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ivica
07-04-2012, 06:06 AM
Does any of the forum member has 2nd and 3rd distortion data for JBL 2245H driver up to 1kHz (or more) frequency.

Regards
ivica

pos
07-04-2012, 07:27 AM
I do have these on another computer (I will upload them in a few hours), but only 3rd distortion (my mic is not good enough to make accurate 2nd order distortion measurement: its own disotrtion tends to dominate...).
That said these measurements are really SPL (and other conditions) dependant, so I doubt you will get any useful info from them (moreover, I have no clue of the actual absolute SPL of my measurements...). The only usefull info you could get from them would be some distortion pics at given frequencies (but there are none with this driver, if I remember correctly).
But I also have the measurements of the TAD TL1801H in the exact same conditions to compare with.

pos
07-04-2012, 11:15 PM
Can't find my measurements anywhere, looks like I lost them, sorry... :(
Regarding the comparison with the TAD TL1801, the 2245H had a little less distortion under 100Hz, and a little more above.
Sound-wise the 2245H seemed a little more colored than the TL1801 in the low mid range.

ivica
07-05-2012, 12:58 AM
Can't find my measurements anywhere, looks like I lost them, sorry... :( Regarding the comparison with the TAD TL1801, the 2245H had a little less distortion under 100Hz, and a little more above. Sound-wise the 2245H seemed a little more colored than the TL1801 in the low mid range. That is 'bad news', because I have find a lot of other JBL drivers distortions data, but for such famous driver as JBL-2245 everything is 'under the cover" over 50Hz. Only I can see in: http://www.lansingheritage.org/html/jbl/reference/technical/1983-subs.htm

Regards
Ivica

yggdrasil
07-05-2012, 01:47 AM
Here's a shot at my system, in room with no treatments... Fresh recone. Crossoverpoint is 250Hz. 2202 from 250Hz.

ivica
07-05-2012, 04:00 AM
Here's a shot at my system, in room with no treatments... Fresh recone. Crossoverpoint is 250Hz. 2202 from 250Hz.

Interesting, but what colors are related to 2245 ??
If "upper red-green' corresponded to 2202 (I guess), means that 2245 'out-performed' 2202 in ALL frequencies.
What would be in such combination the benefits of using 2202?
While You have done your measurements, did You put the same voltage to the drivers, or the same level of the
output. If the voltage is the same, owing to higher 2202 efficiency ( 99dB SPL 1W 1m) then 2245 ( 95dB SPL 1W 1m), output signal would be more then 4dB higher for 2202. But on the presented data, the distortion differences for upper curves are more then 10 dB ???- so it seems to me that it is "better" to use 2245 only.
So please give us more details about the presented data.

Regards
Ivica

yggdrasil
07-06-2012, 01:23 AM
Green = 2nd harmonic
Red = 3rd harmonic
light green = 4th harmonic

Same output level. Different amps, active crossover.

And remember - this is in-room - take it with a grain of salt.

The benefits of using a 2202 from 250Hz is that it is actually designed for that purpose, and therefore performs better. If you need to cross over at !KHz as suggested earlier in this thread you want another (smaller) woofer.


Johnny

ivica
07-06-2012, 01:41 AM
Green = 2nd harmonic
Red = 3rd harmonic
light green = 4th harmonic

Same output level. Different amps, active crossover.

And remember - this is in-room - take it with a grain of salt.

The benefits of using a 2202 from 250Hz is that it is actually designed for that purpose, and therefore performs better. If you need to cross over at !KHz as suggested earlier in this thread you want another (smaller) woofer.


Johnny

Many Thanks, Johnny for the measurement data

Best Regards
Ivica