A three-way DIY project with JBL 2216ND or with 2235H?

[ramin_audio]

Hello my friends,

It is spring-summer again, so I decided to start a new JBL DIY project!

This time I have two pairs of BLIESMA Beryllium midrange drivers and tweeters.
I bought them last year and they are not cheap at all. Must be very good sounding though. Can't wait.

Here are the info:

Midrange (M74B-6):
https://solen.ca//storage/media/HKzz...8HhtTFvG2M.pdf

Tweeter (T34B-4):
https://solen.ca//storage/media/YBn9...LW7p15eXsQ.pdf


As for the woofer I have two pair of 15" JBL woofers (2216ND or 2235H).

So, for now, I am looking for two recommendations!

- Which JBL woofer suits best?
- What cabinet volume and port size?

Any help/recommendation/instruction is greatly appreciated.

Thanks,
Ramin

[Mr. Widget]

Cool project!

For the 2235H use a 5 cu ft box tuned to 28-32 Hz.
For the 2216Nd copy the M2 enclosure and tuning. There are many DIY threads on the topic with useful info.

Tell us more about your HF units.

Widget

[grumpy]

Ha. Same. I’d use the new driver for a 3-way for its articulation to keep up with the be drivers & the 2235 for sub duty or another project. My 2 cents. Monkey coffin? Or unique box design?

Cool project!

For the 2235H use a 5 cu ft box tuned to 28-32 Hz.
For the 2216Nd copy the M2 enclosure and tuning. There are many DIY threads on the topic with useful info.

Tell us more about your HF units.

Widget

[RMC]

Hi Ramin,

The standard 2235H box is 4.5 cu.ft. tuned to 26 hz, as exemplified in the JBL B380 subwoofer cab, its a Qb3 low-frequency alignment. Designed here essentially for lower bass reach in a reasonable size box.

The 5 cu.ft. box tuned to 30hz has a different goal, and comes from JBL alternative "settings" (Vb and Fb) for the pupose of improved sound: max flat response, smallest phase shift and best transient response. They don't necessarily provide the lowest bass response (F3) contrary to some others. Therefore another ball game.

Being what it is, with the 2235H you have two options, one for deeper bass and the other for improved sound. Only you can make this choice based on your DIY expectations, priorities and objectives.

Richard

P.S. There's a notable length discrepancy between JBL's B380 port data listings i have (4 1/8" dia. X 9" long) VS the B380 port length mentioned in the 1983 subwoofer article: area 13.5 sq.in. is pretty much the same diameter as i calculated, but the 12" long duct stated represents 3" more than specs. I would have to "reverse engineer" the B380 port in speaker software to determine which one is right. However, in alternative alignments that issue is irrelevant since the port size is even larger.

[Robh3606]

You goin passive or active/DSP? I would use the 2216. If you go passive you are really going to have to watch driver sensitivity as they are all darn close. If you have to do anything beyond bandpass you might have an issue.

Active no issues obviously. You can set-up a 2216 in the same format as the 2235/B 380 and get almost identical results. With DSP you can set presets for +3 and +6 at box tuning of 26Hz. This gives you some added adjustment in the low bass to help with integration in the room.

Rob

[RMC]

Ramin,

Pics delayed due to site connection problems.

Richard

[ramin_audio]

Hello again guys,

I have been trying to post here, but the site keeps randomly crashing... What is going on?

So, I try to write very briefly and post it before the site crashes again!

I have been reading about JBL M2 and S4700. It seems they are designed without a passive xo and work with active xo with equalizer. DSP?
I want to design an old-school three-way passive system. They are going to be driven by a pair of McIntosh monoblocks (MC611), which I love very much.

So, the JBL cab for 2216ND is around 135L tuned to 32Hz.
However, according to WinISD, a 170L tuned to 35Hz (4" Diameter, 1.68" long) gives a much better curve.

For JBL 2235H, JBL enclosure guide recommends 141.6L tuned to 30Hz. WinISD produces a graph very similar to the above configuration for 2216ND.

I have decided to use the 2216ND.
I want the best quality of bass, not necessarily the deepest or biggest. I want a tight, dynamic, punchy and accurate bass. As long as it goes down to 35-33Hz it is fine by me.

So please give me your best estimates.

The information for the mids and tweeters are linked in the first post.
I don't know much else about them myself yet.

Thanks for all the replies. Please keep them coming.

[Mr. Widget]

Yes, the site is currently hampered by technical issues that will hopefully be resolved before we all lose patience and give up.

Thanks for sharing the driver links. These HF units look very good. Yes, I would definitely pair them with the 2216Nd.
I think you are on the road to an outstanding DIY project!

The only potential issue I see is that the mid driver will likely want to be crossed over no lower than 900Hz - 1,000Hz, certainly doable with the 2216Nd, but maybe not absolutely ideal.


Widget

[ramin_audio]

Yes, the site is currently hampered by technical issues that will hopefully be resolved before we all lose patience and give up.

Thanks for sharing the driver links. These HF units look very good. Yes, I would definitely pair them with the 2216Nd.
I think you are on the road to an outstanding DIY project!

The only potential issue I see is that the mid driver will likely want to be crossed over no lower than 900Hz - 1,000Hz, certainly doable with the 2216Nd, but maybe not absolutely ideal.


Widget

Do you have a better recommendation for the mid?

(I also have a pair of JBL 2441 and a pair of JBL 2123H.)

[rusty jefferson]

I agree the jump from a 4" hard dome mid to a 15" is too far. Better to add a 8" mid bass and go 4 way like the L250. Or maybe a 3.5 way with two 8" drivers in the bass cabinet and the mid/tweeter on top. Smallish floorstanders?

[ramin_audio]

JBL did something similar in JBL 4367.
https://www.stereophile.com/content/...r-measurements

[Mr. Widget]

Do you have a better recommendation for the mid?

(I also have a pair of JBL 2441 and a pair of JBL 2123H.)

This is tough.

Probably the best solution would be to make it an 8" or 10" three-way and add a sub. Or, you can go the classic 4-way by adding in your 2123Hs... or you can give it a whirl with the 2216Nds as a three-way and see how to works.

Damn speakers. They are all compromises!


Widget

[pos]

JBL did something similar in JBL 4367.
https://www.stereophile.com/content/...r-measurements

They 4367 is using a waveguide to ensure the directivity is matched at the crossover point.
That is not the case with a direct radiating mid, especially if installed on a smaller or protruding baffle (not sure looking at your drawing).

You would have to cross the 15" pretty low to somewhat match the directivity of that small mid, like ATC does in its speakers (and even that is not ideal directivity-wise), but that could be problematic with its relatively high Fs (440Hz, vs 300Hz-ish for the ATC dome IIRC).
If that mid is comfortable down to around 500Hz (might well be with its 2.5mm xmax, but you would have to find distortion measurements at different SPLs) and you can use a relatively steep crossover, then why not give it a try (with a full size baffle for the mid).
The crossover would have to be no less than 36dB/oct acoustical, so probably a 24dB/oct filter for the high pass.
If it is a passive crossover you will also have to tame the impedance peak at Fs, as it is pretty close in the stopband.

As other have suggested a 8" or 10" would probably be a better match, but that does not mean it cannot be made to work and sound nice. A 4-way also has it own challenges.

EDIT: this topic seems relevant: https://www.diyaudio.com/community/t.../#post-7302798
That looks like a very good mid.

EDIT2: also very relevant, and you could probably just replace the two 8" woofers with a single 15": https://vcllabs.com/vcl-ex27/

[Ian Mackenzie]

Unless you have a loudspeaker crossover design program like X Sim you will find it very difficult to obtain a reasonable result.

The 2216nd is a pro woofer. It’s not a diy friendly woofer with a flat response and ideal T/L parameters. You will need to subjectively do a lot of trial and error in your own listening room to determine the bass reflex tuning that will work for your preferences.

The short answers to some of your questions

1. Levelled off the 2216nd system sensitivity is about 93 db.There should be enough margin for attenuation of the mid a tweeter dome.

2. The 4700 passive network would be a starting point for the woofer . Your proposal of a Kef reference design has merit. If you angle the woofer baffle back with a windswept profile there will be less irregularities to the dome mid driver in the crossover region.

3. Following measurements try X Sim to determine you passive network for the mid and tweeter. The process is well documented in this website.

http://www.troelsgravesen.dk/Diy_Lou...r_Projects.htm

You’re going to have to do a lot of trial and error back and forth if you opt for a passive network.

If you know how to use REW driver measurements can to saved and exported to a crossover program. REW files can be emailed. When yoh get to that point if you wish contact me off line and l can look at your network proposal in Leap V.

http://www.troelsgravesen.dk/Diy_Lou...r_Projects.htm

[Robh3606]

Since we are talkin 4 ways somethin similar to XPL-200 especially with dome mid and tweeter. Upgrade to an 8 or 10

https://www.lansingheritage.org/html...s/1989-xpl.htm

Rob