how many watts are speakers getting ?

[Dragon_fire]

Okay, when I set up my component speakers, Three way with crossovers. I hook them up to my amp which is rated for 150wattsx2. How many watts is each speaker getting ?
When I take my sub amp and wire my 2 dual 4 ohm speakers(wired in parrellel for 2 ohms each) and wire them into a series for a total of 4ohms onto the amp. The amp is rated for 600wattsx1 @ 4 ohms. Does each speaker in the series get 600 or is it 600/2=300 each ?
NOW , if I take the same two subs, wire them in parrell to present a 1 ohm load to the amp, now making it put out 1200 watts x 1, is it still 1200 to each, or 1200/2= 600 to each sub ??? Very confused please help.....been doing this too long not to know the truth.

[Fishy]

a) 150 each

b) 300 each

c) 600 each

with regards to b):

When wiring a pair of dual 4 ohm drivers for a 2 ohm load, wiring the voice coils in series and the drivers in parallel is consisdered the better option.

Please note that when wiring multiple drivers, whether DVC drivers or their SVC brethren, it is recommended that series connections between drivers be avoided at all costs. This does not include series connections made between voice coils on the same driver.

from here:

http://www.jlaudio.com/tutorials/wiring/index.html

Apparently because speakers present a reactive load there is a phase shift between drivers wired in series. I don't fully understand why, but Jonathan could probably explain.

-Fishy.

[Dragon_fire]

okay, so voice coils in series so each is an 8 ohm driver, then wire them parellel so thats 8+8=16/4=4 ohm load. Thus resulting in 300 to each ?
also, why with situation b & c is the wattage devided between the speakers, but not with components ?

[GlassWolf]

when the speakers are wired together, and they are identical speakers producing the same frequencies simultaneously, the impedance is affected (parallel halved, series doubled etc) but when you have a mid and a tweeter with a crossover, the two speakers are producing different frequencies and thus don't interact and don't affect load.
that is, in simple terms, why a set of separates can have a 4 ohm tweeter and 4 ohm midrange driver, and the total load at the amp is still 4 ohms.
This is also why two subs in parallel will produce half the load of one sub, and two in series produce twice the load, without going into the electrical reasoning.

basically the only time load is affected is when both speakers wired together are producing the same signal or frequencies at the same time.

[William from NOLA]

The only time power will not divide evenly is when the resistors are not all equal.

i.e. You have a 4 ohm and a 2 ohm driver both SVC; the 2 ohm will receive more power than the 4.

[Fishy]

Actually there'so way to guarantee that each component is getting exactly 150 watts. There are losses in the passive xover, each driver may be of slightly different impedance, and of course a 150w amplifier does not supply 150 watts all the time, but the main reason that all speakers in a component set get about the same amount of power is because they all proivide aproximately the same load to the amplifier(~4 ohms in this case). In other words the amplifier sees about the same impedance at most frequencies those components were intended to play.

I know. Hard to understand and even harder to explain.

Maybe someone else could give it a shot.

-Fishy

[Fishy]

lol, beat me to the punch

:)

-Fishy

[GlassWolf]

actually I see a number of separates using 4 ohm mids and 8 ohm tweeters. my point was simply that using two drivers in "parallel" only affects final load when both are producing the same freq range. a tweeter and midrange with proper crossover won't be doing that, so the load will be that of each driver individually.

[William from NOLA]

Ahh, I've wondered about crossovers and how the speakers are "shown" to the amp. I assumed that having two 4 ohm drivers in a crossover are in a sense, wired in parallel. So what you are saying, in effect, the lowest ohm speaker used is the load shown to the amp?

[Fishy]

Yeah my B&W's employ 8 ohm mids and 4 ohm tweets. Its usually the other way around.

-Fishy