Neal82 Posted February 26, 2012 Report Posted February 26, 2012 Building a 4th order box for a 15" Sub... well actually 2 of them for my boat. what info ive gotten from last thread that disapeared was that i need to keep the box as close to 1:1 as possible should be ported to 45-55Hz These will actually be the rear seats so my measurements (rough, to cold to go get actuals) Box 20"W x 20"H x 25"D Port 18.5"W x 6"H Tuned to 48Hz says i need a 16.5"D port Does that sound about right? Or should i tune it lower? BTW that each box. Quote Truck Polk 4x6 Plates Polk 4x6 Polk PA660 4Channel amp JVC USB Deck Wifes Car (under construction) Polk MoMo 6.5" Components Polk 6x9s Polk Pa660 4Channel amp Still trying to talk her into a sub or 2 Boat (under construction) Polk 5.25" Components Polk 6.5" Components 2x American Bass DX15s Polk PA660 4Channel 2x Polk PA880 Sub Amps (hopefully)
Neal82 Posted February 26, 2012 Author Report Posted February 26, 2012 (edited) Hmmmm.... kk scrap those #s.... Rear Chamber 22.5 x 16.5 x 12.5 = 2.685 Front Chamber 22.5 x 13.5 x 17.5 = 3.076 (port displacement calulated into that) Port 22.5 x 3 x 16 = 46Hz Sub displacement 2.862 So, its more like 1:1.5 but to get the Freq i need i think thats what its going to have to be. Edit - The total Length is 33" Edited February 26, 2012 by Neal82 Quote Truck Polk 4x6 Plates Polk 4x6 Polk PA660 4Channel amp JVC USB Deck Wifes Car (under construction) Polk MoMo 6.5" Components Polk 6x9s Polk Pa660 4Channel amp Still trying to talk her into a sub or 2 Boat (under construction) Polk 5.25" Components Polk 6.5" Components 2x American Bass DX15s Polk PA660 4Channel 2x Polk PA880 Sub Amps (hopefully)
Sergeant_Skyrim Posted February 26, 2012 Report Posted February 26, 2012 From what I understand...the 1:1 ratio would be more musical meaning that it'd sound better across a wider range of frequencies. I usually see people suggesting a 2:1 ported:sealed ratio which yields a peakier response I believe. Don't quote me on any of this yet though, wait til somebody more experienced chimes in to either correct or certify this Quote Build in progress
412 CVX Posted February 26, 2012 Report Posted February 26, 2012 Did someone delete my post? lol regardless. 1:1 is more musical, the higher the ratio gets, the peaker it will be. 1:1.5 should be good for your sitch Quote Just say no to Ground Pounder Customs. My temp system build log More box buildssome cars do over 170db with one sub, so clearly my two 12"s can do that in my car, with my knowledge too! look out bitches! I'm with captain stupid.
Neal82 Posted February 26, 2012 Author Report Posted February 26, 2012 (edited) Explain peakier... *higher cut off freq?* warmer day today... going to go get actual measurements, after the Wife goes to work... Edited February 26, 2012 by Neal82 Quote Truck Polk 4x6 Plates Polk 4x6 Polk PA660 4Channel amp JVC USB Deck Wifes Car (under construction) Polk MoMo 6.5" Components Polk 6x9s Polk Pa660 4Channel amp Still trying to talk her into a sub or 2 Boat (under construction) Polk 5.25" Components Polk 6.5" Components 2x American Bass DX15s Polk PA660 4Channel 2x Polk PA880 Sub Amps (hopefully)
Sergeant_Skyrim Posted February 26, 2012 Report Posted February 26, 2012 Peakier meaning that around the peak frequency will sound loud, but then it begins to drop off faster the further you get away from that peak frequency. Musical meaning that it'll sound just as good across that wider range of frequencies Quote Build in progress
Neal82 Posted February 26, 2012 Author Report Posted February 26, 2012 (edited) k, so I guess I assumed something going into this prebuild that I guess I shoulda asked.... so im at www.The12Volt.com and im trying to figure out the port specs for tuning.... well that calc is setup for a ported box... not what im doing... So do I 1. Use the OVERALL box ³ to figure out port... 2 Use the Sealed chamber to figure out port... 3. Use the ported chamber to figure out port... I got the new (REAL) measurements so i'd like to get this figured out K, so if its PEAKIER at say.... 46Hz then anything beyond + or - 10Hz wont be *clean?? Edited February 26, 2012 by Neal82 Quote Truck Polk 4x6 Plates Polk 4x6 Polk PA660 4Channel amp JVC USB Deck Wifes Car (under construction) Polk MoMo 6.5" Components Polk 6x9s Polk Pa660 4Channel amp Still trying to talk her into a sub or 2 Boat (under construction) Polk 5.25" Components Polk 6.5" Components 2x American Bass DX15s Polk PA660 4Channel 2x Polk PA880 Sub Amps (hopefully)
Sergeant_Skyrim Posted February 26, 2012 Report Posted February 26, 2012 k, so I guess I assumed something going into this prebuild that I guess I shoulda asked.... so im at www.The12Volt.com and im trying to figure out the port specs for tuning.... well that calc is setup for a ported box... not what im doing... So do I 1. Use the OVERALL box ³ to figure out port... 2 Use the Sealed chamber to figure out port... 3. Use the ported chamber to figure out port... I got the new (REAL) measurements so i'd like to get this figured out K, so if its PEAKIER at say.... 46Hz then anything beyond + or - 10Hz wont be *clean?? The way I understand it, and somebody correct me if I'm wrong, is that the farther away from the resonant frequency you go, it'll start getting quieter. Not dirty or anything, just not as loud as it could be if it was more musical/flatter Quote Build in progress
Neal82 Posted February 26, 2012 Author Report Posted February 26, 2012 Ha, so I found a "4th order bandpass" Calculater.... hmm... yea that shits like Egyptian to me... Ugh... screw it... ill just throw it together and see what happens!! lol Let me know what you think, and I got this thing to as close to 1:1 as possible!!!! Quote Truck Polk 4x6 Plates Polk 4x6 Polk PA660 4Channel amp JVC USB Deck Wifes Car (under construction) Polk MoMo 6.5" Components Polk 6x9s Polk Pa660 4Channel amp Still trying to talk her into a sub or 2 Boat (under construction) Polk 5.25" Components Polk 6.5" Components 2x American Bass DX15s Polk PA660 4Channel 2x Polk PA880 Sub Amps (hopefully)
Neal82 Posted February 27, 2012 Author Report Posted February 27, 2012 Hmmmmmm, So I know im really getting into some rough territory trying this.... but doing a wedge/wedge style so i can plexi part of the top cause i was wanting to do some custom dust caps with my old company logo on em hmmmmmm....... SHIT Quote Truck Polk 4x6 Plates Polk 4x6 Polk PA660 4Channel amp JVC USB Deck Wifes Car (under construction) Polk MoMo 6.5" Components Polk 6x9s Polk Pa660 4Channel amp Still trying to talk her into a sub or 2 Boat (under construction) Polk 5.25" Components Polk 6.5" Components 2x American Bass DX15s Polk PA660 4Channel 2x Polk PA880 Sub Amps (hopefully)
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