finding the vas value

[polop1]

i have these drivers, FUSION Electronics ? Car and Marine Audio but it does not list the vas value hence simulations do not work properly, is there a way of working it out from the other values given (like compliance) or a rough value that would be suitable for most 6.5 inch drivers, thanks . I am looking to build very small cabinets for them and need to give them ported enclosures to maintain some of the bass. (hence i need to simulate to work out port lengths and stuff)

[PeteMcK]

witha Qts of .7, they are likely to have a large Vas - they will most likely only be suitable for closed boxes.

But if you really want to know, download ARTA:
ARTA ARTA Download
make this simple jig:
ARTA Jig - AudioBlog: A simple loudspeaker measurement jig for ARTA
and measure them...

[polop1]

ok then that is fair enough. i know it has been killed to death, but which drivers would be able to have a small ported enclosure (for max bass for the size) around 3 or 4 inch full range or coax, and the dealbreaker is that any driver would need to be avaliable in the uk without the costomary "twice the value of the item" delivery from the us

[royville]

Hi,
If you go here

Measuring Loudspeaker Driver Parameters

there are two options for finding the Vas parameter.

Regards.

[Ron E]

Originally Posted by polop1

i have these drivers, FUSION Electronics ? Car and Marine Audio but it does not list the vas value hence simulations do not work properly, is there a way of working it out from the other values given (like compliance) or a rough value that would be suitable for most 6.5 inch drivers, thanks . I am looking to build very small cabinets for them and need to give them ported enclosures to maintain some of the bass. (hence i need to simulate to work out port lengths and stuff)

Those parameters are worthless, they don't specify units for the parameters and they don't appear to be consistent with each other.

Here is a complete guess at the parameters from what they have published:
Fs 56.0 Hz
Qts 0.7
Qes 0.77
Vas 13 Liters
Re 3.6 Ohms
Dia 12.3 cm
Xmax 6 mm
Pe_max 70 Watts
Woofer Calculated parameters
Sd 0.01188 m^2
Cms 0.000656 m/N
Mdt 0.0123 kg
Bl 4.50 T*m
no 90.04 dB/2.83V
no 86.57 dB/1W
Qms 7.700

These are not vented box speakers - anything with a Q>0.4 or so is sealed box only unless you want a huge box and probably lots of distortion from overexcursion.

[PeteMcK]

using Ron's numbers in Winisd, I get 35L tuned to 44Hz;
anything smaller will give you a really boomy bass response
as an alternative, maybe something like this: Visaton - Lautsprecher und Zubehör, Loudspeakers and Accessories