It occurs to me that we have a small but diverse group of experts here, and it might be a fun way to 'give back' to the community as a whole if we pooled our resources and designed a really good speaker.
What I have in mind is a speaker (or several) which is small enough that a prototype can be shipped around at reasonable cost, which can be built with easy-to-source drivers, perhaps ultimately being measured and verified on the NFS if Amir is amenable.
The first decision to be made would be what price point we are targeting -
- Very low pricepoint - a speaker using for example Dayton classic tier drivers - not great in terms of distortion, but very inexpensive. This would be an interesting exercise because as we have seen from recent reviews, cheap drivers can be used skillfully to great affect. This also has the advantage of making the project more attractive to builders.
- Low pricepoint - think Dayton or Peerless level drivers. These are very high value and get you well into diminishing returns if used skillfully
- Medium pricepoint - SB Acoustics, ScanSpeak Discovery sort of level. These are essentially high end drivers with great construction quality and terrific value.
- High pricepoint - value starts dropping off dramatically here, but performance could justify it if low distortion, deep bass and a small box are desired.
The next decision would be topology, the basic premise of the speaker.
- A simple two way with baffle mounted drivers can work surprisingly well with a small woofer and/or a robust tweeter, but output is limited. Smooth and wide directivity at the expense of low bass.
- A larger two way (6.5"-8" woofer) works best with a waveguide, and here I think you would want to use an off-the-shelf solution to keep the speaker easy to build. This makes the speaker intrinsically more costly, as there are only a handful of good tweeters with significant waveguides, and none are really cheap. Still, this is the sort of speaker I would build for myself.
- An interesting option would be to make a small stand mount 3 way, but here the problem is that crossover costs essentially double, and the size of the speaker increases. Still, the performance increase is significant, and people do seem to prefer the wide dispersion sound.
For me, I think the most interesting topology is actually the first - a simple two way with a small woofer. Why? Here at ASR we've had many discussions about subwoofers and how preference scores for full range speakers are almost invariably much higher if subwoofers are added. I think it would be really fun to design the 'ultimate satellite speaker', perhaps using a 5" woofer and a nice dome tweeter, focusing on robust output above 70hz or so. In terms of price point, I think this could be accomplished well using the "Low Pricepoint" category I have described, but I wouldn't argue against "medium pricepoint" if we could design something truly excellent.
The second most interesting combination is a cheap 3 way - I think people really do like wide dispersion speakers, and something using again, the "Low Pricepoint" would be appealing to a lot of people. We've had discussions about the excellent performance of inexpensive midrange drivers such as the BMRs and Vifa TG/TC9, coming in at around 15 dollars, and in using drivers such as these, you can use a much less expensive tweeter than a two way with excellent performance.
The third option would be a two way with a waveguide. I'm thinking the Seas DXT or the Wavecor unit would be the best two candidates - I'm not aware of any others. If you combine these with a sb17MFC or something similar, you get a small, high value full range speaker.
Fourth option would be something built for ultra high performance - we have the tools to do this. Perhaps target the Revel Gem2 or some other stand mount 3 way.
In terms of the community aspect, I think we can break down the tasks needed for this project:
- Specifying what we want the speaker to do in order to be successful - target SPL, bass extension and DI.
- Simulation of drivers from datasheets - finding interesting and viable drivers and nailing down the target performance
- Driver distortion measurement and initial characterization as needed
- Enclosure design, potentially for production if interested
- Enclosure prototype construction
- Crossover design
- Crossover construction, potentially PCB design
- Project management - keep the discussion focused, keep the budget on track
- Design verification using $100K measurement platform
I think most of us speaker DIYers can do most of these things, but we all excel or suck at some of them. Speaking for myself, my crossovers always look like hot garbage, and I don't really feel like making cabinets right now. On the other hand, some people have no interest in crossover design, but can make a nice mdf cabinet in an afternoon. Additionally, and most importantly, there are tasks which allow non speaker people to contribute, such as managing the project and tracking the parts cost and availability.
If you are interested in the project, please respond to this thread by telling me how you would like to contribute. We can then proceed to making a thread dedicated to specifying the topology, and nailing down a design target.