L150 Crossover

[Allanvh5150]

Hi all, A question regarding the Zobel on the L150. The pair I have, have 7.5ohm 10w resistors. The schematic clearly shows a 15ohm 10w. Which is correct?

Allan.

[grumpy]

Checked L112 and L96 network schematics?
If you don't get a good answer, I'll pop a woof out of mine and have a peek ...
Might be a few days. (this would be for L150A)

[Allanvh5150]

Thanks Grumpy. The L150A does not have the zobel. The L96 has a 7.5ohm the same as my L150. Good old JBL keeps us confused again.

Next question. I am going to CC all the networks in my system. Maybe I should leave the zobel out of the L150's. I have L150's and L150A's. Any ideas why the 2 are so different?

Allan.

[DavidF]

Hi all, A question regarding the Zobel on the L150. The pair I have, have 7.5ohm 10w resistors. The schematic clearly shows a 15ohm 10w. Which is correct?

Allan.

The 15ohm spec looks like a typo. Two at 15 paralleled would be the 7.5 expected. Doubling up for power handling may have been a preproduction spec or something. Check out the L110 network, Allan. It is similar or the same in most respects and uses a 7.5 ohm with the same part number. I would imagine the zobel was inlcuded on the earlier design to keep the 6dB filter response roll off as predicted. The later design went with a 12 dB and perhaps did not need the zobel.

[Allanvh5150]

I would have to agree David. Most of the diagrams I have looked at include a 7.5ohm resistor.

Allan.

[jfine]

Hi all, A question regarding the Zobel on the L150. The pair I have, have 7.5ohm 10w resistors. The schematic clearly shows a 15ohm 10w. Which is correct?

Allan.

Hi, if you're talking about R8, yes the schematic shows 15. I have 2 pair L150, all have 7.5 ohm 10W for R8. It's a typo.

Another typo is the tweeter circuit, L4. Schematic shows 10mh, 59215. All mine have 1.0mh, 57129.

Another typo is the midrange 3db attenuator circuit, R5. Schematic shows 2.4 ohm 10W. All mine are 2.5 ohm 10W.

Jeff

[Allanvh5150]

Hi, if you're talking about R8, yes the schematic shows 15. I have 2 pair L150, all have 7.5 ohm 10W for R8. It's a typo.

Another typo is the tweeter circuit, L4. Schematic shows 10mh, 59215. All mine have 1.0mh, 57129.

Another typo is the midrange 3db attenuator circuit, R5. Schematic shows 2.4 ohm 10W. All mine are 2.5 ohm 10W.

Jeff

Possibly they made a typo on the model name also.....

Allan.

[jfine]

Possibly they made a typo on the model name also.....

Ah well nobody's perfect.

Next question. I am going to CC all the networks in my system. Maybe I should leave the zobel out of the L150's. I have L150's and L150A's. Any ideas why the 2 are so different?

What does CC mean?

After I read up on Zobel design, I decided to keep it.

I think the main diffs L150 vs L150A is the xover points, xover slope, the tweeters, and the L150A doesn't have any electrolytic caps (I believe) because the zobels are pretty much gone.

[Allanvh5150]

What does CC mean?

After I read up on Zobel design, I decided to keep it.

I think the main diffs L150 vs L150A is the xover points, xover slope, the tweeters, and the L150A doesn't have any electrolytic caps (I believe) because the zobels are pretty much gone.

Yup, That is about right. CC = Charge Coupled.

Allan.

[jfine]

Yup, That is about right. CC = Charge Coupled.

Allan.

Aha. I would be very interested in some pics if you end up doing this to your L150's. thanks, Jeff