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View Full Version : New Built JBL 4355's and full active Behringer 2496 crossover-- settings help!!!



focalguy
01-24-2015, 11:39 PM
Hi all, I need help with the settings for the behringer dcx 2496 xover... setting up the crossover points..290,1.1,9khz was easy but wondering if i missed anything like the eq'ing , slopes are set as per factory. For the bottom i am using a JBL 5234a with the 290 cards. It sounds really good but hasn't got to great yet! or can anyone sell me a set of 3155 cross overs:D?

audiomagnate
02-21-2015, 04:26 AM
Hi all, I need help with the settings for the behringer dcx 2496 xover... setting up the crossover points..290,1.1,9khz was easy but wondering if i missed anything like the eq'ing , slopes are set as per factory. For the bottom i am using a JBL 5234a with the 290 cards. It sounds really good but hasn't got to great yet! or can anyone sell me a set of 3155 cross overs:D?


No, stick with what you have, that is an incredible piece of gear and perfect for what you want to do. Since no one else has chimed in I'll give it a stab. This is my admittedly limited knowledge on the subject:

> JBL almost always used 2nd (12 dB/8ve) order slopes on their monitors
> JBL crossovers are pretty darn simple, but the one "trick" I've seen them use is slightly different crossover points for the two drivers at that 1.1 k crossover point as a form of eq. In other words, the actual crossover point for one of the drivers is not really 1.1k. Maybe someone with more knowledge can chime in with the details, because I forgotten them.
> Whenever I do what you are doing I always leave one speaker stock and play around with the settings for the other one until they sound virtually identical. I use NPR/BBC voices, a variety of music and REW software for this. Make sure you are sending identical signals to both speakers.
> After you've got the settings right and have done both speakers, let the the 2496's dsp function (assuming you have a mic) clean up your room nodes at your listening position.
> I thought the 2496 could do 4 way stereo, so I would just lose the JBL electronics. I might be wrong because I haven't played with one in a few years. I know some people turn up their nose at Behringer gear, but I've heard the 2496 on some extremely revealing systems and it sounds just fine to my ears, and is an incredibly capable and flexible piece of gear.

So you're going with a quad-amped system? That's how I ride. It can get a little confusing, and connection mistakes can be costly if you are riding bareback (no protective blocking caps on the upper drivers). Have fun, I wish I could be there to help; that's my idea of a good time. I guess I need to get out more.

EDIT: I re-read your post and saw that your 4355's are "new built" so maybe you don't have stock passive crossovers (you only need one) so most of the above advice is completely useless!

ivica
02-21-2015, 05:47 AM
Hi all, I need help with the settings for the behringer dcx 2496 xover... setting up the crossover points..290,1.1,9khz was easy but wondering if i missed anything like the eq'ing , slopes are set as per factory. For the bottom i am using a JBL 5234a with the 290 cards. It sounds really good but hasn't got to great yet! or can anyone sell me a set of 3155 cross overs:D?

Hi focalguy,

As I have understood, as 2496 DSP network can support "only" 3-way stereo crossover, you have used JBL active analog network for Bass-the rest of the system , 290Hz crossover. I woul suggest You to
1. install 47uF capacitor "in series " with 2441 VHF driver to protect it from very low frewuency,
2. install 4.7uF capacitor "in series" with 2405 UHF driver to protect it from lower frequency
3. you have to find out the sensitivities of used power amps, after realizing their gain
4. you have to take the calculation of the necessary gain that have to be applied to each of the amps, takin in account the drivers sensitivities
As 4355 used two 2235 drivers mounted near aech other, tu ther sesnitivity it wolud be expected to add about 6dB, so reaching almost about 100dB/2.8Veff.
Such is compatible with 2202 sensitivity too(about 99~100dB/2.8Veff).
I would expect thar 2441 has to be reduced about ( 8~10dB), and 2405 about 5dB.
After raching almost the same level for say 2.8Veff voltage from the peramp, off all driver and applied amps, You have to do some measurements to see if some amount of compensation has to be done. From my knowledge all used driver have almost linear responses in the expectable frequency region of use.

If you prefer to use 2496 full range of dynamic rage usually produced voltage from the peramp of around 2V, has to be enlarged to 2~3 times.
Best wish,
Regards
ivica

dezmond
02-22-2015, 07:36 PM
Try the lr or besel 12db for the mid and high and butterworth 12db on low. This is what I use for triamp 4699b's.

Mctwins
02-22-2015, 11:52 PM
No, stick with what you have, that is an incredible piece of gear and perfect for what you want to do. Since no one else has chimed in I'll give it a stab. This is my admittedly limited knowledge on the subject:

> JBL almost always used 2nd (12 dB/8ve) order slopes on their monitors
> JBL crossovers are pretty darn simple, but the one "trick" I've seen them use is slightly different crossover points for the two drivers at that 1.1 k crossover point as a form of eq. In other words, the actual crossover point for one of the drivers is not really 1.1k. Maybe someone with more knowledge can chime in with the details, because I forgotten them.
> Whenever I do what you are doing I always leave one speaker stock and play around with the settings for the other one until they sound virtually identical. I use NPR/BBC voices, a variety of music and REW software for this. Make sure you are sending identical signals to both speakers.
> After you've got the settings right and have done both speakers, let the the 2496's dsp function (assuming you have a mic) clean up your room nodes at your listening position.
> I thought the 2496 could do 4 way stereo, so I would just lose the JBL electronics. I might be wrong because I haven't played with one in a few years. I know some people turn up their nose at Behringer gear, but I've heard the 2496 on some extremely revealing systems and it sounds just fine to my ears, and is an incredibly capable and flexible piece of gear.

So you're going with a quad-amped system? That's how I ride. It can get a little confusing, and connection mistakes can be costly if you are riding bareback (no protective blocking caps on the upper drivers). Have fun, I wish I could be there to help; that's my idea of a good time. I guess I need to get out more.

EDIT: I re-read your post and saw that your 4355's are "new built" so maybe you don't have stock passive crossovers (you only need one) so most of the above advice is completely useless!


Hallo!

What do you mean by room node? Are you talking about node or anti-node?

What do you see in REW? regarding the settings of the x-overs slope?

What is 12 dB/8ve?

focalguy
03-22-2015, 08:23 PM
I haven't added any caps to protect the 2405's or 2441's. All my amps have a delay relay. I have been running like this for 8 months no issues.... should I be worried? I have 2 dcx 2496 crossovers... one does the top and the second the bottom's. boy having the dcx for the bottoms takes them down alot lower than the 5234A ....i turn my 2 stacked M & k 125mkii off now. Recently have experimented with 8th order slopes.. i think that is a 48 db slope. sounds alot more clear and defined but the warmth is somewhat lost.








Hi focalguy,

As I have understood, as 2496 DSP network can support "only" 3-way stereo crossover, you have used JBL active analog network for Bass-the rest of the system , 290Hz crossover. I woul suggest You to
1. install 47uF capacitor "in series " with 2441 VHF driver to protect it from very low frewuency,
2. install 4.7uF capacitor "in series" with 2405 UHF driver to protect it from lower frequency
3. you have to find out the sensitivities of used power amps, after realizing their gain
4. you have to take the calculation of the necessary gain that have to be applied to each of the amps, takin in account the drivers sensitivities
As 4355 used two 2235 drivers mounted near aech other, tu ther sesnitivity it wolud be expected to add about 6dB, so reaching almost about 100dB/2.8Veff.
Such is compatible with 2202 sensitivity too(about 99~100dB/2.8Veff).
I would expect thar 2441 has to be reduced about ( 8~10dB), and 2405 about 5dB.
After raching almost the same level for say 2.8Veff voltage from the peramp, off all driver and applied amps, You have to do some measurements to see if some amount of compensation has to be done. From my knowledge all used driver have almost linear responses in the expectable frequency region of use.

If you prefer to use 2496 full range of dynamic rage usually produced voltage from the peramp of around 2V, has to be enlarged to 2~3 times.
Best wish,
Regards
ivica

focalguy
03-25-2015, 06:54 PM
Ivica,
do I also add a resistor across the 2405 and 2441 , taking into account the impedence?... would it be 16 ohm 50W resistors?




Hi focalguy,

As I have understood, as 2496 DSP network can support "only" 3-way stereo crossover, you have used JBL active analog network for Bass-the rest of the system , 290Hz crossover. I woul suggest You to
1. install 47uF capacitor "in series " with 2441 VHF driver to protect it from very low frewuency,
2. install 4.7uF capacitor "in series" with 2405 UHF driver to protect it from lower frequency
3. you have to find out the sensitivities of used power amps, after realizing their gain
4. you have to take the calculation of the necessary gain that have to be applied to each of the amps, takin in account the drivers sensitivities
As 4355 used two 2235 drivers mounted near aech other, tu ther sesnitivity it wolud be expected to add about 6dB, so reaching almost about 100dB/2.8Veff.
Such is compatible with 2202 sensitivity too(about 99~100dB/2.8Veff).
I would expect thar 2441 has to be reduced about ( 8~10dB), and 2405 about 5dB.
After raching almost the same level for say 2.8Veff voltage from the peramp, off all driver and applied amps, You have to do some measurements to see if some amount of compensation has to be done. From my knowledge all used driver have almost linear responses in the expectable frequency region of use.

If you prefer to use 2496 full range of dynamic rage usually produced voltage from the peramp of around 2V, has to be enlarged to 2~3 times.
Best wish,
Regards
ivica

ivica
03-26-2015, 02:52 AM
Ivica,
do I also add a resistor across the 2405 and 2441 , taking into account the impedance?... would it be 16 ohm 50W resistors?

Hi focalguy,

I have realized that you have TWO pieces of DCX2496, so each of them can be used as 4-way mono active network, but other configuration is possible, I think you have 2+3=5 stereo application.
1.
Using appropriated capacitors ( 47 uF, and 4.7uF) is just for drivers ( VHF=2441 and UHF=2405) protection of too low frequencies.
More Info:
http://www.audioheritage.org/vbulletin/showthread.php?36797-Biamping-with-2-x-identical-amps-breakthrough&p=373598&viewfull=1#post373598

2.
I think (if using transistor type amps) it would be no need to use any additional resistors, as on the DCX2496 sensitivity of each channel can be adjusted.
If you plan to use tube type of amps, depending of the amp configurations, may be some impedance correction would be an option, or some kind of EQ has to be done.

In any case I would strongly suggest to use the mentioned protection capacitors.

Regards
Ivica

focalguy
04-01-2015, 08:43 PM
thanks Ivica,

I am ordering the caps .... I am using a solid state multi channel amplifier... and two mono blocks for the 4 15's.



Hi focalguy,

I have realized that you have TWO pieces of DCX2496, so each of them can be used as 4-way mono active network, but other configuration is possible, I think you have 2+3=5 stereo application.
1.
Using appropriated capacitors ( 47 uF, and 4.7uF) is just for drivers ( VHF=2441 and UHF=2405) protection of too low frequencies.
More Info:
http://www.audioheritage.org/vbulletin/showthread.php?36797-Biamping-with-2-x-identical-amps-breakthrough&p=373598&viewfull=1#post373598

2.
I think (if using transistor type amps) it would be no need to use any additional resistors, as on the DCX2496 sensitivity of each channel can be adjusted.
If you plan to use tube type of amps, depending of the amp configurations, may be some impedance correction would be an option, or some kind of EQ has to be done.

In any case I would strongly suggest to use the mentioned protection capacitors.

Regards
Ivica