I'm in the market for a new set of loudspeakers. I can justify $10k+ for the speaker build. But here's the thing... and it will come off terrible I know... but I don't have time to learn everything I need to to design my own system. So my preference is to obtain detailed plans and parts lists.
I applaud that you're not just trying to jump in head-first and instead going for something designed by someone that knows what they're doing. There are definitely a lot of great designs out there, but I guess you really have to have a feel for what you want though. The biggest issue is that when you get into the extreme high end, a lot of the best drivers only seem to be used in two-way bookshelves rather than full-on tower-beasts. The full-on tower beasts in turn tend to be convoluted speakers, often utilizing active electronics in the signal chain and very customized controls. Nothing that can't be replicated I'm sure, but you definitely might want to look beyond just designs done with passive crossover components simply because they're fewer apart.
A few questions I have for you would be:
- What are the dimensions of your listening room and how open are you to placement?
- On the note of your listening room, have you looked into getting it professionally designed or "treated" (the former being more ideal than the latter) for music-listening (note: this does not mean stuffing it full of absorption pads)
- Are you attached to any particular electronics, or are you open to perhaps buying and using six or more channels of ampification for stereo sound?
- Are you open to the implementation of multiple subwoofers to ensure tight bass response?
I have probably every tool needed to build anything wood metal or concrete. I can also solder if needed. I'm not a master of any particular thing but I can build it. It will take me more time, but I can do it.
Good to hear.
So, what's the ultimate floor standing speaker build?
Well, TLS Guy's Seas Excel Transmission Line towers are pretty damn ambitious with high end drivers from top to bottom, and they're certainly neutral and praised by some very knowledgable recording engineers and profressionals. I dunno if an "ultimate" build really exists though.
The first thing that I've noticed is the use of MDF... and I'm not trying to get into a debate about that. I just know there are better materials that resonate less and I'm open to using those.
No single material is "ideal" or resonance-free. Steel is useful for bracing due to its very high tensile strength but not so much as a panel material where it's gonna ring like, well, steel. Bitumen is gonna be useful with adhesives due to its damping properties, but it is not stiff at all as a structural element. Void-free Bamboo Ply is gonna be pretty stiff-and-light, but its a ***** on your tools. Concrete (more specifically, Hardiebacker cement board) is another great material but again, you'll need the tools to use it correctly. One nice self-damping material is Polyurethane, but it needs to be molded. All-in-all, you can't expect any single material to be perfect no matter what they tell you. The technique used to build the box is as important as anything else.
If you're really, really looking to make some "extremely" well-constructed boxes, the thing I would recommend the following:
1) A cross-brace every four inches of diameter. This correlates to a rough quarter-wavelength of around 850hz. This also means you have to take bracing volume into account. The internal volume of the box is reduced as you add more bracing, and must be compensated for. Steel L-Angles are nice for this.
2) Constrain layer damping of the cabinet walls using two different materials and an appropriate damping layer in between. Myself, lsiberian and others can help you with further information. Constraining 3/4" or 1" Bamboo Ply with Concrete board, and an appropriate damping material holding them together in between (perhaps 1/4" of green glue) is a much better solution than using a single material. Again, this will reduce your internal air volume. Your baffle (the part of the speaker housing the drivers) ought to be two or three times thicker than the rest of the speaker, as well, as it is mechanically fastened to driver frames.
3) Quality internal absorption fill material such as Roxul Rock Wool or Ultratouch Denim Insulation.
4) PL9000 and Silicon to close down any holes / leaks.
5) Correct roundovers to minimize diffraction. Wood and MDF are a lot easier to work on than other materials.
Of course, all that's a crap ton of work and planning. I am currently building a pair of speakers with 1" MDF, extensionally damped with roughly 1/10th of an inch of roofing-bitumen and braced at roughly about 5-6 inches apart... and that's pretty much "enough work" for me as I don't subscribe to box construction as being a dominant trait of loudspeaker design beyond the essentials. They're pretty solid on the knock test as it is IMHO.
