Hi! I own a pair of vintage JBL 4350B and through months of fine tuning, I have got them to peak performance.
I removed the old passive 3107 crossover and wired each driver out separately
The equipment I used for fine tuning is the following:
- NAD M66 preamp
- miniDSP THx (8 channel): Crossover at original JBL frequencies: 250/1100/9000 Hz
- NAD M23 V2 for both 2231 woofers wired in parallel
- ADA 6 channel 150 W class A amp for the 2202 midrange 250-1100 Hz
- 2nd NAD M23 V2 for both 2440 compression horns
- Topping mini 300 for the 2405 super tweeters
I did a lot of work on gain (old drivers with slightly different sensibilities), balancing of every driver group versus the other (listening and REW), Time delay: 0.24 ms of the 2202 versus the 2231 and 0.44 ms of the upper horn drivers versus the 2231.
I am using the Dirac built into the NAD M66 but only for the range between 17 and 180 Hz, I prefer the sound of the JBL drivers w/o Dirac filtering.
I sometimes connect a Mc2300 with a JBL 4641 subwoofer for more oomph (Fluke "Zion", Trentemoeller "Chameleon") but only with the NAD M66 built in x-over at 40 Hz. My room is 6 x 9 meters but I do get a bass bloom. So, if listening to 98% of music, Dirac cleans up the bass but still lets it be powerful enough. When Im want raw power, I switch off Dirac for full stomach feel.
Question: Now, after optimizing the speakers, I would like to simplify: Retain the active configuration but remove the "amp collection" and put a good 8 channel power amp as follows:
Channel 1: 2231 woofer 1
Channel 2: 2231 woofer 2
Channel 3: 2231 woofer 3
Channel 4: 2231 woofer 4
Channel 5: 2202 midrange 1
Channel 6: 2202 midrange 2
Channel 7: 2440 HF compression horn and 2405 UHF tweeter with a passive x-over (probably a simple high pass protection for the 2405 only, I am 65 years old and don't care much about frequencies over 9000 Hz)
Channel 8: Same
Note: The channels 7 and 8 need to be extremely quiet, no hiss, the 2440 compression horns are very sensitive and revealing.
I am considering a ATI AT528NC (3000 dollars used) but would not like to sacrifice a lot of sound quality. My budget is around 3,000 dollars to replace all these power amp jewels above.
Recommendations?
Note: The JBL 2360 birad horn on the picture (on top of the 4350) is not connected, I have that for a different project
I removed the old passive 3107 crossover and wired each driver out separately
The equipment I used for fine tuning is the following:
- NAD M66 preamp
- miniDSP THx (8 channel): Crossover at original JBL frequencies: 250/1100/9000 Hz
- NAD M23 V2 for both 2231 woofers wired in parallel
- ADA 6 channel 150 W class A amp for the 2202 midrange 250-1100 Hz
- 2nd NAD M23 V2 for both 2440 compression horns
- Topping mini 300 for the 2405 super tweeters
I did a lot of work on gain (old drivers with slightly different sensibilities), balancing of every driver group versus the other (listening and REW), Time delay: 0.24 ms of the 2202 versus the 2231 and 0.44 ms of the upper horn drivers versus the 2231.
I am using the Dirac built into the NAD M66 but only for the range between 17 and 180 Hz, I prefer the sound of the JBL drivers w/o Dirac filtering.
I sometimes connect a Mc2300 with a JBL 4641 subwoofer for more oomph (Fluke "Zion", Trentemoeller "Chameleon") but only with the NAD M66 built in x-over at 40 Hz. My room is 6 x 9 meters but I do get a bass bloom. So, if listening to 98% of music, Dirac cleans up the bass but still lets it be powerful enough. When Im want raw power, I switch off Dirac for full stomach feel.
Question: Now, after optimizing the speakers, I would like to simplify: Retain the active configuration but remove the "amp collection" and put a good 8 channel power amp as follows:
Channel 1: 2231 woofer 1
Channel 2: 2231 woofer 2
Channel 3: 2231 woofer 3
Channel 4: 2231 woofer 4
Channel 5: 2202 midrange 1
Channel 6: 2202 midrange 2
Channel 7: 2440 HF compression horn and 2405 UHF tweeter with a passive x-over (probably a simple high pass protection for the 2405 only, I am 65 years old and don't care much about frequencies over 9000 Hz)
Channel 8: Same
Note: The channels 7 and 8 need to be extremely quiet, no hiss, the 2440 compression horns are very sensitive and revealing.
I am considering a ATI AT528NC (3000 dollars used) but would not like to sacrifice a lot of sound quality. My budget is around 3,000 dollars to replace all these power amp jewels above.
Recommendations?
Note: The JBL 2360 birad horn on the picture (on top of the 4350) is not connected, I have that for a different project
