tunning a ported box
07-22-2005, 09:26 AM
#31
Guest
Posts: n/a
Those are simply variables in the equations, some cars may have brand new weatherstrip, while others are old and cracked. Some may have extra holes in the firewall, while others don't etc. I am sure if you did a 'leakdown' test on the interiors, you would find large variable that while hard to test for, are possible to factor into an equation.
I never said that there was a simple formula, or that using a formula would be quicker and less time consuming than just trial and error testing, just that there is a formula somewhere that would work.
Can you imagine in the future people taking cars into their local SPL specialist for interior leakdown testing? You heard it here first folks
I never said that there was a simple formula, or that using a formula would be quicker and less time consuming than just trial and error testing, just that there is a formula somewhere that would work.
Can you imagine in the future people taking cars into their local SPL specialist for interior leakdown testing? You heard it here first folks
07-22-2005, 01:32 PM
#32
50 Watt CAFz'r
Join Date: Jan 2005
Posts: 65
Originally posted by Livin - Loud:
for any street vehicles physics cannot take of everything!!! EVERY vehicle has differences. I have seen ppl test out 4, or 5 different CRX's (same model, and year though)with the same EQUIPMENT and same BOXES and get a 3 db difference! [img]graemlins/freak.gif[/img]
how does physics help you now?
Livin Loud
for any street vehicles physics cannot take of everything!!! EVERY vehicle has differences. I have seen ppl test out 4, or 5 different CRX's (same model, and year though)with the same EQUIPMENT and same BOXES and get a 3 db difference! [img]graemlins/freak.gif[/img]
how does physics help you now?
Livin Loud
BUT same elevation, same temperature, same time, same mic, same humidity?
There are always variables to every situation. Calculations help, so does testing. It's a sweet science.
07-22-2005, 03:10 PM
#33
500 Watt CAFz'r
Join Date: Jan 2001
Posts: 901
Originally posted by Nathan Siy:
</font><blockquote>quote:</font><hr />Originally posted by Livin - Loud:
for any street vehicles physics cannot take of everything!!! EVERY vehicle has differences. I have seen ppl test out 4, or 5 different CRX's (same model, and year though)with the same EQUIPMENT and same BOXES and get a 3 db difference! [img]graemlins/freak.gif[/img]
how does physics help you now?
Livin Loud
</font><blockquote>quote:</font><hr />Originally posted by Livin - Loud:
for any street vehicles physics cannot take of everything!!! EVERY vehicle has differences. I have seen ppl test out 4, or 5 different CRX's (same model, and year though)with the same EQUIPMENT and same BOXES and get a 3 db difference! [img]graemlins/freak.gif[/img]
how does physics help you now?
Livin Loud
BUT same elevation, same temperature, same time, same mic, same humidity?
There are always variables to every situation. Calculations help, so does testing. It's a sweet science. </font>[/QUOTE]they were ALL in the same shop! they had like 5-6 CRX's man [img]graemlins/freak.gif[/img]
not every car built equal [img]graemlins/dunno.gif[/img]
Livin Loud
07-22-2005, 03:12 PM
#34
500 Watt CAFz'r
Join Date: Jan 2001
Posts: 901
Originally posted by DWVW:
Those are simply variables in the equations, some cars may have brand new weatherstrip, while others are old and cracked. Some may have extra holes in the firewall, while others don't etc. I am sure if you did a 'leakdown' test on the interiors, you would find large variable that while hard to test for, are possible to factor into an equation.
I never said that there was a simple formula, or that using a formula would be quicker and less time consuming than just trial and error testing, just that there is a formula somewhere that would work.
Can you imagine in the future people taking cars into their local SPL specialist for interior leakdown testing? You heard it here first folks
Those are simply variables in the equations, some cars may have brand new weatherstrip, while others are old and cracked. Some may have extra holes in the firewall, while others don't etc. I am sure if you did a 'leakdown' test on the interiors, you would find large variable that while hard to test for, are possible to factor into an equation.
I never said that there was a simple formula, or that using a formula would be quicker and less time consuming than just trial and error testing, just that there is a formula somewhere that would work.
Can you imagine in the future people taking cars into their local SPL specialist for interior leakdown testing? You heard it here first folks
makes sence now...
Hey Perfect Tones offer "leakdown" testing now, for $80.00.00 each!
Livin Loud
07-23-2005, 06:30 PM
#36
the way that sheetmetal is formed into shape, makes variances in thickness from panel to panel.
both of my colts have different resonant frequencies...spl is "vehicle dependant".
with sound deadening,foam,adjusting door/hatch latches, you can alter the frequency..i just need to see how far i can push it
termlab is a very useful tool,and with the proper box (.707 qtc)you can find the frequency,modify,your cars frequency and build a ported box(using a calculator gets you close)
than fine tune with the termlab [img]graemlins/deal4u.gif[/img]
[ July 23, 2005, 07:36 PM: Message edited by: Loud Brown Kicker Colt ]
both of my colts have different resonant frequencies...spl is "vehicle dependant".
with sound deadening,foam,adjusting door/hatch latches, you can alter the frequency..i just need to see how far i can push it
termlab is a very useful tool,and with the proper box (.707 qtc)you can find the frequency,modify,your cars frequency and build a ported box(using a calculator gets you close)
than fine tune with the termlab [img]graemlins/deal4u.gif[/img]
[ July 23, 2005, 07:36 PM: Message edited by: Loud Brown Kicker Colt ]
08-17-2005, 05:31 PM
#39
0 Watt CAFz'r
Join Date: Mar 2005
Posts: 34
The modelling you can perform with LEAP will give you highly accurate results, if you know how to define the interior of the vehicle as an acoustical filter. I'm in broken record mode, having stated this in previous posts. It's expensive as hell, has a learning curve that tolerates no guess-work, and totally kicks ***!
You can accurately model response and SPL with regard to how far the windows are open, so modelling the leakage from the random holes in the vehicle is also on the menu. It's great, it's accurate, but as stated in other posts on this thread, you just don't know for sure until you build the damn thing!
If all these computers, programs, analysis, science and experts are so accurate, why can't they build a simple violin, the like of which a semi-literate Italian turned out with regularity, some 200 years ago?
You can accurately model response and SPL with regard to how far the windows are open, so modelling the leakage from the random holes in the vehicle is also on the menu. It's great, it's accurate, but as stated in other posts on this thread, you just don't know for sure until you build the damn thing!
If all these computers, programs, analysis, science and experts are so accurate, why can't they build a simple violin, the like of which a semi-literate Italian turned out with regularity, some 200 years ago?
09-07-2005, 08:22 PM
#40
0 Watt CAFz'r
Join Date: Mar 2005
Posts: 4
Kevin is that you. I was just in the old school forum and was suprized to C 2001, Gord and my brother mentioned. I had thought of you as well, and to my suprise I found this post from you. Is there any way I can contact you. Maybe you can let RT know that I want to talk to you and to give me your e-mail.
Hope to chat soon
Ryan Sontowski
Hope to chat soon
Ryan Sontowski
