I have been playing around with designs for a new subwoofer for a few months now and just can’t seem to find a combination of driver(s), cabinet and performance that excites me enough to start building. I now run a sono sub with a 15” Blueprint drive tuned to 20 Hz that I’m pretty happy with. The new sub would have to be an improvement over this sub and be attractively priced to justify the cost of the upgrade.
I see that the Shiva-X is on sale for $149 plus shipping. This has got me thinking about building a set of subwoofers, each with 2 drivers, both mounted on the front of the enclosure, tuned to 15-16 Hz. I like the idea of using 12” drivers because it keeps the width of the tower to a minimum. The basic size of the tower would be 13-1/2” wide, 45” tall and 17-1/2” deep, the front wall would be 1-1/2” with the rest being braced ¾”. I can add to the depth to the design if needed. I would wire the drivers in sets of two (wire the voice coils in series and the drivers in parallel to produce an 8 ohm load) and drive each set off one channel of my Yamaha P7000S. This would give me approximately 350 watts per driver from one amp so I may need to add another amp to get top performance.
Here’s the strange thing, using the same drivers with the same power input, in the same cabinet size, the graphs in Unibox are very, very close. I think this is because you have to subtract the port volume which gives you a smaller internal volume for the ported sub verse the sealed sub, 135L vs 110L. This leads to estimated outputs of (sealed vs ported) 109db-109db at 20hz, 104db-106db at 15hz and 98db-100db at 10hz. This does not take into consideration, the second subwoofer. It looks like the sealed design is the way to go considering it doesn’t have any of the drawbacks of the ported design and drop off in performance shouldn’t affect me. If something doesn’t look right in my calculations or assumptions, please let me know.
How would a design like this compare to a Mal-X with two 18” PRs?
I see that the Shiva-X is on sale for $149 plus shipping. This has got me thinking about building a set of subwoofers, each with 2 drivers, both mounted on the front of the enclosure, tuned to 15-16 Hz. I like the idea of using 12” drivers because it keeps the width of the tower to a minimum. The basic size of the tower would be 13-1/2” wide, 45” tall and 17-1/2” deep, the front wall would be 1-1/2” with the rest being braced ¾”. I can add to the depth to the design if needed. I would wire the drivers in sets of two (wire the voice coils in series and the drivers in parallel to produce an 8 ohm load) and drive each set off one channel of my Yamaha P7000S. This would give me approximately 350 watts per driver from one amp so I may need to add another amp to get top performance.
Here’s the strange thing, using the same drivers with the same power input, in the same cabinet size, the graphs in Unibox are very, very close. I think this is because you have to subtract the port volume which gives you a smaller internal volume for the ported sub verse the sealed sub, 135L vs 110L. This leads to estimated outputs of (sealed vs ported) 109db-109db at 20hz, 104db-106db at 15hz and 98db-100db at 10hz. This does not take into consideration, the second subwoofer. It looks like the sealed design is the way to go considering it doesn’t have any of the drawbacks of the ported design and drop off in performance shouldn’t affect me. If something doesn’t look right in my calculations or assumptions, please let me know.
How would a design like this compare to a Mal-X with two 18” PRs?
