topofyourhead', look up ohms law calculators.

I have measured voltage to my panels using a DVM. This is NOT accurate at all, but I double it and call that 'peak'. Music is much quicker than most meters. If I had access to one, I'd use an O'Scope. Preferably one with 'peak capture'.

Good for you that you've never blown a fuse. In maggie circles, the ribbon is known as a fuse protector.
class 'a'?
Pass xa30.5 clean 30x2 which near triples to almost 100 in a/b, both while nearly doubling into 4 ohms.
I wish I could afford Pass for my panels. I'd do so without even extensive audition and doubt I'd ever look back.