airofu Posted May 2, 2020 Report Share Posted May 2, 2020 I'm building up a box for my Skar VXF 12" (0.14ft displacement, pushing around 1700rms currently) looking at 2.5ft net tuned to 28hz and 30sq port. I've designed the box dimensions in subboxpro external height 17.56" x Width 17" x Depth 25.44" to fit in the back and happy with it, but then I checked in Torres and I think I copied it all the same, but I noticed Torres gives me about 0.18 less port displacement so more net volume 2.68 - not sure how Torres is designing the port in terms of location and bends in the box. But basically is the subboxpro design accurate and looks ok? Link to comment Share on other sites More sharing options...
airofu Posted May 5, 2020 Author Report Share Posted May 5, 2020 Hoping to check the subboxpro design I've got here looks ok before I start it? eg. net volume and port length are calculated correctly thanks Link to comment Share on other sites More sharing options...
1point21gigawatts Posted May 5, 2020 Report Share Posted May 5, 2020 You increased the net volume 34% past the recommended max net volume and you and decreased the tuning frequency 15% below recommend. So you must at least increase the port area 34% past the recommended port area. So that means you need about 40sq” of port area. 39.865sq” to be exact, but it doesn’t have to be exact, close as possible though. And personally if the company recommends a certain frequency, in this case, 33hz, I would stay at or close to that frequency level. And I wouldn’t of increased the volume past 20% recommended, especially not 34%. That subwoofer calls for 2 cubic feet of volume after subwoofer and port displacement and you designed an enclosure 2.68 cubic feet after port and subwoofer displacement. .68 is 34% of 2 cubic feet. I wouldn’t design that enclosure past 2.4 cubic foot after displacements making it 20% bigger than recommended and then I would make the port area 20% bigger making it 35.7sq” and I would tune it to 32hz. When an enclosure is too big you loss overall output, lower end too. So when you designed a big enclosure and tuned it low, you wanted low and deep bass but by going too far you have veered away from the goal you were shooting for. But you aren’t too far off course. 2.4 cubic foot tuned to 31-32hz with a port area of 35.7sq” or very close to, will be optimal for that subwoofer and make you a lot happier than that design you posted. “How can we help you?” “And don’t forget to tell them that the customer isn’t always right.” Link to comment Share on other sites More sharing options...
airofu Posted May 5, 2020 Author Report Share Posted May 5, 2020 Thanks for the feedback, the bit I'm still stuck on is that subboxpro gives me 2.5 net after port displacement which is what I was aiming for originally, but Torres/yourself is saying the 2.68 net which is pushing it like you say. Is subboxpro wrong? Link to comment Share on other sites More sharing options...
1point21gigawatts Posted May 5, 2020 Report Share Posted May 5, 2020 14 hours ago, airofu said: Thanks for the feedback, the bit I'm still stuck on is that subboxpro gives me 2.5 net after port displacement which is what I was aiming for originally, but Torres/yourself is saying the 2.68 net which is pushing it like you say. Is subboxpro wrong? I don’t see where Subboxpro offers a pre designed enclosure plan for a Skar VFX 12”, just the VVX 12”. I doubt that subboxpro gave a pre designed plan for that subwoofer with numbers like that. Every time I’ve used subboxpro for pre designed plans, the plans are never above max recommended by the subwoofer company. Either right at it or a point or 2 or few under, not half a cubic foot over max recommendation. That’s critical when it comes to such a small enclosure. 2.68 is 34% bigger and 2.5 is 25% bigger. If you’re bent on keeping is at 2.5 then the port area has to be around 37sq”. But once you increase the port area it will decrease the net enclosure volume. So just increase the port area to 34-36sq” and the enclosure net volume will decrease and you will be at where you want to be or very close to which is fine. “How can we help you?” “And don’t forget to tell them that the customer isn’t always right.” Link to comment Share on other sites More sharing options...
airofu Posted May 6, 2020 Author Report Share Posted May 6, 2020 I really like the subboxpro design program, but I am still not sure why Torres is giving me different net volume unless I did a type somewhere regardless of final volume and tuning? I just don't want to go ahead with anything if subboxpro is somehow wrong vs Torres? Link to comment Share on other sites More sharing options...
1point21gigawatts Posted May 6, 2020 Report Share Posted May 6, 2020 1 hour ago, airofu said: I really like the subboxpro design program, but I am still not sure why Torres is giving me different net volume unless I did a type somewhere regardless of final volume and tuning? I just don't want to go ahead with anything if subboxpro is somehow wrong vs Torres? There are plenty of subwoofer enclosure programs and calculators. But they didn’t design the enclosure. You did. The programs just did the calculations and measurements for you. The figures entered creates the design. Your figures are incorrect, making your enclosure design flawed. Change your figures to what I’ve recommended. Just because a program is good doesn’t mean that it’s going to deliver ideal result because the one putting the figures in the program is putting the wrong figures into the program, thus creating bad results, no matter the program. And I forgot to say that by increasing the port area where it needs to be will not only put the net volume where it needs to be at but it will also raise the frequency a little bit to where it needs to be at. Those are my recommendations. Now love, peace and chicken grease. I’m outtie. Peace out. “How can we help you?” “And don’t forget to tell them that the customer isn’t always right.” Link to comment Share on other sites More sharing options...
airofu Posted May 6, 2020 Author Report Share Posted May 6, 2020 I know I designed it as I entered the figures in myself What I'm trying to work out now is why two different programs are giving me different net volumes when both dimensions are entered the same like in the screenshots. The difference I am seeing is that they are calculating the total port volume differently for some reason which I can't work out. Link to comment Share on other sites More sharing options...
ehall8702 Posted May 6, 2020 Report Share Posted May 6, 2020 3 hours ago, airofu said: I know I designed it as I entered the figures in myself What I'm trying to work out now is why two different programs are giving me different net volumes when both dimensions are entered the same like in the screenshots. The difference I am seeing is that they are calculating the total port volume differently for some reason which I can't work out. Maybe the bass box program isn't compensating for 3 common port walls like Torres? Since it's such a small amount of more volume that'd be my guess. Out if all the programs I have used , Torres seems to be the most accurate as far as getting me the tune I want ( last box at 27hz and subs barely move at 27hz for instance). I also see you don't have a double baffle in Torres, maybe it's already figured in on bassbox? 2009 Silverado 1500, 7.5" lift, 37x12.50r17s, Built Gen 4 5.3L ( 4.8l flat pistons, decked 243s, SS2 Cam, Pac 1218 springs, ported intake, 120mm TB, Long tubes, 3" duals HP tuner software tuned by me), 4l80e swapped and 4.56 gears. All done by me. stereo is Pioneer avh 600ex, all stinger rca, jp23 v1.5, skar rp150.4, and hertz hpd4. 2 SHCA 6.5 8ohm, 1 SHCA 3.5", and 1 DS18 tw120pro in each door. The 3.5 mid and 3.5" tweeters are powered by the skar rp150.4, the 6.5s are powered by the hertz bridged @4 ohms. Dual runs of 3/0 welding cable, 300a alternator, 2 Vmax AGMs up front. current sub is a AB XR 12 ( dual 2 ohm) with bottom spider cut out in 2.25 cubes at 32hz Link to comment Share on other sites More sharing options...
1point21gigawatts Posted May 6, 2020 Report Share Posted May 6, 2020 Different enclosure programs almost always never match exactly when you enter the same figures in both. That’s not the problem I’m trying to fix. The problem is the figures you entered. Just pick subboxpro and enter better figures. Don’t use different programs and compare them because it’s just gonna mess with you. Just find one good program and run with it. “How can we help you?” “And don’t forget to tell them that the customer isn’t always right.” Link to comment Share on other sites More sharing options...
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