That is pretty ugly and will sound terrible nearfield and close to a wall, more like a one note bass that you hear from those sub-woofered cars, doof-doof.
A better option will be sealed, or aperiodic loading.
Trying to follow along here XRK, you say in the text the FF85WK but your XO schematic
shows an RS100-8, picture looks like the FF85WK - was that just a typo in the schematic?
I've been curious about using the Fountek FE85 in your FAST design with the 8" Dayton,
any chance you've tried it?
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You can use almost any 8ohm impedance full range driver with sensitivity of at least 82.5dB and up. Simply adjust resistors R1 and R2 to level match the output. I have not tried Fountek FE85 but it should work with 85.7dB. That’s 2 dB less sensitive than 10F so I would think R1 at 2.2ohms and R2 at 8.2ohms should work.
Agreed.
Here is my set of sims. Looks like 13 litres is close to optimum. The higher tuned version requires a high aspect ratio slot vent to deal with the slight peaking. A regular cyrindrical vent for the other. Even does a decent job sealed if you can take advantage of room gain.
With your larger box you may want to damp the vent and push it towards aperiodic.
dave
Attachments
Jeff's image was of my tuning for the prototype box where I used the T/S for the 8ohm version on accident.
What I'm getting now looks close to what Dave just posted.
I'm going to try a 13L vented box with varying degrees of stuffing and take some measurements.
What I'm getting now looks close to what Dave just posted.
I'm going to try a 13L vented box with varying degrees of stuffing and take some measurements.
What closed box resonant frequency (Fc) do you design for with say the 10F or in general?
It’s not important as I cross at 600Hz to 900Hz. But generally 1.5L in a Dagger (3 to 5 sided tall pyramid circa 10in to 12in deep is good. The Dagger has very low coloration.
New enclosure plan 14.5L volume minus bracing and stuffing should be about 13L.
1L sealed enclosure for the FF85WK. Dotted blue lines are internal bracing and enclosure for the Fostex, dotted pink for 1/2" roundover on the baffle at port holes, solid green internal port length. Measurements are in inches because I don't have a long enough metric ruler for cutting the foamboard.
I'm going to build a foam board version for measurements once the nice weather ends in a few days, and try to cycle as much as I can in my spare time until then.
1L sealed enclosure for the FF85WK. Dotted blue lines are internal bracing and enclosure for the Fostex, dotted pink for 1/2" roundover on the baffle at port holes, solid green internal port length. Measurements are in inches because I don't have a long enough metric ruler for cutting the foamboard.
I'm going to build a foam board version for measurements once the nice weather ends in a few days, and try to cycle as much as I can in my spare time until then.
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I'm thinking about doing an FE85 version with a MiniDSP crossover and the 4 ohm version
of the woofer. Are the design equations explained anywhere? I can reverse engineer this
but equations would be easier.
Nice thing about the MiniDSP is that it should be easy to do a B6 alignment for the woofer.
FR58EX looks good also but the sensitivity is rather low, not a problem with active XO.
FR59EXE is 4 ohm and higher sensitivity, looks good but currently out of stock at PE.
FR59EXE is 4 ohm and higher sensitivity, looks good but currently out of stock at PE.
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