Tjwubs34 Posted January 5, 2017 Report Share Posted January 5, 2017 So i took a swing at building a box for my brand new FI sp4 15" v2. And it sounds terrible. Currently the sub is wired to 2 ohms on a soundqubed 3500. I am running stock so once i upgrade my power ill wire to .5 ohm. Anyways i used the box program called Torres and i think its inaccurate because the subwoofer doesnt hit hard at all. My old Sundown x 10 hit harder. First i thought it was my amp settings. I have my subsonic at 20 hz, my lpf at 50 hz, my bass boost at 0, and my gain at about half. I sort of think its just my power. I know this is a 4" coil and will require alot of power so maybe it is not coming "alive" but this is the quietest sub ive ever owned. And yes its wired right i checked with a multimeter its wired to 1.8 ohm. Let me provide my torres box specs and if someone can check if its right that would be very cool. And also provide a better box that will fit this sub. My car space is 39" wide, 18" high, and 23" deep. i drive a hatchback so its 18" to the bottom of the back window. Heres my box specs based off torres.... Box is: 32" Wide 18" High 23" Deep Port is: 4" Wide 16.5" High 31.5" Long (its an L port. The first peice is 19 inches long and the 2nd peice is 14 long) Torres says with my threaded rod bracing, my subwoofer displacement of .21 cuft^3 and my extra baffle (the sub is on top i glued 2 layers of 3/4mdf together for the top) box is Tuned to ~31HZ Port Area is: ~66 inches of port area Box size: 4.4 Cuft^3 Which puts it at roughly the 12-16" port to box size range....... Is torres accurate? I literally wasted $70 on this box with the time and work. If the box is correct i know its my power or maybe i bought a bad amp.... If its the box i will make a new one if someone can provide a better 15" sp4 box... Im going for the lows and decent highs. I figure 31hz is pretty good place Thanks!!!! Link to comment Share on other sites More sharing options...
teardrop Posted January 5, 2017 Report Share Posted January 5, 2017 it looks good to me also id say thats not enuf power for that sub Link to comment Share on other sites More sharing options...
Triticum Agricolam Posted January 5, 2017 Report Share Posted January 5, 2017 Your box specs look fine to me. There are two things that could be causing reduced output. One is if you have a leak in your box somewhere. Any leak at all will be VERY detrimental to output. You might want to check everything over to make sure its sealed up well. The other thing it could be is your amp just isn't putting out much power. Having your "gain at about half" really means nothing. You might be only sending your sub 100 watts. I'd suggest finding someone with a DD-1 or o-scope so you can set your gain properly. Having your LPF set at 50 hz is really low IMHO, but to each their own. "Nothing prevents people from knowing the truth more than the belief they already know it.""Making bass is easy, making music is the hard part."Builds: Link to comment Share on other sites More sharing options...
neuspeedescort Posted January 5, 2017 Report Share Posted January 5, 2017 why is this the second time you have posted this under a different heading? must not have liked the same answers the first time. Link to comment Share on other sites More sharing options...
Tjwubs34 Posted January 5, 2017 Author Report Share Posted January 5, 2017 13 minutes ago, Triticum Agricolam said: Your box specs look fine to me. There are two things that could be causing reduced output. One is if you have a leak in your box somewhere. Any leak at all will be VERY detrimental to output. You might want to check everything over to make sure its sealed up well. The other thing it could be is your amp just isn't putting out much power. Having your "gain at about half" really means nothing. You might be only sending your sub 100 watts. I'd suggest finding someone with a DD-1 or o-scope so you can set your gain properly. Having your LPF set at 50 hz is really low IMHO, but to each their own. So I actually bought that amp off a guy and found out later it blew a MOSFET and was repaired which he failed to tell me when buying. He did play it on his subs and they were loud so I doubt its the amp.. A local builder said my port length is too long he did the math and it's suppose to be only 13" long not almost 32". So idk what to do honestly. I can try to seal the box better than I did but maybe only being wired to 2 ohm is my prpblem. Super frustrating Link to comment Share on other sites More sharing options...
Tjwubs34 Posted January 5, 2017 Author Report Share Posted January 5, 2017 1 minute ago, neuspeedescort said: why is this the second time you have posted this under a different heading? must not have liked the same answers the first time. I realized I submitted it under wrong topic Link to comment Share on other sites More sharing options...
neuspeedescort Posted January 5, 2017 Report Share Posted January 5, 2017 4 minutes ago, Tjwubs34 said: So I actually bought that amp off a guy and found out later it blew a MOSFET and was repaired which he failed to tell me when buying. He did play it on his subs and they were loud so I doubt its the amp.. A local builder said my port length is too long he did the math and it's suppose to be only 13" long not almost 32". So idk what to do honestly. I can try to seal the box better than I did but maybe only being wired to 2 ohm is my prpblem. Super frustrating what if you cut the end off the box that the port turns 90 degrees. causing you to loose no airspace and shortening the port to just 19 inches. that would raise the tuning of the box. may bring life back into it. it looks to only raise your tune about 5hz. so 36ish wouldn't be a bad thing. then just run thru the box with some silicone or wood glue to fill in any gaps. Link to comment Share on other sites More sharing options...
Tjwubs34 Posted January 5, 2017 Author Report Share Posted January 5, 2017 14 minutes ago, neuspeedescort said: what if you cut the end off the box that the port turns 90 degrees. causing you to loose no airspace and shortening the port to just 19 inches. that would raise the tuning of the box. may bring life back into it. it looks to only raise your tune about 5hz. so 36ish wouldn't be a bad thing. then just run thru the box with some silicone or wood glue to fill in any gaps. I don't think I'll be able to rip out that 2nd peice I screwed it in from top and bottom. The whole box is glued with titebond.. I think either I made my box out of spec because maybe Torres is crap, don't have enough power, or maybe even a bad amp. I need to to process of elimination to figure it out.. I was hoping someone could do the math and tell me if my box is even appropriate enough Link to comment Share on other sites More sharing options...
neuspeedescort Posted January 5, 2017 Report Share Posted January 5, 2017 the portion of the port that is running the back side of the box you leave there. it's the portion of the port you can see into that i was suggesting removing. Torres is not the issue. that is a very nice simple program. Link to comment Share on other sites More sharing options...
Tjwubs34 Posted January 6, 2017 Author Report Share Posted January 6, 2017 23 minutes ago, neuspeedescort said: the portion of the port that is running the back side of the box you leave there. it's the portion of the port you can see into that i was suggesting removing. Torres is not the issue. that is a very nice simple program. If I take off the port side going length wise it would just leave a big hole in the box... What purpose does leaving the peice along the back do Link to comment Share on other sites More sharing options...
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