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Project Summary:
http://audiokarma.org/forums/showthread.php?p=1856214#post1856214
Member Projects and Acknowledgments:
http://audiokarma.org/forums/showthread.php?p=2260584#post2260584
Member Listening Impressions:
http://www.audiokarma.org/forums/showthread.php?p=2528142#post2528142
Supplements:
Wayne Parham White Paper -- High-Fidelity Uniform-Directivity Loudspeakers
WIRED Wiki
YouTube Video
EconoWave Info
HPM-Econo Redo
BarzilayWave Project
Large Advent
Large Advent Utility
KLH-17 Tutorial
Wharfedale W60
MAKE
Nor Cal DIY 2009
Comparo
Floorstander Deluxe
Line Arrays
About Waveguides :
Waveguides
Practical DIY Waveguides
Waveguide Benefits/Drawbacks - Ongoing Studies
Vertical Nulls Video
********
Some combinations just seem to work better than others.
Member Jackgiff sent me pairs of two different inexpensive Selenium compression drivers for measurement and evaluation with Altec 811B horns in another thread. He also asked that that I do the same mating them with the $9.90 JBL Progressive Transition (PT) waveguide member Mxlews and I used in project speakers. Here's the scoop on PT waveguides:
http://www.jblpro.com/catalog/support/getfile.aspx?docid=277&doctype=3
This particular one has a 90° (H) by 50° (V) dispersion pattern, has thread-on driver mounting, and is used in several JBL Sound Reinforcement (SR) products. Dimensions are 12" W x 6.5" H, JBL part #338800-001.
Results for Selenium D210Ti and D220Ti on this waveguide appear below:
1) D210Ti impedance
2) D220Ti impedance is "friendlier."
3) D210Ti frequency response shown unfiltered, with simple R||C filter, and on Altec Model 19 crossover with full HF compensation.
4) D220Ti frequency response, unfiltered, with "T-filter," and Model 19 XO. Only ~6 dB of compensation is required to make it play flat (+/- 2 dB) out to 18+ kHz.
5) D210Ti vs. D220Ti on Model 19 crossover (Oops, legend reversed. D220Ti is Red & Org). D220Ti has better VHF frequency response, but unit-to-unit uniformity is not as good as D210Ti for these samples. Results were similar on 811B.
6) D220Ti on PT waveguide with Model 19 crossover, decidedly the preferred driver based upon both measurements and listening evaluations.
Drivers and waveguides are now going back to Jack, who has a specific project already underway. I've ordered a pair of D220Ti, and parts for a DIY crossover which anyone should be able to construct, the concept being an economical high-frequency section for members who've been wanting to "try the horn thing." It'll mate with just about any woofer (less than 101 dB/W sensitivity for full VHF compensation) capable of playing competently up through 1.2 kHz or higher.... :thmbsp:
Project Summary:
http://audiokarma.org/forums/showthread.php?p=1856214#post1856214
Member Projects and Acknowledgments:
http://audiokarma.org/forums/showthread.php?p=2260584#post2260584
Member Listening Impressions:
http://www.audiokarma.org/forums/showthread.php?p=2528142#post2528142
Supplements:
Wayne Parham White Paper -- High-Fidelity Uniform-Directivity Loudspeakers
WIRED Wiki
YouTube Video
EconoWave Info
HPM-Econo Redo
BarzilayWave Project
Large Advent
Large Advent Utility
KLH-17 Tutorial
Wharfedale W60
MAKE
Nor Cal DIY 2009
Comparo
Floorstander Deluxe
Line Arrays
About Waveguides :
Waveguides
Practical DIY Waveguides
Waveguide Benefits/Drawbacks - Ongoing Studies
Vertical Nulls Video
********
Some combinations just seem to work better than others.
Member Jackgiff sent me pairs of two different inexpensive Selenium compression drivers for measurement and evaluation with Altec 811B horns in another thread. He also asked that that I do the same mating them with the $9.90 JBL Progressive Transition (PT) waveguide member Mxlews and I used in project speakers. Here's the scoop on PT waveguides:
http://www.jblpro.com/catalog/support/getfile.aspx?docid=277&doctype=3
This particular one has a 90° (H) by 50° (V) dispersion pattern, has thread-on driver mounting, and is used in several JBL Sound Reinforcement (SR) products. Dimensions are 12" W x 6.5" H, JBL part #338800-001.
Results for Selenium D210Ti and D220Ti on this waveguide appear below:
1) D210Ti impedance
2) D220Ti impedance is "friendlier."
3) D210Ti frequency response shown unfiltered, with simple R||C filter, and on Altec Model 19 crossover with full HF compensation.
4) D220Ti frequency response, unfiltered, with "T-filter," and Model 19 XO. Only ~6 dB of compensation is required to make it play flat (+/- 2 dB) out to 18+ kHz.
5) D210Ti vs. D220Ti on Model 19 crossover (Oops, legend reversed. D220Ti is Red & Org). D220Ti has better VHF frequency response, but unit-to-unit uniformity is not as good as D210Ti for these samples. Results were similar on 811B.
6) D220Ti on PT waveguide with Model 19 crossover, decidedly the preferred driver based upon both measurements and listening evaluations.
Drivers and waveguides are now going back to Jack, who has a specific project already underway. I've ordered a pair of D220Ti, and parts for a DIY crossover which anyone should be able to construct, the concept being an economical high-frequency section for members who've been wanting to "try the horn thing." It'll mate with just about any woofer (less than 101 dB/W sensitivity for full VHF compensation) capable of playing competently up through 1.2 kHz or higher.... :thmbsp:
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