Posted August 21, 200619 yr I need clarification on something. I am doing a weird wiring scheme for some tweeters, well I think I might. I have 10 tweeters that have a nominal impedance of 6 ohms. I need confirmation on the load if wired in this fashion.3-2-2-3By my calculation this would give me a final load of 3.75, correct?Each set is wired in series, then all 4 sets are wired in paralell.
August 21, 200619 yr 3 in series is 18ohms. 2 in series is 12ohms.1/R = 1/9 + 1/6 = 10/36R = 3.6ohms.
August 21, 200619 yr Author 3 in series is 18ohms. 2 in series is 12ohms.1/R = 1/9 + 1/6 = 10/36R = 3.6ohms.<{POST_SNAPBACK}>It appears I am wrong then. That is not how I cam up with my answer.Thanks. I am teh ohms n00b Can you answer this question for me then?If A passive crossover is a 5th order elliptic high pass set to 4.3Khz for a 4 ohm driver, how much difference will being .4 under make?
August 21, 200619 yr 3 in series is 18ohms. 2 in series is 12ohms.1/R = 1/9 + 1/6 = 10/36R = 3.6ohms.It appears I am wrong then. That is not how I cam up with my answer.Thanks. I am teh ohms n00b Can you answer this question for me then?If A passive crossover is a 5th order elliptic high pass set to 4.3Khz for a 4 ohm driver, how much difference will being .4 under make?it will screw up the transient response of the gravty valve that blocks the intake part of the spaker manifold...in other words, i have no fawkin' clue. Edited August 21, 200619 yr by Adrian_D
August 21, 200619 yr Author 3 in series is 18ohms. 2 in series is 12ohms.1/R = 1/9 + 1/6 = 10/36R = 3.6ohms.<{POST_SNAPBACK}>It appears I am wrong then. That is not how I cam up with my answer.Thanks. I am teh ohms n00b Can you answer this question for me then?If A passive crossover is a 5th order elliptic high pass set to 4.3Khz for a 4 ohm driver, how much difference will being .4 under make?<{POST_SNAPBACK}>it will screw up the transient response of the wiggle valve that feeds the intake port of speaker.<{POST_SNAPBACK}>Funnay.I am not that much of teh n00b lol.I know it will affect the point at which the frequency gets attenuated, but I am not sure which way and by how much.
August 21, 200619 yr Going from 4ohm to 8ohm with the same caps and or coils raises the cutoff frequency if I'm not mistaken. So in your case it would lower it . Not sure exactly how much though. Where's jim when ya need him
August 21, 200619 yr Author already have the x-over ?<{POST_SNAPBACK}>Ya. I just wanted to make sure it isn't terrible to use in this instance.
August 21, 200619 yr Author Going from 4ohm to 8ohm with the same caps and or coils raises the cutoff frequency if I'm not mistaken. So in your case it would lower it . Not sure exactly how much though. Where's jim when ya need him <{POST_SNAPBACK}>That's what IO was thinking is that it would be lowered. I just want to make sure it wouldn't lower it too much to make it useless on a tweeter. The tweeter has a fs of 1700, so technically I can cross it at 3400 steeply and be fine in theory. So I just wanted to confirm I was lowering my point below this. Otherwise it's back to the drawing board.
August 21, 200619 yr If you are doing this active you will have no problem; however, passive it may not be great. The reason being is that an elliptical crossover is typically a LR crossover with a notch filter. These are both tuned to the impedance of the circuit so if you change the impedance the zobel and the crossover may no longer line up and therefore create a strange response. If you are running that many drivers that are capable of playing beyond the frequency range that you require I would stick with a more simple crossover design.
August 22, 200619 yr Author If you are doing this active you will have no problem; however, passive it may not be great. The reason being is that an elliptical crossover is typically a LR crossover with a notch filter. These are both tuned to the impedance of the circuit so if you change the impedance the zobel and the crossover may no longer line up and therefore create a strange response. If you are running that many drivers that are capable of playing beyond the frequency range that you require I would stick with a more simple crossover design.<{POST_SNAPBACK}>Well I just have a set of CDT Satnet 480s lying around doing nothing. I was thinking of using them in my home line array project. So yes, it is a passive setup. I am using a crap load of the NSBs that I bought quite a while ago and a good amount of 3/4" dayton tweeters.
August 22, 200619 yr Author Where's jim when ya need him <{POST_SNAPBACK}>Looks as though I may need to link him here via PM lol.
August 22, 200619 yr I know I would never even attempt that in a car ..... a line array for a home speaker might sound good though. And yea, those CDT satnet's are specifically made for the drivers it came with.
August 22, 200619 yr Author Well I guess I will just stick to some simple 12db crossovers @ 4500 then. I will design the cabinet so I can switch out XOs and try others in there or build one specific to this appliaction.
August 22, 200619 yr Do you have a way of measuring the impedance after wiring up your tweeters? You may need a zobel circuit to compensate for impedance rise if you are really getting deep into it. It isn't all that hard though, but a little time consuming to do with just a signal generator and DMM. It can be done though.
August 23, 200619 yr Author Do you have a way of measuring the impedance after wiring up your tweeters? Edited August 23, 200619 yr by IamDeMan
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