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In the Forum: Horn-Loaded Speakers
In the Thread: Midrange driver suggestions
Post Subject: The Derivative Design MethodologyPosted by Romy the Cat on: 1/2/2008

 homebuilder wrote:
I am new to this interesting site, and am hopeful of getting some assistance with a project.  I have purchased a set of TAD 1201 mid-bass drivers to begin a 4-way active system for critical home listening.  (in a dedicated room, 21' x 25' with peaked seilings at 11.5')  I already have the balanced x-over, and tube and solid state amps.

I plan on either the JBL 2226H or 2241H for the bass, and the 2404H for the treble. My problem lies in the midrange.  I'd like to use the 2344a horns with 2426 drivers, but cannot locate any of the horns.  Any help there?  Or, I have considered using either one, or a pair of large cone midranges, such as the JBL 2012H.  Is it practical to use large drivers such as the 2012 in an MTM arrangement?

The cabinet will be built of HDF, and will be multiple layers laminated on top of each other. It will be nearly round. Very heavy, massively braced.  I have friends with a CNC router, so that is a huge help.

Does anyone have any suggestions for the midrange? Other horn combinations?


So, it will be:

2241H for the LF
2404H for HF
TAD 1201 for mid-bass
MF channel

….the 4-way system. What kind enclosures are you intend to use? The 2241H is a ported-type driver, with somehow pro-like bass. Thos pro drivers are better in midbass then in lower bass. The 2404H is high-power SS-require tweeter, something suggests me that it might not be your finals chose if you consider “critical home listening”. TAD 1201 is a “terra incognito” for me but it looks like a very interesting driver. Still it is unknown how you will be using then: horn of boxed. If your go for no-horn-loaded MF and they all will be boxed then you might consider symmetrical double driver configuration with a tweeter in a middle and then two MF driver, two midbass drivers and two woofers.  As MF might be anything you like, but I would start with JBL L8. I hope your rest of the driver will be able to keep up with L8’s tone (and you should not wary about the sensitivity as it will be active anyhow). You might consider even to put MF in open baffle in that case… If you go for TAD 1201 in horn then it would be a different game and you might look for a compression driver for MF.

I generally am very uncomfortable with recommendations unless a lot of specifics in play. At this point I do not feel that you have a clear and defined vision what you are trying to build. I might advise you to do what I always do - starting to talk with your driver that you already have. Connect your TAD 1201 to the amp that you know and play it full-range for a while. Use different music, learn how the driver reacts to damping, reacts to volume, reacts to crossover and etc, etc, etc… You need to get a feeling where are the strong and week moment in a given driver and then come up with an enclosure that will accent the driver best qualities and shadow out the driver weak qualities.  Pay particular attention to the diver upper range as wherever you feel it will “slip” you would need to introduce a MF driver. Then, when you will try the MF driver you would need to look for the midbass and midrange driver TTH compatibility…

I call this approach a “Derivative Design” and it is the only approach in my view how an acoustic system might be planed. I have writhe about is many times. This method organically includes the person understanding of sound and the ability of acoustic system to present sound… The problem with this apprise that it takes time…

Rgs, the Cat

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