white4d96 Posted November 5, 2009 Author Report Share Posted November 5, 2009 (edited) Alrighty, so I did some number crunching and came up with some quick dimensions but I wanted to check and see if they were alright. I'm using the full width of the trunk (36") and full height(16") (External dimensions), one ported chamber at front of trunk (near seats) and one sealed chamber in back. I got 14" internal depth for the ported chamber and 7" internal for the sealed, for a total EXTERNAL depth of 26" if I double-baffle the sub baffle. Port has not been decided on yet placement wise but I was thinking about doing two 6x9-10" ports using the factory 6x9 holes for minimal hackage. Any thoughts on that? If I went this route port length would be about 44" for a 40Hz tune so I think I would have enough port to get there. Edit 'Cause I'm an idiot Edited November 5, 2009 by ktownsdriftking Quote Too many projects, too little time... Link to comment Share on other sites More sharing options...
white4d96 Posted November 5, 2009 Author Report Share Posted November 5, 2009 Just realized I would probably need to do internal ports so the ported chamber will likely be deeper. How would you recommend running the ports? Or would you recommend a different setup? Maybe like a 34.5x3 slot across the bottom then curving up out the box and through the tray? Or bad idea? I also am unsure about angling the port after the tray. I can guesstimate an angle but am not sure how to make the cuts to do it. Quote Too many projects, too little time... Link to comment Share on other sites More sharing options...
Boon Posted November 5, 2009 Report Share Posted November 5, 2009 Errr... if those plots are accurate, the frequency response of both those boxes is AWFUL. You know how people think bandpass boxes are 1-note-wonders? That's because of boxes that plot like those.... A good bandpass plot should go up - FLAT FLAT FLAT - down. Quote 10.x volts fo' life! Link to comment Share on other sites More sharing options...
white4d96 Posted November 6, 2009 Author Report Share Posted November 6, 2009 (edited) Good point. I was hoping that cabin gain would boost the decline above the peak but on second thought... I also messed with the upper limit of the chart on WinISD because the top was chopped off, if that clears anything up maybe...probably not. Edited November 6, 2009 by ktownsdriftking Quote Too many projects, too little time... Link to comment Share on other sites More sharing options...
white4d96 Posted November 6, 2009 Author Report Share Posted November 6, 2009 Got a new plan i spec'd out in WinISD, if anyone else has it maybe they could look at it? (these are all with the type r's TS params plugged in btw) IDK how well this will work though, I just started with the above plan and tweaked until I got a flatter curve 4 cubes sealed 4 ported to 40Hz with 1 34.5x3 slot port (35" port length) It's showing 110dBs at 20Hz, 119.8@30Hz, 124.2@40Hz, and descends from there (this is assuming 1500w and 2ohms) Idk if the huge sealed chamber will be an issue though, loss of cone control a possibility? a guarantee? Quote Too many projects, too little time... Link to comment Share on other sites More sharing options...
Boon Posted November 6, 2009 Report Share Posted November 6, 2009 (edited) Dude what's the EBP of a Type R? It may just be that they suck ass in a bandpass. EDIT: That's still a shithouse response man, +-7db response is pretty awful. Why do you care about 20hz response anyway? Edited November 6, 2009 by Boon Quote 10.x volts fo' life! Link to comment Share on other sites More sharing options...
white4d96 Posted November 6, 2009 Author Report Share Posted November 6, 2009 I listen to a lot of C&S music, hence the 20Hz response. Sorry I'm a newb at this, whats EBP? Quote Too many projects, too little time... Link to comment Share on other sites More sharing options...
Boon Posted November 6, 2009 Report Share Posted November 6, 2009 Efficiency Bandwidth Product. Fs divided by Qes. Tells you what sort of box the woofers suit. Yours is 56hz so they should work in a 4th order. But first we need to review your goals. 20hz? Seriously? If you want a box that plays 20hz loud it's going to suck awful shit at anything above about 30hz. We're talking seriously specialist application. That's WAY WAY below the natural roll-off of your subs. Without having the numbers and box programs here you're probably going to want a TINY TINY little sealed chamber to control excursion at that frequency with a HUGE ported chamber. Or maybe even a series-tuned 6th order. But it will be a 1 note wonder and sound like shit. Honestly. 20hz. Maybe a horn would get you there and still have a reasonable bandwidth but it'll be simply ENORMOUS. Quote 10.x volts fo' life! Link to comment Share on other sites More sharing options...
white4d96 Posted November 6, 2009 Author Report Share Posted November 6, 2009 should I tune around the EBP? I'm sorry if I'm being a hassle, you are being a huge help though, thanks a million. Quote Too many projects, too little time... Link to comment Share on other sites More sharing options...
Boon Posted November 6, 2009 Report Share Posted November 6, 2009 EBP tells you what kind of box to put it in. A million other things tell you where to tune it. No hassle But yeah. We need to decide on a big pile of things and then I'll do a box design for you. Can be my project for the weekend or something (Sorry if these have been answered above, I skim-read it) 1. Do you REALLY want to play down to 20hz? 2. What car is this going in? 3. What dimensions do we have to work with? Quote 10.x volts fo' life! Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.