Help with 3133A network

[ngccglp]

http://www.jblproservice.com/pdf/.../3133A Network.pdf

Hi, may I know if the correct interpretation of the schematic is that only the 2405 is connected in reverse polarity with the 2420 and 2231?

thanks.

[ivica]

http://www.jblproservice.com/pdf/.../3133A Network.pdf

Hi, may I know if the correct interpretation of the schematic is that only the 2405 is connected in reverse polarity with the 2420 and 2231?

thanks.

Hi ngccglp,

I think that polarity connection of the 2405 is less important as in 4333 speakers used horn ( I think 2312) is so long that comb-filter effect would be present in the frequency response.

regards
ivica

[ngccglp]

Hi Ivica,

Surprisingly it does make a lot of difference, I actually adapted the 3133A to make a 3-way using 4530/2220H with 2441/2390 and a recently acquired 2402H. Initially I followed the 3133A schematic i.e. I flipped the 2402H. But it sounded shut in and dull. So i tried connecting it in phase with the 2441 and 2220. OMG... The sound is open and airy, most noticeable on classic Jazz cymbals ... Also the snare drums gained body and texture... I don't recall my 2405 slot sounding quite like that even though many claimed that the 2402 and 2405 are in fact the same tweeter.

Later I found out that the component series manual actually did recommend connecting the 075 in phase with MF when using the N7000 network.

I got a new found respect for the bullet tweeter...

[ivica]

Hi Ivica,

Surprisingly it does make a lot of difference, I actually adapted the 3133A to make a 3-way using 4530/2220H with 2441/2390 and a recently acquired 2402H. Initially I followed the 3133A schematic i.e. I flipped the 2402H. But it sounded shut in and dull. So i tried connecting it in phase with the 2441 and 2220. OMG... The sound is open and airy, most noticeable on classic Jazz cymbals ... Also the snare drums gained body and texture... I don't recall my 2405 slot sounding quite like that even though many claimed that the 2402 and 2405 are in fact the same tweeter.

Later I found out that the component series manual actually did recommend connecting the 075 in phase with MF when using the N7000 network.

I got a new found respect for the bullet tweeter...

Hi ngccglp,

As I remeber, 2402 is about several dBs higher efficiency, and is more directional then 2405.
On the other side may be some measurements would give exact answers what is going on.
For sure a kind of comb-filter effect would be present around crossover region.
Depending on the polarity of the UHF driver I can imagine that notches would shift less then 1kHz, I would expect.

Regards
ivica

[ngccglp]

Hi Ivica, Noted. A friend of mine says he can use Smaart7 top help me fine tune my system. I have no idea what that is. ha ha