Hello Herve
"The bass level is insufficient. Conclusion: imbalance."
Across the board 20hz to 300hz or say 40Hz and down?? Padding the mid/compression drivers down?? The 2123 is 101 compared to a 2231 much more sensitive. The K140 won't have the last octave but comporable sensitivity. I don't see any pads in your schematic. The 4430/4435 and 4345 all have pads on the 2420/2421's as well as the Lpads for level. Just a thought.
Rob
"Across the board 20hz to 300hz or say 40Hz and down?? "
Robh,
40 hz to 300 hz !
See schematic : I use two L-pad 8 ohm 50 w MONACOR.
"- The 4348 hf network is tailored to the specific response characteristics of the 2430 with the 4348 horn. The network has no HF tailoring or midrange suppression and as such is meant to be used with a tweeter"
EarlK,
I would ultratweeter to buy. To take in consideration.
Robh,
40 hz to 300 hz !
See schematic : I use two L-pad 8 ohm 50 w MONACOR.
I saw them but they don't provide enough attenuation. I mean a pad to match the driver sensitivities. Look at the schematic Ian posted R4 and R5 are the pad for the compression driver. R8/9 and R10/11 are the pad in the 4348 schematic for the compression driver.
Rob
Last edited by Robh3606; 08-26-2003 at 03:05 PM.
Hi Herve
Just so you don't think I'm ignoring your dilemma .
I'm away till the weekend. When I'm back, I'll check in to see what progress has been made here.
- RobH(s) notes about additional fixed pads for the 2123h have merit. Also, the 2123h is a pretty low impedance speaker ( its not 8 ohms ) - you could probably get away with just adding some series resistance ( 3 to 5 ohms ) to that part of the circuit - in addition to the existing Lpad. This is another reason why JBL has started to incorporate "J" suffix midrangers into their newer 4 way speakers. Those J speakers can have a hard time getting beyond 11 ohms - which helps in balancing them in these type of hybrid style speakers .
- I'd also go back to the woofer section of the crossover to see if anything is stealing bass energy. FWIW, ( temporarily ) disconnect those 2 loading resistors that you have in there - and reconnect your 100uf capacitor . I'd also check the box tuning (Fb) for your woofer to make sure it wasn't "saggy" in the last octave - from a too low tuning.
- What is the box size & tuning ? ( forgive me if this is already posted - I'm now in a hurry here ). You mentioned this part of the circuit was inspired by the S9800 woofer circuit. Well, the K140 is not the 1500Al , so it has different electrical needs.
- I'd go with Ians' good suggestion of horn-compensation a la the n3155 circuit - even though you have plans to eventually acquire a tweeter. ( IME ) , all JBL compression drivers should be HF compensated (some ) when running without a tweeter .
regards <. Earl K
Last edited by Earl K; 08-26-2003 at 08:12 PM.
Hi Herve
I just realized ( had to get up out of bed ) - the capacitor value in the woofer section of your crossover is much too large - in should be in the 40 to 50uf area - not 100 uf - since I don't know the AC impedance of the K140 I can't be any more exact than a suggested 45uf.
What you have now ( for that 100uf cap ) works out to a second pole point of @ 150hz for your low pass circuit .
So I think all your cap values need accurate remodelling - especially those values derived/borrowed from the modern "Charge- Coupled" networks .
regards <>Earl K
Last edited by Earl K; 08-27-2003 at 04:10 AM.
I going to study! thank you!Reply in few days.
New replacement : 2231 with 2235h.
2235h very good ! The bass level is perfect and the medium/high level is balanced!
Actually, biamplification test with Behringer active crossover 2310.
Biamping
Well , there ya go.
Another "happy customer" for biamping. Glad it worked out !
<> EarlK
Originally posted by Ian Mackenzie
Herve,
Can I suggest the 3135 network EQ compensation will be the closest approximation to the eq required for the DMS1 CD horn.
I refer to this as the DMS1 voltage drive is surprisingly similar to the 3135.
Otherwise you are looking for a needle in a haystack
Ian
Hello ian,
Can you to do a drawing (schematic) ?
Well for an artist of my reputation I am sure I can assist,
A bottle of French wine to steady my hand of course would be nice....(joke).
Now where was that drawing
Ian
Ha Ha ! "drawing"!!
Where modification for my HFnetwork????
Ian,Originally posted by Ian Mackenzie
A bottle of French wine to steady my hand of course would be nice....(joke)
Ian
All our distributors receives a wooden box of 6 bottles of Baron Philippe de Rotschild "MOUTON CADET" (which is the result of a rigorous selection of wines from the most important Bordeaux names from grapes issuing from most noble strains: Cabernet Sauvignon, Merlot and Cabernet Franc; their blending, carried out by the Baron Philippe de Rothschild oenologists, give this wine force and vivacity, characteristics of a young wine; the tannins are frank without being aggressive) with each significant order!
Cheers ...
Hello, Here project passive network modifications for HF (2430+2332) :
1. either he I use 4348 schematic and I disconnect L4 (0,1mH),c15 (2,4yF) C17 (2,4yF) and R24 . ( NO UHF!)
2. Or I use 4430/4435 schematic. However, I would uhf in the future...
Today, I prefer the first hypothesis project. :o
Hervé
simplified schematic for hyph number one:
There are currently 1 users browsing this thread. (0 members and 1 guests)
Posting Permissions
Reply With Quote