Yet another 4425 DIY

[jerv]

I'm in the process of building a 4425 DIY. Just for the fun of it, I plan to design new crossover networks in addition to replicating the originals. Maybe the difference (?) could provide some insight and learning experience.

However, somehow I seen to have gotten into some momentarily trouble with my soundcard/measuring gear, and need some verifying. Does anyone have impedance plots (or even better: impedance files) for the 2214H and the 2416H on 2344 horn?

Thanks, Espen

[Don Mascali]

Look here:
http://www.audioheritage.org/vbullet...highlight=2342

The L200t3 is nice. There is alot of info from the Zilch project cronicled
in the "Quick and Dirty" thread. He tested that horn amongst many others. There are many strategies for dealing with CD horns in the X-over topologies shown in that thread and many other places here.

The search fucntion is your friend. You could spend weeks reading up on this stuff.

Good hunting,

Don M

[Zilch]

Does anyone have impedance plots (or even better: impedance files) for the 2214H and the 2416H on 2344 horn?

I believe you mean 2342 horn, which is thread-on and accepts 2416H. The larger 2344 is bolt-on, and NLA.

Here's the roadmap for Q&D:

http://audioheritage.org/vbulletin/s...ead.php?t=9901

[Don Mascali]

The 2344 has about a 12.25" square mounting area where the 2342 is 8.75". JBL used 1000 HZ on 2344 and 1200 HZ on the 2342 as the nominal X-overs. Both have the infamous butt profile.

The 2344s show up now and then here and on E-bay. I even found a pair that were modified by JBL to have the ports behind the Buns. They work nice for my side H/T speakers where they need to be mounted flat to the wall.

I am about to try a 2426H driver with the bolt flange removed on a 2342 for a rear surround project. It is kind of a waste for that driver though. I have some 2416Hs too... so we shall see.

I'm glad Zilch stepped up with that link. I could never find it. I have it saved now.

[jerv]

Yes, it is the 2342. A slip of the finger.

Cabinets are ready, units are mounted. I have already made one version of the L200t crossover (as described in varoius other threads) and one (slightly simplified) version of the original crossover. These are fun to compare.

I am also working on a crossover design of my own (with somewhat steeper crossover slopes and different eq, taking care (among other things) of the annoying bump the 2214 has at 1,9kHz) and an also an electronic version. Needs something to do when winter sets in.

I'll report back with measurements and listening impressions in due time.

[Don Mascali]

Sounds like a great plan. Good listening.

Don M

[Dougie]

I'm in the process of building a 4425 DIY. Just for the fun of it, I plan to design new crossover networks in addition to replicating the originals. Maybe the difference (?) could provide some insight and learning experience.

However, somehow I seen to have gotten into some momentarily trouble with my soundcard/measuring gear, and need some verifying. Does anyone have impedance plots (or even better: impedance files) for the 2214H and the 2416H on 2344 horn?

Thanks, Espen

I happen to have a new pair ( not broken in ) of 2214-H drivers here. I could do an impedance/phase run on them this weekend with LMS if you like And post it in pdf format. I could also send you the pdf file via email for you to print. Let me know.

Dougie

[jerv]

Thanks, Dougie!

I very much appreciate your suggestion! However, I traced my problems to a faulty connector on the sound card, which is now fixed. I managed to get some good plots tonight. (Hope yours looks about the same).

Here are the frequency and impedance plots of the 2214H in my 4425-box:

[jerv]

And here are the plots for the 2416H on the 2342 horn:

[jerv]

I first tried with this variant of the L200t3 crossover, as in the thread http://audioheritage.org/vbulletin/s...ead.php?t=7110 which was a great inspiraton for my project.

[jerv]

Here are the simulation (top) and the real measurements (bottom) for the 2214H/2416H+2342 with the L200t3 variant crossover in 4425 cabinet. As you can see, these curves are quite similar. That means (I hope) that the simulation and measurements basically works.

[John W]

They have some 4425 networks in the tent sale (3rd page in).

http://www.jblpro.com/commerce/tent_...x.php?cPath=23

I just picked up a pair for my DIY project.

[Titanium Dome]

Nice shots.

[jerv]

I have done some additional work on the 8th order filter. Frequency response is now within plus/minus 2 dB from 200-20000 Hz, and phase tracking is very good. See attached graph - version 1 is black, version 2 is the red curve.

Unfortunately, the number of components has gone up somewhat. To get rid of the 1.3 kHz peak in the 2416, I used a parallell notch filter in series.

To my ears, the new crossover sounds very good - as dynamic and engaging as the original L200t, but with less perceived high-frequency harshness.

[4313B]

Unfortunately, the number of components has gone up somewhat.

Yeah, that happens.

Nice job!