Hi, I wonder if anyone knows the crossover design used in the Castle Knight 5 or Avon 5 speakers? These quarter wave designs both have two identical drivers, one of which is bass, the other is configured as a bass/mid. The idea is apparently to excite the line at different points in order to smooth out the bass response. I have a pair of the Knight 5 speakers which are excellent (and highly under-rated), but I wish to construct a larger speaker using the same principles to extend the bass response. I have drivers, but the key will be to understand and construct appropriate crossover networks. I'm a little reluctant to remove and un-solder the Knight 5 crossovers in order to measure the component values (which I could do - but!) so I was wondering if anyone on here has the circuit diagrams and would be prepared to share them? As always, many thanks for any information!
You need to at least know what the XO in your current boxes are.
These look to be quite different, the first a 2.5 way, the second a 3-way with an MTM up top.
The XOs will be quite different. The 2.5 way will have the top midBass XOed to the tweeter and the lower midBass just an inductor to roll the woofer off lower (usually somewhere just under BS9-3).
Do note that Castle around here usually implies 1 driver (midBass) firing forward and one firing upward, a tribute tto the Castle Howard.
dave
Often seen in Castle microTower builds. 3rd frame a standard, non-castle microTower.
dave
These look to be quite different, the first a 2.5 way, the second a 3-way with an MTM up top.
The XOs will be quite different. The 2.5 way will have the top midBass XOed to the tweeter and the lower midBass just an inductor to roll the woofer off lower (usually somewhere just under BS9-3).
Do note that Castle around here usually implies 1 driver (midBass) firing forward and one firing upward, a tribute tto the Castle Howard.
dave
Often seen in Castle microTower builds. 3rd frame a standard, non-castle microTower.
dave
Thanks Dave. My cabinets have been designed for me by the designer of the Castle Howard (my good friend Colin Walker) but based on 8 inch bass mid. Unfortunately he doesn't have any details for the crossovers, but your suggestion of crossing over the bass / mid to the tweeter and rolling off the bass with an appropriate l / c network seems very sensible. A lot of experimenting in 2022 I think! Thanks for your help!
Why not use the 2.5 way approach. This typically puts the transition from one woofer to two in between the line range and the crossover range. It's usually not too difficult.
Locate your baffle step, take down the bottom woofer with an inductor, then treat it as a simple two way up at the crossover.
My comments align with Allen’s. This is what a 2.5 way XO looks like.
First approximation of BS(-3) =4560/(baffle widtht [inches]). Generally one looks to XO at 0.707x<BS(-3)=1x. I tend toward the lower. You will often see commercial offerings with the second woofer XOed earlier, ie 100Hx-ish.
dave
First approximation of BS(-3) =4560/(baffle widtht [inches]). Generally one looks to XO at 0.707x<BS(-3)=1x. I tend toward the lower. You will often see commercial offerings with the second woofer XOed earlier, ie 100Hx-ish.
dave
Last edited:
Nope, the coil from the upper woofer to lower woofer is connected after the lowpass xover. This allows the second woofer to be lumped in with impedance and resonance control of the upper woofer.
Wolf
Wolf
I have as well, but the benefit is less copper in that extra coil, piggybacking the one in the lowpass. It's pretty much wasteful to not do it after the lowpass.
To be honest I'd rather define it as a curve, and such a curve would be speaker specific. However the inductor method rarely disappoints, and makes a good starting point in any case. It's interesting that the baffle frequency and crossover frequency are typically (eg the speaker in question) related to the same woofer dimension so many 2.5 ways are not especially different.