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Looking for some advice: RSS315-PR vs SD315-PR

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  • Looking for some advice: RSS315-PR vs SD315-PR

    I'm looking at a build with passive radiators and I'm trying to decide between using a single RSS315-PR or a pair of SD315-PR. The RSS315 is listed as having an XMECH of 26mm and the SD315 is listed as having an XMAX of 10mm. Assuming that the discrepancy between XMECH and XMAX are a moot point (maybe XMECH of the SD315 is 13mm?), the RSS315-PR would yield a slightly higher Vd since I would use two of the SD315. I have modeled both, and in the same enclosure I can achieve the same F3, within a couple Hz. I can achieve a slightly shallower roll-off with the pair of SD315-PR, but it's not a huge difference between the two.

    My biggest concern is that in my opinion, the RSS315 appears a little more rugged (Aluminum cone vs paper cone, slightly beefier surround, etc). The pair of SD315 would also be slightly cheaper. Has anybody seen/used both of these and could provide some input on which they would choose? Anybody else have any input or recommendations?

  • #2
    As long as the SD315 can handle the load of added mass, you should be fine. Those are the weak points- Not enough Xmax or Mms capabilities in the SD product line.

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    • #3
      Since you're looking at a passive device and don't have a speaker with a motor and voice coil, Xmech = xmax.

      As you approach xmech there will be some non-linearity as the suspension reaches its limits, so having a bit of excursion to spare is never a bad thing. Other than that, the suspension just has to be capable of carrying the weight, I don't know if the RSS-PR has a single or dual spider, if its just a single it likely has similar weight capacity to the SD line, but with the obvious extra excursion capability.
      "I just use off the shelf textbook filters designed for a resistor of 8 ohms with
      exactly a Fc 3K for both drivers, anybody can do it." -Xmax


      • #4
        Thanks for the input guys. Since the RSS315-PR went on the flash sale today... I think I'll go that route. Plus, like dcibel said, a little spare excursion to keep the PR linear isn't a bad idea.