Still a newbie, looking to build some 3-ways to replace my front and center, and wanted to build surrounds first (to learn, since they are easier, cheaper and less visible). My plan is to use RS100-4s for the mid-range of my 3-way, and originally was to have the same drivers and crossovers for the surrounds.
After considering budget and placement, I am thinking of using the RS100-4s as full range in a ported enclosure, with both the port and driver facing upwards. I have a good sub, so if I can hit the 72Hz F3 listed on parts-express for this driver, I don't need a low range driver. With the top-firing design, the extra detail from a neo-tweeter will probably get lost (not much detail here on most movie tracks anyway), which adds $40 to my cost (per speaker) mostly due to crossover parts. I am also considering dipole, bipole and transmission line configurations, if I can get them to go low enough without taking up to much space or costing too much money. Another issue is these will be placed relatively close to the listener, possible as close as 3 feet, which is why I like the top-firing idea.
I don't understand ported designs as well as the other designs. There is plenty on the Internet about theory, and lots of calculators to give dimensions, but putting it to practice is different. I know getting precise enclosure volume is important, and know to add roughly 20% for stuffing with acoustic absorption and take off volume used by the driver and port. However that gives me a very rough estimate, and I need a precise volume.
I also know people 'tune' these to specific frequencies by measuring impedance and changing the port length. And I think I understand how to do it. What I don't understand is why this is important. If my actual port is tuned higher than the frequency I want, I lose low end - a bad thing. But what if my port is tuned too low? Is that really a bad thing? I can imagine it wouldn't be good, otherwise everyone would tune a 3" driver to 20Hz, but I don't why it is bad or how precise it needs to be.
After considering budget and placement, I am thinking of using the RS100-4s as full range in a ported enclosure, with both the port and driver facing upwards. I have a good sub, so if I can hit the 72Hz F3 listed on parts-express for this driver, I don't need a low range driver. With the top-firing design, the extra detail from a neo-tweeter will probably get lost (not much detail here on most movie tracks anyway), which adds $40 to my cost (per speaker) mostly due to crossover parts. I am also considering dipole, bipole and transmission line configurations, if I can get them to go low enough without taking up to much space or costing too much money. Another issue is these will be placed relatively close to the listener, possible as close as 3 feet, which is why I like the top-firing idea.
I don't understand ported designs as well as the other designs. There is plenty on the Internet about theory, and lots of calculators to give dimensions, but putting it to practice is different. I know getting precise enclosure volume is important, and know to add roughly 20% for stuffing with acoustic absorption and take off volume used by the driver and port. However that gives me a very rough estimate, and I need a precise volume.
I also know people 'tune' these to specific frequencies by measuring impedance and changing the port length. And I think I understand how to do it. What I don't understand is why this is important. If my actual port is tuned higher than the frequency I want, I lose low end - a bad thing. But what if my port is tuned too low? Is that really a bad thing? I can imagine it wouldn't be good, otherwise everyone would tune a 3" driver to 20Hz, but I don't why it is bad or how precise it needs to be.
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