Simplexx 15/18 Subwoofer cubic feet and tuning frequency

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AcousticScience
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Joined: Tue Jan 20, 2015 4:37 pm

Simplexx 15/18 Subwoofer cubic feet and tuning frequency

#1 Post by AcousticScience » Mon Apr 11, 2016 12:11 pm

What is the size and tuning freq of the Simplexx subs?
I modelled a 3015lf to play 98.5dB sensitivity flat to 40Hz (and not hit Xmax until 50V) with a 6.5 cubic foot box tuned to 41Hz. This is both far superior to the 3015lf Simplexx 15 and the Tuba 24, as it seems the 3015lf needs an unusually large box volume to get the best out of it. Perhaps the 3015 is better in a box even bigger than the 18 sub?

Is there any driver protection/unloading advantage to a smaller box than optimum for best performance?

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Bill Fitzmaurice
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Re: Simplexx 15/18 Subwoofer cubic feet and tuning frequency

#2 Post by Bill Fitzmaurice » Mon Apr 11, 2016 1:33 pm

The S15 Sub pro version is 4 cu ft net tuned to 35Hz. On paper a higher tuning looks a bit better, but on paper the result is half-space anechoic. When used in a room, especially when wall loaded as it should be, lower tuning gives a better overall result. I considered making it larger, but it's not our top of the line sub, it's our entry level sub.

AcousticScience
Posts: 53
Joined: Tue Jan 20, 2015 4:37 pm

Re: Simplexx 15/18 Subwoofer cubic feet and tuning frequency

#3 Post by AcousticScience » Thu Apr 14, 2016 7:40 am

FYI I did a hornresp of the 3015lf at 35Hz tuning. It didn't reach its full potential until you use a box of (including the volume of air in the ports) 9 cubic feet!! At this size it is getting as big as some of the smaller horn cabs. Perhaps this driver really is a wide cab wonder. At this it reaches its xmax at one point around 40Volts for a theoretical max SPL (excluding power and port compression) of 121dB in half space (corner gave 131dB to 30Hz). Most 15s won't need that size box for their full potential, but won't give you 98dB sensitivity all the way to tuning. Larger boxes did have a disadvantage of needing a steeper high pass filter.

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