[Skott2772]

Hi, I'm new to OB's and I am not hot on the physics and maths surrounding which drivers will and won't work in OB's

I am looking at adding a bass unit to my Visaton B200 and the Eminence Alpha 15a seems to be the one of choice.

However I happen to have four Kef B200's SP1014's from an old pair of Linn Sara Isobariks.

Would anyone in the know be able to have a look at the spec sheet and tell me if these would be suitable as an open baffle bass only, either one or two per speaker.

Many thanks in advance

http://p10hifi.net/TLS/drivers/images/B200_SP1014.gif

[mcgsxr]

The main specs to look at are QTS, FS, and XMAX. 

The KEF B200 has FS of 25 (fine), QTS of. 0.51 (0.7 is ideal, but this can work), and XMAX of 6mm (quarter inch).  This last part (limited XMAX) is less than ideal for a bass driver on OB. 

A good sub often has 4x that. 

So, 2 of those KEF's per side could work, but watch the volume, or you may find you run out of excursion on them with low bass, and higher volume.

Worth a shot, you own them!

[Skott2772]

Many thanks Mark, I think I'll give it a go. As you say, I have them hanging around so no outlay.

What I would like to do is not use a crossover as such just an inductor (or four I assume). I have read that about 1khz is a good point to roll off the bass.

If that is so could you (or others) let me know how I work out what size inductor to use.


Thanks again

Scott

[opnly bafld]

You only need to use 1 inductor for each pair, unless you plan on rolling them off at different frequencies.
I would roll them out much lower since it is only 6 dB/oct.

http://www.diyaudioandvideo.com/Tables/XOver/1stOrder.aspx

Lin

[Skott2772]

Fantastic and thanks for the link Lin

Regards

Scott