Some friends of my wife and I just got officially married last weekend. They knew each other since childhood and reconnected 10 years ago. He has a record player on an LP storage stand, but that is it. He has been looking around for vintage stereo systems. So I figured I could build them a set of monkey coffins! Everyone can appreciate low distortion sound, but I bet there would be no critical listening going on. Just background music use, maybe turned up a bit for a party. So I can tweak the voicing for a little more “excitement”.
Drivers:
I’ve had some DC25T-8s for years, and I picked up some PC105-8s at the garage sale durring last year’s SDC. Then a foundation of white cone GRS 10" woofers (10SFPC-W).
(Note .5db increments) F3 45ish hz with a near 2.5db hump. This is with a half-ohm added for estimated coil DCR.
I played around with the dimensions in MSpaint to get a better idea of the proportions. Experimenting with a couple M-T offsets. One a little off center, and another more extreme like the L100s. Though high offset might look a little odd without the port taking up visual space on the baffle next to the mid:
I was going for a slightly scaled down JBL L100 idea with the combo… Since the most recent version has a large flange titanium tweeter, 5.25" midrange, and white cone 12" woofer. However I’m pretty sure noone else but us speaker nerds would understand the correlation. I’m tickling the idea of instead using Peerless white cone TG9FD10 that would match the woofer perfectly. And MCM 53-5165 for it’s near white aluminum dome. That would be pretty damn cool having all that white peeking through the grill cloth. But probably another $100 after all the shipping and taxes tacked on. hmmm.
The 53-5165 does seem to have a livelier top end which is probably more what I’m going for. By contrast the DC25T is pretty much the opposite… Think I’m starting to answer my own question
I was hoping to use up some of this laminate I got from Clay. I think there was some decent looking dark walnut grain stuff in my stack. But they live in a real log cabin construction. Seems sacrilige to not get some real wood involved. Maybe shellac over walnut veneer. I’d probably still use black laminate on the back and baffle. I’ve got some with a dimple pattern that could break up the dead visual space on the baffle a bit.
Snow cones got the mojo rising.. Wow the size difference is quite stark! I suppose big woofers and small midranges are kindof a shtick with monkey coffins though.
Probably multiple reasons. But I’d bet marketing was a big part of it (bigger woofer is closer to what folks saw at the concerts). On a more practical side, high excursion heavy cones didn’t seem to be current dogma at the time. So to dig deeper you’d use big cones instead.
Many cheaper 3-ways ended up crossing the woofer much higher than we typically would think nowadays (1.5khz+). So realy the “mid” was more of a basic cone tweeter, with the smaller tweeter just picking up the top octave as more of a super tweeter.
Had some plans canceled for today due to rain. So I got boards and mid chambers cut just before rain started up again this afternoon. I had to reduce the overall height slightly due to board lengths and blade kerf. However, some of the Menards shelf boards in my stash were a hair over 11.5" (often 11.25"). So I’ll be able to make the cabs a little wider to maintain internal volume.
I’m planning to have the mid chamber extending all the way front to back. I’ll cut a groove in both boards for the ends to nest into with the circle jig. The pipe does double duty as a brace. Then I’ll add one or two side to side braces.
Interestingly the cone color on the GRS woofer is not off-white paper color. It is more of a “pure” bright white. The back of the cone is black. This leads me to believe they added paint or some sort of other coating for the color change. I suspect the black cone varient uses the same cone, but absent the coating. It alters them enough that the factory specs were not copy/pasted between the cone colors. For example white cone Mms 46.8g, black cone 38.2g. And they do tune a bit differently.
Made layout adjustments for new dimensions and new drivers. 3.5khz crossover would need close M-T spacing, 3khz would allow some gap. (differences shown below)
I set the boards together on the floor to get a feel for the real size. When I sit on the floor they come up a little under my chin. Oah yeah, I’m getting definite 80s-early90s medium size speaker vibes..Cerwin-Vega? … milk crate stands?
I had a chance this weekend to talk with them about it. They requested black instead of wood grain on the speakers. I suppose they are suffering a bit of wood grain overload, which is understandable.
… milk crate stands?