Andrew Storlie Posted March 30, 2015 Report Share Posted March 30, 2015 im designing and very soon building a wall for 4-HDC4 15s and would like to learn about putting 45s in all the corners to "improve airflow". now i do plan to coat the entire inside with resin and sand to either 3000 or 4000 grit for smooth as glass finish for those extra few db. but wanted to see if adding the 45 will improve the db at all, or lower port noise or anything. i have a 3D render on google sketchup of the wall and i can upload pics if requested. about the wall: -4 HDC4.0 15s -2 Q1-4500D.1 amps -16.75ft^3 net volume before woofer displacment -270in^2 port area 20" deep for 36hz tuning. -All walls will be 2x4s with mdf inside and some internal bracing -walled from the B-piller back in a 2004 jeep grand cherokee 4.7L v8 plain with no 45s render with the 45s Link to comment Share on other sites More sharing options...
hdorre Posted March 31, 2015 Report Share Posted March 31, 2015 you're wasting a LOT of time -45s in every corner -resining the whole inside to seal -sanding to 4000 unless you're going for every hundredth, hell, thousandth of a dB. On 5/8/2011 at 7:38 PM, Kranny said: On 5/8/2011 at 7:35 PM, 'Maxim' said: It hurts me inside when I read stuff like this and remember you're 15 LMFAO so true Mitsubishi 3000GT (Old Build) Headunit: Pioneer 80PRS Frontstage: (2) McLaren Audio MLT-2 Tweeters & (4) PRV Audio MR Series Neo 6.5" Mids Substage: 4 15" Hybrid Subs - Tantric Motors & Sundown Softies Amps: Banda 2.4D Amp (Tweets), American Bass VFL 350.4 (Mids), and (2) Ampere 3800s Electrical :Singer 260A Alt & JY Power Lithium 2005 Chevy Colorado Ext Cab Headunit: Pioneer 80PRS Frontstage: 4 PRV 700Ti Tweets & 6 10" Delta Mids on 3000wrms Substage: 6 Fi BTL 18s in a 4th Order Walkthrough on 3 Wolfram 4500s Electrical: Singer "390" and JY Power My Official Feedback Thread Link to comment Share on other sites More sharing options...
sirhutson Posted March 31, 2015 Report Share Posted March 31, 2015 I don't know but you should try it both ways to see the difference. boss 1200 and a ipod nano. Link to comment Share on other sites More sharing options...
Kyblack76 Posted March 31, 2015 Report Share Posted March 31, 2015 you're wasting a LOT of time -45s in every corner -resining the whole inside to seal -sanding to 4000 unless you're going for every hundredth, hell, thousandth of a dB. I get a "round over" or some "angle help" here and there........ What i do love, is the smooth transition.... Look at this shit..... its a mirror... https://www.youtube.com/watch?v=WBxPHBo5lqc SMD SUPER SELLER The Burban Build Blazer Build sold Acura trunk build sold Link to comment Share on other sites More sharing options...
ALPINE408 Posted March 31, 2015 Report Share Posted March 31, 2015 99% of the time 45s hurt loudness but YOU won't know for sure unless you test it for your car.. No I here this all the time .... To improve air flow..... Like the air is flowing like water sorry subs don't make air "flow" it shakes the fucking shit out of air at a fast pace .... That's why when people put things in there port it does not shoot it out but instead makes it float the air is getting moved back and forth not just out so there is no "flow" Take a half filled water bottle and shake it as fast as you can that's what subs are doing to the air Have you ever had your woofers blown? Link to comment Share on other sites More sharing options...
Krakin Posted March 31, 2015 Report Share Posted March 31, 2015 Smooth doesn't always make for better flow. Krakin's Home Dipole Project http://www.stevemeadedesigns.com/board/topic/186153-krakins-dipole-project-new-reciever-in-rockford-science/#entry2772370 Krakin, are you some sort of mad scientist? I would have replied earlier, but I was measuring the output of my amp with a yardstick . . . What you hear is not the air pressure variation in itself but what has drawn your attention in the two streams of superimposed air pressure variations at your eardrums An acoustic event has dimensions of Time, Tone, Loudness and Space Everyone learns to render the 3-dimensional localization of sound based on the individual shape of their ears, thus no formula can achieve a definite effect for every listener. Link to comment Share on other sites More sharing options...
Hugh G. Rection Posted March 31, 2015 Report Share Posted March 31, 2015 Your dealing with aerodynamics. 45s can help in some cases, but they can also hurt in some cases. The best thing to do is test both ways and see. Making things nice and smooth helps though. Just go to world finals someday and notice all the loud guys with how they wax and buff the insides of their walls with parrifin wax. Owner of BigAss Ports Link to comment Share on other sites More sharing options...
Jessica Posted March 31, 2015 Report Share Posted March 31, 2015 im no expert but air in a sub encosure is a cushion or suspension. if you put a bunch of 45 and a glass smooth surface it might be bad. I mean, air doesnt just flow out the port, it flows both ways following the stroke of the driver. You are just pressurizing and depressurizing and chamber. Dont confuse this with something like a combustion cylinder where air flow is basically one direction. I'm thinking that haveing some resistance is probably a good thing otherwise you will lose some of that suspension the air in the box provides. Rest in peace, walled 87 accord build log 03' Corolla build with AA Mayhem inside. My super random youtube channel and terrible camera work. Wiring comparison by CaptainzPlanetz Wire and fuse guide by Guest SyKo13 Link to comment Share on other sites More sharing options...
Andrew Storlie Posted March 31, 2015 Author Report Share Posted March 31, 2015 well im not chasing the db as its more for show and fun then competition, but ive heard alot of places "claim" that sanding to 3000+ grit allows sound to "flow" along the surface with out getting distorted. im not new to car audio but i am new to walls and systems like the one im building. its over double the power ive dealt with before and if im spending $6k on a system i want to do it right... so recommendations would be to resin and sand a little, test it... then add 45s and see if i like it more, if not take them out... or resin them in if i like it better? Link to comment Share on other sites More sharing options...
Kyblack76 Posted March 31, 2015 Report Share Posted March 31, 2015 Smooth doesn't always make for better flow. well.... I like it over a 45 everywhere on the planet....... i like it period... and i see what your saying..... Me? id put a 2x4 on all the wall sides..... and bust it up a bit...... Smooth surface CANT hurt..... No way... Not from "what ive seen, and whos told me to do it".. I also like the "round over" idea port baffle, and back driver baffle style...... but.. meh...... SMD SUPER SELLER The Burban Build Blazer Build sold Acura trunk build sold Link to comment Share on other sites More sharing options...
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