I'm simulating the box of the FaitalPro 18xl1600,
it will be used in a 4-way hifi system from 30 to 100hz
this driver has a 176 liter vas and a 32hz fs.
The best result that is
vb = 190 liters
fb = 32hz
f3 = 32.5 hz
is it possible to have the VB greater than or equal to the VAS?
it will be used in a 4-way hifi system from 30 to 100hz
this driver has a 176 liter vas and a 32hz fs.
The best result that is
vb = 190 liters
fb = 32hz
f3 = 32.5 hz
is it possible to have the VB greater than or equal to the VAS?
If Qtc is high it is actually necessary that Vb is bigger than Vas. You should check plots of excursion and thermal power handling too.
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If the qts = .4, then yes, volume of the box is about equal to the speaker's vas.
And you tune to the speaker's fs, which winds up being the f3 of the system.
If qts goes higher, box gets bigger, and you tune below the speaker's fs, and the f3 is below the fs.
And you tune to the speaker's fs, which winds up being the f3 of the system.
If qts goes higher, box gets bigger, and you tune below the speaker's fs, and the f3 is below the fs.
thanks, I learned something else.
i checked the updated data from faitalpro and the vas is different:
vas: 201 liters
fs: 32hz
qts: 0.31
FaitalPRO | Woofer | 18XL1600 (4Ω)
i checked the updated data from faitalpro and the vas is different:
vas: 201 liters
fs: 32hz
qts: 0.31
FaitalPRO | Woofer | 18XL1600 (4Ω)
With Qts around .3 and mounted in an enclosure of Vas, a driver will exhibit a downward slope towards the lower frequencies. This might be just right for use in medium sized rooms because of the room gain.
These PA drivers are intended to be used in enclosures significantly smaller than Vas, with a higher Fb than Fs. They are not sub woofers.
These PA drivers are intended to be used in enclosures significantly smaller than Vas, with a higher Fb than Fs. They are not sub woofers.
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It can be used, but you need a large enclosure and perhaps some equalizing. For hifi subwoofer use, typically drivers are used with lower efficiency (smaller enclosure/more low extension).
With specs like this [and up to a ~0.403 Qts'], the pioneers determined that the optimal box/driver compliance with best transient response [least 'hangover./'boom'], max gain BW is [measured] Vas/1.44 tuned to Fs.
Qts' = Qts + any added series resistance [Rs]: HiFi Loudspeaker Design
[Rs] = 0.5 ohm minimum for wiring, so may be higher if a super small gauge is used as a series resistor
i did not understand well,
to have deeper bass I have to increase the qts
and build a bigger box so that fb = f3 = fs?
if I understand correctly how much must be the qts to build a 230 liter box?
to have deeper bass I have to increase the qts
and build a bigger box so that fb = f3 = fs?
if I understand correctly how much must be the qts to build a 230 liter box?
Not 'deeper' [lower in frequency] bass since this is a function of net box size [Vb], tuning [Fb], but 'deeper' in that it will have a flatter response to a lower [F3].
Why 230 L? Vas = 201 L and per my preferred basic vented box design a T/S max flat vented alignment is when Vb = Vas, Fb = Fs when Qts' = 0.403: Margolis-Small's HP 67/97 & 41C calculator program: AES E-Library » Personal Calculator Programs for Approximate Vented-Box and Closed-Box Loudspeaker System Design
Net volume [Vb] [L] = 20*Vas*Qts'^3.3
Box tuning [Fb] [Hz] = 0.42*Fs*Qts'^-0.96
Solving for a high enough Qts' to 'fill up' a Vb > Vas box:
Qts' = 0.403412*230^0.303/201^0.303 = ~0.4202
In short, for 230 L net, add enough series resistance to increase Qts' to ~0.4202; otherwise recalculate for a Vb = Vas, Fb = Fs
That said; if this woofer is driven regularly at enough power [HT and/or pipe organ] to cause its effective motor strength to weaken [increasing Qts'/lowering BL], then better overall not adding any extra series resistance.
Why 230 L? Vas = 201 L and per my preferred basic vented box design a T/S max flat vented alignment is when Vb = Vas, Fb = Fs when Qts' = 0.403: Margolis-Small's HP 67/97 & 41C calculator program: AES E-Library » Personal Calculator Programs for Approximate Vented-Box and Closed-Box Loudspeaker System Design
Net volume [Vb] [L] = 20*Vas*Qts'^3.3
Box tuning [Fb] [Hz] = 0.42*Fs*Qts'^-0.96
Solving for a high enough Qts' to 'fill up' a Vb > Vas box:
Qts' = 0.403412*230^0.303/201^0.303 = ~0.4202
In short, for 230 L net, add enough series resistance to increase Qts' to ~0.4202; otherwise recalculate for a Vb = Vas, Fb = Fs
That said; if this woofer is driven regularly at enough power [HT and/or pipe organ] to cause its effective motor strength to weaken [increasing Qts'/lowering BL], then better overall not adding any extra series resistance.
See what I mean? With this lowish Qt, having Vb=Vas will lead to a down sloping response towards the low end. This might need to be equalized. Adding a series resistor would also work but I would regard that as a dirty solution.
With a different driver and the same volume, you can go below 20 Hz for living room use. Just not with professional drivers because they are high efficiency.
With a different driver and the same volume, you can go below 20 Hz for living room use. Just not with professional drivers because they are high efficiency.
i will use a dcx2496 as a crossover and dsp.
I think I will easily be able to achieve good linearity in the room.
Also I will have 126db to use in various ways, like a party
I think I will easily be able to achieve good linearity in the room.
Also I will have 126db to use in various ways, like a party
Right, it's sometimes called an extended bass shelf [EBS] alignment for better integration in room, particularly when the speaker is near/at a wall boundary or corner, though technically it requires a 0.62 Qts' IIRC.
Yes, originally for factoring in a low DF tube amp's output impedance, then later replaced with a pot and/or a fixed resistor somewhere in the signal chain for high DF amps, though now with relatively inexpensive DSP it's the best overall choice if the amp doesn't need to be preloaded, such as when a high power amp is used in a high enough efficiency system that it normally operates down in its non-linear [noise floor] BW.
I'm not one for a bass shelf.
Running my 6th order without 6db boost at tuning, using qts .3 and fs 27hz, theoretically f9 of 27hz, f3 may have been 55hz, i can't remember.
Very very lean.
Using a receiver that i could boost 40hz (equalizer even on subwoofer), sounds amazing.
Ported f3 of 27hz is plenty deep and quick for me.
Still wanting to try sealed f3 of 30hz.
Running my 6th order without 6db boost at tuning, using qts .3 and fs 27hz, theoretically f9 of 27hz, f3 may have been 55hz, i can't remember.
Very very lean.
Using a receiver that i could boost 40hz (equalizer even on subwoofer), sounds amazing.
Ported f3 of 27hz is plenty deep and quick for me.
Still wanting to try sealed f3 of 30hz.