TributaryVikings Posted October 6, 2011 Report Share Posted October 6, 2011 Ah another chore!! I have a minivan which currently houses a bigger version of a decware Wicked One horn box. In it I used a pair of Power Acoustik p3-15 subs. The size of the subs required major modification to the concept design of the box, but that's not important. Bass plays as low as 5hz but barely...and not really a desire anyway. 25 hz....sucks....40hz ok....anything above that....I have to turn it down because it gets too loud. I do not care for higher hz bass...I appreciate 25-40hz range which is why I went with 15s. Good news though. I have plenty of room to work with. The box currently used is 48x36x19...the 48 is as big as can be but the 36 has about 8 inches to play with. I am concerned with the QTS of these subs being used for low Freq...but hell the Fs is already there. Am I stranded with useless subs? According to Power Acoustik the specs on the subs are: Fs is about 25hz Qts is .707 Qms is 7.66 Qes is .780 Xmax is 13.25mm Vas 5.67 Link to comment Share on other sites More sharing options...
eltortuga94 Posted October 6, 2011 Report Share Posted October 6, 2011 How I understand it about your qts & qms is that since they're high you will be more "peaky" at 25hz which in your case is good. System: Basically Stock In process of upgrading Link to comment Share on other sites More sharing options...
TributaryVikings Posted October 6, 2011 Report Share Posted October 6, 2011 How I understand it about your qts & qms is that since they're high you will be more "peaky" at 25hz which in your case is good. This is true....And while the port would have to be all the bigger there is quite a bit of room to work with. Ah I forget the frequencies but isn't 25 a little low for the human ear? ahh even if it were I'm sure the vehicle's cab will resonate a higher frequency anyway. So how about both subs facing rear with the port right next to them (on one side or the other) also facing rear? If I remember right it's best to point ports to the sides of a vehicle? If that's the case then I'd have an additional 8-10 inches of room to play with (I accomodated that room for area between port and rear hatch). I can't face the subs to the side as the wheel well would become an issue, but the rear, up, or front are options...I never had any luck facing them forward though. Is there a goal for 'sealed' or I guess 'chambered' volume is a better word before the port begins? Also would pvc pipping filled with great stuff for all the bends work well? Of course the piping diameter would have to match the port width. Link to comment Share on other sites More sharing options...
STEvil Posted October 7, 2011 Report Share Posted October 7, 2011 Subs up Port back usually works best for large cabin vehicles (van/suv). edit though i'm not sure why you're asking this in a t-line thread.. MickyMcD - "Capable of making some serious trouser flapping volumes at where's-my-testicles frequencies, the Servo-Drives used to be fairly jaw dropping..." Any time you have have a power wire next to your frame put some rubber hosing (or cut up an innertube) around it. The wire is bound to wiggle (due to driving or flex) and the casing will eventually wear through. Hammerdown... 1% no links to outside websites, business related FB/YT pages allowed. Link to comment Share on other sites More sharing options...
TributaryVikings Posted October 7, 2011 Report Share Posted October 7, 2011 Subs up Port back usually works best for large cabin vehicles (van/suv). edit though i'm not sure why you're asking this in a t-line thread.. Well if the purpose of a T-Line design is to get optimum output from a sub then I imagine placement of the sub in not only in the cab...but also in relation to the output of the port are significant. For example...I assumed having the sub as close to the open port as possible would provide best accurate response? Link to comment Share on other sites More sharing options...
STEvil Posted October 9, 2011 Report Share Posted October 9, 2011 If you want the "best" t-line you build it like a horn basically. Mounting surface and exit should be relatively close to each other but it doesnt really matter. MickyMcD - "Capable of making some serious trouser flapping volumes at where's-my-testicles frequencies, the Servo-Drives used to be fairly jaw dropping..." Any time you have have a power wire next to your frame put some rubber hosing (or cut up an innertube) around it. The wire is bound to wiggle (due to driving or flex) and the casing will eventually wear through. Hammerdown... 1% no links to outside websites, business related FB/YT pages allowed. Link to comment Share on other sites More sharing options...
TributaryVikings Posted October 10, 2011 Report Share Posted October 10, 2011 If you want the "best" t-line you build it like a horn basically. Mounting surface and exit should be relatively close to each other but it doesnt really matter. Hm well it seems the easiest way to build one of these usually ends up with them close together anyway. As I am using 15s I have come to the sad conclusion that attempting to use a pair of them seems illogical...but possible. however, for the time being, I will use just 1 for now. I can always install a second one next to it later if the application turns out well. Basically, the enclosure ends up being 48x19 1/4x16. I am using a baffle/support making all four sides even. If one were to begin the port at this position it ends up being 76" long total...This is assuming the length travels around the 180 evenly down the middle as I am using pvc piping (or equivalent) to curve the corners fairly well. If one were to measure from the center of the sub instead it's nearly 84"...Given the possibility that the port could be too short what type filler would be best? Link to comment Share on other sites More sharing options...
eltortuga94 Posted October 12, 2011 Report Share Posted October 12, 2011 I've heard that you want the port & speaker close to each other so the waves lineup as one or something like that. You could try a isobaric T-line so you use both woofers & have twice the motor force, not 100% sure how it'd work though, might want another opinion on it. System: Basically Stock In process of upgrading Link to comment Share on other sites More sharing options...
STEvil Posted October 12, 2011 Report Share Posted October 12, 2011 Motor force isnt an issue with a t-line so isobaric loading has no positive influence on the average t-line. MickyMcD - "Capable of making some serious trouser flapping volumes at where's-my-testicles frequencies, the Servo-Drives used to be fairly jaw dropping..." Any time you have have a power wire next to your frame put some rubber hosing (or cut up an innertube) around it. The wire is bound to wiggle (due to driving or flex) and the casing will eventually wear through. Hammerdown... 1% no links to outside websites, business related FB/YT pages allowed. Link to comment Share on other sites More sharing options...
TributaryVikings Posted October 12, 2011 Report Share Posted October 12, 2011 Motor force isnt an issue with a t-line so isobaric loading has no positive influence on the average t-line. Well my amp is rated at 1ohm mono and my subs are 2+2 so running just one sub at full power wouldn't bother me much anyway HA...I never go by what watts an amp says it puts out. I go by the fuses and type of amp. This one has 5 40 amp fuses on it and it's Class D. For the record it says it's 3200 rms 5500 max. The subs are rated at 1400watts rms, but I wonder how it will react to the box?? They seem to like the current box they are in with the exception of the Low Hz not as loud as I figure they should be. Link to comment Share on other sites More sharing options...
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