Once the backs go on, there is nothing that can be done about a misaligned brace or inadequate clearance, so everything has to be right before this happens.
#90° SPEAKER ENCLOSURE DESIGN DRIVERS#
Figure 5 shows one box from the front, with the drivers mounted to check that everything lines up. Now that the boxes are basically assembled, the corner braces, panel braces and rear panel support trim can be added. A nail gun is very fast, and does a great job, but is fairly useless in the first stages of the assembly where initial alignment is critical. All panels are glued and screwed or nailed - the selection of screws or nails was based on the stage of assembly. As you may be able to tell from the photos, these shots were taken shortly after assembly - the glue is not dry yet. The front view of the left speaker shows the cutout for the felt around the midrange and tweeter. At this stage, no corner reinforcements or 'minor' internal braces have been added - these are being prepared from various offcuts, and will be added next. The block of plywood below the midrange cutout forms the tweeter enclosure, and again, you can see the tee nuts glued in position. In Figure 3, you can see the rear view of the two boxes (upside down).
#90° SPEAKER ENCLOSURE DESIGN FULL#
The preparation took the best part of a full weekend.įigures 3 and 4 - Rear View of Cabinets. Once all the panels are cut, holes drilled and rebates rebated, the actual assembly is fairly fast, and the boxes were brought from basic bits of MDF to their current status in less than one day. As always, the initial preparation takes the longest in terms of assembly. The enclosures are quite intricate, and represent a significant amount of work (not to mention sawdust!). The small section beside the midrange enclosure forms part of the main cabinet, and will be stuffed full of fibreglass before final assembly. The brace above the woofer and the base and side of the midrange enclosure are also seen. Those for the woofer are visible in the photo. The latter are very firmly attached and glued in position to ensure that they don't come off while I am assembling the system. No grille cloth will be used, as the frame would cause refractions I would much rather be without.Īll drivers are secured with metal thread screws and tee nuts. This necessitated the separate tweeter enclosure, since the mounting flange no longer seals the tweeter properly. To this end, the bottom of the tweeter has been cut off so it sits closer to the midrange than would otherwise be possible. All drivers are mounted as close to each other as possible. Midrange and tweeter are to be surrounded by a felt-filled cutout, and the front edges of the enclosure will be rounded to reduce refraction. The tweeter is in its own tiny enclosure, fully isolated from any back pressure from the midrange. The midrange is in its own sealed enclosure of approximately 14 litres, and the total volume for the woofer is 35 litres. The boxes are very solidly braced, and the various stages of the construction are shown below.
![90° speaker enclosure design 90° speaker enclosure design](http://diyaudioprojects.com/Technical/Aperiodic/enclosure.jpg)
![90° speaker enclosure design 90° speaker enclosure design](https://eaw.com/wp-content/uploads/2020/04/MW10_iso.jpg)
Figure 1 shows the laminating in progress - I used every clamp I could find to keep them together.įigures 1 and 2 - Laminating the Baffles. The cabinets are made from 18mm Medium Density Fibreboard (MDF), with a laminated construction for the baffle. The stands were also replaced by ones that are a little more elegant than the originals shown further below. Otherwise, the boxes are as originally built and are still just as satisfying as when they were first made. * The Audax tweeter was replaced by a ribbon tweeter in 2010. The Focal 5K4411 is described as a 5¼" Polykevlar Midrange with phase plug, and although I am normally not a great fan of Kevlar, the cone is well treated to prevent the normally nasty breakup effects at high frequencies. Each is excellent in it own right - not necessarily the most expensive, but all have very good performance.
![90° speaker enclosure design 90° speaker enclosure design](https://www.monitoraudio.com/site/assets/files/26366/ma_radius_90_walnut_iso_pair.jpg)
The drivers are as described below, with each having been selected for response, linearity and power handling. Midrange and tweeter drivers have been carefully located so that diffraction effects are minimised, by ensuring that the distances are different from the centre to each edge of the baffle. The enclosures are designed as mirror image pairs for the best imaging. I am using the Linkwitz-Riley crossover (Project 09), my existing amps for the bass and midrange, and (probably) Project 19 LM3876 amp for the tweeters (this is still to be decided at the time of writing). The speaker system shown here is part of my own system, and is intended for tri-amping, so there will be no passive crossover details. Note: Click on any photo to enlarge image. Main Index Articles Index Part 2 - The Electronics