Enclosure for crossed over fostex

[AllenB]

I want to build a box for my Fe108e sigmas that I want to use with my tapped horn sub. I think I'll cross the sub over at 100Hz and I don't think I'll need a horn with the fostexes because of the crossover frequency but I'm not sure. I'm thinking of a small closed box with a suprabaffle. Does it sound OK? How should I cross it over? I can do active or passive if it's best.

[GM]

Originally posted by AllenB

Does it sound OK?

Not really, this driver wants a ~1.1 L sealed cab based on published specs and at minimum an XO point at its F6 around 134 Hz, but it ideally needs a mid-bass/lower mids system filling in between ~500 Hz and a somewhat lower TH XO point (< 80 Hz).

Active is best with low XO points due to high parts cost, insertion losses.

GM

[AllenB]

Thanks GM.

So if I understand, you're saying that without a BLH or something, there will be a loss of sensitivity below 500Hz. Even if I did baffle step compensation, I'd have excursion issues? So I'll have to either use a horn or a different sub?

[GM]

You're welcome!

Right, it starts running out of Xmax, but the main thing is you're asking a ~3" dia. driver to pump out a near 4 ft dia. WL at up to rated power and it just falls apart since it's designed to be a wide BW tweeter. This driver is already dynamic headroom challenged, so you want the TH and filler driver or 108 BLH to be the BSC.

GM

[AllenB]

OK, so it looks like I need a horn that goes up to 500Hz.

One thing, If I make the front baffle big enough for a wavelength at 100Hz, will it mess up the effect of a BLH?

[GM]

You've 'lost' me, please elaborate.

GM

[LilMik]

what about the metronom?

The Metronome

sounds already stunning fullrange . if you use a sub under 100 hz, it even gets better . but you have to use a bsc, that's right.

the 108es, a nice little driver , though not easy to handel.

greetings from germany

[AllenB]

Originally posted by GM
You've 'lost' me, please elaborate.

GM

I'm thinking of doing a frugel-horn and what if I made a suprabaffle that is much bigger than usual that boosts frequencies much lower than 500Hz. This is where the horn would be boosting the response and I don't know what to expect from them both together.

Originally posted by LilMik
what about the metronom?

I looked at that and I like it but I want an enclosure that gives some boost up to 500Hz.

I've listened to this speaker already in a box for another speaker and I really like it and I like the way the highs don't sound harsh and stand out like tweeters sometimes do.

Greetings to you too.

[planet10]

Originally posted by AllenB
I'm thinking of doing a frugel-horn and what if I made a suprabaffle that is much bigger than usual that boosts frequencies much lower than 500Hz. This is where the horn would be boosting the response and I don't know what to expect from them both together.

Ron chose the supraBaffle size specifically to meet the gain from the horn.

dave

[AllenB]

Oh, I'll leave it as it is see how I go. I've been reading good things about the frugalhorn.

Also some don't agree but I think they have WAF. Hopefully if I veneer them well they'll take the focus off my TH