FISHKILLER Posted January 30, 2015 Report Share Posted January 30, 2015 I understand the size of enclosure. Have been crunching numbers most of day. I am currently running a pair of dc 2k strapped. Link to comment Share on other sites More sharing options...
Triticum Agricolam Posted January 30, 2015 Report Share Posted January 30, 2015 So here is an idea: This T-line is tuned to 25 Hz and has a net internal volume of about 17.1 cubic feet. That may sound huge, but a non tapered T-line of the same tuning would have been closer to 28 cubes. A ported box, by the time you add in the port displacement, may not be much smaller either. The path tapers down from about 350 sq in at the closed end to about 175 sq in at the mouth. This is enough area to keep the air velocities under 28 m/sec. If you think this would work I can give you more info. I've got another design that is tuned to 30 Hz. Its about the same size, but it gives more of a boost around 30 Hz. "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...
FISHKILLER Posted January 30, 2015 Report Share Posted January 30, 2015 Looks like a nice curve. As in I could change my crossover points nicely for my mids. Being a tapered line versus a horn, what output effects would this have? Yes, I am interested. Link to comment Share on other sites More sharing options...
FISHKILLER Posted January 30, 2015 Report Share Posted January 30, 2015 I just designed a standard ported box with an internal of 18.6 BEFORE port dis. Figured I could go ahead and knock this out so I don't rush on a t line, which I would have the tendency to do. Link to comment Share on other sites More sharing options...
Triticum Agricolam Posted January 31, 2015 Report Share Posted January 31, 2015 The output effect of the tapered line is a slight reduction in efficiency, it ends up being a couple db of output. That's the price you pay for an enclosure that's less than 2/3rd as big as an un-tapered t-line. This T-line is designed for the subs to be placed 1/3 of the distance from the closed end. What this does is it gets rid of the giant peak in response you get a 3x the tuning frequency and the giant dip at 4x the tuning frequency. It really smooths out the response. Here is what I'm talking about: The lighter line is the T-line above with the subs mounted at the closed end. The dark line is with them mounted 1/3 of the way down the line from the closed end. The specs you need to know to build it are: Closed end = 352 sq in Open end = 176 sq in Total line length = 113 in Subs should be 38.5" from the closed end The hard part is making the above specs fit your space. If you need help with that let me know "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...
FISHKILLER Posted January 31, 2015 Report Share Posted January 31, 2015 I am still leaning towards doing a reduced line area t line tuned in the lower to mid 20s. If I reduce the area by 35 or 40 percent I can make it work. Do you think I would be ok with this much reduction in area? It's still almost 230 inches.... Link to comment Share on other sites More sharing options...
FISHKILLER Posted January 31, 2015 Report Share Posted January 31, 2015 I do have a design question for above mentioned line. With my space configuration, in order to mount TWO subs to port into line, do they have to be in the exact same orientation to line? Example is if I mount my subs on top of box, subs take up AT LEAST 36 inches of width. Obviously my line is not that large, so one will be more or less centered over line and the other will be offset a bit. Will this cause a phase issue? Link to comment Share on other sites More sharing options...
Triticum Agricolam Posted January 31, 2015 Report Share Posted January 31, 2015 I am still leaning towards doing a reduced line area t line tuned in the lower to mid 20s. If I reduce the area by 35 or 40 percent I can make it work. Do you think I would be ok with this much reduction in area? It's still almost 230 inches.... You can reduce the area of the line, but it will come at a cost of reduced efficiency. You need to keep the mouth area the same to avoid vent noise. If you reduce the taper the line will probably have to lengthen to keep tuning the same. Its all a big balancing act and everything you change will have an effect. As far as how to mount the subs on the line, you want the middle of each sub to be equal distance from the ideal mounting point (38.5" from the closed end in this case). So if you can't mount them side by side, you could mount one 6" or whatever in front of the ideal spot and the other 6" or whatever behind the ideal spot. As long the they are both equal. I didn't really explain that well, but hopefully you get what I'm trying to say. "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...
FISHKILLER Posted January 31, 2015 Report Share Posted January 31, 2015 I understand completely sir. Thanks. What I do not know, is where the 38.5" Figure comes from? Is that based on tuning I assume to keep things in phase? Link to comment Share on other sites More sharing options...
Triticum Agricolam Posted January 31, 2015 Report Share Posted January 31, 2015 I understand completely sir. Thanks. What I do not know, is where the 38.5" Figure comes from? Is that based on tuning I assume to keep things in phase? Yeah 38.5" is roughly 1/3rd the length of the total line. You want the subs to be mounted 38.5" from the closed end of the line. "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...
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