agf144 Posted March 17, 2014 Report Share Posted March 17, 2014 ok so i am getting ready to build my first 4th order bandpass soon and have a question. The port area for a 4th should be much bigger than a normal ported box right? using this calculator i am getting around 188" of port area, which seems like a lot, would it be ok to have around 132" of port area? my ski hole in my car is only 13.5"x12.5" so my port would have to be 12"x11" internally edit: im running 2 soundqubed hds312s Chick took 3 shots of Jager, and then, pissed in my mouth.. oh.. wait.. naw.. that wasnt weird.. He probably tearin dat ass up every night. Reason for "insomnia" Ain't sleeping cause he's like a horny hamster on coke. 2000 grand prix gtp: SOLD My Home Theater Build (working progress) 2002 accord coupe subs: 2 soundqubed hds300 12s 4'1" towers tuned to 29hz sub: AQ hdc3 12 Amp: pioneer gm9061 amp: poineer gm9601 headunit: kenwood kdc 255u mids: SQ pro mids midbass: polk db 8s highs: stock mids/highs: shitty off brand Link to comment Share on other sites More sharing options...
agf144 Posted March 17, 2014 Author Report Share Posted March 17, 2014 Bump Chick took 3 shots of Jager, and then, pissed in my mouth.. oh.. wait.. naw.. that wasnt weird.. He probably tearin dat ass up every night. Reason for "insomnia" Ain't sleeping cause he's like a horny hamster on coke. 2000 grand prix gtp: SOLD My Home Theater Build (working progress) 2002 accord coupe subs: 2 soundqubed hds300 12s 4'1" towers tuned to 29hz sub: AQ hdc3 12 Amp: pioneer gm9061 amp: poineer gm9601 headunit: kenwood kdc 255u mids: SQ pro mids midbass: polk db 8s highs: stock mids/highs: shitty off brand Link to comment Share on other sites More sharing options...
Triticum Agricolam Posted March 17, 2014 Report Share Posted March 17, 2014 I would think your 132 sq in number should be enough, but the specs of the box will have an effect, so this is just a guess.. Things like flaring the ends of the port will help. What are your proposed box specs going to be? What xmax did you enter for the calculator? How much power are you going to put to these? "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...
agf144 Posted March 17, 2014 Author Report Share Posted March 17, 2014 I would think your 132 sq in number should be enough, but the specs of the box will have an effect, so this is just a guess.. Things like flaring the ends of the port will help. What are your proposed box specs going to be? What xmax did you enter for the calculator? How much power are you going to put to these? i put in 20 for xmax just a guess because soundqubed never released the specs. and the sealed will be 1.12 per chamber and ported is 4.4 here's a pic of what i have so far. and only plan on 1.2k per sub after i upgrade my electrical and buy new amp. edit: port is 23.75 " long tuned to 46hz Chick took 3 shots of Jager, and then, pissed in my mouth.. oh.. wait.. naw.. that wasnt weird.. He probably tearin dat ass up every night. Reason for "insomnia" Ain't sleeping cause he's like a horny hamster on coke. 2000 grand prix gtp: SOLD My Home Theater Build (working progress) 2002 accord coupe subs: 2 soundqubed hds300 12s 4'1" towers tuned to 29hz sub: AQ hdc3 12 Amp: pioneer gm9061 amp: poineer gm9601 headunit: kenwood kdc 255u mids: SQ pro mids midbass: polk db 8s highs: stock mids/highs: shitty off brand Link to comment Share on other sites More sharing options...
timc31610 Posted March 17, 2014 Report Share Posted March 17, 2014 I can't help you at all but I'm tuned in to see how it turns out! My Build Log 94 Civic http://www.stevemeadedesigns.com/board/topic/188644-94-civic-4-door-build-loq-suggestions-wanted-will-be-super-slow-mo/ Faceebook reluctantly Link to comment Share on other sites More sharing options...
Triticum Agricolam Posted March 17, 2014 Report Share Posted March 17, 2014 Thanks for your box specs. I plugged all the number into WinISD to see what it would say your port velocity is going to be. With 66 sq in of port area and 1200 watts of power for each driver it shows your max port velocity to be 17 m/sec. That's just about perfect IMHO. 18 m/sec is the number I try to stay under though I've found you get can get up around 23 m/sec or so if you have well flared ports, but really less is better. So here is what I think is going to be the hard part about building that box; figuring out how long the port needs to be. Depending on what port calculators you use and whether they use end correction or not, you are going to get numbers anywhere between 15.75" and 30.3". I see you have it as 23.75", how did come up with that number? Looking at your design it looks like the top and bottom of the port are close to the top and bottom of the enclosure. This is going to make it behave kinda like it has two port walls in common with the rest of the enclosure. That will make your tuning lower than you want based on the length most port calculators will give you. To get your tuning right I highly recommend you make your port removable so you can test and trim. You can measure the port tuning by doing an impedance sweep. There will be a dip in the impedance at the tuning frequency. If you make your port long to begin with you can then trim down and test until you get it where you want. "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...
agf144 Posted March 18, 2014 Author Report Share Posted March 18, 2014 Thanks for your box specs. I plugged all the number into WinISD to see what it would say your port velocity is going to be. With 66 sq in of port area and 1200 watts of power for each driver it shows your max port velocity to be 17 m/sec. That's just about perfect IMHO. 18 m/sec is the number I try to stay under though I've found you get can get up around 23 m/sec or so if you have well flared ports, but really less is better. So here is what I think is going to be the hard part about building that box; figuring out how long the port needs to be. Depending on what port calculators you use and whether they use end correction or not, you are going to get numbers anywhere between 15.75" and 30.3". I see you have it as 23.75", how did come up with that number? Looking at your design it looks like the top and bottom of the port are close to the top and bottom of the enclosure. This is going to make it behave kinda like it has two port walls in common with the rest of the enclosure. That will make your tuning lower than you want based on the length most port calculators will give you. To get your tuning right I highly recommend you make your port removable so you can test and trim. You can measure the port tuning by doing an impedance sweep. There will be a dip in the impedance at the tuning frequency. If you make your port long to begin with you can then trim down and test until you get it where you want. well i chose 23.75 because it gave me the 4.4 cubes i wanted for the ported section. changing the length just made it smaller or bigger but tuning freq didnt change more than about 1hz. i checked the 23.75 and box specs on the calculator above, torres, and win isd. and the port top and bottom will be touching the top and bottom of the box i have already taken into account the displacement and common walls. part of the reason i would like the port to be those dimensions is because it acts as bracing for the box also. i will definitely have flared ports even if i dont need them i like to flare them for looks and in my head they make it better even if the port is huge and doesnt need it. heres a couple different angles. Chick took 3 shots of Jager, and then, pissed in my mouth.. oh.. wait.. naw.. that wasnt weird.. He probably tearin dat ass up every night. Reason for "insomnia" Ain't sleeping cause he's like a horny hamster on coke. 2000 grand prix gtp: SOLD My Home Theater Build (working progress) 2002 accord coupe subs: 2 soundqubed hds300 12s 4'1" towers tuned to 29hz sub: AQ hdc3 12 Amp: pioneer gm9061 amp: poineer gm9601 headunit: kenwood kdc 255u mids: SQ pro mids midbass: polk db 8s highs: stock mids/highs: shitty off brand Link to comment Share on other sites More sharing options...
agf144 Posted March 18, 2014 Author Report Share Posted March 18, 2014 This will be my first attempt at a 4th does everything look right? Chick took 3 shots of Jager, and then, pissed in my mouth.. oh.. wait.. naw.. that wasnt weird.. He probably tearin dat ass up every night. Reason for "insomnia" Ain't sleeping cause he's like a horny hamster on coke. 2000 grand prix gtp: SOLD My Home Theater Build (working progress) 2002 accord coupe subs: 2 soundqubed hds300 12s 4'1" towers tuned to 29hz sub: AQ hdc3 12 Amp: pioneer gm9061 amp: poineer gm9601 headunit: kenwood kdc 255u mids: SQ pro mids midbass: polk db 8s highs: stock mids/highs: shitty off brand Link to comment Share on other sites More sharing options...
Triticum Agricolam Posted March 18, 2014 Report Share Posted March 18, 2014 Only thing I can think of is make sure your magnets will clear with your baffles angled like that. You may have to change the angles a bit. "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...
agf144 Posted March 18, 2014 Author Report Share Posted March 18, 2014 That's my biggest concern if they don't fit I'll make some angled spacers Chick took 3 shots of Jager, and then, pissed in my mouth.. oh.. wait.. naw.. that wasnt weird.. He probably tearin dat ass up every night. Reason for "insomnia" Ain't sleeping cause he's like a horny hamster on coke. 2000 grand prix gtp: SOLD My Home Theater Build (working progress) 2002 accord coupe subs: 2 soundqubed hds300 12s 4'1" towers tuned to 29hz sub: AQ hdc3 12 Amp: pioneer gm9061 amp: poineer gm9601 headunit: kenwood kdc 255u mids: SQ pro mids midbass: polk db 8s highs: stock mids/highs: shitty off brand Link to comment Share on other sites More sharing options...
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