[floobydust]

 Well, my latest little diversion is getting some Moose BVR boxes built for my recently acquired D-5nf drivers. I opted to build in red oak. This is very hard wood and some of the boards (like the sides) cupped slightly from the time they were cut to the time they were assembled. This required some creative clamping to set them straight (pun intended). Here's a couple pics after the first coat of tung-oil. I hope to have them playing sometime next week.

 Regards, KM

[Scottmoose]

Ooohh. Lovely work. :^) A nice oil finish is always worth seeing.

If you can, line the top, rear & one side-wall of the reflex chamber with your favourite material. I like wool carpet underlay myself, but YMMV. I based the chamber HxWxD dimensions roughly on an old acoustic ratio (with a couple of adjustments) so it shouldn't need much. Beyond that, it's a case of damp to suit your room / system / taste. As it's oak, which can ring a bit, you might find you'll need a bit extra compared to, say, BB ply.

Scott

[floobydust]

 Thanks Scott,

 My Dad found some poly-fil type stuff which is preformed in sheets that are 1-inch thick. I was thinking it might be a good choice. I also have some Blackhole products around so that's an option. I'm also planning on filling the lower triangle section with some shot or other damping material... your thoughts? Still some work to do... like mounting the driver, installing a rear driver brace and the back with binding posts, etc.

 Regards, KM

[richidoo]

Be careful that your lining material doesn't change the volume of the chamber too much. I used 1" thick cotton bat and it killed the bass, plus lost a lot of sensitivity. Pulling out all but a pad over the rear panel was just about right, but could use more absorbtion on the other surfaces. A thinner material, like Scott's wool felt should be a lot better. How thick is it Scott? Get it from carpet store? Thanks

flooby, I suspected you were KM from the other forum, but now I know for sure haha

Any update on the phat freddie project Scott? Thanks
Rich

[Scottmoose]

Doesn't exist per se -that's the Maiko cabinet. Basic cabinet design is complete -it's the design details that are slowly being worked on. Usually the way. The basic cabinet only takes 40% of the time. The remaining 60% is in detailing, determining suprabaffle sizes, shapes etc., base designs, bracing etc.

About 1/4in thick is plenty for the damping material. Your local carpet store should have plenty -you might even be able to raid their skip with their blessing for offcuts, which are of no earthly use to them. One of the main differences IMO between a good box and a mediocre box with ~identical modelled (or measured, for that matter) responses is that the former will do everything the latter does with minimal damping. More and you will get that dreaded subjective sucking of life from the sound. Microdynamics tends to be the first to go with overdamping, the exception to this being a good example of a sealed or aperiodic TL, where the back-wave is almost entirely damped & the main object is simply to improve driver behaviour / cone control.

Re the void, there are supposedly a couple of good options. One is cat litter. The other is that green foam (I forget what it's called) florists use for artificial (and occasionally) real, flower decorations. Lead shot should be fine, but I'm not totally convinced about the merits of having lead about the house, even if it's sealed in the base of my speakers, and it'd need to be carefully packed in with glue, resin or some such to avoid rattling.

[jrebman]

KM,

Looking forward to some listening reports.  Have you been doing any pre-installation break-in of the drivers?

-- Jim
S

[floobydust]

Hi Jim,

 Yes, I have been "playing with" the D-5nf drivers.... picked up a Woofer Tester/2 and have done some serious break-in hours using the Fs of the driver and 1 and 2 octaves below that for several hours each. It would appear the T/S parameters have settled out now. I've not tested Vas as I refuse to put anything on the cones.... but at some point will use a test box for Vas. As soon as I get them completed I'll put some listening hours on them.

 Scott,

 Again, thanks for the info.... I know what you mean about lead shot... but I've had this in my Arcici stands for 20 years holding up the Quads. I've never had any rattles however... but I really filled them up too. Based on the dimensions, I'm thinking each will require over 40 pounds of lead! I guess they'll be setup for playing "heavy music"? I'll take more pictures once they're closer to completion.

 Regards, KM

[floobydust]

Be careful that your lining material doesn't change the volume of the chamber too much. I used 1" thick cotton bat and it killed the bass, plus lost a lot of sensitivity. Pulling out all but a pad over the rear panel was just about right, but could use more absorbtion on the other surfaces. A thinner material, like Scott's wool felt should be a lot better. How thick is it Scott? Get it from carpet store? Thanks

flooby, I suspected you were KM from the other forum, but now I know for sure haha

Any update on the phat freddie project Scott? Thanks
Rich

 Hi Rich,

 Yes, I've used floobydust as a handle for many decades now (including IM).... but oddly it was already taken on the DIYaudio forum and the Puremusic forum would not accept it as an id.... bummer. As many probably know it comes from the last section of the National Semiconductor Audio Handbook from the 70's, noted to be derived from an old Greek term where the literal translation was "a mixed bag". I was given a copy by the National Semi rep when it first came out... so yea, I'm old!

 Regards, KM

[floobydust]

 Well, the holidays and 4Q ending at work pretty much consumed my time for the past 4+ weeks... so the enclosures just sat. I also noticed later that the wood (which I had cut by a shop this time around... to save me time, ha!) had some cutting errors... some as large as 1/32" and the spec'd 3/4 thick wood was actually thicker. Doesn't seem like much of an issue until you try and mount the backs on, then it's too late. I had specifically asked that they ensure the cabinet rear width be adjusted in case the board were a bit thicker than 3/4" but alas, reading and thinking is not what they do, so the backs were a good 32nd of an inch too narrow, talk about sux.

 So, I mounted the backs over the past two nights.... required clamping as well (some board cupping) and used 24 #10 wood screws 1-3/4" long. The belt sander got a great workout... it's amazing how quickly a 80-grit belt will completely take off the tung-oil finish! Took a couple hours, but everything fits properly now and has two new coats of tung-oil applied, the binding post holes are drilled and stepped and I added 4 adjustable spike feet to each bottom which required lots of drilling with faustner bits for a 3-step 1-1/8" deep hole (yes, I doubled up on the bottom board for 1-1/2" of solid oak). A few odds and ends to finish up, then I can mount the drivers and fire em up. Pictures will follow shortly.

 Regards, KM

[jrebman]

Sounds like it was a real time-saver. ::

Sounds like it all worked out though.

-- Jim