strocket Posted June 19, 2015 Author Report Posted June 19, 2015 Dont laugh... And I cant get everything to line up perfectly
Triticum Agricolam Posted June 19, 2015 Report Posted June 19, 2015 Looks like you have a good start. Nothing to laugh at there. It will make your life with Sketchup a lot easier if you put every piece into a group. After you make a piece, triple click on it and select "Make Group". This will keep your pieces from interfering with each other when you work on them. To edit a piece that is in a group just double click on it and then you can do whatever you want. If I understand you correctly you want to put an angle on your bottom piece to match the sides? To do that use your Tape Measure Tool to make a guideline running down the edge of your side piece. Just select the Tape Measure tool and click somewhere on the edge, then click a little farther down the edge and that will create the guideline. You can then click the bottom front edge of your bottom piece and drag it till its on the line. I probably didn't describe that well, hopefully you can follow. "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:
Joe X Posted June 19, 2015 Report Posted June 19, 2015 Op I love the effort you have put in your build, asking myself what's not going well with it, probably you should show better pics of how it was mounted showing clearance of the ports ans subs and all, also measurements of the box and calculations you did, also, have you considered different drivers? There are few 8" drivers that really hit hard which seems like what you are wanting, subs like the Sundown SA-8? You could probably fit one there or a 10" sub maybe in similar airspace.
strocket Posted June 19, 2015 Author Report Posted June 19, 2015 Joe X, Thanks for your support! This has been a lot different than what I was used to in the past. I remember throwing sealed boxes together back in the day and it being so easy. I would make cuts on the table saw free hand and my "precision cuts" were made with a jig saw! LOL!! I knew I was going to need a tube of silicone at the end, and the carpet would cover everything else. Now being older and more experienced I take a lot more pride in my work! The box I posted pictures of went together so perfectly I didn't need any additional sealing with caulk or silicone when I was done. Not saying caulk or silicone is a bad thing, but its definitely a jump from how I built things in the past. Now that I decided to do my first ported build I'm realizing its not as simple as making the box a little bigger and throwing a piece of PVC in there. I've decided to scrap the other box. I spent about 30 min the other day trying to get it apart.... trust me, its not happening. I've done a lot of research and Triticum has pointed me in a new direction and has given me a lot of help thus far in the new build. I realize that there are tons of other options as far as drivers are concerned. My brands of choice have always been Rockford or Kicker and have been pleased with their results. I've always had trucks with minimal room for a box and what they had to offer was more than sufficient. Moving up to these JL Audio drivers excited me, and unfortunately I'm stuck with them at the moment. I'm not expecting competition levels by any means. I've got an 03 F150 with a ProBox and 2 10" Kicker Comp CVRs and 400W and it bumps quite a bit. That's pretty much what I'm comparing too. If you could hear how the box I just finished sounds you would laugh at me and then agree that there is much more bump that can be squeezed from these little 8s. The dimensions that must stay constant are the height and the depth since they're going behind a seat. Height is 18", depth is 8.25" on the bottom and 5" on the top. Width is limited to about 35" if possible, 40" at an absolute max. The drivers also have to sit flush with the face of the box as you can see in the pics because the back of the seat is not just fabric, its plastic. I was playing around with WinISD and had a width of 28" with the above dimensions which gave me 1 cu. ft. of net volume, with a slot port tuned to 35Hz with a dimension of 3.5" x 4.75" x 35" , which was roughly 16.62 in sq cross area. I'm not sure if I'm reading it correctly but the driver is peaking at 60Hz @ 1.3dBs. Shouldn't it be peaking at what the box is tuned to? If so, the only way to get it to peak close to 35Hz was to increase box volume to 3 cu. ft. and make the port 3.5" x 4.75" X 8.77". Which makes me lost again I can send you the WinISD file if needed
Triticum Agricolam Posted June 19, 2015 Report Posted June 19, 2015 I plugged your numbers into WinISD and got the same results you did. Just because you are tuned to 35 Hz doesn't mean you will have peak output there. Actually the frequency response you are getting is what I would consider to be very good. Cabin gain is going to boost your low end output significantly. With that boost from cabin gain your frequency response in your vehicle will probably be peaking somewhere in the area of 30-40 Hz, which is just what you want IMHO. You can get a ROUGH approximation of what cabin gain will do by adding a filter in WinISD. If you click on the filter tab and click add you can then enter in the filter like this: Since your vehicle is a truck I'd change f0 from 60 Hz to 75 Hz. This will just be a very rough approximation of what cabin gain is going to do, but it will give you an idea at least. "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:
strocket Posted June 19, 2015 Author Report Posted June 19, 2015 So the numbers we've been working with is going to give us the hardest/loudest hitting bass for these drivers? The only other "issue" I've notice has been with the port noise. WinISD is showing an 89 Ft/s peak. Should I increase port area a little to try and get that down or am I sill in the right range?
Triticum Agricolam Posted June 20, 2015 Report Posted June 20, 2015 89 Feet/sec is OK. You should be fine. "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:
strocket Posted June 20, 2015 Author Report Posted June 20, 2015 OK!! So I figured this thing out... kinda This is where I am Here is my issue. My port length is supposed to be 33.06" long, but the length from the beginning of the port to the center radius of the bend is 27.875", and from that point down to where the bend should start bending back is 2.9". Which leaves me about 2.25" left of port length. I still need to add some 45s in the corners (which I cant figure out how to do)... I figured by the time I add the second one on the bottom of the bend that will pretty much account for that last 2.25". Would you agree? Also... I cant for the life of me figure out how to get this cut up But every time I delete the last little piece this happens... Could you help me out with that and point me in the right direction to make those 45s Thank you sir!!
Triticum Agricolam Posted June 20, 2015 Report Posted June 20, 2015 ... Here is my issue. My port length is supposed to be 33.06" long, but the length from the beginning of the port to the center radius of the bend is 27.875", and from that point down to where the bend should start bending back is 2.9". Which leaves me about 2.25" left of port length. I still need to add some 45s in the corners (which I cant figure out how to do)... I figured by the time I add the second one on the bottom of the bend that will pretty much account for that last 2.25". Would you agree? Also... I cant for the life of me figure out how to get this cut up ... So for your port, WinISD doesn't calculate the length of slot ports correctly and you will end up tuning lower than you want. I'd just put the top 45 piece in there and call it good. That should bring your effective port length to about 29", which is closer to what you want to be to get the tuning right. As far as making the roundover on the bottom port piece, I don't worry about roundovers on pieces with angled edges like that. The problem you ran into isn't uncommon and it just isn't worth the time to make it look right. In my mind I know the roundover will be there and that's good enough. "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:
strocket Posted June 20, 2015 Author Report Posted June 20, 2015 Alright..... I finally finished it. The only thing that I might have an issue with is the three braces that are behind the sub bracket. Originally I was planning on using the far left side of the box as one mount and one brace to hold the other side. But I couldn't stand the way it looked with the subs offset to one corner. So I centered it. With me centering it I now needed three braces. I've seen how the braces that are hallowed out are weighed to find the volume the brace takes up but I don't have a scale. So I have no clue as to how much "extra" space is going to be taken up... I"m guessing hardly any? And just to get an idea of how basic it is outside.... I'm also going to put a chamfer on it the way I did the other box, but I cant figure out how to do that on sketchup. Any feedback would be greatly appreciated!!
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