Enclosure for FE207e and AN Super 8 CF Comparison

[edjosh23]

Fellas,

So I haven't done woodwork in months and am itching to hear some of the drivers that I have and never listened to. I was given a pair of AN Super 8 Cast Frame drivers and a pair of FE207e.

I would like to build a single pair of enclosures that I can use for both drivers so I can have an apple to apple comparison.

Any suggestions for enclosures? I was thinking an MLTL...

Thanks,

Josh

[planet10]

If the AN specs are even close i don't think you will find 1 enclosure that is even a good compromise for both.

dave

[edjosh23]

My original plan was to try MJK's 206/207 Project, but my understanding is that that was originally designed for Lowthers, which have an even lower VAS than the Fostex.

I also thought about the Half Chang, but decided that may not be the best idea either.

I did find an old post Scott made:

Originally Posted by Scottmoose

Hmm. Assuming the published specs. are accurate (dubious) the AN isn't ideal for this kind of load without some form of correction as it's a very low Q unit. However, there are ways around that.

HC is a bit small for it. Here's an MLTL though: 54in tall, 82.5in^2 CSA, 3in diameter x 1in long vent 2in up from the base. Driver-centre (Zdriver) 19.125in down from the top. Line top, back & one sidewall with 1in acoustic fiberglass or similar & adjust to taste from there. Dimensions all internal. FR plot assumes 5ohms of series resistance added; depending on where they're positioned & what your amplifier is, you might be able to get away with less or none. There are plenty of other MLTL options / sizes etc too of course.

I know somewhere out there are measurements for some AN driver(s), but I couldn't find them. I would like to see what parameters are different and was thinking if perhaps Audio Nirvana would sway the same parameters in the same direction...... man do i need to be able to test drivers.

Dave,
I'm sure you've got a suggestion for me.

Josh

[Scottmoose]

It's apples & oranges. They're two different drivers, with very different specs., which nominally at least means intended for different purposes (although the CSA site might suggest otherwise... ) A closer comparison would be the AN & FE206E; comparing to the 207 wouldn't tell you a whole lot that you couldn't already tell from a basic FR / impedance graph.

[Godzilla]

These BIBs are close but not exact. Maybe a compromise between the two will work ‘well’ for both. Just a suggestion, build a BIB with a line of 176 (88” tall) x 10.5 x 14. It’s a little bit big for the Fostex and a little bit small for the AN… I think it will sound very good with either once stuffed. Or build the smaller Fostex BIB and use a circuit on the AN… it probably needs one anyway.
Godzilla

http://www.zillaaudio.com/bigger_is_...iioNirvana.asp

http://www.zillaaudio.com/bigger_is_...bib-fostex.asp

Fostex FE207E
L = (Line length) 174"
Zdriver = Driver 35" down from sealed end of cabinet
Sm = 133.875"^2
*Frequency response below is for this BIB

Audio Nirvana Super 8
L = (Line length) 180"
Zdriver = Driver 36" down from sealed end of cabinet
Sm = 168"^2

[edjosh23]

Godzilla,

I like that idea. When I was in class I started to draw everything and then realized that this was 7'-4"... too big for me.

So I modelled the Fostex in Scottmoose's MLTL and it looks to perform pretty well.

Josh

[InclinedPlane]

Are your drivers 'broken in'? I listened to my AN drivers for, uh well, like 4-5 months and then one day they sounded different (and better). If your 207 and AN aren't, run them for a few hundred hours first. But as others have said, it may not be the best comparison. Try the 206 instead. But I'm biased. The AN is a much better driver.

[edjosh23]

InclinedPlane,

I have heard neither driver. Both pairs were given to my by an audio dealer in Atlanta. He was trying to get into the whole fullrange idea... it never stuck. He had the 207s in a BR, similar the the 167 BR (with the port in the stand) and he heard about the Audio Nirvana drivers so he bought the Super 8 Cast Frame and tried those in the same enclosure (He sells, not builds). He is a friend of mine and was very generous and gave me all 4 drivers. Both sets of drivers have been broken in under his watch for many hundreds of hours, I'm sure the suspension has tightened up since it has likely been a while since they have had any play.

Josh

[edjosh23]

I started work today, got 2 sheets of 3/4" BB. And made all the main cuts. Just need to cut the braces and start with the glue tomorrow.
I did find some very unfortunate news today... the 207 and super 8 have different mounting locations. While the driver cutout is within 1mm from one another, the mounting hole location is >.25". Tomorrow I'm gonna try and work on it and take some pictures. I'm very excited to hear these drivers, but i don't know what to do about comparing them.

Does anyone have a good idea on how I can test each driver in the cabinet without making 2 sets of mounting holes. Is temporarily mounting a baffle acceptable?

With the extra wood and the bit that I found in my shed, I may be able to make another enclosure for the 207 without buying any more wood.

Josh

[planet10]

Either have 2 sub-baffles, or use a clamping mechanism that puts the mounting bolts outside the frame.

dave