rusty959 Posted April 12, 2009 Report Share Posted April 12, 2009 I had a thread somewhere a few weeks ago about this box for my probe, but this a completely different topic so I just made a new one. Anyways, im trying to finish up the design for my two lvl4 18's. I think ive figured out what I need to do to get it all in, but after looking at this design and thinking about the airflow, im wondering if something more comes into play as it seems as the entire box is just a large funnel to the port. I don't think it could be considered a horn at all, but im not completely sure and wanted to get some opinions. Anyways this isn't a final design, I just sketched this one up, and its a little off. Somehow I messed up my squareness a tad somewhere, but besides that I need another cube and a half of airspace, so ill probably lengthen it a little and maybe make the port a bit smaller. but anyways it will still be the same general idea of box, and ill fix that stuff when it isn't 3 am.... Right now its tuned to about 31-32 hz and 10 ft^2 or so any opinions? Quote 2013 Subaru BRZ12" Orion HCCA on AQ 22001967 mustang restoration project: http://www.stevemeadedesigns.com/board/topic/110765-mustang-restoration-build-2011-edition/ Youtube: https://www.youtube.com/user/therusty959 Link to comment Share on other sites More sharing options...
BanginOnABudget Posted April 12, 2009 Report Share Posted April 12, 2009 dont u mean 10^3? box looks ok. Quote im taking out my passenger seat, battery is disconnected, going to unwire and take out the three amps, take out the 70+ lb box, then the platform so i can crimp 1 wire. Almost as bad as those fegs that put those horns in their grills and roll down the street distorting the block.... 1990 Jeep Cherokee 2 Dr. Big-3 in 0g on Stock Alt. Pioneer 6.5" and 5.25"s temp. until i can afford the new crescendos. Pioneer 6000ub Reciever NO amps at the moment. SA-15 on 1kw coming soon. MSG Me for a free enclosure design!! Flared port kits coming soon!! Link to comment Share on other sites More sharing options...
Boon Posted April 12, 2009 Report Share Posted April 12, 2009 Hmmm.... Yeah, should still behave like a normal box... Quote 10.x volts fo' life! Link to comment Share on other sites More sharing options...
01xtreme Posted April 12, 2009 Report Share Posted April 12, 2009 If there is not increase in port area along the port length, then it's not a horn. Looks like a normal ported box to me. Shaped quite different, but still a normal ported box. Quote My System: Pioneer AVH-P3200BT 4-Dayton 7 inch reference series (front doors) 8-Onkyo 3/4 inch tweeters (dash) 1-Sundown Audio 100.4D (mids/highs) 2-18" BTL's (for now) Crescendo 3kwp (for sale) Complete rebuild coming soon... Link to comment Share on other sites More sharing options...
aznboi3644 Posted April 12, 2009 Report Share Posted April 12, 2009 still a ported enclosure Quote Link to comment Share on other sites More sharing options...
rusty959 Posted April 12, 2009 Author Report Share Posted April 12, 2009 dont u mean 10^3?box looks ok. lol, yea.... like I said it was late... :01nocomment8so: Hmmm.... Yeah, should still behave like a normal box... If there is not increase in port area along the port length, then it's not a horn. Looks like a normal ported box to me. Shaped quite different, but still a normal ported box. still a ported enclosure ok, thanks guys. I was thinking it should still be, but I now feel better going with this type of design knowing some other opinions. That being said... I think I need some substantial modifications still.... looking at it with some sleep, the effective port im sure wraps a lot more than I had calculated it... I don't have the time right now to do the calculations.... I want to do some work on my fiberglass amp mount before I have to go to work... but im thinking if I make the port height .25-.5 inches lower, and tune it about 1hz higher, the port should be a good deal shorter so ill have my airspace without having to extend this box into my back seat. right now im a tad under 200 in^2 of port, which puts me around 18 in^2/ft^3 (assuming my guestimate of the displacement of two lvl4 18's) lowering the port a half an inch will put me to 180 or so in^2 or 16.6 in^2/ft^3, which is probably better anyways. I can then shorten my port around 4 inches I believe, which will keep the effective port from wrapping around as much. (guess I did part of the calculations anyways...) /random babbling... Quote 2013 Subaru BRZ12" Orion HCCA on AQ 22001967 mustang restoration project: http://www.stevemeadedesigns.com/board/topic/110765-mustang-restoration-build-2011-edition/ Youtube: https://www.youtube.com/user/therusty959 Link to comment Share on other sites More sharing options...
Boon Posted April 12, 2009 Report Share Posted April 12, 2009 Indeed your effective port would have been quite long, probably extending someway back into the airspace of the box after it curved around. Drop to like 15in^3/ft^3, even 16.6 is a bit on the SPL side of things IMO. Quote 10.x volts fo' life! Link to comment Share on other sites More sharing options...
Ben Building Posted April 13, 2009 Report Share Posted April 13, 2009 Because of the funnel shape of the enclosure, the air has to speed up to exit the enclosure into the port and slow down to exit the port on the reverse stroke. With a box wide enough to fit 2 18s though, that effect almost certainly won't be distinctly audible. Other than that, normal ported box in my view. Quote Link to comment Share on other sites More sharing options...
rusty959 Posted April 13, 2009 Author Report Share Posted April 13, 2009 Because of the funnel shape of the enclosure, the air has to speed up to exit the enclosure into the port and slow down to exit the port on the reverse stroke. With a box wide enough to fit 2 18s though, that effect almost certainly won't be distinctly audible. Other than that, normal ported box in my view. hmm... I see what you are saying.... hopefully it won't cause any problems... I don't have too many choices of the shape anyways, with boon's suggestions, ive drawn up a new box. This one is right about 15 in^2 port per cube. This could be extremely close to the final design. The airspace is almost dead on. Im thinking if I extend the box .75-1 inch forward it will be perfect. right now about 11 ft^3 main airspace, 170 in^2 port, 32 or so hz tuning. Thanks to all for helping me get this designed. Quote 2013 Subaru BRZ12" Orion HCCA on AQ 22001967 mustang restoration project: http://www.stevemeadedesigns.com/board/topic/110765-mustang-restoration-build-2011-edition/ Youtube: https://www.youtube.com/user/therusty959 Link to comment Share on other sites More sharing options...
Boon Posted April 13, 2009 Report Share Posted April 13, 2009 Make sure you brace that port. When you think about it that 'shelf' is effectively a wall of your box, you don't want it flapping around. Quote 10.x volts fo' life! Link to comment Share on other sites More sharing options...
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