In Januari 2001 I was reading an article in Speaker Builder magazine about the Aria 5r speaker. This is a bass reflex speaker, with two Focal 5inch 5K4211 mid/woofers and a Raven R1.0 ribbon tweeter in D'Appolito configuration.
I had bought some year-sets of back issues of Speaker Builder magazines, because in late 2000 I had gotten interested in building my own set of speakers. I did not want to design my own speakers, because that is very complex, and building a set of speakers to an existing design seemed a much better idea.
In contrast to other speakers featured in Speaker Builder, the Aria 5R was reviewed quite favorably, and especially the tweeter was very appreciated by the people that had listened to this speaker.
So, I thought, this will become the speaker that will be my first venture into DIY-speakerbuilding. I reread the article and the remark that the speaker was I little light on bass attracted my attention. Indeed, these two small woofers, seemed just a little TOO small to produce real bass.
That would be a problem, since a lot of the music that I listen to has got a rich bass content, and I was looking for a speaker that could reproduce that part of the music convincingly.
So, I thought, maybe I should change the design to having two Focal 7inch woofers. That shouldn't be too difficult, since the Orcadesign website (the home of the Aria 5R), already has some designs with this arrangement.
Focal is readily available in the Netherlands, the Raven tweeters aren't. I bought the Raven tweeters online, from E-speakers, and they arrived within a week! For the woofers, I went to Speakerland.
I explained my plans, and told that I thought that two Focals 7k4411 per speaker would get the job done. Ruud -the shop-owner- gave me his famous: "well, that's ok, but if you really want something that works well", go for the Scan Speak 18w/8546.
Of course I knew the Scan Speaks, but I thought using Focal drivers would work better, because that wouldn't deviate too much from the original design. But I let Ruud convince me otherwise, and went for the Scan Speak units.
Well, so even with my best intentions, I ended up not building something after an existing design, but creating my own speakers. The only thing my new speakers would have in common with the Aria 5, was the Raven R1.0. But since I can count on some help from more experienced people, I hope this won't be to big of a problem.
Ruud did some simulating on a vented enclosure and advised me to go for a box-volume of about 40 litres. I went home, with two woofers (the Scan-Speaks cost double the price of the Focals, so I bought half of what I needed) and started drawing.
And this is what I came up with:
This is the drawing of the cabinet, for aesthetics I narrowed the front at the location of the tweeter. A design gimmick I copied from an exististing Scan Speak design. This is the right speaker, the left is a mirror copy of this one. Click on the image above for a vector graphic.
This drawing shows some extra detail. My CAD-skills aren't the best around, so I figured that some extra info wouldn't hurt. I'm convinced that making a drawing of the speaker -especially when it's a more complicated design, or your first...- is important. It really makes you think about how it is to be put together. This helps to prevent problems further on in the process.Click on the image above for a vector graphic.
The speaker is built from panels of 22mm MDF and 18mm Birch plywood glued together. Several people have told me that making speakers from two materials glued together would help in eliminating resonances. I did not want a black speaker, but one with a nice wood-finish. I made the Birch plywood the outer layer so that would give me a nice finish and eliminate the need to veneer the speaker later on.
If only I had known that birch plywood is available in different qualities, I would have looked for a better quality. The sheets that I bought had several oval repair pieces in them and were also rather rough, which ment a lot of sanding later on. That's something to keep in mind for the next project.
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