help diy speaker design

[caydan]

hi all jbl fan,
i've been a reader of Lansing Heritage for a long time and finally decide to build myself a system for music, some movies and occasional reshearsal. I need the speaker to be more livingroom friendly than the one i currently have (sr4722 on pole). I am thinking about using drivers and network from my sr4722 and add a 15" or 18" with an external crossover to cross at 80 hz. I found something similar from Gold Sound http://www.goldsound.net/kit11.htm
but they uses the 8" (2118h) for midrange and I wonder if I can use the same 8" driver with the sr4722 network or do i need the keep the 12" (2206h) that the network was build for. also, if i decide to go with the 8" (2118h) can I still crossover at 80hz with the external crossover and will I loose much midbass and warmth with that setup. thanks in advance for your response.
cd

[Zilch]

http://www.jblproservice.com/pdf/SR-Series/SR4722.pdf

http://www.jblproservice.com/pdf/SR-Series/SR4722A.pdf

Your two-way SR4722 uses a 2416H compression driver for the HF on a 2342 biradial horn. With 2206H as the LF driver, it's not surprising there's little bass below 80 Hz.

The Gold Sound system you cite is a three-way using the smaller 2404H UHF driver, more a derivative of the 4628B, a different system entirely.

http://www.jblproservice.com/pdf/Cabaret%20Series/4628B.pdf

Instead, use this as your model:

http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L200t3%20ts.pdf

That box will work for you, and the crossover will give you better HF extension, as well, pushing out to 20 kHz.

Building the NL200t3 crossover is well documented in my "Quick & Dirty" thread(s):

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

Shortcut: the hotrod biased and bypassed version is here:

http://audioheritage.org/vbulletin/showthread.php?p=70214#post70214

[caydan]

Thanks for your response Zilch, i guess i have a lot more research to do.