My most demanding project has started

mykey wrote: deadbeat is right, you have thrown him by saying "FULLRANGE" you want to use it as a mid-hi driver is what you should have said   just read today that F1 have just brought out a new model cabinet that uses a bass driver and a 5'' driver that does exactly what you want it too.   If I remember rightly it was 40hz to 15k cab. axe head fitted to the 5''    is this the route your taking?

Deadbeat wrote: Can't see how an axehead would work in the big horn itself, could you kindly explain?

Getting the required bandwidth from a cone driver on a horn is going to be hard enough, but combining four such drivers into one horn may prove impossible.  While the F1 boxes can achieve a very high crossover point for an 8", it would be as much a function of the driver specs as the geometry.  A driver rising frequency response is certainly required for this, but whether the driver is up to the task, and whether you can optimise the thoat geometry to achieve your bandwidth would remain to be seen.  In order to load the driver at higher frquencies, your horn would need a faster initail expansion rate (a slow expansion rate at the start will harm the HF response), which brings with it many physical difficulties, especially when combining drivers.  I have managed to sucessfully combine two 6" drivers on one horn by arranging the phase-plugged throat sections to enter the horn as closely spaced cross-firing vertical slots, but even this is only good to about 3.5kHz - how you would combine four drivers with greater bandwidth I don't know.

As far as I know, the size and placement of the mid throat holes in the Unity is very critical for summation, and does not allow for a high crossover point anyway.  I don't think this technique will be of any use for the bandwidth you want.

rich_gale wrote: im not using the jordan as a 'mid' driver.  im using it as a full range driver, but high passing it at 250hz.  seeing as it will not be used in the bass frequencies, your talk about ebp etc goes pretty much out the window.  before tom danley designed the lab 12, most people would have moaned about the specs and said it didnt suit a horn loaded cabinet.

Hehe.Rich knows enough to be dangerous. If your starting with a mud motor,low fs and high Qts its not such an ideal start.

 I think you need to aquaint yourself with whatl happen at the top end Fhm=2(Fs)/Qts
http://db.audioasylum.com/cgi/m.mpl?forum=hug&n=114759&highlight=fhm&r=&session=

http://db.audioasylum.com/cgi/m.mpl?forum=hug&n=46331&highlight=fhm&r=&session=


Good luck with project.

Rich! this may interest you.

just was on the phone to a friend with jordan tls, apparently one main factor in their extended HF response is that the jordan people have managed to manipulate the flexing of the driver much like the Manger planar drivers. taking advantage of non-pistonic motion.