What enclosure type for this cheap trick driver?

[Ibex]

Cheers!
I've got a punch of these low price 5" bass drivers and I want to design a suitable sub for these cheap woofers.
Do you have any recommendations for me referring to the enclosure type to get a serious low end out of these 5"?

Here are the TSP:

fs = 72,6 Hz
Re = 7,5 Ohm
Qes = 0,41
Qms = 2,37
Qts = 0,35
Vas = 5,25 L
Cms = 0,47 mm/N
Mms = 10,13 g
Sd = 88 cm²
BxL = 9,2 N/A
Rms = 1,9 kg/s
Le = 1,77 mH

I was thinking of some type of bose 8th order bandpass style would do the job, but I would prefer something hornloaded ( i.e. TH/RLH or compound horn style).
Thx in advance for your help!
gzg

[chris661]

Horn loading might work (not my area of expertise), but a sealed box with eq would work, especially if you have a lot of the drivers. What are the size limitations?

[zobsky]

Here's a tapped horn design, and tweak in horn resp as desired. The throat size is too small, so my suggestion would be to use a multiple of drivers (say 2), and increase all the cross sectional areas by that number.


I don't know what X max is but I managed to drag response down to 40 Hz (about an octave below driver Fs) where you're Xmax limited to 5 watt input per driver . SPL at that point is about 105 - 110 db, with room gain flattening out the response.

[GM]

Originally Posted by Ibex

Do you have any recommendations for me referring to the enclosure type to get a serious low end out of these 5"?

Greets!

It will take ten drivers to = a 15", though with only 2-3 mm of usable excursion at best and with a ~15 Hz low cutoff capability (FL) you'll have to define 'serious' to see if you have enough drivers to go low with any authority.

GM

[Ibex]

Thank you for your replies!
Of course, my intension was to use multiple drivers in a single enclosure, let's say about 8 pieces. I was thinking of an push-pull arrangement as well, like in danley's DTS-10, to avoid linear harmonic distortion caused by the motor and to get a better cone control due to less excursion.
To get the smallest excursion as possible I thought a TH design would be the best choice. What do you think?
Unfortunately I don't know the Xmax of the driver and I realy don't know what the driver is capable to do. Power ratings are 90W continous/180W programm.

What about these bose type woofers in the acoustimas sub modul? I always thought that they are small and offer a small Xmax as well or am I wrong?
That's why I first was thinking to suit my 5" drivers in a bose style bandpass enclosure... would you disadvise me to design something similar?

Size limitations of the whole enclosure would be about ~500L brutto.

[Dr.EM]

In that case, that tapped horn scaled to utilise 8 drivers might be nice

[tb46]

Here is a tapped horn with throat chamber coupled to horn.

[Ibex]

Wow, the TH design looks quiet good!

I got the chance to take measurements of the voice coil and the pole plate to caculate the linear excursion of the driver. Here you are:

Magnetic Gap Depth = 5.25mm
Voice Coile Winding Depth = 10.5mm

I would assume that Xmax would be 2.5mm in one direction...?

Would be interesting to see where the output of the TH is limited by the excursion.

[Ibex]

Originally Posted by tb46

Here is a tapped horn with throat chamber coupled to horn.

why did you implement a chamber between the driver and the throat?
is there a reason to port the chamber with an offset into the horn and not at the beginning of the TH?

[tb46]

Hi Ibex,

I added the throat chamber as an option, and to minimize the L12 distance. Shortening L12 strongly affects the impulse response. Without knowing the rough external dimensions desired this looked like a reasonable first stab at a simulation.

As to the Xmax, even if you add half the gap depth you don't come anywhere close to what you would like to see in a driver build for subwoofer duty (see Post #4 by GM).

Regards,