Miscellaneous designs - Markaudio, Fostex, TB, Dayton, SEAS etc

I can remember assisting a couple of buddies with cutting materials for the large Fostex/ Nagaoka inspired BLH for the 166/206 a decade or so ago. A $hi-ton of plywood - the number 5 sheets rings a bell- and frankly I found the much simpler Terry Cain Abby to be just as satisfying, certainly more practical in terms of placement* and while aesthetics are entirely subjective, more attractive.

Never got a chance to hear Ron Clarke’s Dallas, but once sorted, the A126 certainly worked very well.
Would Joan be a better candidate from the FH family for the 168. Aiko certainly proved to be a good match for the 108EZ, as did Victor for the 166, so that should be on a short list.

*fridge dolly with chiropractic visit recommended after moving;)
 
Last edited:
I couldn't think of anywhere else to put these, so here it will be: Umbriel and Cressida -two traditionally aligned vented boxes for the Markaudio CHR90 to go alongside the others I've worked up.

The CHR90 doesn't seem to be well-known, but it's based around a slightly trimmed-down Alpair 10.3 cone with new cap, basket, motor etc. so it has many of the latter's characteristics. Goes in slightly narrower boxes too. And yes, in case anybody's wondering, they are indeed named after two of the moons of Uranus, purely because I have a long-standing interest in the Voyager flights, and I felt like calling them something. ;)
 

Attachments

  • Umbriel CHR90 traditional vented box standmount.PNG
    Umbriel CHR90 traditional vented box standmount.PNG
    181.6 KB · Views: 497
  • Cressida CHR90 classic DCR.PNG
    Cressida CHR90 classic DCR.PNG
    69 KB · Views: 494
...and while I'm lurking, one I had half-done a while back, but never finished, for the Tang Band W5-1611SAF.

Depending on room acoustic, this one may require a low-pass shelving filter. I'd personally try without first; assuming a reasonable accuracy to the factory data, it's a moderately damped alignment that should work reasonably near boundaries, which in turn should reduce the perception of losses. So I would try without initially, and if you feel it needs some after a while: that is the time to apply, in a quantity suited to the room positioning.
 

Attachments

  • Sun Bear W5-1611SAF vented box standmount.PNG
    Sun Bear W5-1611SAF vented box standmount.PNG
    468.1 KB · Views: 474
Rats... one I did a month back & forgot about.

Do you iron creases in your jeans? Do you dislike the Lamborghini Countach because it's the most violent looking car ever made? Do you object to The Sensational Alex Harvey Band singing 'Gang Bang'? You're not going to like this at all. :devilr:

I even remembered to remove the MA logo from this sketch... this is what I get for partially recycling 'base' images...:rolleyes: Although they're certainly welcome to it.
 

Attachments

  • CHR90 Vesuvius top-firing vented box.PNG
    CHR90 Vesuvius top-firing vented box.PNG
    353.9 KB · Views: 548
  • Like
Reactions: 1 user
Many many thanks Scott,

Your generosity with your time and expertiese is greatly appreciated. I have built 3 different pairs of single driver speakers to your designs and have been very impressed with all of them. Designing a truly good cabinet for a single driver speaker is not a trivial process (despite what some appear to believe) and your knowledge is, in my opinion is top shelf.

Best,
Jay
 
  • Like
Reactions: 1 user
Rats... one I did a month back & forgot about.

Do you iron creases in your jeans? Do you dislike the Lamborghini Countach because it's the most violent looking car ever made? Do you object to The Sensational Alex Harvey Band singing 'Gang Bang'? You're not going to like this at all. :devilr:

I even remembered to remove the MA logo from this sketch... this is what I get for partially recycling 'base' images...:rolleyes: Although they're certainly welcome to it.
Looking at your requirements, why do you say that you prefer to use fibreglass but not acoustic foam.

Is there a difference in how they absorb?

Oon
 
Absolutely. All damping materials have different coefficients; generally speaking bonded acoustic fibreglass board (usually something like OC-703) for a given thickness is significantly superior to most foams, and was one of the traditionally favoured options by the pioneers, as 'somebody' taught me. As such, it's my 'default' for an efficient, reasonably-priced lagging material. If you're bothered about lose fibres, which to be honest doesn't seem to be an issue in practice, you could always stretch some fine material over the vent. A natural fibre equivalent is something like SAE-F10 rated wool felt, jute underlay or similar.
 
Last edited:
Hi Scott,

I will be building the Sun Bear cabinet for the Tang Band W5 1611 SAF in the next few days. The design calls for a double layer of the 1/2" jute on the bottom panel.
I have a couple of questions. I use 3M medium strength spray adhesive to adhere the jute to the walls in all of my speaker builds and wonder if using it to glue together two layers to get the required thickness for the bottom panel will block the necessary porosity of the double layer. Should I instead use tacks? Also, out ot curiosity, what is the design reason for the double layer on the bottom?

Best,
Jay
 
Since it's at the bottom, frankly I would rely on ye olde faithful standby called 'gravity' and not worry about it. ;) If you want to put a light spray of the adhesive between the two layers, it won't do any harm. You can increase the thickness of the damping out to 20mm or even 25mm providing you keep it away from the cone (clearance is the issue here), but it may end up being a little over-damped.

Pedantry on my part to a point. It's the largest dimension, so I tend to put a little extra on one to help kill it off. It's at a relatively high frequency, so not too difficult to damp down.
 
They who ask, shall receive. Occasionally. Assuming I have time, which isn't always the case. ;) And not with fonts that can be adjusted by smartphones -my design, my choice, 'adjustment' of the sketch not necessary. Live with it. :p

I couldn't find the original, so I re-did it, with a single-chamber design with the same nominal combined Vb tuning. This will actually be tuned a touch lower than the original, with slightly more alignment damping < 100Hz. Apologies for the lack of variety in the sketches which is a matter of convenience (read 'bone-idleness') on my part, as my drawing skills are somewhere south of nill and I have to use an old version of Windows Paint.
 

Attachments

  • Miranda Alpair 10.3 traditional vented box standmount.PNG
    Miranda Alpair 10.3 traditional vented box standmount.PNG
    227.7 KB · Views: 458
  • Oberon Alpair 10.3 classic DCR.PNG
    Oberon Alpair 10.3 classic DCR.PNG
    224.6 KB · Views: 465
Last edited: