Passive Crossover true or false

[naughtyca]

Can you please tellme if the below statment is true?

"If you are sending 125 watts @ 4ohm to the component set, and the mid is 4ohm and the tweeter is 4ohm, then the mid will receive 125 watts and the tweeter will also receive 125 watts. Let's pretend theoretically that we are running a 125 watt @ 4ohm amp full range. That amp (theoretically) puts out 125 watts at all frequencies at 4ohms, correct?? Now, pretend that we are running that amp to a component set (with all 4ohm speakers) through a passive crossover with a crossover point of 3500hz. So, we are taking that full range signal from the amp and splitting up the frequencies between the mid and tweet at 3500hz. Now, since we are splitting the frequencies and nothing else, there is still going to be 125 watts worth of power at all frequencies below the crossover point and at all frequencies above the crossover point, just the same as there was before we split the signal (since it was putting out 125w at all frequencies)."

so If I have four 8" mids and four super tweeters and i put a passive crossover on each pair I only need to run 1 amp to power them?

mids 125watts 4ohm

super tweeter 100 watts 4ohm

with this statement If I have an amp that powers 125 watts per channel @ 4ohm both mids and super tweeters are getting 125watts each?

[Kevin M]

Your mids will typically take the lion's share of the power when hooked up to a passive x-over. That being said you still have to be careful to not over power them depending on setup. i.e. I wouldn't run ribbons that need 30 watts on a passive x-over if say, 500 watts was going into it. Regardless if it were a two or three way.

You should be fine with that setup with each x-over on a single channel. It will get plenty loud and I don't see any danger to the tweeters providing they have a high enough x-over point and slope. What x-overs and tweets are we talking about here? Edit saw the 3500hz. Should be okay but some tweeters can only play lower if on lower power.

[Skullz]

Some crossovers have tweeter protection preventing them from getting an excessive amount of power and blowing.

Another thing to consider is the loss of power the passive have, i have heard that they can consume up to 30% of the power being fed to them.

Most often times you'll rarely ever hear of people with passive crossovers blowing speakers from over powering them, unlike an active setup will as the speaker sees full power from the amplifiers dynamic power exceeding the speakers capabilities.

[mrd6]

Maybe I read the first statement wrong but wasn't the guy trying to say that he had 125 watts rms sending to two different speakers claiming that each speaker would be getting 125 watts rms because of some BS he made up about how splitting the frequencies meant there would still be that much power sent to each speaker? Like he was trying to say 125watts below 3500hz and 125 watts above 3500hz was split?

Well, its hard to explain what he was saying well because it doesnt make sense since it is not true for the reason he gave. Now, in theory if you have 125 watts at 4ohms and have two 4 ohm speakers that you wire in paraller to a nominal load of 2 ohms then that 125 @ 4 should be closer to 250 @ 2 if it can support it. I dont think thats what he was saying tho.

IMO the guy who is responsible for that quote has no idea what he is talking about lol. OP, you could still run one amp for all your speakers but not like or for the reasons that quote is describing. Power does not work like that.

[naughtyca]

your ohm load theory is wrong, on component sets if your mids is 4 ohm and your tweets are 4 ohm when you put a passive crossover the amp will see 4 ohm

what he is saying if you put a 125 watts on that 4 ohm crossover when the power is distributed 125watts will go to mids to a certain frequency and another 125 watts goes to tweeters.

[mrd6]

your ohm load theory is wrong, on component sets if your mids is 4 ohm and your tweets are 4 ohm when you put a passive crossover the amp will see 4 ohm

what he is saying if you put a 125 watts on that 4 ohm crossover when the power is distributed 125watts will go to mids to a certain frequency and another 125 watts goes to tweeters.

Lol my theory is not wrong, I was refering to the simple parallel wiring of two 4 ohm speakers to 2 ohms without a passive network. Also, passive networks can present a variety of nominal loads. It does not have to be 4, it depends on the design and components.

Right, so if that is what he is saying then he is completely incorrect. I can try to explain that a bit if you are interested in learning why?

[naughtyca]

lol i know it can but im just giving that as majority of components

[mrd6]

okay...so question answered? Original statement is false

[naughtyca]

i got this from a different forum

"Somewhere out there this myth has been told over and over and over again, it's a great question to ask. I think it came from Crutchfield catalogs long ago, when they used to have little wiring diagrams in them that didn't exactly explain what they were talking about."

[mrd6]

Cool, quote has no context so it means nothing lol...