The cabs I am using are unusual in the type of plywood used. the construction consists of .5 x 1.5" solid wood strips glued together with 1/8" Birch glued to both sides. This seems to form a pretty stout laminate. As I sawed a larger hole for the 15" woofer, there was very little vibration caused by the jig saw and the panel seemed very solid, with a lack of voids.
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While it may seem solid and vibration free, I think you will find that a competent woofer will have the sides moving quite a lot. That is what gives rise to the "boxy" sound many unbraced cabs exhibit.
Only one way to find out if it's acceptable to you, listen. Also feel the different panels, checking for vibrations while they are playing loud. (Stupid-Loud, just for the test.)
Me, I learned to brace, and brace some more, and coat it if it moves, or if you don't want it to move. That's why I am using about 8 2X3 studs and 10-15 tubes of construction glue inside my pair of 7 cu. ft boxes.
Hey! I just fixed up my AK account today and started browsing. Posted a video in the General Forum. Scanning posts. Wow! I've got a lot of reading to do. Great to see you!Nice to see some more Ewave faces from the past. Is Skywaverider out there?
Russellc
Nice to hear from all the old ewavers! I spend time here, and over on diyaudio.com's Pass forum building class A amps.Hey! I just fixed up my AK account today and started browsing. Posted a video in the General Forum. Scanning posts. Wow! I've got a lot of reading to do. Great to see you!
View attachment 1015071 View attachment 1015073 View attachment 1015075LE14A E-waves finished with Selenium D220ti and appropriate crossover in 4.0 cu.ft. mdf cabinet with Duratex on five sides and cherry veneer on the front tuned to 33Hz.
QUESTIONS - having a second pair of LE14As available would there be any benefit to cutting in another LE14 below the existing one and using an inductor to create a 2.5 way? Would I need to double the volume of the cabinet to reap the benefit? (I would re-tune the LF crossover because BSC is addressed in the current crossover.)
Can you draw a schematic of this? I can't stop and will likely get these drivers. I have the "horns."I should have qualified my earlier statement by saying " of the obtainable 12" wide waveguides , the H290x is my go-to-choice .
It would be nice if there was a 15" wide version of the H290x .
Yes, the pic ( above ) shows an on-axis measurement . The response "weakness" seen in the < 1300hz area can be addressed with a simple 2-pole "bump" filter ( flip the roles of the 2 poles & then slide their reactive points towards each other to adjust the "Q" of the boost / ie; large cap - small coil ) .
Since you're focused on directivety ( rather than distortion in the crossover region ), here are Wayne's measurements ( I expect similar from any H290x variant ) .
Hi,
The schematic for the HF compensation shown in that picture lays out like this;
View attachment 1018184
Unfortunately ( for your use ), that only shows a compensation network ( not a full HiPass section of a complete network > that doesn't exist ).
Your best bet ( at using your other pair of le14a's ) is to simply build the le14a deluxe version using the following network from JackGiff .( since the B&C de250 is readily available, as is the $10.00 PRV clone of the QSC 152i waveguide ) .
I don't own any de250's so I can't compare that B&C's response directly to that of a CDX1-1747 for interchangeability .
- For all I know the Celestion might be a simple swap / but without actual A/B testing I won't ever know .