ckeeler11 Posted October 12, 2016 Report Share Posted October 12, 2016 6.5" square will probably be pretty good. for 45 Hz tuning it will need to be about 27" long. Link to comment Share on other sites More sharing options...
Evilthx Posted October 12, 2016 Author Report Share Posted October 12, 2016 If I can, I'm going to try to keep it close to the manufacturer recommendation. If their graph is accurate to that port size, it should be good at 40hz and my amps bass boost is centered at 45hz I think. It should sound great. The goof is, RF has a 12 with almost identical specs... Kenwood Excelon KDC-X998 JBL GTO608C Components JBL GTO628 Coaxials JBL P1224 12" dual 4ohm Subwoofers Alpine MRV-F545 - Alpine MRX M100 Hand Built by Me 5.9cu.ft. slot ported enclosure tuned to 27hz Link to comment Share on other sites More sharing options...
Triticum Agricolam Posted October 12, 2016 Report Share Posted October 12, 2016 So you are going to start with the 55 Hz front chamber tuning? "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...
Evilthx Posted October 13, 2016 Author Report Share Posted October 13, 2016 So you are going to start with the 55 Hz front chamber tuning? Oh I have no clue... I have little knowledge of how each chamber affects the sound on a band pass box. I have been trying to use WinISD Pro but the damn program won't let me save it when I put in the speakers parameters. I used a pre-loaded speaker that I thought was close to the specs so I know the program will do what I want it to do but man I want to use my speakers specs. Kenwood Excelon KDC-X998 JBL GTO608C Components JBL GTO628 Coaxials JBL P1224 12" dual 4ohm Subwoofers Alpine MRV-F545 - Alpine MRX M100 Hand Built by Me 5.9cu.ft. slot ported enclosure tuned to 27hz Link to comment Share on other sites More sharing options...
Triticum Agricolam Posted October 13, 2016 Report Share Posted October 13, 2016 Putting the parameters into WinISD can be a hassle. Here is a driver file I did for you: https://dl.dropboxusercontent.com/u/1642665/JBL%20P1224.wdr "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...
ckeeler11 Posted October 13, 2016 Report Share Posted October 13, 2016 If I can, I'm going to try to keep it close to the manufacturer recommendation. If their graph is accurate to that port size, it should be good at 40hz and my amps bass boost is centered at 45hz I think. It should sound great. The goof is, RF has a 12 with almost identical specs... So you are going to stick with 2x 4" round ports? as the port gets bigger it needs to get longer to keep same tuning. if you are going with a 6.5" square port at 7" long the tuning will be ridiculously high. Link to comment Share on other sites More sharing options...
Evilthx Posted October 13, 2016 Author Report Share Posted October 13, 2016 Thanks everyone, you are a big help. I found Steve Meades write up on 4th order boxes and that also will help a lot. The build should start a week or so into November. Kenwood Excelon KDC-X998 JBL GTO608C Components JBL GTO628 Coaxials JBL P1224 12" dual 4ohm Subwoofers Alpine MRV-F545 - Alpine MRX M100 Hand Built by Me 5.9cu.ft. slot ported enclosure tuned to 27hz Link to comment Share on other sites More sharing options...
Evilthx Posted October 14, 2016 Author Report Share Posted October 14, 2016 Putting the parameters into WinISD can be a hassle. Here is a driver file I did for you: https://dl.dropboxusercontent.com/u/1642665/JBL%20P1224.wdr I tried... it still won't save or load in WinISD Pro but did load into WinISD (older version). If the experts could check out this pic and let me know if it is a good curve or not, that would be cool. I literally changed it from a round to a square port and set the tuning at 47hz. This made the smoothest curve. Kenwood Excelon KDC-X998 JBL GTO608C Components JBL GTO628 Coaxials JBL P1224 12" dual 4ohm Subwoofers Alpine MRV-F545 - Alpine MRX M100 Hand Built by Me 5.9cu.ft. slot ported enclosure tuned to 27hz Link to comment Share on other sites More sharing options...
Triticum Agricolam Posted October 14, 2016 Report Share Posted October 14, 2016 A 4" x 4" port is going to be much too small. I think its under the "Plot" tab you can enter in how much input power you will be running, then you can watch the "Vent Mach" number in the "Vents" tab to see what your port velocity will be. Keep it under .08, under .06 would even better. "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...
Evilthx Posted October 15, 2016 Author Report Share Posted October 15, 2016 The plot tab helped. Thanks. Seems like a 6th order covers way more frequencies than a 4th order. Is it any less effective to NOT port a Bandpass box through the rear deck and just have the ports firing into the trunk? Kenwood Excelon KDC-X998 JBL GTO608C Components JBL GTO628 Coaxials JBL P1224 12" dual 4ohm Subwoofers Alpine MRV-F545 - Alpine MRX M100 Hand Built by Me 5.9cu.ft. slot ported enclosure tuned to 27hz Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.