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View Full Version : JBL 045Ti measurements, crossover points and polarity help needed



sebackman
04-16-2013, 01:37 AM
Dear all,

Is there anyone here who have done some CLIO (or similar) measurements of the 045Ti on either the K2-S9800, K2-S9900 or the Array 1400 horns?

The K2/Array crossover points are very different, in the 9900 they are crossed at 15k and in the 9800 it is lower. In the Array 1400 they are crossed at half that, 8k. It would be interesting to see the curve to get an idea of what would be possible. I will measure my units later and it would be good to have someone else’s measurements/ideas to compare with.

I will use the JBL045Ti’s on K2-S9800SE horns with JBL2451Be and 2332’s below. All ideas and information is much appreciated. My basic idea is to crossover at 1200Hz (2332 does not go very much lower) and 10kHz in an active setup.

Special thanks to the fellow forum members that helped in sourcing 045 drivers, 9800SE horns and 4” BE diaphragms. Thank you.


Also, does anyone know the polarity of the 045's? The have flat connectors in the back and one is wide and the other one is narrow. Which one will cause the diaphragm to move towards the front with a positive voltage applied to it, ie positive polarity. On the "normal" compression drivers this was the “black” terminal. My 045’s does not have any markings on them.

All the best and thank you

//RoB

Robh3606
04-16-2013, 07:06 AM
I have some measurements of 045Be's on the Array horns. If you want I can post them.

Rob

4313B
04-16-2013, 08:34 AM
I think this is the only set of measurements for the 045Ti-1 that I have from G.T.

I dumped everything below 800 Hz so be aware of the x-axis scale.

I measured a pair years ago, but I'd be hard pressed to find the files at this point.

sebackman
04-16-2013, 09:18 AM
4313B, thank you for the info and the curves. What horn was that, SAM-1H in Array 1400? Do you think that is similar to the K2-S9800 horn I bought?

Any input as to why the crossover in the 1400 Array is so much lower than in the K2’s? -Let alone the E2…

Robh3606, please post your curves if they are for a different combination. Well, oh please post anyway. The more info the better.

I did find the answer to the polarity question in the “Tech section”. Albeit for the 045Be but they should be the same I guess. It is also visible in the cut-away drawings from the K2 series but I did not realize that the numbers on the connectors in the crossover schematics were really the physical with of the connectors...

Still learning…

All the best and thank you

RoB

4313B
04-16-2013, 10:02 AM
4313B, thank you for the info and the curves. What horn was that4365

Do you think that is similar to the K2-S9800 horn I bought?I don't know.
Any input as to why the crossover in the 1400 Array is so much lower than in the K2s? -Let alone the E2I could speculate but I won't.

And don't forget about the SAM1HF too. We all finally figured out that whole network schematic a few years back for comparison purposes.

sebackman
04-16-2013, 11:44 PM
Please speculate.... :)

ivica
04-17-2013, 12:13 AM
I think this is the only set of measurements for the 045Ti-1 that I have from G.T.

I dumped everything below 800 Hz so be aware of the x-axis scale.

I measured a pair years ago, but I'd be hard pressed to find the files at this point.

So, may be for the initial experiment

http://www.audioheritage.org/vbulletin/showthread.php?33024-why-does-JBL-4365-only-rank-10th-in-Japanese-eyes&p=334205&viewfull=1#post334205

can be useful. As I can understand efficiency can not be more the about 93dB/1W/1m ( 2.83Veff), and UHF beaming (over 10kHz) can be expected, as been presented in:

http://www.cieri.net/temp/JBL_4365_-_Test_di_Audio_Review_(05-2012).pdf

http://www.audioheritage.org/vbulletin/showthread.php?33024-why-does-JBL-4365-only-rank-10th-in-Japanese-eyes&p=344924&viewfull=1#post344924



Regards
Ivica