12" woofer with ff85k

[murphythecat8]

Look at Beyma 12b70 or the other 12inch would do.
AE is another option I never heard though

[SpirosZ]

I was looking for something similar a few days ago but I remember than none of the 12" woofers I could find could excite me enough to go that route. That's why I had decided to go with an 8"woofer or a 10" at max.
I checked again and the only one that looked at least descent in that price range was the ESS 689-1220 which looks like a quality build and WinISD reports a Qtc of 0.9 in your enclosure sealed with a 40Hz f3. It has 91.5db sensitivity but it is 4ohms so make sure your amp can handle it nicely (that could be a problem with tubes).
Since your box is ported perhaps some light port stuffing will turn it to a sort of aperiodic box and lower the Qtc a bit. (just a wild guess I could be wrong)

[talaerts]

Not sure if it is a really good idea, vut the fostex ff225wk seems interesting. It will have similar looks and some tonality resemblce. I also offers decent bass (i heard it) and is so widerange that you could try many crossover points.

[SpirosZ]

Originally Posted by talaerts

Not sure if it is a really good idea, vut the fostex ff225wk seems interesting. It will have similar looks and some tonality resemblce. I also offers decent bass (i heard it) and is so widerange that you could try many crossover points.

There are many good options for a 8"-10" midbass. I don't think the FF225 is an optimal choice though.
Having said that perhaps a 10" (easy to fit with an adapter baffle) would be a better choice than a 12" at that price range.

[tinitus]

I supppose you first and most need a woofer with appropriate SPL to match your fullrange driver, and with enough 'headroom' to do the BSC thing
and not forget it should ofcourse have decent bass

I would be tempted to try the 'famous' Seas Prestice A26RE4

[SpirosZ]

Originally Posted by tinitus

I supppose you first and most need a woofer with appropriate SPL to match your fullrange driver, and with enough 'headroom' to do the BSC thing
and not forget it should ofcourse have decent bass

My understanding is that one needs a midbass with higher sensitivity than the full range driver so there is no need for BSC circuit.
My guesstimate was around 3db (or more) higher at the midbass frequencies (not the stated SPL which could be at higher frequencies) but that like I already said is just a guesstimate.
Do you (or anyone else) know what sensitivity one should look for to match the ff85wk without the need for a BSC circuit?

[tinitus]

depends
if your woofer have very good low bass, you might get away with less BSC
also consider that the little Fostex fullrange may not be for playing very loud
so you need a woofer that 'comes alive' at moderate SPL, but may not need the higher SPL 'control'

[wicked1]

Thanks everyone again.. all the conversation is helping fill in the blanks in my speaker knowledge.
I have noticed all the affordable "woofers" are wide range PA speakers. Maybe I should increase my budget to 300 per driver.. then plan on getting nice true woofer drivers that I re-use in a different cabinet some day.
The adapter and 10" isn't a bad idea either.. but opens up too many new options .

Any parameters I should be focusing on, other than the db/w/m and frequency? I guess my build isn't anything too unique or specific.. Nice sized box, can leave the port or seal it, don't need a huge frequency range, etc.....

Tinitus makes a good point, in that most of the listening will be moderate SPL.. It'll get loud occasionally, but those will be times I'm not critical of sound quality.

Ok, one real question.... Am I on the right track with wanting to stick to a simple first order filter? I realize the inductor for the woofer will be large and expensive. I'm coming from a low wattage SET background (as far as my hi-fi experience) so still always have the idea of a very simple signal path in mind.

Someone mentioned 4 ohm drivers, and my transformer does have 4 ohm taps. But then I'm confused about the final impedence of the whole speaker.. that isn't going to be an even 4, 8, or 16. (yep.. more reading to do)

[tuxedocivic]

Originally Posted by planet10

The Q on the alphas is suitable for OB. I'd personally not consider them anywhere else.

I just had a closer look, wow, ya, that thing doesn't quite work thanks for catching that. I've used the 8" and figured it would be along the same lines.

Anyways, given what you've now said about budget and such, how about this guy: The Madisound Speaker Store

Stuff the cabinet well and it'll be pretty much a sealed box, but lots of extention. About the right sensitivity match.

[tuxedocivic]

Oh and, you could do a 1st order cross over. I have my reasons for using second order, but a lot of people do first order. A second order will have better phase tracking, suppress woofer break up better, reduce excursion on the full range better, less driver interference in the high frequencies. But the first order is cheaper, easier, and less phase rotation. There may be other pros and cons, I'm just thinking off the top of my head.