Offical Thread - Loudspeaker Design Seminar in Kokomo

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johngalt47
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Re: Offical Thread - Loudspeaker Design Seminar in Kokomo

Post by johngalt47 » Mon Feb 03, 2014 9:54 pm

Well, since they were PE cabs they won't look anything special but maybe I will take some pics. I used the component values in Jeff's spreadsheet #7 except I substituted a 2.0 coil on the woofer. The clarity is exceptional, IMHO, but I prefer more bass. I went back to the spreadsheet and played with the woofer circuit to see what values were possible. I concluded that I could go as high as 2.7 on the coil and 11 uF on the cap. When I get motivated I will do some tweaking to see where I end up. I feel that most people would like it the way it is though.

Jeff B.
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Re: Offical Thread - Loudspeaker Design Seminar in Kokomo

Post by Jeff B. » Mon Feb 03, 2014 10:31 pm

johngalt47 wrote:Well, since they were PE cabs they won't look anything special but maybe I will take some pics. I used the component values in Jeff's spreadsheet #7 except I substituted a 2.0 coil on the woofer. The clarity is exceptional, IMHO, but I prefer more bass. I went back to the spreadsheet and played with the woofer circuit to see what values were possible. I concluded that I could go as high as 2.7 on the coil and 11 uF on the cap. When I get motivated I will do some tweaking to see where I end up. I feel that most people would like it the way it is though.
If you port it you will get a bit of midbass hump in the response. This might get you what you are looking for. Model it and see what I mean.

Jeff
Jeff's Excel Loudspeaker Design Software
http://audio.claub.net/software/jbabgy/jbagby.html

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bkeane1259
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Re: Offical Thread - Loudspeaker Design Seminar in Kokomo

Post by bkeane1259 » Mon Feb 03, 2014 11:13 pm

johngalt47 wrote: The clarity is exceptional, IMHO, but I prefer more bass.
This is exactly why I will be doing the MLTL version of the Docere -more bass plus a floor-stander with a small foot print. The eventual owner will love them, guaranteed.
Bryan K.
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Jim Griffin
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Re: Offical Thread - Loudspeaker Design Seminar in Kokomo

Post by Jim Griffin » Thu Feb 06, 2014 5:56 pm

Johngalt47 (aka Ren) asked about more bass for the Docere kit and Bryan mentioned the MLTL version that he is building. In the Docere thread on the Parts Express forum late in 2013 I presented a MLTL design which solves the more bass desire while maintaining Jeff Bagby's crossover as is. Those of you who haven't read the P-E Tech Talk Docere thread go to

http://techtalk.parts-express.com/showt ... ght=docere

My MLTL design is discussed within this thread and the drawing for the floor standing version is given in message #67. You shouldn't wish for more bass with this design. Paul Kittinger also proposes a folded or 'book shelf' version of the same MLTL within the text.

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bkeane1259
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Re: Offical Thread - Loudspeaker Design Seminar in Kokomo

Post by bkeane1259 » Thu Feb 06, 2014 6:22 pm

Jim Griffin wrote:You shouldn't wish for more bass with this design.
Speaking in general terms, one can always wish for more bass....right?
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Re: Offical Thread - Loudspeaker Design Seminar in Kokomo

Post by Jim Griffin » Thu Feb 06, 2014 9:02 pm

Wishing for and getting more bass are when reality enters the room.

johngalt47
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Re: Offical Thread - Loudspeaker Design Seminar in Kokomo

Post by johngalt47 » Sun Feb 16, 2014 4:54 pm

Ok, here is a pic as promised.
Attachments
Closeup of one of the baffles
Closeup of one of the baffles

johngalt47
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Re: Offical Thread - Loudspeaker Design Seminar in Kokomo

Post by johngalt47 » Sat Feb 22, 2014 5:27 pm

It isn't really *more* bass! but some male voices sound a little lean or something. Brook Benton's voice on Rainy Night in Georgia does not have the same weight I normally hear with other speakers. Also, on the T. Rex song 20th Century Boy, the lead singer's voice is weird.

Jeff B.
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Re: Offical Thread - Loudspeaker Design Seminar in Kokomo

Post by Jeff B. » Sat Feb 22, 2014 6:11 pm

johngalt47 wrote:It isn't really *more* bass! but some male voices sound a little lean or something. Brook Benton's voice on Rainy Night in Georgia does not have the same weight I normally hear with other speakers. Also, on the T. Rex song 20th Century Boy, the lead singer's voice is weird.
That seems odd. The inductor I used on the lowpass circuit gives it a full 6dB of baffle step compensation and the frequency response I measured at home and at the seminar was flat down to the bass range. I never noticed any vocals sounding off and I listened to quite a bit of my normal voicing vocal tracks before the seminar.
Jeff's Excel Loudspeaker Design Software
http://audio.claub.net/software/jbabgy/jbagby.html

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