2235h subwoofer build for JBL 4343B

[DingDing]

Hi,

Got a spare pair of 2235h. The 4343B I already have has 2235h. My plan is to build two single or one dual ported subwoofer with 2235h drivers. The idea is to have 4343B play to 35 Hz (I limit the low end with a 24dB/oct high pass filter with miniDSP 4x10 HD). I was thinking of running the subs from around 200-300 to 35 Hz with 12 or 24dB/oct rollof. It's important that they play similar.

Will use WinISD to estimate and Sketchup to draw if there are no good designs out there that can already do the job well. Also, I'm wondering what 4343B is tuned to? My logic is that if I tune the subs similarly to 4343B they will play well together.

I have no need to go deeper than 35 Hz with this build as I have other subs that does that job.

So to summarize; what is 4343B tuned to, is it possible to build a pair of subs that integrate well even though there will be an overlap in frequency? Does a good design already exist, and if not, what do you guys think I should tune the sub(s) to.

[ivica]

Hi,

Got a spare pair of 2235h. The 4343B I already have has 2235h. My plan is to build two single or one dual ported subwoofer with 2235h drivers. The idea is to have 4343B play to 35 Hz (I limit the low end with a 24dB/oct high pass filter with miniDSP 4x10 HD). I was thinking of running the subs from around 200-300 to 35 Hz with 12 or 24dB/oct rollof. It's important that they play similar.

Will use WinISD to estimate and Sketchup to draw if there are no good designs out there that can already do the job well. Also, I'm wondering what 4343B is tuned to? My logic is that if I tune the subs similarly to 4343B they will play well together.

I have no need to go deeper than 35 Hz with this build as I have other subs that does that job.

So to summarize; what is 4343B tuned to, is it possible to build a pair of subs that integrate well even though there will be an overlap in frequency? Does a good design already exist, and if not, what do you guys think I should tune the sub(s) to.

May be I do not understand your idea, as I know, 4343 speaker is almost linear up to the 35Hz, so why to put another player in the game. As there are two vents, closing one of them the box res.frequency would be reduced from about 28-30Hz by 1.4 times , reaching about 22Hz, so with some kind of proper pre-amp filtering some additional LH response can be get, (but at he lower level of sound in order to protect the bass driver not to overcome Xmax) .
I think that the interaction of the other pair of bass driver can introduce much more troubles in the listening room, especially if expected to operate over 100Hz. Some ideas can be get from B380 subs.

regards
ivica

[DingDing]

Hi and thanks ivica.

Know how this sounds, but it would be a fun experiment to double up on the 2235h drivers and see what happens, if not for anything else, then experience. Got some left over MDF from my subwoofer builds and it's not that I need more low end (they would have a digitally set HPF @ 35-40 Hz anyways, just like the 4343B's does now), as I've got something else to do the heavy lifting down low.

Contemplating on adding to my stack of a single miniDSP 4x10 HD by getting openDRC and learn using FIR, maybe I could make them play well together through construction, placement, acoustical measurements and DSP?

It was suggested to me that I just get what I'm lacking to build a pair of 4350 with 2235h, and it would be awesome to do so, but the problem is that I have zero experience or skills to start messing with passive xover. Could probably build it if I had a list of parts some pictures of how to physically build it and a schematic, but I'd have to learn to read schematics first. Soldering it would be OK, but picking parts and making decisions, no way.

[ivica]

Hi and thanks ivica.
Know how this sounds, but it would be a fun experiment to double up on the 2235h drivers and see what happens, if not for anything else, then experience. Got some left over MDF from my subwoofer builds and it's not that I need more low end (they would have a digitally set HPF @ 35-40 Hz anyways, just like the 4343B's does now), as I've got something else to do the heavy lifting down low. Contemplating on adding to my stack of a single miniDSP 4x10 HD by getting openDRC and learn using FIR, maybe I could make them play well together through construction, placement, acoustical measurements and DSP? It was suggested to me that I just get what I'm lacking to build a pair of 4350 with 2235h, and it would be awesome to do so, but the problem is that I have zero experience or skills to start messing with passive xover. Could probably build it if I had a list of parts some pictures of how to physically build it and a schematic, but I'd have to learn to read schematics first. Soldering it would be OK, but picking parts and making decisions, no way.

Hi DingDing,

My personal experience comparing 4355 vs 4333 (either DIY), neglecting the upper frequency, bass seems to be almost the same character, and is quite different in comparison with the 2245 character, so I would not expect that you will get any noticeable difference in the sound character if you introduce 2235 as a kind of 'helping bass driver' to the 4343 speakers (in either case it is expected that compensation of the sensitivity has been done). May be you can experiment with 2245 but without F-R overlapping between 2245 (as added subs) and 2235 (in the 4343). I have no idea where crossover has to be but (as B460) it is expected that something around 80~100Hz would be acceptable.

If you plan to use miniDSP 'open DRC' ADSP in order to apply FIR filter phase compensated crossover network I think you have to use several of them. Our forum member POS can give you many useful suggestions.

regards
ivica

[honkytonkwillie]

Sounds similar to the "2.5-way" arrangement in the 4435 vs the conventional 2-way arrangement of the 4430.

Maybe look at the 4435 crossover schematics and try and find what frequency and slope the narrower bandwidth woofer uses.

[DingDing]

Sounds similar to the "2.5-way" arrangement in the 4435 vs the conventional 2-way arrangement of the 4430.

Maybe look at the 4435 crossover schematics and try and find what frequency and slope the narrower bandwidth woofer uses.

Thanks for the idea. The 4435's extra 2235h driver sets in @ 100 Hz according to spec.



Hi DingDing,

My personal experience comparing 4355 vs 4333 (either DIY), neglecting the upper frequency, bass seems to be almost the same character, and is quite different in comparison with the 2245 character, so I would not expect that you will get any noticeable difference in the sound character if you introduce 2235 as a kind of 'helping bass driver' to the 4343 speakers (in either case it is expected that compensation of the sensitivity has been done). May be you can experiment with 2245 but without F-R overlapping between 2245 (as added subs) and 2235 (in the 4343). I have no idea where crossover has to be but (as B460) it is expected that something around 80~100Hz would be acceptable.

If you plan to use miniDSP 'open DRC' ADSP in order to apply FIR filter phase compensated crossover network I think you have to use several of them. Our forum member POS can give you many useful suggestions.

regards
ivica

Thanks again, ivica. How are the characteristics of 2245 and 2235 different, please? Been working on aligning the impulse response of my subs, 2235 (in 4343) and the mid, hf and uhf. After a lot of tweaking, I ended up putting a LR 24dB/oct HPF @ 80 Hz for the 2235h, and will probably not introduce the second pair as aid.

The subs I've built but are not finished with yet dig down really low and are great. They are a pair of TC Sounds LMS Ultra 5400 in large sealed enclosures with Linkwitz-Transform applied. The amp driving them is not in the room, as it makes a ton of noise. The QSC you see there drives the 2235h and the Denon the rest of the 4343B.

62825

The JBLs are awesome, but they need help down low imo.

Think I'm going to change my long term goal into making 4343 fully active and get IIR.