Contemplating the Silburys

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Hi, I've just joined the site! I would appreciate some input on cabinet designs.

On a whim, I recently bought an unused pair of Alpair 10m, 3rd generation, and am contemplating which design to build.

A couple of years ago I by chance heard a pair of Quali-fi speakers using one of the smallest Mark Audio drivers. I was pretty gobsmacked by the sound of those tiny drivers and so when a pair of 10m's showed up on the second hand I grabbed them. (No retailers carry them here in Sweden.) I absolutely love the simplicity of a single driver design with no crossover.

By far the most intriguing enclosure design I've seen is the Silbury. I'm no bass junkie but too little bass kills any speaker.

A simpler, cheaper, and smaller alternative would be the Pensil. I'm on the fence on which of them to build.

Some points in favour of the Silbury are the relatively small footprint for such a large speaker, the fact that the three sides of a speaker juuust fit on one sheet of 2440mm x 1220mm raw material (I think?), and the presumed higher value should I decide to sell them in the future. The only real downside that I can see is that they are not fun to move.

The points in favour of the Pensils is the simplicity and lower material cost. WAF is not a factor since I have no W.

I'd appreciate input, particularly in terms of sound!

A thought also struck me: would a half Silbury work? I. e. only building the lower half of the speaker.

Thanks!
 
By far the most intriguing enclosure design I've seen is the Silbury. I'm no bass junkie but too little bass kills any speaker.



A simpler, cheaper, and smaller alternative would be the Pensil. I'm on the fence on which of them to build.

As an alternative, there is the Frugel-Horn XL or FH-XL too.

A thought also struck me: would a half Silbury work? I. e. only building the lower half of the speaker.

Again, if you are inclined towards a horn with rear loading, then the FH-XL is an option.

I have not heard the Silbury, but having listened to other Scott Lindgren designs for wide-band (full-range) drivers, suspect that they would be pretty good. And they would look grand in your room. :D

Btw, how big is your listening space?
 
And they would look grand in your room. :D


Oh yes they would :cool:
My listening room is ... undefined. I currently live in a 32 square meter, one-room apartment which is largely one space (apart from the toilet.) But I'll be moving some time later this year, no idea where to really.

The thing that puts me off the FH XL is the larger depth, I don't know the exact figure but I think I've read that it is greater than 50 cm, whereas the Silbury is 40 cm.

Actually, a hifi shop a few hours away has the Quali-fi Wagner in store, I've seen them but not listened. They are big front-firing horns, based on the 12p I think, that were (just realized this) co-developed with Scott. I should listen to them! :)
 
While I’ve not heard the Silburys, I can relate my experience with A10.3 in the Pensil and FHXL - something I’ve posted several times before. If you have the floor space required, the XLs will deliver a more enveloping spread of soundstage and “fuller” bass than the Pensils. Indeed, I’d go so far as to extend that postulation to all three sizes of FrugelHorns vs floorstanding MLTL, etc variants I’ve heard with numerous different full range drivers.
That said, as one who has long adapted to the domestic constraints of smaller enclosure footprints, the Pensils are far from a compromise.
 
Thank you for your input. Actually, the Silburys and Pensils have nearly identical footprints, which is a big reason why I like them. Chris, is there something that the Pensils do better than the horns? And Scott, would you mind expanding a little on the design objectives?
 
Dr Lindgren may have his own observations/ technical comments, but at least for me, the only thing a Pensil family design “does better” than the appropriately sized Frugel Horn for any given driver is take up a smaller footprint. That remains the singular reason I don’t have a FH in either of my two systems.
In addition to their DxW area, his rear mouthed horns and taller Olson style manifold designs (Maeshowe, Silbury, Avebury, or their Fostex siblings) have the requirement for a minimal clear distance to rear wall that the Pensils, Poplar MLTL and numerous other front vented enclosures do not.
 
A bit of a YMMV case. Optimally damped the pensils are a very flat / TL style impedance load, which is useful in some circumstances. And while they're acoustically large for a vented alignment, they do take up a bit less space. Rear termini shouldn't need all that much space to the front wall / corner since boundary loading is part of the expansion, though they do need some, & this will vary depending on room construction &c., so as you say, they do (or can) score on that front also.
 
Fostex FE166 might need corner loading to achieve the same bass extension that any of the 10cm class Mark Audio drivers deliver without it. Some drivers just need more help in the bottom several octaves - I certainly found that to be the case when I’ve played FH, Valiants, even the Horneshoppe Horns fitted with FE126E.
 
frugal-phile™
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With the same drivers (A10x/A11) neither horn really needs a corner, but those corners can be used to reduce the ripple and perhaps give a bit more extension. Depending on how much bass you need there may be a need to use. a bit more damping in them to trim back the bass.

A wall/floor gives a nominal 4x effective mouth size, a corner 8x, so an octave lower full horn loading.

FHXL using FE166En, FE168e∑, FH3 with FE126 would all really like to see a corner.

dave
 
My drivers have been delivered and I've built a pair of temporary open baffles that I'll use to break the drivers in at low volume while I'm building the cabinets. Sounding very promising so far! I've planned on using birch plywood as a material, but I'm also considering some type of wood. Maybe birch, what do you think? Price isn't really an issue as long as it's reasonable.
 
What Dave said -if you're an experienced woodworker with a good understanding of the acoustic requirements then solids are OK. Otherwise, a quality void-free plywood (Baltic birch, apple, marine, bamboo) is more consistent / stable. Chris & Bernie are better placed to comment on the details, but as I recall general recommendation on solids is tight, straight grain; maple, alder, pine, spruce, birch etc. If you can get oak or ash like that, you're bobbing, obviously. An alternative, as the late Terry Cain favoured for larger panels IIRC, is to laminate your choice of suitable and properly dried / sealed solids to a stable high-grade particleboard core.
 
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