I chose "A". No, just kidding. I went with "C". Not a gazilion off axis spin-o-rama measurements. Just enough to say "yeah, this is a project that should move forward".
Since it's impossible to get accurate measurements under about 400 Hz in my room I'm going to have to use some educated guesses, then correct by ear. Should work out well in the end.
Worked on simulating a crossover at lunch today. I have something that looks like it should be worthy of building a prototype. 2nd order LR slopes on both xo points. Excellent phase tracking. Impedance drops to 3 ohms in one spot arounf 700 Hz but the impedance phase angle throughout is super benign. Don't think any of my amps will have an issue driving these.
The crossover points kind of surprised me though. W-M is higher than I expected at 650 Hz and M-T is lower at 2.2 kHz. Probably will be ok. These won't be high SPL, ground pounding speakers. If I end up liking how they sound I might build an upgraded pair with bigger/better woofers. There is a lot of padding on both the mids and the tweeters.
Looking at my sim I am throwing away so much mid output with padding resistors. I might try disconnecting the top mid and remeasure everything. Could make for a simpler project and maybe a higher impedance. Fun project for me so far.
@PWRRYD said:
Looking at my sim I am throwing away so much mid output with padding resistors. I might try disconnecting the top mid and remeasure everything. Could make for a simpler project and maybe a higher impedance. Fun project for me so far.
Long shot idea here> play with the lower mid as a .5 way vs padding both mids ????
I'm just curious, but how did you take measurements and design a crossover for an omni-directional speaker?
Could it be the same as a 'normal' front facing design with the same drivers, but then, 'off axis' measurements would be different for the woofer because it doesn't really have 'axes'?
As I have only a very basic understanding of crossovers and design, this project got me thinking!
Thanks, and good luck with this project: perhaps you could have another naming competition here as per the Tre Stemmes?
What about something like this: very expensive in Oz and the cabinets look a real nightmare to make. Interesting that unlike Visaton's other kits, there's no supplied FR graph. Is that because the response would be impossible to measure?
My trying to make cabinets fancy means I make cabinets every 10 years - if I keep them functional I get one set per year out of my efforts and a lot more experimentation done . . .
Oof, I have yet to muster up the gumption to try a standard 90deg miter on a box let alone doing it 8x on one enclosure. Then the glueup I'm envisioning something similar to herding cats.
Visaton's kits give you the cabinet layout and cut list, provide the driver details and supply the crossover schematic. I should load the drivers and crossover into Xsim and see what that looks like. I know it will be traced on data and not measurements but will be interested to see the results.
I haven't. I have used these TC9FD's before (a single per side) OB and like them best almost nude, ie as narrow of a baffle as possible. I think the omni GF180-4 can make this work. I'm making a second MTM baffle tonight/tomorrow so I can actually listen to a pair and decide. I have high hopes... but if it doesn't work out it was low dollars lost in wood. That said, if this experiment sounds good/great I might ratchet it up to the next level with bigger and better woofers. Current measurements are a green light. Ears will tell the truth.
Comments
Complete with Zobels and L-pads
I have the house to myself this afternoon for a few hours. And it's raining. Should I:
A - Sit on the couch and watch the NASCAR race?
B - Sit on the couch and watch the Cowboys get beat by the Falcons?
C - Take some woop woop measurements?
Hmmmm?
C señor
I've been woop wooping since 1:00. Just about done.
C , go C
I chose "A". No, just kidding. I went with "C". Not a gazilion off axis spin-o-rama measurements. Just enough to say "yeah, this is a project that should move forward".
Since it's impossible to get accurate measurements under about 400 Hz in my room I'm going to have to use some educated guesses, then correct by ear. Should work out well in the end.
I am hoping that you try listening to the open baffle part by itself...
I have. Those TC9FD's sound really clear and completely awesome OB. They just don't have anything home below about 300 or 400 Hz.
Which for mids - works
Worked on simulating a crossover at lunch today. I have something that looks like it should be worthy of building a prototype. 2nd order LR slopes on both xo points. Excellent phase tracking. Impedance drops to 3 ohms in one spot arounf 700 Hz but the impedance phase angle throughout is super benign. Don't think any of my amps will have an issue driving these.
The crossover points kind of surprised me though. W-M is higher than I expected at 650 Hz and M-T is lower at 2.2 kHz. Probably will be ok. These won't be high SPL, ground pounding speakers. If I end up liking how they sound I might build an upgraded pair with bigger/better woofers. There is a lot of padding on both the mids and the tweeters.
Looking at my sim I am throwing away so much mid output with padding resistors. I might try disconnecting the top mid and remeasure everything. Could make for a simpler project and maybe a higher impedance. Fun project for me so far.
Long shot idea here> play with the lower mid as a .5 way vs padding both mids ????
This project looks really cool!
I'm just curious, but how did you take measurements and design a crossover for an omni-directional speaker?
Could it be the same as a 'normal' front facing design with the same drivers, but then, 'off axis' measurements would be different for the woofer because it doesn't really have 'axes'?
As I have only a very basic understanding of crossovers and design, this project got me thinking!
Thanks, and good luck with this project: perhaps you could have another naming competition here as per the Tre Stemmes?
Geoff
Think about it like this....a woofer in a three way is basically Omni anyways.
That makes sense, thanks
What about something like this: very expensive in Oz and the cabinets look a real nightmare to make. Interesting that unlike Visaton's other kits, there's no supplied FR graph. Is that because the response would be impossible to measure?
https://www.soundlabsgroup.com.au/p/V-5937-Fontanella-Sat.html
Geoff
Two way, where you'd require midrange from the woofer, would take standard off axis measurements.
I'd forgo the ^ agony of hexagonal cabinet construction in favor of Sonotube (Concrete pour forms).
What fun is that? I'd take it a step further, hexagonal truncated encloser.😆
Hexagon is not that difficult, just set the angle an rip the boards the same as any other cabinet except there's eight
Go for it, Mr. Skillz!
My trying to make cabinets fancy means I make cabinets every 10 years - if I keep them functional I get one set per year out of my efforts and a lot more experimentation done . . .
Where do you put the spare 2 boards in a hexagon?
I'm guessing that's referring to Nicks miscalculation?😆
...it's early, Nick, we understand.
Oof, I have yet to muster up the gumption to try a standard 90deg miter on a box let alone doing it 8x on one enclosure. Then the glueup I'm envisioning something similar to herding cats.
You need a baffle and a back, right?
Those cabinets look octagonal to me.
They are actually octagons. I hate typing, so my posts are usually brief and not always completely explained.
Visaton's kits give you the cabinet layout and cut list, provide the driver details and supply the crossover schematic. I should load the drivers and crossover into Xsim and see what that looks like. I know it will be traced on data and not measurements but will be interested to see the results.
Apologies, I didn't want to derail the thread
Geoff
@PWRRYD any interest in experimenting with side wing/s to get some bottom end back on the tc9?
I haven't. I have used these TC9FD's before (a single per side) OB and like them best almost nude, ie as narrow of a baffle as possible. I think the omni GF180-4 can make this work. I'm making a second MTM baffle tonight/tomorrow so I can actually listen to a pair and decide. I have high hopes... but if it doesn't work out it was low dollars lost in wood. That said, if this experiment sounds good/great I might ratchet it up to the next level with bigger and better woofers. Current measurements are a green light. Ears will tell the truth.