Full range stereo project

[Triticum Agricolam]

For a while now I've been wanting to build a full range stereo speaker setup focused on sound quality. If you aren't familiar with "full range" speakers, they use a single driver to produce the entire (or vast majority) of the audio spectrum compared to a more conventional multi-way system (2-way, 3-way, etc) which uses separate woofers, mids, & tweeters, etc to break up the audio spectrum.

Full range systems have several advantages and disadvantages compared to a more common multi-way system. The primary advantage is simplicity, they don't use crossovers. With multi-way systems you have to integrate the various drivers together, while a well designed crossover can do that pretty well, its never perfect and there will always be some distortion and phase alignment issues which will color the sound. This is particularly a problem since most crossovers are in the 300-3,000 Hz range, where human hearing is the most sensitive. Full range systems don't have this weakness. In addition to simplicity, with full range systems all different frequencies originate from the same point source, which helps with integration. They are also generally less expensive because all you are buying are speaker drivers, no crossover components costs.

Full range systems have several disadvantages, though there are generally ways to work around them. Producing the complete audio range with a single driver is tricky task and there are trade-offs. Full range speakers range in size from about 2" up to 12" inch cone sizes, with 3" to 6" being the most popular. Smaller drivers generally have better high frequency performance while larger drivers do better with lower frequencies. No matter what you pick you are probably going to give up a little bit of performance on either the top or bottom end of the frequency spectrum. Another disadvantage is full range systems generally aren't very efficient and don't do well trying to play at really high volume levels. They can struggle with with complex music and as such play some genres better than others.

Fortunately these disadvantages can be overcome fairly easily by adding either a super tweeter in the case of larger full range drivers, or adding a subwoofer with the smaller drivers. While this does involve adding a crossover the system, the crossovers can usually be of very simple design and the crossover points are either above or below the 300-3,000 Hz range so their drawbacks are significantly reduced. In the case of a system using a full range driver and subwoofer, taking the burden of playing the bottom couple octaves off the full range driver allows it to play cleanly at MUCH higher volume and to handle complex content much more effectively. These type of systems let you get the best of both worlds (full range & multi-way systems).

Now that I've explained what full range systems are and why they are desirable, I'll go over what my project is going to be. For this system I am going to use a pair of Mark Audio Pluvia 7 4" full range drivers. They will be going in a double mouth big vent reflex (BVR) enclosure. A BVR enclosure is a type of ported box that has a horn type flare and the port mouth/s. The enclosure for a full range driver is especially important since that is how you get the best low frequency performance out of them. This particular design I will be using is called the Coniston by Woden Design and it was made specifically for this driver. Its a fairly complex enclosure, which is one of the reason it appeals to me, I like to build more difficult stuff. There are lots of full range enclosure designs that are relatively simple though.

There will be two phases to this project, the first is to build the Conistons and get them playing. After they are complete the second phase is to add some 15" dipole H-frame subwoofers to handle the bottom couple octaves. I'll be using a MiniDSP for active crossover duties. I'm going to start off with one sub crossed over around 80 Hz. If I like how its performing I'll add a second sub and then be able to cross them over a bit higher, up to around 250 Hz or so.

Anyway, on with the build.

[Triticum Agricolam]

Here is what the Pluvia 7 drivers looks like:

And here is the Coniston enclosures:

Time to make sawdust. Panels have been cut and I'm getting started with the layout:

Gluing the port pieces together:

The hole in the baffle has been cut, now its time to chamfer the back side, I use little spaces blocks in the screw hole to keep them from getting chamfered out:

Chamfer is done:

Here it is with the spacer blocks gone:

Cutting out the internal braces, I cheat and use the CNC router :-)

A quick test fit, still more fitting work to do before I can start gluing things up:

Gluing the ported chamber top and bottom on:

After the glue dried I trimmed the top and bottom ported chamber panel flush with the front panel and started in on the internal bracing:

Getting started on the second enclosure:

I added some cutouts to the bottom of the side panels with the CNC router for more aesthetic appeal:

Here I'm cutting the top and bottom reflectors. The angle of the cut is 51.8 degrees, which requires the use of my 45 degree sled:

Gluing the reflectors on the side panel:

I cut a recess for the terminal cups in the back panels. Took me a while to get the size dialed in right on the CNC, but its a one-time hassle:

Gluing the back panel to the side & reflectors:

[ckeeler11]

Sounds like fun. cant wait to see the box design.

[Triticum Agricolam]

More progress.

The cabinets will be lined with 1/2" felt carpet underlayment, here I'm cutting it out from the roll:

All the pieces are cut, time to glue them in:

Here it is glued in:

[MrSkippyJ]

This is a little amazing sir! Look forward to the end results!

[bsneon98]

Your fab work is out of this world man!

[DLHgn]

Tuned in for the final results

[bsneon98]

Also, nice collection of tools you have man, that looks like one hell of a shop!

[2loud4uboyz]

I hate you. Man that's some clean work so far.

[Kyblack76]

Sick ass work dude.