Resistance confusion

[cajunduck]

It's been a while since I did electronics calsultaions, so I found a calcultaor online to help. The crossover that is found at
http://sites.google.com/site/undefin...htsensationmtm
has me so confused. I am getting 0.6073 ohms. I get 1.09 for the mids and 16 for the tweeter. Aren't the tweeter side and Mids side parellel to each other?

[djg]

I'm not sure what you're trying to do. I built this speaker, and it's a fine sounding speaker indeed. The text would indicate that it is a nominal 4 ohm speaker, with two 8 ohm woofers in parallel.

[moosespeaker]

Yes you have forgotten a few finer points regarding AC and DC circuit theory.
Speaker ohms are really impedance values not DC resistance values even both are measured in OHMS. Cannot measure speaker impedance with an Ohm meter.

DC ohms are true resistance. AC ohms is a mathematical mix of capacitive reactance (measured in ohms), inductive reactance (also measured in ohms) and true DC resistance. Need to recall complex number (real and imaginary, i.e., x + iy where i is the square root of negative one) theory to sum the DC resistance and AC impedance into obtain the ohm value.

I have no idea which on line calculator you are using. What are you trying to calculate. The XO components are chosen to obtain a network that separates the high and low frequencies and directs them to the respective tweeter and mid range (in a two speaker system). The impedance (AC "resistance" ) varies with frequency so even if you were to calculate some numerical "ohm" value, it will change in value as the frequency varies.

One could perform these calculation but they are not needed when using a program such as PCD (passive crossover designer).

George

[cajunduck]

Ok, well, i will have to figure something else out because I can only run 8 ohms.

[Jeff B.]

Ok, well, i will have to figure something else out because I can only run 8 ohms.

It sounds like you are measuring DC resistance of drivers with a crossover and getting the DCR of the shunt elements.

[cajunduck]

What I am trying to figure out is if I can run this with my receiver. My receiver is good for only 8 ohms. That's why I was trying to figure it out.

[Jeff B.]

What I am trying to figure out is if I can run this with my receiver. My receiver is good for only 8 ohms. That's why I was trying to figure it out.

If you're still talking about the Overnight Sensation MTM's that you linked above, then the impedance curve was posted in that link. It clearly shows this to be a 4 Ohm speaker in the bass and midrange regions. If a 4 ohm load will cause you problems, then this speaker is not a good choice.

[cajunduck]

If you're still talking about the Overnight Sensation MTM's that you linked above, then the impedance curve was posted in that link. It clearly shows this to be a 4 Ohm speaker in the bass and midrange regions. If a 4 ohm load will cause you problems, then this speaker is not a good choice.

Right. That I realize. I need to find somewhere that it states how to figure out what will work.

[moosespeaker]

If I understand you remark (above) the answer is you need an amp that is capable of handling a 4 ohm load will work.

If this answer does not answer your question, can you please explain in greater detail what you are trying to figure out.

George

[cajunduck]

I already have a receiver. but it is only capable of 8 ohms. I was hoping to do a wtw or mtm for the front, wmtw for center, and mt for rears.