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ddragg1
03-21-2011, 07:40 AM
I am currently rebuilding a pair of C36 speakers which did not include the crossovers or 075 bullets. The d130's are 8 ohm. I have been able to locate some 8ohm 075's, but I cannot locate the 8ohm n2400 crossovers, but only the 16ohm. My question's are: Can the 16ohm crossovers be converted to 8ohm? I thought I read somewhere that reducing the capacitance by 1/2 will bring the 16ohm to 8ohm. Can the diaphragms in the 16ohm 075 be changed to the 8ohm version to make them 8ohm? What can I do? Thanks

Baron030
03-21-2011, 08:21 AM
Hi ddragg1

The N2400 is an easy crossover to build or rebuild from scratch.
Since all of the part are readily available from dealers like parts express.
While it could be possible to convert a 16 ohm network to 8 ohms, it would involve changing so many parts that about the only original JBL part that would remain would be the aluminum case.

So, rather then buying some 16 ohm JBL networks and converting them, why not just building some networks from scratch. One advantage would be that you could use a large 14 gauge Ė 1.0 mH air core coil, which would never fit inside the small JBL N2400 network case.

But, if you already have the JBL networks, then here is a link to a complete 8 ohm N2400 network overhaul: http://www.audioheritage.org/vbulletin/showthread.php?12938 (http://www.audioheritage.org/vbulletin/showthread.php?12938)

Baron030:)

ddragg1
03-21-2011, 09:07 AM
Hi ddragg1

The N2400 is an easy crossover to build or rebuild from scratch.
Since all of the part are readily available from dealers like parts express.
While it could be possible to convert a 16 ohm network to 8 ohms, it would involve changing so many parts that about the only original JBL part that would remain would be the aluminum case.

So, rather then buying some 16 ohm JBL networks and converting them, why not just building some networks from scratch. One advantage would be that you could use a large 14 gauge – 1.0 mH air core coil, which would never fit inside the small JBL N2400 network case.

But, if you already have the JBL networks, then here is a link to a complete 8 ohm N2400 network overhaul: http://www.audioheritage.org/vbulletin/showthread.php?12938 (http://www.audioheritage.org/vbulletin/showthread.php?12938)

Baron030:)

Thanks Baron. Do you have a parts list for building the crossovers? I think that would be a better idea and probably more cost efficient.

Do you think these would be sufficient? http://www.amazon.com/Dayton-Audio-XO2W-2-5K-2-Way-Crossover/dp/B0002ZPLAW or these http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=230597007573&fromMakeTrack=true#ht_3293wt_1139

Baron030
03-21-2011, 10:12 AM
Do you think these would be sufficient? http://www.amazon.com/Dayton-Audio-X.../dp/B0002ZPLAW (http://www.amazon.com/Dayton-Audio-XO2W-2-5K-2-Way-Crossover/dp/B0002ZPLAW) or these http://cgi.ebay.com/ws/eBayISAPI.dll...ht_3293wt_1139 (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=230597007573&fromMakeTrack=true#ht_3293wt_1139)

Sufficient???
Absolutely NOT!
Do not use a generic Dayton-Audio 2,500 Hz crossover and I would not recommend that ebay JBL crossover either. It looks like itís build for a car audio system and not the JBL 030 system which is what you are trying to build.

Itís not just the correct crossover point that is the issue here. Itís the correct response and impedance curves that will match the D130 and the 075 drivers.

So, stick to the N2400 network schematic. Unfortunately, I donít have a part list on hand. Itís been a few years since I did those N2400 rebuilds. Now, thatís not to say that I canít come up with a part list, just give me a few hours to come with a list.

Baron030:)

ddragg1
03-21-2011, 11:19 AM
Sufficient???
Absolutely NOT!
Do not use a generic Dayton-Audio 2,500 Hz crossover and I would not recommend that ebay JBL crossover either. It looks like itís build for a car audio system and not the JBL 030 system which is what you are trying to build.

Itís not just the correct crossover point that is the issue here. Itís the correct response and impedance curves that will match the D130 and the 075 drivers.

So, stick to the N2400 network schematic. Unfortunately, I donít have a part list on hand. Itís been a few years since I did those N2400 rebuilds. Now, thatís not to say that I canít come up with a part list, just give me a few hours to come with a list.

Baron030:)

Thanks mate. Looking forward to it.

Baron030
03-21-2011, 12:11 PM
Here is a listing of the parts needed to make a N2400 network including the parts-express part numbers.

1 Ė 1.0 mH Ė 18 ga. Erse ďIĒ core iron core coil (266-550)
4 - 3.0 uF Solen Metallized Polypropylene Caps. (027-542)
2 - 5.0 ohm 12 watt Mills resistors, (005-5)
1 - 8 ohms 15 watt Dayton L-Pad (260-250)
1 - Dayton Binding Post Pair Gold (091-1245) (optional)
Other misc hardwareÖ

Please Note: that parts-express does not carry a 6.0 uf cap value. So, you need to wire 2 Ė 3.0 uf caps together in parallel to create the correct 6.0 uf cap value for the network.

And if you not trying to fit a coil into a JBL network case, then I would recommend using the Erse 1.0mH 14 ga. air-core inductor (266-350) instead of their ďIĒ core iron core coil.

Baron030:)

ddragg1
03-21-2011, 12:22 PM
Here is a listing of the parts needed to make a N2400 network including the parts-express part numbers.

1 – 1.0 mH – 18 ga. Erse “I” core iron core coil (266-550)
4 - 3.0 uF Solen Metallized Polypropylene Caps. (027-542)
2 - 5.0 ohm 12 watt Mills resistors, (005-5)
1 - 8 ohms 15 watt Dayton L-Pad (260-250)
1 - Dayton Binding Post Pair Gold (091-1245) (optional)
Other misc hardware…

Please Note: that parts-express does not carry a 6.0 uf cap value. So, you need to wire 2 – 3.0 uf caps together in parallel to create the correct 6.0 uf cap value for the network.

And if you not trying to fit a coil into a JBL network case, then I would recommend using the Erse 1.0mH 14 ga. air-core inductor (266-350) instead of their “I” core iron core coil.

Baron030:)

Awesome Baron. I'll get on it. I would like to find some JBL network cases for the aestetics aspect and since the cabs are already cut for them. I can probably get away with using most any similar size case I assume.

ddragg1
04-25-2011, 12:13 PM
Hi ddragg1

The N2400 is an easy crossover to build or rebuild from scratch.
Since all of the part are readily available from dealers like parts express.
While it could be possible to convert a 16 ohm network to 8 ohms, it would involve changing so many parts that about the only original JBL part that would remain would be the aluminum case.

So, rather then buying some 16 ohm JBL networks and converting them, why not just building some networks from scratch. One advantage would be that you could use a large 14 gauge Ė 1.0 mH air core coil, which would never fit inside the small JBL N2400 network case.

But, if you already have the JBL networks, then here is a link to a complete 8 ohm N2400 network overhaul: http://www.audioheritage.org/vbulletin/showthread.php?12938 (http://www.audioheritage.org/vbulletin/showthread.php?12938)

Baron030:)

Excellent. I built them with your recommendations and they sound awesome. Thanks again.....:D