My First Speakers

Well, at least the first speakers I have designed from the ground up, and I use the term "design" loosely.  Component selection was mine, cabinets are from Lee Taylor of Taylor Speakers, partial crossover design was from Madisound.  I say partial because they designed a crossover for a different tweeter than you see here.

The cabinet is much better looking than this, especially the veneer.  I'm afraid my phone doesn't do the quality of Lee's work justice, so please bear that in mind.  His web site has pictures much closer to reality.

In a sense, this is a fail.  I was trying to design some smaller satellites with these components, and Lee was trying to guide me to a floor stander.  These speakers are really very tall and deep so I'm not sure most satellite stands would work for them.  It's a bit like trying to have a baby and getting twins though, I am not at all unhappy!  I just got more than I was expecting.

Drivers

The original design called for a smaller Mundorf AMT tweeter but that was out of stock and weeks away from arriving in the U.S. so i went for it's bigger brother the Mundorf AMT 25CM1.1-R.  One weird thing about this driver is that it takes banana plugs, not spades or bare wires.

Thd mid-woofer remains the same though, the ScanSpeak Revelator 18W/4531-G00 7" driver.  The 4 Ohm version is more sensitive so mean less damping is needed in the tweeter section.   I chose the Revelator in part out of cost ($220 vs. $320 ea.) concerns but part was also that in the high end of the driver I liked the response better than it's Illuminator counterpart, then when I read that Zaph rated the Revelator better than the Illuminator in terms of distortion that cinched it for this design.  I admit the basket does not look as cool though.  

Despite the larger tweeter having a lower useful crossover point I'm keeping the crossover frequency the same for a number of reasons.

1. I don't want to redesign the crossover from scratch
2. Higher crossover frequency = higher power handling

 One big advantage here as well is controlling the vertical dispersion.  The taller the tweeter, the less floor and ceiling reflections and clearer the sound at the listening position.  Like ribbons and electrostatic speakers, we should get enhanced clarity and detail than with conventional round drivers. 

 

Test Wiring

Per Lee's suggestion I'm going to keep the crossover external until I have tweaked it perfectly.  For this to work of course I'll use a separate pair of banana jacks for each driver.  Internally I'm using plain old 14 gauge zip cord which happens to be made by Monster.  I had it lying around from the surround sound installations in previous apartments.  It's thick, flexible, finely stranded and best of all, free and taking up space under my bed in the wiring box.

The white cable with the bananas of course goes to the tweeter, the pinkish cable to the SS woofer.  This being a test harness I didn't want to spend too much effort, but after installation and looking at the kinks in the wires I decided that the heat shrink was going to be necessary for proper strain relief.

The Sound! 

Of course, anyone with a checkbook and drill can get speakers this good looking, but how do they sound?  Magnificently quiet.  You've never heard speakers that disappear like these..... My secret?  They don't work yet! :(  Crossover parts were delayed due to a series of errors on my part but I should be able to start putting that part together soon.  Of course, being unable to resist, I am currently breaking them in by running the woofer's full-range.  They sound surprisingly good by themselves!  I had to go back to the charts and look but they have useful output to 10 kHz so I can run these as my main speakers without going completely nuts due to the lack of treble.