thegr8cody Posted October 24, 2012 Report Share Posted October 24, 2012 Well with all the talk about bandpasses i decided to give a shot designing one. Ive never built one or.designed one. I have built quite a few boxes though. I did come across one snag which ill bring up in a second. Rear chamber 6 cubes. 3 per sub. Front chamber is 18. Box dimensions are 38x31x44. Inside dimensions are 36.5x29.5x42.5 this will allow me to slide it in through the back then double/triple wall it after its inside. Port is 29.5x9 and 7" long which is 270 sq in at 44hz i believe? I know its a little on the low side but i mainly want it for lows.now my snag is that i cant fit the 18's side by side to do a flat wall for the rear chamber. And i heard of some claiming firing woofers towards each other causes cancellation.? But i dont want subs on one.side as port is in the middle of the.box so i was thinking one on each side inverted. I gave myself .4 for sub displacement and 1.4 for port. The box comes out to 26.4 then minus port and subs leaves me 24.6 im gonna try to avoid internal bracing and go with double wall and 2x4's. Any input on this box? criticism? Things i left out? 1998 gmc sierra h/u:eclipse cd3200 sub:dd9518g d1.5 amp:jl e300/4 sub amp:dd m2a front stage:id ctx65cs dc power 270 alt lots of kicker 1/0 Link to comment Share on other sites More sharing options...
OldsBoomer Posted October 24, 2012 Report Share Posted October 24, 2012 The cancelation will reinforce the lows slightly more. Hence why clamshell walls work so well on the lows. It cause more resistance in large movement of the cone. If you dont want them facing eachother directly make the angles about 45 itll greatly reduce the cancelation affect your talking about. Just curious are you going for SPL? A 3:1 ratio is more amed toward spl and a narrower bandwidth. Try 2:1 for a flatter response Suburban Coming Soon Link to comment Share on other sites More sharing options...
thegr8cody Posted October 25, 2012 Author Report Share Posted October 25, 2012 Im shooting for daily, I just read where a 3.1 Is more efficient. If i go 2:1 i can fit 3 18's. I can do 9 sealed and 18 ported but sub placement is an issue as i dont know how i would place three subs. 1998 gmc sierra h/u:eclipse cd3200 sub:dd9518g d1.5 amp:jl e300/4 sub amp:dd m2a front stage:id ctx65cs dc power 270 alt lots of kicker 1/0 Link to comment Share on other sites More sharing options...
OldsBoomer Posted October 25, 2012 Report Share Posted October 25, 2012 If it'll be that hard to fit a third sub its better not to try and shor horn it in there. The higher the ratio the bigger of a peak you'll have when i built my bandpass i did a 2:1 and it was extremely flat. I was using Fi Q's Suburban Coming Soon Link to comment Share on other sites More sharing options...
barney91 Posted October 25, 2012 Report Share Posted October 25, 2012 Sorry to butt in but I've designed a 4th oder as well and I have a 1:1.5 ratio is that good for daily not spl Alpine 9884 RF T2 comp set up front The Epicenter 2x RF T10001bd 2x Sundown sa-15 t-line Big 3 Smd DD-1 Link to comment Share on other sites More sharing options...
OldsBoomer Posted October 25, 2012 Report Share Posted October 25, 2012 Sorry to butt in but I've designed a 4th oder as well and I have a 1:1.5 ratio is that good for daily not spl like i said the bigger the ratio the more spl oriented. If i end up building my 4th order wall ill be around 2-1.5:1 Suburban Coming Soon Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.