Can i use Scanspeak 18S/8531 and 18W/8531 together in the same speaker?

[s3tup]

The only difference i see between these two drivers are as follows:

    18W  18S
BL  6.8  6.4
Qes 0.39 0.44
Qts 0.36 0.4

Thougth, the Qms remains the same for both drivers (5.1). Frequency response seems the same.

Looks like the only difference is in the magnet system. I wonder what would happen if i'll remove the shielding magnet off the 18S driver? Would it become 18W?


I already have a pair of non-shilded 18W, and want to use two midbasses per speaker so i'd like to modify the 18S to make it become 18W.


Thanks!

 

[Moondog55]

If nobody else wants to answer this ; I'll give you my opinion.

if this is for a sealed box 2.5 way and one of these drivers is going to use a first order cut down as low as practicable, the do your box calculations and use the appropriate box size for each driver, and I would use the woofer with the higher "Q" as the low boost woofer.

I have no idea if you want to use a ported box

 

[rabbitz]

The individual values are not as important as the ratios Fs/Qts and Vas x Fs² and if they are close then it's fine. You usually find more variation (10% or so) in manufacturing tolerances of driver to driver.

Model both in the same size box and tuning and you will find they wouldn't vary more than about 0.5dB-1dB. Don't go by the optimum calculated size for both as that could vary significantly. You are interested in their performance in the same conditions.... volume and tuning.

If they are for a 2.5 way, then use the 18S as the 0.5 woofer. For an MTM you are better off with the same drivers but I doubt you would hear a difference unless you had golden ears.

Don't try and remove the shielding and no it wouldn't make it a 18W.

 

[Jimmy154]

How would one remove the shielding off of a 15S?

I read recently how some one removed the shielding off of a 18S, but I can't find the thread now.

I have 26 spare neodymium magnets I want to symmetrically place on the back of each driver, around the vent that comes out the back. Is this a bad idea, lol

I have a 15S/8530K01, I want to use as a midrange, so I want to make the BL a little higher so it might approach the BL/performance 15W/8530K00 model.

I been thinking and I have come to the conclusion that this is a really bad idea due to the nature of magnetic fields. Can't believe I overlooked it earlier.