PDA

View Full Version : Biamping 4315B



Chevelle
01-29-2017, 10:15 AM
Has somebody modified a 3114A crossover in the 4315B for biamping ? What crossover frequency and slope is best ?

Hjalmar

Chevelle
02-12-2017, 09:41 AM
Is there nobody who tried to biamp the 4315 4-ways ? Is there any improvement ? There is enough space on the back terminal for a second pair of connectors and a multiswitch. It is easy to disconnect the woofer from the crossover and the 52uF cap plus 2.25mH coil from the lo-mid way.

Hjalmar

Flodstroem
02-12-2017, 01:49 PM
You have some more data here but no big help I guess:
http://www.lansingheritage.org/html/jbl/specs/pro-speakers/1977-4315.htm

bldozier
02-12-2017, 02:17 PM
Why would you disconnect the two mf caps
for the internal/external switch?
i'm sure I read about this before

how much power are you driving with.
Brian.

Chevelle
02-12-2017, 11:22 PM
Why would you disconnect the two mf caps
for the internal/external switch?
i'm sure I read about this before

how much power are you driving with.
Brian.

Brian,

the passive crossover of the woofer and the lo-mid is set at 400Hz. When I go bi-amping I will eliminate this passive crossover and use an active crossover with two poweramps. The passive 400Hz network consists of the 72uF and 3.8mH low pass and 52uF and 2.25mH high pass.

Hjalmar

bldozier
02-14-2017, 02:56 PM
sorry the naming confused me. So the switch
which your referring is just for the two separate
amplifiers. Not a active or passive switch
like on the 4344

Chevelle
02-14-2017, 11:53 PM
The internal /external switch on my 4343 is doing exactly the same, removing the passive high- and low pass filters from the 2235 and 2123.

bldozier
02-15-2017, 07:08 PM
Hjalmar
are you considering adding a switch to the
backplate, sorry if the album of questions are badgering
I too will be using a 3114 network and
like to know all I can about any modification to them
for future reference of course, if you wanted add the extra
switch to the network, then how come delete the two caps
brian
Thanks

Chevelle
02-16-2017, 09:37 AM
Brian,

let me explain the conversion as simple as possible:

First add a second pair of terminals and a simple 2-position 6-pin toggle switch to the rear panel. To the extra terminals connect the LF way of the crossover and leave the rest on the existing terminals. Then the toggle switch has to be connected as in my drawing.

In the "external" position the switch shortens the inductor and opens the way of the cap to ground in the lo-path, it shortens the cap and opens the way of the inductor to ground in the hi-path. The HF and UHF path stays untouched. Also the zobel is still active.

In the "internal" position the switch leaves everything as it was. It is important to link the terminals of the hi and lo connections.

Hjalmar

bldozier
02-18-2017, 07:57 AM
I will consider this hjalmar.
thanks. Do you consider the move to
add the second set of pins and the switch a
partaking for a novice.

Can you if if your still consider doing the reconstruction
add a diy

Robh3606
02-18-2017, 09:18 AM
You might want to run the crossover in a simulator. There are bound to be changes when you take out the 2 lower poles on the mid bass. They may not be significant but you should take a look just in case.

Rob:)