another crazy idea... I see in your pic the speaker is actually up a bit off the floor, how about a pillow (diffuser/absorber) under/forward of the front end?
I agree with the "ignore it" comments. The problem I always have is getting the tonal balance between the woofers and mid/tweeter set properly (i.e., applying the proper amount of BSC). This dip messes up your ability to see the relative SPL's of the woofers verses the mids. Since one of your two woofers is fairly close to the floor, it will pick up additional floor boundary reinforcement effect, which, in turn, reduces the amount of BSC that is necessary.
1) John you are right about two woofers being too much for the TC9s
2) when you think your ears are broken and you are about to find a new hobby, do a listening distance measurement and find that HiVi has your tweeter polarity marked backwards!
I was able to make a much nicer looking graph with the one woofer (feel free to throw in a told ya so, John!). I haven’t put the parts to it and listened but it looks promising. The one woofer largely solves the floor bounce issue too. Not sure if I will build new boxes or just mod these.
(The woofer impedance shown is just temporarily using the other woofer as a makeshift PR for the sweep)
I thought about it, maybe even down firing, but I still think it will be too much, or bloated. I actually disconnected the bottom one to keep the ctc spacing closer. Seems to have minimized the bounce null too. Plus it was nice having the extra impedance to work with. I can use the extra woofer in another project.
That’s a good suggestion John, thanks I’m working on the crossover and trying to get it lower.
Just an update on these (not that anybody was losing sleep over them ) I built two new 1.4 ft3 (gross, expected net about 1.25ft3) cabs for a single one of my home brew 8” woofers (paper cone, titanium coil, copper sleeve, 2” 4 ohm coil) in each cab. Sealed f3 is around 55 and ported is 28. Also, these will remain unnamed at this time. Bill asked if these will be the zoinkers as previously discussed but I want to keep that name for an 8” two way to keep with the theme of the name’s lineage.
I got the smaller single-woofer cabs put together. I ended up going with the woofer at the floor. Just using menards shelving. I am leaving the sides showing the vinyl wood grain and going textured black on top and front, simply because it’s easy and fast. Sorry if the pics are massive on PC, whenever I choose a smaller size on my phone, which is also my camera and only device I use for browsing, it rotates the pics 90 degrees..
I know, still using alligator clips. Until I get some wago connectors I am trying to just use the clamps to hold leads together and use my heavier alligators when I need to use the wire.
Anywho.. im in the final stretch. Right now I am just running the woofer sealed. It sounds very nice but I think would disappoint as a party speaker or in a big room. Porting it would be a different story. I will probably pop a port in back that can just be plugged. The enclosure size is optimum for ported but works just fine sealed. The woofer is content either way. Mid bass sounds very nice and clean with the woofer hugging the floor.
I am running a very simple crossover, seven parts in all. I had an earlier version with twice the parts, but the vertical off axis sucks either way being an mtm, so I went simple.
Tweeter is 1st order elec, kind of 4th Bessel acoustic at 3500. Mid is 1st elec both ways, 2nd Bessel-ish LP and BW4 HP at 550. Woofer is 2nd order elec and BW2 LP. Drivers are almost time aligned, the mids being 5mm behind the tweeter.
Had some interesting capacitor observations during the voicing of this basic crossover. I seriesed two 3.3uf caps to get what I needed for the tweeter cap. I tried some small polyester film ones I snipped off some terminal cup boards I got cheap for parts at the tent sale. They are yellow oval labeled CYC MKT-70 335k 250v. Don’t use them on your tweeter. They sound terrible. Dull and closed in. I’m trying to use parts I have. I would have gone Q4 but didn’t have any. I’m not the fondest of the Daytons but I had some and sounded leaps and bounds better than those little CYC things.
While I’m being all subjective, my mid hp cap is 20uf. I ended up choosing a pair of parallel 10uf old yellow Madisound buyout caps over the Solen. The stage was bigger and imaging was better with the solen, but they kinda sounded meh so I swapped in the yellow mads and things were much more alive (probably too forward to a critical ear) but the stage suffered. The mads made me happier so they stay.
Soldered up the crossovers and wired them. The mid/tweeter crossover is external, with an external cord to the terminal cup. The woofer crossover lump just gets glued in the woofer box. Someday when I feel like it I will haul them back outside to clean up some cosmetic issues and punch a hole in them for ports. Other than that they are pretty much done. Maybe one day I’ll order a better tweeter cap (these Dayton’s are polyester). That about wraps them up.
I had to add some parts, so not so simple anymore. They had no highs, and measurements confirmed they were rolling off at 10k. The only thing I can figure is the shallow roll off of the open backed mid was cancelling the tweeter once they were moved into position closer to walls.
I upped the mid low pass one electrical order with an 8uf cap and added 2 ohms out front. I upped the tweeter to third order electrical, 2.2uf-.17mH-4uf. And added 3 ohms out front. It dialed them in nicely. I don’t want to say they sound great because I built them and am biased of course, but I will say that I am very pleased with them. I will also say that HiVi planar is a special tweeter; Very nice all around.
Comments
I see in your pic the speaker is actually up a bit off the floor, how about a pillow (diffuser/absorber) under/forward of the front end?
1) John you are right about two woofers being too much for the TC9s
2) when you think your ears are broken and you are about to find a new hobby, do a listening distance measurement and find that HiVi has your tweeter polarity marked backwards!
Just an update on these (not that anybody was losing sleep over them
https://diy.midwestaudio.club/discussion/1246/new-diy-woofer-with-diy-titanium-vc
Brad (Hifiside) is the master of driver building/rebuilding and got me interested in it. Fun spinoff of the hobby!
Anywho.. im in the final stretch. Right now I am just running the woofer sealed. It sounds very nice but I think would disappoint as a party speaker or in a big room. Porting it would be a different story. I will probably pop a port in back that can just be plugged. The enclosure size is optimum for ported but works just fine sealed. The woofer is content either way. Mid bass sounds very nice and clean with the woofer hugging the floor.
I am running a very simple crossover, seven parts in all. I had an earlier version with twice the parts, but the vertical off axis sucks either way being an mtm, so I went simple.
While I’m being all subjective, my mid hp cap is 20uf. I ended up choosing a pair of parallel 10uf old yellow Madisound buyout caps over the Solen. The stage was bigger and imaging was better with the solen, but they kinda sounded meh so I swapped in the yellow mads and things were much more alive (probably too forward to a critical ear) but the stage suffered. The mads made me happier so they stay.
Ignore the floor bounce, that is the measurement from when the woofer was not at floor level.
I upped the mid low pass one electrical order with an 8uf cap and added 2 ohms out front. I upped the tweeter to third order electrical, 2.2uf-.17mH-4uf. And added 3 ohms out front. It dialed them in nicely. I don’t want to say they sound great because I built them and am biased of course, but I will say that I am very pleased with them. I will also say that HiVi planar is a special tweeter; Very nice all around.
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