Hello, I need help choosing a housing for this speaker 18 inch, the parameters are in the photo below. I want it to be a very efficient design and tune around 35 Hz. I don't want it to be a folded horn design.
High Q, not going to work well vented, it will need to be big sealed.
Do you already have this/these woofers?
dave
Do you already have this/these woofers?
dave
That will likely not work at all well.
Scoops are typically too-short a horn so don’t go low.
Likely best bet is sealed with EQ. And a big amplifier.
And with 2 do you build one with plush-push woofers or 2 woofers. Be nice if you had 4.
dave
Scoops are typically too-short a horn so don’t go low.
Likely best bet is sealed with EQ. And a big amplifier.
And with 2 do you build one with plush-push woofers or 2 woofers. Be nice if you had 4.
dave
A big vent reflex. The driv er does not need bass reinforcement, it needs excess bass taken away.
Ideal box Q for a woofer is 0.5-0.707. Putting a driver in a sealed box always goes up from its Qt of the driver.
The smallest reasonably useably box is sealed, 200+ litres/Q ≈1.0. It does reach into the mid20s F10. Any horn that does not increase the bass above ideal a significant amount will be much, much larger. If doable at all.
Any reflex is also going to elevate the bass. I did sim a 400 litre box tuned to 12Hz, it did get a bit better, but not much, and giving the cost, difficulty/complexity, size i would judge not worthwhile.
With this kind of woofer, one has 3 sensible options.
1/ mount it in the wall and use the next room as a box.
2/ as large a box as you can live with and make it aperiodic
3/ put in a smallish sealed box (100 litres?) and EQ it. If you have EQ it could be OB as well.
dave
Ideal box Q for a woofer is 0.5-0.707. Putting a driver in a sealed box always goes up from its Qt of the driver.
The smallest reasonably useably box is sealed, 200+ litres/Q ≈1.0. It does reach into the mid20s F10. Any horn that does not increase the bass above ideal a significant amount will be much, much larger. If doable at all.
Any reflex is also going to elevate the bass. I did sim a 400 litre box tuned to 12Hz, it did get a bit better, but not much, and giving the cost, difficulty/complexity, size i would judge not worthwhile.
With this kind of woofer, one has 3 sensible options.
1/ mount it in the wall and use the next room as a box.
2/ as large a box as you can live with and make it aperiodic
3/ put in a smallish sealed box (100 litres?) and EQ it. If you have EQ it could be OB as well.
dave
Likely more suitable for a horn or a reflex but the really low Q will limit the potential bass extension.
dave
dave
Driver brand/model for my records?
Hmm, for a parabolic compression BLH: fhm = ~2*Fs/Qes = ~94.2 Hz upper loading BW, Fb = ~0.42*Fs*Qes^-0.96 = ~19.7 Hz, so could be tuned higher (under-damped), so ideally will require some form of damping (DSP nowadays). Vb = 20*Vas*Qes^3.3 = ~1556 L and using Fb = 35 Hz, then a' = (Fb*Qes)/Fs = 0.743, Vb = Vas/a' = ~172.3 L
HR calcs a ~752 L, ~44 - 94 Hz/101.5 dB/w/m
Hmm, for a parabolic compression BLH: fhm = ~2*Fs/Qes = ~94.2 Hz upper loading BW, Fb = ~0.42*Fs*Qes^-0.96 = ~19.7 Hz, so could be tuned higher (under-damped), so ideally will require some form of damping (DSP nowadays). Vb = 20*Vas*Qes^3.3 = ~1556 L and using Fb = 35 Hz, then a' = (Fb*Qes)/Fs = 0.743, Vb = Vas/a' = ~172.3 L
HR calcs a ~752 L, ~44 - 94 Hz/101.5 dB/w/m
