DiBo Posted November 24, 2018 Report Share Posted November 24, 2018 Building an enclosure for 2x sundown nsv2's and the woofer displacement and ported volume seem wrong to me. I believe it was .17 displacement ( for an 18?) And 3ft² sealed and 4ft³ ported. If these specs are indeed correct then I don't have an issue but before I build this box is there anybody that can verify that this 18 will work in an 8ft³ ported enclosure? This sub also has a high Qes and low fs which makes it a great 4th order woofer. Anyone have any idea of what the sealed side would look like? Suggested parameters are 3 foot sealed and 4 foot so do I just make a 6-foot sealed section if I decide to do a 4th order? Link to comment Share on other sites More sharing options...
DiBo Posted November 25, 2018 Author Report Share Posted November 25, 2018 Enclosure recommendations are accurate. Guess I'll be building an 8ft³ box for 2-18's... That just sounds off to me. We'll see what happens. Link to comment Share on other sites More sharing options...
Joe X Posted November 25, 2018 Report Share Posted November 25, 2018 Overtime Ive seen faulty driver displacements at least from sundown and RF they were later fixed, as for 4 net for a single 18" Zv3 18s worked in that same space, best is to model the driver to make your mind about what you are being given. Sometimes there's a catch running a sub specified for low operating net airspace. Link to comment Share on other sites More sharing options...
DiBo Posted November 25, 2018 Author Report Share Posted November 25, 2018 By model you mean plugging in box and woofer specs to see response curve rt? That's a skill I have yet to learn. Definitely on my "must learn" list. If I post enclosure specs here can you model it for me? I'll be learning this very soon. 48x20hx30d Port 17.5x7.5x30 1.5" port thickness .75 baffle thickness. Triple baffle Link to comment Share on other sites More sharing options...
Joe X Posted November 26, 2018 Report Share Posted November 26, 2018 So let's try their ported recommendation (4 net) and a 6 net alternative ( yellow plot ) picked 3K per driver for power: You can see that 4 net projected performance will be near flat, the 6 net peaks more and you are getting more output for your power, the SPL guy will pick 6 net of course. Now the excursion plot, they say it's above 2 inches peak to peak assuming it's linear excursion Xmax would be say 2.2 inches p-p/2= 1.1 in or like 28mm: Again assuming they are giving linear excursion, there would be no problems even if the box was 8 net per driver. Finally here's vent airspeed, just me picking a port area to match 23-24 m/s peak airspeed: Results are 60 square inches per driver for 4 net per driver and 70 square inches per driver for the 6 net. So if the question is if you are limited to 4 net with those drivers then the answer seems no even if you are over powering some. Will work on 4 net? Yes in a flat like alignment losing about 3dB of tuning bass to the 6 net, Link to comment Share on other sites More sharing options...
DiBo Posted November 26, 2018 Author Report Share Posted November 26, 2018 So I can go basically build this 4-6ft³ with 60-70sq in of port area. 4 nets a flatter response and 6 gives me about a 3db bass boost. 6ft³ net doesn't seem too peaky at all. I wonder why Sundown recommends 4ft³ when 5-6ft³ seems the better recommendation. I appreciate the lesson sir. Link to comment Share on other sites More sharing options...
Joe X Posted November 26, 2018 Report Share Posted November 26, 2018 Fi gives you a range to work with but I guess is more appealing to someone looking for a driver that works on a small box to see it's specified for a small box than to be given a range. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.