I wouldn't worry too much about it since that network probably wouldn't be optimal for a 2397 anyway.Originally Posted by dkalsi
Start with the L-Pads, get everything dialed in, and then replace the L-Pads with fixed resistor pads.
Hey Giskard,
Are you suggesting that I not include any inductor as a replacement for the one mentioned in the schematics?
Thanks,
D
:dont-know I don't know what schematic you are working off.
I do know that I never did any schematics for the 2397.
Haha - sorry for not being clear - I am using the "Charged Coupled Crossover" schematics you had posted for the stock 4345.
For my build purposes, I was going to leave the opening for the 2420 in the baffle closed and set a 2397+2441 driver on top as a replacement for the mid-high.
I thought I could use the same crossover. I believe this is what Jerry (a fellow forum member) did (except he used a 2235 as oppose to 2245).
In the charged coupled crossover - using stock drivers - the schematics indicate a 18 gauge 0.6 Mh and 0.53Ohm inductor being used for the mid high.
I will try to post a picture of the schematics im using shortly.
No, he is saying that since the 2397 horn has different characteristics than the 2307, the exact values are less critical... not less critical per say, but since you don't have a network that has been optimized for a specific horn, driver, and physical placement, everything will be SLIGHTLY less optimal... audible? Maybe. Very audible? Maybe. It is hard to tell. Essentially the phase characteristics at the crossover point will be different due to path lengths and physical layout. Still, chances are that using his network will give you the desired results.
Realize that way back when in the early days when JBL designed the 43XX monitors none of today's computer modeling was available and the knowledge and theory that has since been developed simply didn't exist. That said, by trial and error, they did do some great work.
Just use any good quality 0.6mH coil you can find.
Widget
Even if it's resistance does not match that stated in the schematics? Unfortunatley, I just don't know enough about crossovers to determine how much of a material affect this will have.
There are really only two values of an inductor... it's inductance and it's internal resistance. (OK, there are the issues of saturation, precision, mechanical quality, etc. etc.... but let's keep it real.) The internal resistance will have an effect on the network, but it is generally quite subtle. Most crossover schematics don't even spec the resistance.
As 4313B and I both stated, since your network isn't optimal don't sweat it. Build it and listen to it, if it sucks, and I really doubt it will, then fix it.
Widget
Got it!
Hi dkalsi,
- If you don't mind a bit of advice / do a mock up of the passive horn circuit using the standard capacitor topology ( non -CCed ).
- Then measure its acoustic performance with that horn/driver combo / then post the results here .
- Use as inexpensive poly-type ( mylar or polypropylene ) capacitors as you can find / you'll likely need to junk them anyway .
>< cheers
Hey Earl,Hi dkalsi,
- Use as inexpensive poly-type ( mylar or polypropylene ) capacitors as you can find / you'll likely need to junk them anyway .
>< cheers
Unfortuantely - I have no testing equipment
http://www.parts-express.com/pe/psho...=255-412&DID=7
Quick question:
A fellow forum member has offered me a 2245H for a relatively cheap price. I already have three 2245h (two of which were reconed last week and the last one is all original).
Again, I am getting ahead or myself, but for little cost, I could create another box that would sit on top of the the 4345 I am currently building.
I currently have an Ashly Xr-2001 which has the potential to control four 2-way systems. It would be very easy for me to have the Ashly setup to sent 300hz to the two 2245H seperately (on each side of a stereo setup). Accordingly, this setup would require no additional crossover work to the passive crossover in the 4345.
My only concern is that is all this even worth it? - will the system sound too bass heavy? Based on my reading thus far here at the forums, people often give the 2245H a little boost using an active crossover when one is working with a bi-amped 4345 setup. Given the fact that 2245H is rated at 95db sentitivity, would using two 2245h would increase the sentivity to 98db (making it a little closer to the sensitivity of 2122H) and hence requiring no additional boost?
By moving to dual woofers (as oppose to using boost), would that end result be a more balanced sound in the bass spectrum?
Kind of like the Westlake Tower SM-1 setup:
I wouldn't go that route myself... but more importantly as you deviate from a known design, the need for experience and testing equipment goes up significantly.
I'd highly recommend you closely copy the 4345 and keep it simple.
Widget
1) Should I install the fiberglass (stuffing) before I paint the baffle?
2) Which L-pads should I be ordering if I want to intall them in the cabinets (ie, like the original design).
3) Any recommendation for a good wood filler (hopefully one that is available at Home Depot / Lowes).
Anyone,
As you all know, I am building a pair of 4345. One of Greg T's suggestion was to make the enclosure volume a little larger. Hence, I decided to increase the depth on the inside of the speaker from 16" (according to plans posted by Tecbot) to 18".
After subtracting the dog-house volume and the volume eaten up by the extensive braching, I am coming out with approximately 10.2 cubit feet of internal volume.
I was hoping someone could help be determine what modifications this would require to the port length (if any). According to Techbot's plans, the port length on the 4345 is 8.25" -->for my enclosure volume, could someone please help me determine what the appropriate port length with be?
Thanks,
D
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