Mounting a Fostex FF 165 WK inside a cabinet

[Vincent79]

Hello,

I am currently working on a replica of an 1980's boombox. I'd like to use a couple of Fostex FF 165 WK drivers for this.

Design is of paramount importance, and I'd like to integrate the speakers as much as possible in the object.

My question: can the red parts (cf. image attached) be hidden behind (and in contact with) a wood panel? Or do they absolutely have to be visible?

Any input on this point would be very appreciated, thanks very much!

Vincent

 

[planet10]

When mounting from behind the cutout needs only be large enuff to leave the surround visible.

dave

 

[Cal Weldon]

The answer is yes, it can be hidden but do not encroach into the black (surround) as dave has mentioned.

 

[Vincent79]

Many thanks Dave.

As a follow up, would you expect noticeable degradation in sound quality if they're hidden (but have a couple of millimeters to move)?

 

[planet10]

The hole would need to be beveled so that the citout does not produce a resonant cavity.

dave

 

[Vincent79]

Thank you both for your input. Will leave apparent only the first surround, and hide the 2nd and 3rd one under the front cover. They'll have 3/4 mm of space to move.

 

[planet10]

Will leave apparent only the first surround, and hide the 2nd and 3rd one under the front cover.

There is only 1 surround. The part that flexes is the bit that needs to be revealed.

dave

 

[chrisb]

No doubt they'd work just fine, and to be frank the benchmark of "80's boombox" isn't all that lofty a goal in terms of the sonic performance to which many of us would aspire for a home system, but I don't think this series of drivers is particularly well designed for rear mounting.

If by "second surround" you're referring to the raised plastic (diffraction?) ring, I'd be inclined to size ID of the through-hole to nest outside of that ring. Otherwise l think you'd risk either bending the rather thin stamped flange when tightening the mounting screws, or not completely sealing around the driver.

Another concern would be that by the time you bevel or radius the front side of through hole sufficiently to mitigate edge diffraction / resonance, there may not be enough core material (assuming nominal 3/4" thickness) to use much longer than 1/2" screws in the mounting screw holes. You might need to use something like 2 large fender washers & screws mounted outside each of the pincushion frames' corners.

(grammarians awake - I proffer something different for your bloviation / delight - what is the proper spelling and use of apostrophe in the last sentence above? 🙄)

 

[Vincent79]

Thank you Chris for your message.

If you (or any forum members) have suggestions for rear mounted drivers, feel free to share them. They do not have to be full range, as I could easily add a couple of tweeters to the boombox.

Fostex seem to do the job but are 1/ expensive and 2/ not adapted for rear mounting as you pointed out, so I am willing to explore alternative options at this stage.

 

[Cal Weldon]

<snip> outside each of the frame's pincushion corners. 🙂

Hey mister, how come you have time for the forum? I thought you were busy building speakers. 😉

 

[planet10]

If by "second surround" you're referring to the raised plastic (diffraction?) ring, I'd be inclined to size ID of the through-hole to nest outside of that ring.

I'd be inclined to rebate the inside so that the decorative ring fits into the rebate, allowing the frame to lie directly on the back of the baffle with the cut out starting on the outer edge of the surround.

dave