JBL 2206H, 2118H, 2406H 3-way Project

[pos]

I suppose you mean 2404 when you write 2406?

[frank23]

I tried a two way combination with the 2206’s with 2425 and 2450 compression drivers and much preferred covering the bulk of the 300 hz through 3000 hz voice range with the 2118 8 inch cone drivers. I also tried a 10 inch 2123. All things considered my preference is the smaller 2118 midrange.

I have been playing with the 2123 and 2420/2344 combination for years. Crossover at 1600Hz is the way to go here. The 2123 goes higher cleanly, but the radiation pattern becomes to focussed, so the 1600Hz crossover is to match the 100x100 pattern of the 2344. This is also something you should consider when combining drivers as the radiation pattern influences your reflections and therefore your room averages response.

When looking at the 2118 specs I see a bump at 1kHz and a not very much extended hf in comparison to the 2123. And I think the 2118 beames too much for a nice crossover to the 2404.

See here btw for some response measurements for the 2123 / 2122 that are abit more accurate than the horizontal line that JBL has published. And there is also one somewhere in black and white on the internet: http://www.audioheritage.org/vbullet...h-out-of-specs

[DualTriode]

I suppose you mean 2404 when you write 2406?

Oops yes that is a Baby cheeks 2404 I am talking about.

DT

[DualTriode]

I have been playing with the 2123 and 2420/2344 combination for years. Crossover at 1600Hz is the way to go here. The 2123 goes higher cleanly, but the radiation pattern becomes to focussed, so the 1600Hz crossover is to match the 100x100 pattern of the 2344. This is also something you should consider when combining drivers as the radiation pattern influences your reflections and therefore your room averages response.

Brother you said a lot in just a few words.

There is a lot of complexity to all of this, we try different things and make hopefully informed compromises. Looking at the JBL 2404 frequency response there are serious peaks and valleys above 4K hz. The response at 3K is 10db down compared to what it is at 5K. I thought I would give it a try with the 2118 crossed over to the 2404 at 3K hz. To my impression that did not work out too well. I think that in this case beaming of the 2118 is minor compared to the dip in the on axis frequency response.

The crossover from a cone driver to a lumpy bumpy frequency response of a JBL Bi-Radial Horn is interesting. The Bi-Radial Horn -6db beamwidth is 100 degrees. Ideally you want to match the -6db 50 degree off axis response of the cone driver (+-50 degrees equals 100 degree beamwidth) response of the cone driver to the 100 degree -6db beamwidth of the horn. Plus something I often forget; even with the horn tweeter mounted as close to the cone driver as you can place it, the drivers do no radiate from a single point. As a result there is a complete frequency response null (0 db) at some off axis angle determined by the distance between the points and crossover frequency, so much for maintaining 100 degrees beamwidth at the crossover point.

In the end we build these things, the beamwidth may not be text book and the frequency response may not ruler flat, I am still enamored with the result. JBL sold a million studio monitors just like this and continues to sell a gob today.

Rock On
DT

[frank23]

In the end we build these things, the beamwidth may not be text book and the frequency response may not ruler flat, I am still enamored with the result. JBL sold a million studio monitors just like this and continues to sell a gob today.

Rock On
DT

Rock on indeed! :-)

But JBL did not sell "a million studio monitors just like this" :-) The JBL 4628 with this configuration was meant as sound reinforcement for a band or so. Not for monitoring purposes where JBL would really consider radiation patterns, phase etc. in much more depth than with a sound reinforcement monitor with much simpler crossovers. Although the drivers in itself are great (I use the E145 bass myself in my home system), the Cabaret series mix does not result in monitor standards sound.

[DualTriode]

The reference was to the 4430/4435 Bi-Radial Studio Monitors that used the Dolly Parton horn. They did sell a million of these.
The frequency response did have some peaks and valleys.
All just for fun!
DT

https://www.jblpro.com/pub/obsolete/443035.pdf
http://www.audioheritage.org/html/pr...bl/4430-35.htm

[DualTriode]

Happy New Year!

Back to the same indoor sports as a year ago!

There have been several versions of rough cabinets so far. Woofer cabinets, mid cabinets and high frequency cabinets for stack em up mix and match.

After trying the lineup of JBL high frequency drivers there are currently a pair of 2425HS (this was the name prior to being 2426H) compression drivers with screw on 2342 Bi-Radial horns on top of the 3-way speakers.

The mid-range is a JBL 2108.

I like the feel and sound of this current combination of drivers.

DT

[srm51555]

Happy New Year!

I like the feel and sound of this current combination of drivers.

DT

This is all that matters.

Picts?