JBL 2235H and Faital HF20AT

[xecluded]

I have a pair of JBL 2235 & Faital HF20AT drivers (Faital Pro HF20AT - Faital Pro HF20AT 2" neodymium high frequency compression driver. Faital Pro HF20AT HF drivers available here at US Speaker.) and looking at their chart, the 2235h is very smooth up to 900hz; do you think i can use them at 800hz with 1st order. If not can i please get some suggestion on what is the best way to optimize them. Horns are 500 hz Bruce Edgar salad bowl. Thanks.

[badman]

Your crossover point would be fine with a steeper filter. You'll likely want a zoebel on the 2235H and probably a 3rd/4th order electrical. The similarly coned 2226h is what I use and it does like a relatively steep (edit: filter) stopband.

Start with the woofer then get the horn rolled in, but remember always that you need a pretty solid cutoff for any compression drivers.

[xecluded]

****Your crossover point would be fine with a steeper filter. *****

Heheehm the problem with that is steep filters are not always easy to tune unless you can do it for me

[badman]

Yep, that IS the problem. Go active?

But you'll hear that rough >1k stuff if you try first order, particularly if you don't do a zoebel too. And first order highpass would give your CD fits at 300-400Hz.

[Robh3606]

You can't use factory FR curves to design a crossover. You need to measure the 2235's in their boxes and the Compression driver with your horn positined on top of as part of the speaker enclosure. You are going to need impedance plots as well of the drivers in the box and with the horn. The horns lower cutoff is going to determine where your crossover should be.

Rob

[xecluded]

Badman, Rob,

I dont have sufficient equipments to do much test/measurements plus don't really know much about how to do this to begin with. I thought 1st order is the simplest design hence trying.

Anyway, I played around with the setup last night and used a 3.0MH choke for the low pass and just a 27uf cap for the high and Highpass filter with CD compensation. The setup sound pretty decent to my tin ears. Will play around with it a little more and tune it with my ears to my liking

[badman]

That's fine for getting started. You can simulate and get pretty close (but measurements are best). Those drivers/design definitely need a steeper filter though, for best quality.

[tinitus]

Originally Posted by xecluded

I thought 1st order is the simplest design hence trying.

compression drivers and horns have more complicated ressonance impedance peaks
one reason why a good crossover for those may be different than ordinary

[xecluded]

Using compression drivers/horns sure is complicated things a bit. When i first doing it without the compensation network, i can't stand to listen to it for very long. Now with the setup below, things are a lot more easier on ears, not perfect but very nice. The JBL 2235H sure give a very upbeat sound - nice and powerful low frequency.

[badman]

Try throwing a 10R and 30uF in series, and that in parallel with the woofer (zoebel). You might need to retune the inductor (lower value). You might also consider omitting the RC network on the tweeter, as you're trying to squeeze out the last little bit of top end with that, and a 2" exit CD really shouldn't be tasked with doing 15khz.