Something doesn't look right to me, tweeter in horn being 110-115 dB, and both woofers 75 dB. Maybe I'm missing a point. The 1 m full sweep appears to be correct.
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The measurements were done in exactly the same way. I turned off all eq, including level controls, so as basic and raw as I could get them.
I'll trace the graphs from page 12 and compare to textual files.
edit: Checked it, your textual tweeter file without filter is approx.35 dB higher in spl than the screenshot of it. Must have been an error while exporting.
edit: Checked it, your textual tweeter file without filter is approx.35 dB higher in spl than the screenshot of it. Must have been an error while exporting.
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Any recommendations yet on crossover point and slopes, anyone? Your input would be most appreciated
I would do:
LF:
LP: LR4 1kHz
500 Hz -3 dB Q=3
HF:
HP: LR4 1kHz
Gain: -4 dB
2KHz -3dB Q=3
Play it! 🙂
Just to try something 🙂
//
LF:
LP: LR4 1kHz
500 Hz -3 dB Q=3
HF:
HP: LR4 1kHz
Gain: -4 dB
2KHz -3dB Q=3
Play it! 🙂
Just to try something 🙂
//
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Thanks tnt. Am trying it now. I did exactly what you said. No lp on the hf, and no hp on the lf. Doesn’t sound bad. Little bit like a b&w. Slightly Muted character. Thanks for the effort
Definitely sounds more balanced
Definitely sounds more balanced
Use those few "filters" to alter the sound to your liking.
If it's muted, you need more hf. Do HF Gain: -3 dB
and see what happens. Measure before and after all alterations. You want a flat byt slightly downwards tilted response towards higher frequencies. Say 2-3 dB going from 500->15k
I'm sure someone more skilled will make it better.
Looking at your driver measurements there is definitely hope here 😉
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If it's muted, you need more hf. Do HF Gain: -3 dB
and see what happens. Measure before and after all alterations. You want a flat byt slightly downwards tilted response towards higher frequencies. Say 2-3 dB going from 500->15k
I'm sure someone more skilled will make it better.
Looking at your driver measurements there is definitely hope here 😉
//
Twiddle with it. But also, measure!
Do 2 metre measure and post the result?
Describe what you hear, balance wise.
//
Do 2 metre measure and post the result?
Describe what you hear, balance wise.
//
Brendan,
Should you ever get that requested impedance setup working, it'll also help others determine what your current box tuning is ( since you also asked for help in that area ).
🙂
Should you ever get that requested impedance setup working, it'll also help others determine what your current box tuning is ( since you also asked for help in that area ).
🙂
Hi earl. I will get it working this week. Am taking my laptop and jig to my tech friend , and we will rectify to get it working. As always, there has to be something to delay the process. Not anything that will keep me down though.
What were your estimates on the crossover specs, if you don’t mind me asking
What were your estimates on the crossover specs, if you don’t mind me asking
Look to your ( REW ) distortion pane ( as well as FR of course ) for guidance.
The following is the distortion profile of a Celestion CDX-1747 driver on a JBL 2344 biRadial horn ( from some of my own inventory ) .
Setup your distortion window options ( as I have done, by clicking the sprocket icon seen in the top right of my pic ).
The normalized distortion display gives a really good indication of where the driver/horn combo loses acoustic loading ( below that point, the ratio of distortion to signal starts climbing ).
- Crossing out of the horn/driver combo before that upwards climb is a very good idea!
( At normal home listening levels ) I wouldn't have any qualms in using a 1K crossover point for this combo ( assuming the frequency response also looked good in that area ).
LR4 slopes should workout & sound fine.
🙂
Attachments
You have just taught me something invaluable. Thank you Earl. I will set mine up the same and double check. What else can the distortion measurement tell. I haven’t found that in any literature yet, which is why I consider all the input as “superfood”. Thanks again
Would the same principle apply for the bass drivers? The increase in distortion indicating cone breakup, or am I wrong?
If so, things are starting to make good sense to me now
Would the same principle apply for the bass drivers? The increase in distortion indicating cone breakup, or am I wrong?
If so, things are starting to make good sense to me now
Distortion readouts can also give an indication of when a driver needs some attention by an expert.
Here's a comparative study showing two Altec drivers ( same model ) on the same horn.
The top driver has a healthy diaphragm while the bottom doesn't.
Under these ( low voltage drive ) conditions, 3Hd ( third Harmonic Distortion ) shouldn't ever be more than 2Hd ( IME ).
The bottom driver with the poorly performing diaphragm needs it to be re-centered ( or replaced if that doesn't work ) by someone with the experience & know-how ( which would be me in this circumstance 😱 ).
🙂
If you look at your top graph of the healthy driver, would you say it also let ads at around 1k? Why does the distortion pick up again straight after? Driver/horn comparability? The first graph with the Celestion indicating a better driver match?(based on lower distortion)?
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