Up next?

jr@mac

OK, done farting around with the budget projects so I have a couple coming up that use a little better drivers. Have not decided which ones will be first, but I know one of them will be using the 5" 8 ohm poly SB and Hiquphon tweeter (I don't remember model number, but it is a pair that Dave had machined to a 92mm faceplate) and another will use the 8" Rival CF and the CF TL tweeter in a custom waveguide machined by our very own Ugly Woofer. Since it is ass cold here for the next three months, I think I will enlist the services of another member and their CNC table to cut flatpacks and use their nice heated shop to do the glue-up etc.

Both will use faceted baffles as there is no real reason not to, even with the guide on the TL being the dominant factor in diffraction control.

Anyways, not letting the ass cold weather disrupt my hobby. I gotta get it out of my system since this coming spring/summer/fall I plan on getting back in to distance running. I have dropped about 60 pounds and have 25 to go to hit my old fighting weight. My reward to myself is I plan on running a 10K in September. We will see how the knee reacts, but early testing is positive. I may also get the old Karategi out of retirement and dust off those skills. See how interested mama is in that, she knows my love/hate relationship with martial arts.

So, what is everyone going to be doing this winter?

Wolf

Just completed a subwoofer for a coworker. Overheard her talking her husband wanted one for Christmas, and so the conversation started. SVS sub was inferior for more money. I saw the MX10-22 and SPA300D and made a plan, was given the go ahead, and then came the site wide -15%, Perfect! Her son is a friend of mine, and works wood for a living. He said he would build the box, and I showed him the 0.75ft^3 knock down kit, which he ordered. It ended up I also built, rounded, epoxy coated, and finished the box with 3 coats of Duratex. I also added an external cavity for the plate amp on the back and finished it the same. It looked great! Something didn't sound right, and it wasn't as loud as it should've been. I got out the Crown and tried to break in the driver and torture test the box. I found 2 causes of noise; air leak into the amp cavity, and the feet were rattling the embedded washer against the mounting screw. I tightened the feet and filled the leak, but output was still a problem. I tested both 300D amps I have, and the one used herein produced 169W into a 4 ohm driver with boost on at -10 on the pre. That's not 300W! I checked the second one, which is older by 3-4 months, and it was bottoming the test subject sooner. I got higher voltage where I could get a reading than the previous unit. It also gave the MX10 a better output potential. Suffice to say I got a bad amp unit, and PE will be replacing it when back in stock. It's a nice looking and basic 13" cube roughly, that sounds taut and clean. I'm pretty sure they'll be happy.

Wolf

The indents on the baffle are embedded Neo magnets for a to be added grille.

jr@mac

So sealed it is for the Rival 8".

Here it is in 1.5 cubic feet, modeled with 0.5 ohms series resistance:

Here are measured parameters:

Depending how wide I make it will determine if I actually go the facet route or stick with something like a 1" to1-1/2" round-over. Facets are undeniably cool IMNSHO, but can make for a pretty wide baffle speaker. Minimum these will be 12" as-is and with the bigass waveguide there will not be much room for useful facet geometry.

I'll start cabinet design possibly tonight. Will have removable rear baffle so I can glue in the MDF waveguides for a seamless appearance. Tentative plans are to paint them piano black, so some careful body work is in order - hence the CNC approach to cutting etc.

Anyways, when I get actually going on this I will start a dedicated thread. Right now I plan on buttoning up the TMM portion of the SB series. I am not going to spend any more time on them, something goofy with the bass alignment on them I have yet to figure out. My cabinets may be bigger than I thought. Wouldn't be the first time I fuckered that part up. Oh well, lot easier to remove volume than add it back in.

Wolf

Took some better photos..

That box sim looks really nice, JR! Congrats on getting your weight down.

jr@mac

Figured out what I fuckerated... Made ports 2x as long as they need to be. Oh well. Easier to cut ports down than to make them longer. Maybe now there will be some bass out of these little towers. For the life of me I could not figure out what the hell, why the little desktop versions with a single woofer were playing so much better bass.

Fuckerated model:

Unfuckerated model:

The difference in port length, much like my idiocy, is not subtle. Off to the garage to cut the ports down.