Deang Posted December 24, 2005 Share Posted December 24, 2005 If you cross a 400Hz horn at 500Hz -- does it still load properly? Quote Link to comment Share on other sites More sharing options...
sfogg Posted December 24, 2005 Share Posted December 24, 2005 Of course. No different then if you played music that had material at 500hz but not 400hz... the horn still works. Shawn Quote Link to comment Share on other sites More sharing options...
boom3 Posted December 24, 2005 Share Posted December 24, 2005 In fact, conservative design says the horn should be crossed over about one-half octave above its cutoff. If memory serves, the K400 actual cutoff is 250 Hz,(as installed in the baffle) so the 400 Hz crossover point is appropriate (at least for the mid horn, not considering the bass horn) Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted December 24, 2005 Share Posted December 24, 2005 All good answers............[] Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted December 24, 2005 Share Posted December 24, 2005 Interesting. thanks guys. Quote Link to comment Share on other sites More sharing options...
sunnysal Posted December 25, 2005 Share Posted December 25, 2005 Dean, It depends on what you mean by 400hz horn. You need to know the cut off frequency, people sometimes use the phrase 400hz horn to mean one with a cut off of 400hz, others mean a horn that loads down to 400hz. the rule of thumb re: cut off is that you should not use them below twice the cut off frequency so a horn with a cut off of 400hz should not be run much below 800hz. However if the 400hz horn in question loads down to 400hz then you are fine down to that point, slow slope crossovers and loud volumes may mean you need to leave more space though. Tony Quote Link to comment Share on other sites More sharing options...
DrWho Posted December 26, 2005 Share Posted December 26, 2005 If you cross a 400Hz horn at 500Hz -- does it still load properly? I've been trying to figure out exactly what you mean by this question...so why do you wanna know? Btw, a 500Hz and 400Hz horn do not share the same expansion rate which means if you change the horn while leaving the crossover at the same point, then you end up with a different off-axis response. (But in theory you will still have the same on-axis response). Is that more along the lines of what you were getting at? Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted December 26, 2005 Share Posted December 26, 2005 Dean, . the rule of thumb re: cut off is that you should not use them below twice the cut off frequency where did you come up with that R.OT., Tony .... I'm having hard time thinking of a speaker that goes by that .... it sure aint Klipsch, JBL, Altec Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted December 26, 2005 Share Posted December 26, 2005 an interesting Horn topic, particulrly as it applies to PWK's designs ... is compression ratio ... I assume the small throats on the horns were chosen to increase Efficiency ... but they also increase Distortion, which is very unlike PWK ....[8-)] Quote Link to comment Share on other sites More sharing options...
DrWho Posted December 26, 2005 Share Posted December 26, 2005 PWK felt that horn throat distortion was inaudible...and smaller throats also allow for more control over the dispersion pattern, and more control over the driver (so FMD goes down with smaller throats too). Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted December 26, 2005 Share Posted December 26, 2005 when did you speak with him ...?? Quote Link to comment Share on other sites More sharing options...
sunnysal Posted December 26, 2005 Share Posted December 26, 2005 Remember Duke I was talking about "cut off frequency" that is why I wanted dean to specify what term he wanted used..some spec horns using the term cut off frequency and others simply spec what is trhe lower frequency limit the horn loads to...twice the cut off frequency is what is used. I will look for some references for you and post them. tony Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted December 26, 2005 Share Posted December 26, 2005 take Altec for example....'cause its simple 811 511 311 run down to ....800, 500, 300 hz @ 12dB/ octave ..in various speakers like A-7 VOTT ..for example ...511 horn, 500 Hz. X-Over Now, Tony .... that 511 horn in no way is large enough, to be capable of your rule of 2x ...Fc Quote Link to comment Share on other sites More sharing options...
DrWho Posted December 26, 2005 Share Posted December 26, 2005 when did you speak with him ...?? lol, it's in the Dope from Hope - I believe he used the term "not noticeable" instead of "inaudible" - I'll have to go find it. Nevertheless, I've read of other horn gurus making the same claims too. (and then I've read "horn bashers" that say the opposite). The only point I was trying to make was it is a system of compromise. Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted December 26, 2005 Share Posted December 26, 2005 PWK felt that horn throat distortion was inaudible.. well, so much for that ... just listen to, for example , the KH mid horn ....[] Quote Link to comment Share on other sites More sharing options...
DrWho Posted December 26, 2005 Share Posted December 26, 2005 lol - he was probably too excited with the huge gain in sensitivity and reduction in FMD to care. Quote Link to comment Share on other sites More sharing options...
sunnysal Posted December 26, 2005 Share Posted December 26, 2005 maybe I should state this another way. one should crossover at twice the cut off frequency. that is to say set the lower crossover at 600hz for a 300hz horn. Like 1/2 the desired crossover frequency for the flair frequency (cut off) of the horn to keep stored energy low is good. Or .7 x the flare frequency (cut off) as a max. I am pretty sure I got this idea form LeCleach among others, I will continue to look for references. Tony Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted December 26, 2005 Share Posted December 26, 2005 one should crossover at twice the cut off frequency. that is to say set the lower crossover at 600hz for a 300hz horn. I don't know about that, Tony ..... like I said, it's just not done .... your saying the Fc, for say the k-400 horn, should be 200 hz ... can't be now to make matters worse ... let's go back to Altec .. Quote Link to comment Share on other sites More sharing options...
sunnysal Posted December 26, 2005 Share Posted December 26, 2005 no, I am saying the k-400 should be crossed over at 800hz, assuming the flare of the k-400 was 400hz not the lower loading limit...but now I fear I may be all messed up...anyway...I originally wanted to point out that the terminology about crossover poinbts for drivers/horns was not totally standardized...tony Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted December 26, 2005 Share Posted December 26, 2005 didja look at the Altec chart ....??? they show the " cutoff" figure, and thats where the Xover freq is .... sooooooooo ....in essence they are loading the horn Below fc w/ 12 dB/octave xover, right ..??? Quote Link to comment Share on other sites More sharing options...
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