When watts aren't watts!

So I just got home for a two day event where I was hired to come in and mix for a couple bands. The people putting on the event bought a brand new sound system for this event. It was top of the line stuff. It had five different models of Seismic Audio speakers that were very efficient at 96dB 1W/1M, two different models of Gemini amps, some miscellaneous stuff that they were convinced they needed and most importantly none of the stuff that they really needed. All this for a 12,000 sq ft ball room gig!

So I brought my own console and mics. Luckily I also brought a couple dozen mic cables too.

They had a 50' snake because the 100' one was too expensive, no sub snakes so lots o' cables going across the stage. No power distribution for the performers.

They did have a couple mics that I chose not to use.

They were all amazed at how it didn't get loud with those 3000 watt amps. They kept asking me to turn down the drums and turn up the vocals. "No can do!" P.A. is maxed and no drums in the mix! I looked up the specs on the POS gemini amps that they thought were 3000 watts. Only after a long search I found the manual on line to find that they were indeed 200 watts per channel at 4 ohms. They label them as 3000 watts and advertise them as 3000 watts "Instantaneous." All Complete BULLSHIT! Luckily the monitor amps were 150 watts per channel at 4 ohms. We were running everything at 4 ohms.

So if you are ever called upon to mix a gig with Seismic Audio speakers and 3000 watt Gemini amps, please understand that you won't have fun and you may want to spend more time with your wife instead!

End of Rant!

Ryan
 
Re: When watts aren't watts!

It turns out you were lucky it was a fifty foot snake - a hundred footer would have put you out of range of the "PA".

?;o)
Al
 
Re: When watts aren't watts!

http://www.danleysoundlabs.com/pdf/danley_tapped.pdfThe people putting on the event bought a brand new sound system for this event. It was top of the line stuff. It had five different models of Seismic Audio speakers that were very efficient at 96dB 1W/1M, two different models of Gemini amps,

( emphasis mine )
Many would call this a oxymoron.
It's unfortunate that purchasers don't want to pay for someone to research and save them the inevitable long term grief of a bad purchase based on price and bogus wattage figures.
Did the amps even have UL listings or documentation.
It would be interesting to see what a volt meter read or a scope trace.
The average consumer doesn't understand the log nature of power and how they are being manipulated by ads that exploit their ignorance.
 
Re: When watts aren't watts!

I think Ryan would call that sarcasm.
On this forum: I would assume that - however on another forum was this:
" As an installer, ...Say what you want, but I can tell you first hand, if you need a speaker for a small install enviroment, then hands down you can't loose. I highly recomend ..."
( no emphasis or correction added; though necessary )
And the assault on those Seismic speakers there is brutal.
 
Re: When watts aren't watts!

What people to quickly forget is that years ago (back in the dark ages (60's-70's) MANY gigs were done with 100 watt PA systems. Think Shure Vocal Master

I read that "back in the day" when Cream was their height, they were using a FIVE HUNDRED WATT PA system. WOW! Thats a lot of watts. NOt hard to belive when you read about what The Who used to use "back int he day"

http://www.thewho.net/whotabs/gear/pa/pa.html

When Deep Purple set the record for the worlds loudest band back in '74 or '75 (IIRC) they were using a 10Kw PA systemand got to 110dB. That barely makes a decent drum monitor now a days.

Oh how times have changed
 
Re: When watts aren't watts!

:D~:-D~:grin:Last time I checked, watts were a measure of power which is a ratio of energy per time. Measured over a short enough time, I guess you could express the number as any large number you like. Numerically all sorts of neat yet meaningless things happen when that denominator approaches zero.:D~:-D~:grin:

"Pushing for a new job in marketing"
 
Re: When watts aren't watts!

Many years ago there used to be underdash car amplifiers that claimed to be 2,000 watts. They were supplied by a 12 volt wire with a 2 amp fuse in it.
Fast forward to today: Both JBL and QSC (and most likely others) are playing the numbers game in their active speakers by adding up total amplifier power where the amps are rated for 2 ohms yet one or more of the actual loads is 8 ohms.
 
Re: When watts aren't watts!

Fast forward to today: Both JBL and QSC (and most likely others) are playing the numbers game in their active speakers by adding up total amplifier power where the amps are rated for 2 ohms yet one or more of the actual loads is 8 ohms.
... and they are heavily limited - especially the 500wrms amp feeding the QSC's horn :roll: .
 
Re: When watts aren't watts!

Many years ago there used to be underdash car amplifiers that claimed to be 2,000 watts. They were supplied by a 12 volt wire with a 2 amp fuse in it.
Fast forward to today: Both JBL and QSC (and most likely others) are playing the numbers game in their active speakers by adding up total amplifier power where the amps are rated for 2 ohms yet one or more of the actual loads is 8 ohms.

And thus the FTC 1/3 power pre-conditioning warm up, and other rules about power specs, legislated back in the '70s.

Rating powered cabinets by their power amps is ass backwards anyhow, what matters is SPL output. When you use separate amp sections for the different bandpasses, a more realistic approximation of a single external amp is those voltages superimposed on each other (if all drivers same impedance). So even more effective power than simple addition of the sundry amp sections. It is pretty common to use a lower impedance LF driver to get more output from internal amps where you need it.

This is like buying a vacuum cleaner based on how many amps it draws, not how hard it sucks.

JR
 
Re: When watts aren't watts!

This is like buying a vacuum cleaner based on how many amps it draws, not how hard it sucks.

JR
Back in the 90's it was real common to see "17 cleaning amps" and such on vacuum cleaners-even though they only drew 10 amps. What is a "cleaning amp"?

SOmehow this became a "standard" at least back then. I haven't bought a vacuum cleaner in many years so do not know what the standard is now.
 
Re: When watts aren't watts!

Back in the 90's it was real common to see "17 cleaning amps" and such on vacuum cleaners-even though they only drew 10 amps. What is a "cleaning amp"?

SOmehow this became a "standard" at least back then. I haven't bought a vacuum cleaner in many years so do not know what the standard is now.

I just bought two sump pumps. One is 1 HP and draws 7.5 amps, and the other is 1/4 HP and draws 8.5 amps. The smaller one does pump a bit less than the big one. Price difference is about 50%. Strange.
 
Re: When watts aren't watts!

... and they are heavily limited - especially the 500wrms amp feeding the QSC's horn :roll: .

Hey Ron, I agree that there is certainly heavy continuous/thermal limiting in there, but due to the impedance peaks and transient power capability of compression drivers, I bet most of that '500 watts' (actually, the voltage) is actually used on peaks.
 
Re: When watts aren't watts!

I just bought two sump pumps. One is 1 HP and draws 7.5 amps, and the other is 1/4 HP and draws 8.5 amps. The smaller one does pump a bit less than the big one. Price difference is about 50%. Strange.

1 HP is around 750W of power. 7.5A seems close enough to continuous draw for making 1 HP from 120V mains. The 8.5A seems like either a peak (starting or stall) current draw, or perhaps some funny load angle measurement.

JR
 
Re: When watts aren't watts!

Back in the 90's it was real common to see "17 cleaning amps" and such on vacuum cleaners-even though they only drew 10 amps. What is a "cleaning amp"?

SOmehow this became a "standard" at least back then. I haven't bought a vacuum cleaner in many years so do not know what the standard is now.

Vacuum cleaners suck.. Mine just threw the belt driving the beater brush, and when I replaced the belt, it ate that too... Apparently the rotating brush rides on a plastic bushing which has melted and deformed.. arghh not going to be easy to fix that.

Coincidentally my old vacuum brags that it only draws 7.3A while delivering a cleaning effectiveness of 20. Apparently there is a ASTM test standard for ability to pick up dirt... Maybe they can come up with a standard for powered speakers ,,, oops we already have SPL. :)

Of course now we have that insufferable twit on TV arguing that his cyclonic vacuum cleaner (with 500 patents) makes 100,000+ Gs of centrifugal force to suck the eyeballs off dust mites.

I wonder if I can find a car motor camshaft bushing to replace my melted beater brush bushing? I don't want to buy a new one. but then I'd need to find another replacement belt... arghhhh Oh well it still sucks, just doesn't beat up the dirt.

JR
 
Re: When watts aren't watts!

Vacuum cleaners suck.. Mine just threw the belt driving the beater brush, and when I replaced the belt, it ate that too... Apparently the rotating brush rides on a plastic bushing which has melted and deformed.. arghh not going to be easy to fix that.

Coincidentally my old vacuum brags that it only draws 7.3A while delivering a cleaning effectiveness of 20. Apparently there is a ASTM test standard for ability to pick up dirt... Maybe they can come up with a standard for powered speakers ,,, oops we already have SPL. :)

Of course now we have that insufferable twit on TV arguing that his cyclonic vacuum cleaner (with 500 patents) makes 100,000+ Gs of centrifugal force to suck the eyeballs off dust mites.

I wonder if I can find a car motor camshaft bushing to replace my melted beater brush bushing? I don't want to buy a new one. but then I'd need to find another replacement belt... arghhhh Oh well it still sucks, just doesn't beat up the dirt.

JR

Hey JR, I bet Willimantic, CT has one of the last vacuum and sewing machine repair shops in the country. I just looked them up and am dumbfounded that they have a website.

Although, I'm sure you'll be far more satisfied with a DIY vacuum repair.

Edit: how did this thread get from overrated amplifiers to vacuum repair?