Posted by FredT [ 24.175.121.118 ] on December 29, 2005 at 14:56:03:
So far all the speakers I have built have fallen into two very different categories: 1) Serious speakers, like the Selah Audio XT8 line arrays and the Speakerbuilder.net Eros MKII's, which were designed and tested by experts, and which use expensive drivers and botique quality crossover parts, and 2) Fun speakers, like the FredArrays and the AnoreXiarrays, which were designed using basic programs (Win ISD, etc.), tested by ear, an use very inexpensive drivers ($4-12) and budget crossover parts.
This latest project falls somehwhere in between. Each speaker uses a single $70 Seas L18 aluminum cone woofer and a $35 27TBFGC alloy dome tweeter. The crossover parts are good (better than you would find in the typical $2K mainstream speaker) but not ridiculously expensive. For example, instead of a $50 12 Ga copper ribbon inductor I used a $19 Dayton 15 Ga air core. Instead of $20 Northcreek film caps I used $5 metallized polypropylenes. The project summary can be seen at http://www.zaphaudio.com/audio-speaker17.html
The pair I built, which I completed this morning, is a floorstander instead of the stand mount speaker in the Zaph audio project pages, but the internal volume and tuning are identical to the Zaph Audio design. I simply extended the enclosure height to 36" and used the empty space below the actual enclosure space for a crossover chamber and a separate sand fillable chamber below that. Building a floorstander is more economical than building a stand mount and buying good quality speaker stands.
My hat is off to John "Zaph" Krutke for making this excellent design available to the DIY audio community. Even right out of the cooker these are very impressive. Good tight bass, very clear midrange, and all the other reviewer buzzwords apply. Total cost to build them was about $300, and I'll spend another $50 veneering them later. The nearest mainstream speaker I am aware of (uses the same woofer a very similar tweeter (but a fabric dome instead of alloy), but a different crossover design, is the $2.5K Joseph Audio RM22Si, which can be seen here http://www.josephaudio.com/product.rm22simk2.html
Come to the Lone Star Bottlehead meeting in Houston on Jan 14th and hear these for yourself. I have included a picture of the unfinished speakers playing for the first time in the link below:
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