hi
i have jbl 2426 with horn, 15 inch bass eminence.
i read about crossover design, d some measurements:
for the bass i measure near field and from the port.
for the jbl horn i take measure from 0.5m
measure impedance and build zobel network, now the impedance is flat +-2db
i prefer cross point at 400hz, i love the horn sound, but i see its not easy.
thanks for the help
i have jbl 2426 with horn, 15 inch bass eminence.
i read about crossover design, d some measurements:
for the bass i measure near field and from the port.
for the jbl horn i take measure from 0.5m
measure impedance and build zobel network, now the impedance is flat +-2db
i prefer cross point at 400hz, i love the horn sound, but i see its not easy.
thanks for the help
Attachments
JBL seems to recommend 800Hz 2nd order minimum.
http://www.music.mcgill.ca/caml/lib/exe/fetch.php?media=equipment:jbl2426.pdf
http://www.music.mcgill.ca/caml/lib/exe/fetch.php?media=equipment:jbl2426.pdf
Don't forget about matching directivity. A frequency at that sweet spot will help make a crossover sound seamless. A 2-way with a 15" woofer needs careful driver selection because of this.
hi
"JBL seems to recommend 800Hz 2nd order minimum"
yes i know, but i have bigger horn and the driver down to 400hz, there is a problem to down to this frequency with 3nd order?
about the directivity: if the woofer is up to 400hz, i think it not so direct, even i move it, till 400hz is the same FR.
is it possible to reach this frequency point?
thanks
"JBL seems to recommend 800Hz 2nd order minimum"
yes i know, but i have bigger horn and the driver down to 400hz, there is a problem to down to this frequency with 3nd order?
about the directivity: if the woofer is up to 400hz, i think it not so direct, even i move it, till 400hz is the same FR.
is it possible to reach this frequency point?
thanks
Crossing at very low frequency may damage the driver if you play very loud. How is the distortion at low frequency?
How are you compensating for the 10db dip below 800hz? Not being a cd/horn specialist I'm not sure how you'd be able to use a 1" driver to 400hz. Even with a large horn, seems that it would be tough. Which 15" driver do you have? Will it play decently to 1500hz so you could cross @ 800hz?
thanks for the help, the 2nd 3nd harmonic is about 50db lower than the signal.
i can upload the graph
i tray to compensating with EQ and it fix it. as far as i know, dip that come from the speaker can compensate with EQ, but not dip that comes from ROOM MODES. but maybe im wrong and need to crossover at 800hz
the blue line in the pic is measure (JBL) from 1.5 meter, and the brown is from 30cm
thanks
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Or 70 W/4 = ~17 W/400 Hz, though horn needs to be big enough to support it, so is 10log[17] = ~12 dB of dynamic headroom sufficient?
GM
jbl's recommended 800hz. and 500hz
look at the PDF
"Horn isn't big enough for 400 Hz" yes the limit is 500hz in the horn pdf.
so go to 500 hz cross 24db\oct or 700hz 12db\oct?
thanks for the help
look at the PDF
"Horn isn't big enough for 400 Hz" yes the limit is 500hz in the horn pdf.
so go to 500 hz cross 24db\oct or 700hz 12db\oct?
thanks for the help
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you need to look at what the pdf says right after what you circled...the amount of power it will take is reduced.
What's the deal with wanting a 4-500hz xo? Does the woofer sound like a$$ @ 800hz? I don't understand all the effort you're putting forth to justify that low of a xo. The makers spec sheet clearly indicates a min 800hz, backed up by their freq. response graph. Surely there are more important things to address in your project than battling laws of physics.
GL anyway.
GL anyway.
maybe you are right, thats why i advice in the forum.
the jbl is very good compression driver so i just want to optimize it.
you see the graph in 700 hz?
thanks
I see the graph, however, your suggesting an EQ solution just to make a lower xo point seem possible. Your project will likely have terrible off axis response because of it. If the woofer isn't up to it, you might consider one that can play/sound nice up to 1200hz or higher. I think then that you would be very happy with the effort you make. If it is fine, move on.
GL
GL
the bass is fine, but when i cut at 700hz i here 2 point of source. but when i cut at 500hz i here and feel only one point of source.
measure from now, 500 hz, 12db\oct + EQ
just want to be sure before build the crossover 🙂
thank
about the off axis response, if this is the only problem i can live with that.
measure from now, 500 hz, 12db\oct + EQ
just want to be sure before build the crossover 🙂
thank
about the off axis response, if this is the only problem i can live with that.
Attachments
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