Is a 3000W amp really a

[3stagevtec 2]

I was doing some thinking..

Taken from http://www.rockfordfosgate.com/rftech/wire_calculator.asp

quote: Because music is dynamic in nature, it will be easier for the amplifier to reproduce than test tones. Our testing has shown that it is typical for an amplifier to consume on average roughly 50% of its maximum input current on such.

If it is consuming 50% of its max input current on average, isn't it correct to say that when playing music, the amp might have peak outputs of up to 3000Wrms, but on average, might only give out 1500Wrms (over the length of an entire song)..

so from that theory, isn't a 3000Watt amplifier better suited to play a 1500Wrms sub??

thoughts?

Edited May 27, 2009 by 3stagevtec

[shizzzon 461]

let me put it like this-

Lets take a 1000w sub, any sub, 1000w and it's nto some crap u find at the flea market for $40 either, ok? Let's say somethin that SSA sells.

I'm not gonna run a 1000w amp on it. Oh no, i think that's stupid. You need headroom. Headroom allows a clean signal to always pass to the sub without clipping. No clipping, less heat build up...

So, i'm gonna run double the rated power! Sometimes more if for competition but for music, definitely double!

This accounts for multiple things-

1 - music is dynamic and changes power consumption very rapidly. This allows more power to be installed than what will be used (as long as u have a clean signal)

2 - impedance rise plays a big factor. You may be able to run a 5kw amp on a 1kw sub all day without clipping and be fine if your rise was hella high.

3 - headroom never hurt and is preferred ONLY if you know how to properly setup an amp.

Simply put, noobies may think a gain control is a volume knob and as long as there is no immediate distortion or smell then all is good... Well, that's La La land.

If the gain isn't set right, if it's set too high, a 500w amp can kill a 1kw sub any day.

Oh and to answer the question about the Sundown amp.. NO, it's not a 1500w amp.

Go to competition with it and burp test tones, OR play constant bass lines with music. You will have the potential to pull that power out of that amp, or any amp rated that.

Rule of thumb when finding out power draw when preparing to buy new electrical system is take 50% of all fuse ratings of amps and you need that much charging current from alt or aH for batts.

[jonbearsmt 919]

whats the question?

[3stagevtec 2]

i know the 3000D is not a 1500W amp! lol

my question was mainly on the dynamic nature of music vs amp rating / sub ratings...

lets say you use a 1500W amp on that 1000W sub.. that way you should have adequate headroom to prevent clipping.. BUT according to the above theory, that 1500W amp might only put out 750Watts on average for music purposes only..

in that case, we still would not be utilizing the full potential of the 1000W sub...

i only want to consider the actual power reaching the sub, so that's why i'm ignoring impedance rise for now..

[3stagevtec 2]

whats the question?

does a 3000Watt amp only put out 1500Watts on average while playing music??

[power-fanatic07 0]

what does all this have to do with the 3000d being a 1500 watt amp..

[3stagevtec 2]

grr, re-read my 1st post and give your thoughts.. i ONLY used the Sundown amps as examples as i use them... the make of amp is not at question here..

[Raymond Farmer 4]

grr, re-read my 1st post and give your thoughts.. i ONLY used the Sundown amps as examples as i use them... the make of amp is not at question here..

To answer your question, yes a 3k amp COULD and I mean COULD, be best suited to play a 1500 sub. At anytime and at any frequency or any note, the box rise could double, triple or quadruple. So, lets say your box rise is 3 times the impedance, you are at one ohm, at some frequencies, the box rise goes up to 3. Yes the 3k amp at that note/frequency is putting out about 1100 watts. But you have to be careful. If your box rise is not not high through out the bass frequencies (40 - 120 hz), if a song stays at a particular note or frequency too long, and you get no box rise, POOF there goes your sub!!!

I dont know if you know this, but that is why spl competitors drop the impedance low (ex. 0.25 ohms), so if the box rise goes up to one ohm, they get the true RMS power of the amp for that 3 seconds at one ohm.

Edited May 27, 2009 by Team Man-Up (Ray)

[Adrian_D 520]

whats the question?

does a 3000Watt amp only put out 1500Watts on average while playing music??

Totally music dependent. It could output an average of 200w or even 2000w, peaks will be higher.

[Derrick824 4]

This is something the average consumer shouldn't worry themselves with. The majority wouldn't understand it & it would lead to mass confusion and hysteria.

[sundownz 197]

Don't concern yourself with impedance curves "daily" -- match up a 1500-watt amp with a 1500-watt sub and you are good

Music is not the same as playing one sine wave after the other either... so impedance graphs don't tell you what is going on with music :

http://www.audiograph.se/subpages/technica...odamplifier.htm

[CrazyKenKid 64]

Don't concern yourself with impedance curves "daily" -- match up a 1500-watt amp with a 1500-watt sub and you are good

Music is not the same as playing one sine wave after the other either... so impedance graphs don't tell you what is going on with music :

http://www.audiograph.se/subpages/technica...odamplifier.htm

wow that was a pretty good read! very informative to me!

[KU40 173]

I believe you are thinking about that statistic incorrectly. While over the course of a song the average of the whole song is 50%, you likely have many spikes to 100% (3000 watts), as well as dips to 0%. You need the subwoofer to be able to handle those 3000 watt spikes, which are those bass hits which normally last maybe a quarter of a second or whatever. In fact, with a subwoofer, it's often either on or off. So you do basically have either 3000 or 0. So while the average may be 1500, I think a better way to look at it is that half of the song is 3000 and half is 0. That will lead you to know why you need a sub that can take the 3000.

Also, as with car engines, the heat takes a while to dissipate from the motor. So you need the sub to be able to handle the 3000 watts continuously, because that's sort of like the temperature your car engine runs at and when the thermostat opens and the correct rate of heat dissipation over the radiator as the engine creates it. With a 1500 watt sub on a 3000 watt amp, it's kind of like running a Toyota Tercel cooling system on a Ford F350. Eventually the heat buildup will overcome the cooling system, even if you drive it for a second, turn it off for a second, drive for a second, turn it off, etc (dynamic song).

[3stagevtec 2]

^ excellent argument! makes sense..

new question, how does PEAK power fit into this equation when you consider a subwoofer with the following power ratings..

a typical subwoofer will be rated at 1500Wrms and 3000Wpeak.. which will work nicely with a 1500W amp as shown above..

BUT what about a sub rated at 5000Wpeak and only 800Wrms!

assuming a 1500W amp is used, would such a subwoofer be able to handle those 1500Wrms spikes while being able to dissipate the heat produced at the 50% mark (or at least most of it)...

(i also assume that a 1500W amp might produce around 3000W of peak power)

what do you all think? correct me if i'm wrong anywhere..

[KU40 173]

Peak ratings are worthless. With a subwoofer, you have no idea how long they made it last with that peak rating. Some sub companies may say if it lasts for 5 seconds, that's peak. Others maybe 1/2 second. And others simply double the RMS or even just make something up with absolutely no basis. I have no idea what JBL does, and I'd just run an 800 watt RMS amp on that sub. I'd say it's impossible to tell if that sub can handle 1500 watts RMS without actually getting one and testing it. Especially since RMS numbers can be made up themselves, or at least measured differently with different companies. Back in the day it was said that JL Audio set the RMS for their subs by playing the wattage for 24 hours continuously on the sub. If it survived, that was the RMS. Other companies set the power ratings strictly by coil size standards. I forget what they are, but it's like a 2" coil is rated for 500 watts, 3" coil 1000, etc. That is independent of any cooling mechanisms that the manufacturer built into the motor. Other manufacturers have their own tests. There are nearly as many ways to rate a subwoofer's power handling as their are companies that sell them.

[3stagevtec 2]

thanks for the info!