Without any BSC it should be approximately the same as the woofer sensitivity right? Oh wait just looked at PE's published FR graph Yuck! Hard to tell actual driver sensitivity from that, I'd guess 91-93db.....
Does this work with Bill's XO? Also, can I removed the LPAD from the shematic? *Suggested enclosures: Vented cabinet: Type: Bass reflex; Size (internal) including volume displaced by driver and port: 2.0 ft³; Internal cabinet dimensions (golden ratio): 24-3/4"H x 15-1/4"W x 9-1/2"D; Port dimensions (with flared exit): 2" dia. x 6"L. Typical results: 3 dB down-point (f3): 40 Hz; Tuning frequency (fb): 28 Hz; Low frequency limit at rated power without exceeding conventional Xmax (i.e. (voice coil length – gap height) / 2)): 22 Hz.
you need either an lpad with a knob on it, or the two resistors shown in the dotted block. An lpad would let you adjust treble up or down if you wanred.
An L-Pad is basically two variable resistors controlled in opposite directions by the same knob. So if you don't want it variable, you can just use the resistor values corresponding to that knob position.
Revised Version 2 of the SEOS12/Designer12 crossover circuit After listening some to the speakers Erich put together, I've made some changes to the crossover circuit to clean up around the crossover point and to further tame down the high end which seemed a little hot to me. I took new measurements on the drivers inside his tower type box and the new files are at http://libinst.com/SEOS/SEOSDES12Aug2012.zip. The revised schematic is at https://www.circuitlab.com/circuit/bwq7a8/seos12-designer12-v2/ As before, if you plan on pounding hard on these, you can change the 5W resistors to 10W types (probably only for R8 and R9)
Bill, I also did some tweaking....but it was simple. I removed the ports and took them down to 4.25", which now tunes them around 29hz. Before the change they were tuned around 23.5hz. Surprisingly I could tell a difference. At some point I may take them out of the 3.5 cu ft box and put then in a 3 cu ft tuned a little higher just to see what they sound like. Right now I would definitely call them full range with the ability to rattle the living room.
Re: Revised Version 2 of the SEOS12/Designer12 crossover circuit I admit I am a moron with schematics. But I don't see where the (-) input goes. Looks like it's tied with the (+) input?
it's tied to common (somtimes called "ground"), that little upside down triange symbol. Basically, assume that all the common connections are conneted to each other. Its a way to make the diagram less cluttered byavoiding drawing a separate wi lre to each common point.
i am embarrassed to ask, but does that means the (-) input does directly to the (-) of the tweeter and woofer?
Smokarz, there's a quick tutorial somewhere on the PE site. I'll see if I can find it again. I'm slowly learning all the parts as well so I know exactly how you feel. Luckily Bill puts up with my ignorance on the subject, but some day he might just smack me upside the head for asking the same question 9 times! He hasn't yet though!
Bill or Erich did you evaluate off receiver power. If yes how many watts and did it still seem dynamic as to/ or close to the higher efficiency Eminence?
Yeah, Erich is finishing up on a final cabinet design, and is getting quotes on an etched set of circuit boards for crossovers. So it will happen, just takes some time, we both have other fulltime jobs that get in the way.
Re: Revised Version 2 of the SEOS12/Designer12 crossover circuit Bill, Do you think you will make similar changes to your Designer 10 plans? I'm cranking up a surround build with your Designer 10 plan and before I order the xover gear from PE, I wanted to check. Thanks, Java
Let me ask it differently. Should the Designer 10 xover be update based on your assessment of the Designer 12? I'm assuming that I can tame the highs in EQ, but the crossover point concerns me. Thoughts?
Hi Java, I looked at the model for the Designer 10 again. About the only thing I'd change would be to maybe make the CD compensation cap (C2 in its schematic) 0.47uF instead of 1.5uF. 1.5uF is more flat but I've been finding I like there to be a downward tilt at hf. Might be a matter of taste (and maybe room acoustics), though. My room is pretty reflective. Also, when used with a sub so the bass goes nice and low, having the top end more flat seems to work better, so take that into account. If using it just for surrounds, I'd leave it as-is. The crossover point is about right for the woofer diameter (look at the directivity curves, nice and continuous):
Bill, in the dotted square marked L-Pad, if we skip the L-pad, do we skip the resistors in the box as well?
No, it's either the two non-adjustable resistors **or** the L-Pad. They serve the same function, just that one is not adjustable (but is more reliable and much less expensive) than the other. In other words, the two resistors are either a physical L-Pad or two separate resistors.