PS: to save on shipping get them from Bob in Abbotsford vrs direct from Madisound. (Creative Sound Solutions - Loudspeakers, Parts and DIY Speaker Kits)
Looks good
I was hoping to stick with a conventional port (1.75" diameter if possible). I am doing this box in birch, I've done all my others in MDF and I'm not terribly confident in my ability to make those visible edges on the front baffle look ok in the slot port arrangement.
High aspect slot vents effectly add an R to the vent making the box less susceptible to dynamic changes in T/S causing the tuning to be off. As well in this case the box is too small to get a nice alignment with a plumbing pipe port.
http://frugal-phile.com/boxlib/Changing-Port-Size.pdf
dave
Thanks for the clarification. I think I will go ahead and go with the slot port then.
If I'm reading the plan correctly, the front baffle is basically cut a bit shorter than the opening left by the flanking pieces, so if it is secured on the top side, it leaves that gap for the slot? No actual special cutting on the baffle itself?
Does standard multi-ply birch look ok with those edges exposed? Would it be able to be rounded over? Rookie questions I know, not a real expert on woodworking.
If I'm reading the plan correctly, the front baffle is basically cut a bit shorter than the opening left by the flanking pieces, so if it is secured on the top side, it leaves that gap for the slot? No actual special cutting on the baffle itself?
Does standard multi-ply birch look ok with those edges exposed? Would it be able to be rounded over? Rookie questions I know, not a real expert on woodworking.
In case anyone is interested, there is a mini Karlsonator scaling that works well for the Pluvia7. It's a taller aspect ratio box at 0.56x height and depth (16.25in tall) and 0.4x width (about 6in wide). It is tuned to 61Hz but will give you 88dB at 75Hz and f3 of 56Hz. No BSC is needed with deep rich sound.
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This is from a woodworking perspective more than as a speaker expert, since I'm not one. As long as you maintain the internal volume and the port dimensions, you can cut the pieces and fit them together however you want. So, if you don't want to see the edges of the plywood from the front, simply shorten the depth of the top, bottom, and sides of the box by the width of the plywood, then increase the front baffle height and width by 2x the width of the plywood, so that the baffle overlays the front edges of the sides, top, and bottom. This means you have to cut a slot for the port opening, but that shouldn't be too difficult if you take your time. Assembly will also be a bit trickier, but still doable.
That being said, you either like the look of plywood edges or you don't. If not, there's the paint or veneer option. (or the mitered assembly option, but that's a bit advanced).
Looks good
I put the slot in the rear facing downward and plan on elevating the speakers via spikes and some sort of open fold directing towards the front- still experimenting but so far they sound great to my old ears--
I've built literally dozens of pairs of this very flexible design format, and would suggest the following would make for easiest assembly:
- overlay the sides so that the other 5 pieces can be cut from a single rip of 140mm material
- run the back full length, and the front 1/2" longer, so that the top is fully inset on all edges
- if concerned about exposed ply edges there are iron-on edge tapes available, but part sizes would need to be adjusted (approx .5mm) after taping to ensure perfectly flush fit
- even on material as thin as 1/2" ( which works perfectly fine on these little guys), it's very important that the rear side of driver hole be chamfered or radiused. As the fronts are so short on these, I cut them to length from a longer piece after cutting the holes with a hole saw and chamfer with a laminate trim router. Also, due to the 1/2" thickness of stock, there's not a lot of depth of cut a available with a bearing tipped router bit, I clamp the long workpiece to a 3/4"'scrap of MDF etc before cutting the holes and routing. Takes less than 5 min to do a pair of baffles that way
- assuming accurate cutting of the parts, these can easily assembled without the use of brad nails or screws, but are tiny enough that even if you have suffix to number of clamps to attempt all at once, you'll likely run out of room!
- overlay the sides so that the other 5 pieces can be cut from a single rip of 140mm material
- run the back full length, and the front 1/2" longer, so that the top is fully inset on all edges
- if concerned about exposed ply edges there are iron-on edge tapes available, but part sizes would need to be adjusted (approx .5mm) after taping to ensure perfectly flush fit
- even on material as thin as 1/2" ( which works perfectly fine on these little guys), it's very important that the rear side of driver hole be chamfered or radiused. As the fronts are so short on these, I cut them to length from a longer piece after cutting the holes with a hole saw and chamfer with a laminate trim router. Also, due to the 1/2" thickness of stock, there's not a lot of depth of cut a available with a bearing tipped router bit, I clamp the long workpiece to a 3/4"'scrap of MDF etc before cutting the holes and routing. Takes less than 5 min to do a pair of baffles that way
- assuming accurate cutting of the parts, these can easily assembled without the use of brad nails or screws, but are tiny enough that even if you have suffix to number of clamps to attempt all at once, you'll likely run out of room!
Hi Dave, between the Pensil and the slim reflex design, what is the most notable difference in sound?
My room has a low wooden table approx 45cm in height. If I want to go with the slim reflex, do I need to place it on a stand of some kind?. I'd like it to resonate and sound 'big' to fill a small room of 16m2? Also, does the slim reflex design needs stuffing inside?
If I go with the Pensil, the driver would be about 120cm from the floor, and I wonder if this is a good setup for listening in my room. Thanks so much.
I suspect it will be primarily in the bass extension, but the smaller enclosure may suffer from a bit more reflection thru the cone from the inside making the mids a bit "cloudier". I have only heard Pluvia in Frugel-Horn Mk3.
dave
Jonathan - re your question on differences between a Pensil design and compact "desk-top" / bookshelf monitor such as in Dave's drawing posted above, it's been my experience with every FR driver for which I've built enclosures or heard by others - numbering well into the scores of different designs - that a properly designed floorstanding enclosure will generally deliver deeper, fuller and more dynamic bass response than the bookshelf .
Well noted with thanks, chrisb. I'm debating if I'm gonna go small and equally good, or big but really really good.
So deeper, fuller, more dynamic bass, and clearer mids. Floorstanding looks like the clear winner here. Thank you very much.
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