Looking at the question from an 'ohms law' perspective, it is a red herring question.
Even my (alleged) current hungry Magnepans have only a 4 amp fuse on the mid / tweets. Say the low is good for 6 amps.....so the speaker can take a total of 10 amps.
I2R=watts.....so 10*10*5=500 watts at about 5 ohms. That's about it.
Well, the other way to go about it is to MEASURE your speaker. I stuck a DVM on my panels......About 8vac was about the highest value I saw flicker by. Say I double that to 16vac. Since Watts=E2/R That gives me just over 50 watts.
I'll give everyone the benefit of the doubt and double that twice for 200 watts per channel into my panels.
That, sir, is loud....no LOUDER
That is why my opinion, strongly held is that amp amps while not meaningless sure depend on the ability of it to drive those amps at a reasonable voltage to provide POWER.
Don't forget the SOR of a semiconductor. Safe Operating Range. You'd need a real bunch of 'em to sustain 50 amps at 50 volts..........=2500 watts. |
Yeah, Tony, That's why I doubled the 8vac I saw flicker by, TO 16v for my calculations.
I am well aware of power factor and the math involved. cosine of the angle and all. I've been a 'fan' of that approach to evaluating speakers as 'good' or 'bad' load for quite a while. Tube amps, for example simply do not like certain reactive loads......I don't 'member if it is capacitive or inductive......
People are stuck in the impedance / sensitivity paradigm for 'goodness' of load and usually fail to consider reactance.... / power factor.
And, from our FWIW department, a good cheap addition to your kit may be the purchase of a 'kill-a-watt' meter. Reads out KWH, voltage, PF, Watts / VA and current. Not bad for 25$
Anyway, I may have simplified the math, but in principle I think I'm right. People do not need these wacky current ratings which are 1. meaningless 2. not measured to a standard.
People also use far less power than they think they need. I doubt I've ever been more than about 15% of my amps RMS rating. Most people also really love their 'd' amps and the artificially hi power rating. The ASP1000 module, for example has only a 30 second rating while my ASP500 module has a 60 second rating. Even counting a 10x crest factor, I doubt I've even approach 200 watts total output....and that is LOUD. |
AHHHHH! Atmo:
Good answer! Also, tube amps are considered a 'current source', right?
So the right speaker for a tube amp differs from the right speaker for a SS amp.
That's why the 'comparison' threads between tube and SS are not quite......meaningful.
I'd LOVE to hear a 100x2 tube amp with my panels. I'll bet it'd work just fine, thank you very much! |
One possible solution to giving an amp some 'figure of merit' based on reactive loads is to Standardize such a load and let amps fight it out.
Also, I've seen an amp tested the following ways.
Into a resistive load....Try it at 4, 8 and 16 ohms.
Into a +45degree reactive load at the various resistances
Into a -45degree reactive load at the various resistances.
Afte the above, you can draw a very nice plot....would be a 3-d plot and visually tell how an amp performs into real world loads at a glance.
However, for easy of testing, the 'standard' speaker load makes more sense.
It could be reproduced anywhere at any time by any competent tech and the results would compare with all others using the same method.
But, that's just my take. |
You bring up a good question and I'll be interested to read what others think.
I know that to go louder will start requiring wacky amounts of power. If you go for more power, don't even think of anything less than double+ what you now have.
Also, panels will only go so loud.
You MAY end up moving away from Mac. Sorry, but you are one of the few I've read who make that pairing.
If you can find a Bryston or Pass of similar power, you may find the 'missing slam'. |
I hear about few people who have Mac/Maggie. Not to say it wouldn't work or isn't a great combo.....just not 'common'.
Expensive, too, if you go to the MA6900 / MA7000 level.
I had a Rotel RB1070 of 130x2 @8 with NO factory 4ohm rating. That should have been a 'clue'. The amp simply didn't have the guts at higher levels. The Rotel was also 360 'bridged' to which I took to imply 180@4.
When I pulled the trigger on an upgrade I went with nearly 3x the power in a 'd' amp. Even though 'd' amps are time limited at max power, the dynamics are there, which is all that really matters, as far as power goes. IMO. |
If I'm ever up in LaLa Land, I'll be sure to drop in. Woodland hills is a nice place.
I'm way South down the coast in SD. It was where wife and I could afford to buy when we got hitched....back in '86. I love it down here. |
Ear is most sensitive to THD at higher frequencies. I'll let the guys that know fill in the blanks. Your ear is most insensitive at very low frequencies......which is why subs can get away with 5% distortion or whatever.....which, if it happened at 1000hz, would drive you from the room.
Don't worry about specs. Their is a relationship to feedback which some persons object to. Just for example, the Japanese amps of the 70s had amazingly low #s, but were high feedback designs. Again, the knowledgable ones will be along in a minute.
As for Emotiva? You could build the identical design of amp....#1 used all premium components, matched semiconductors, huge heatsinking on outputs, heavy gauge chassis, transformers it takes a forklift to move, and other 'quality' touches. MTBF is very high. Before being mass produced the piece was 'voiced' and sounded GOOD.
#2? Built with parts from Fry's or some catalogue. Just the values called out, with no matching, or thought of other characteristics of the part.....Caps have a resistive and an inductive component, for example. Everything else was built or sourced with price in mind. Meets specs? Sure. Sounds good, too....but not quite up to #1s level. More production variance and less lifetime. Sales price point?.....A heck of a lot lower than #1.
Just my opin. |
Specs are advisory to the knowledgable and misleading to those who aren't. |
Atma,
Just read your reply from last month to my specs comments.
You could be right. Bottom line? Don't believe everything you read, even if you think you know something about it....
figures lie and liars figure......
And yeah, my now ancient, long gone Carver Cube was 0.5% distortion and who cared? Sounded fine at the time., |
