Silver Member Username: GoatinU.S.A Post Number: 158 Registered: Jan-06 | Can I find what my box is tuned to with a mic of some kind and where would be a good place to find one if so? |
Platinum Member Username: GlasswolfWisteria, Lane USA Post Number: 10919 Registered: Dec-03 | you'd need a tuned mic and an RTA. got about $2500? |
Silver Member Username: GoatinU.S.A Post Number: 159 Registered: Jan-06 | well then.. is there any other cheaper way? |
Platinum Member Username: GlasswolfWisteria, Lane USA Post Number: 10924 Registered: Dec-03 | sure. find the internal net volume of your box after driver displacement, then measure the port length and inner diameter, and graph it to see what the frequency is. |
Silver Member Username: Terry6405Sullivan, IN US Post Number: 220 Registered: Sep-05 | sure. find the internal net volume of your box after driver displacement, then measure the port length and inner diameter, and graph it to see what the frequency is. uh....... what |
Silver Member Username: GoatinU.S.A Post Number: 162 Registered: Jan-06 | GlassWolf if I give you the numbers can you do it? 4.7 cubic feet of air and 49.5 inches of port just an educated guess would be nice I already built the box. |
Platinum Member Username: GlasswolfWisteria, Lane USA Post Number: 10942 Registered: Dec-03 | what's the ID of the port? 3", 4"? is it round? what sub is this for? |
Bronze Member Username: Safe_crackerChicago, IL US Post Number: 87 Registered: Jan-06 | Can't you just play a test sweep through your amp and see where it is the loudest? Polo. |
Silver Member Username: GoatinU.S.A Post Number: 179 Registered: Jan-06 | what do you mean test sweep? I dont understand what you mean. |
Silver Member Username: GoatinU.S.A Post Number: 180 Registered: Jan-06 | GlassWolf the port is 3 inches wide and 16.5 inches high rectangular |
Bronze Member Username: Safe_crackerChicago, IL US Post Number: 89 Registered: Jan-06 | A Built enclosure, complete with a sub and ports will resonate at a certain point. By using a signal generator on a laptop plugged into your amp running your sub you can test frequencies until you find at which it resonates at (will be the loudest point). You can trial and error tune for a set that you are looking for. It would be easier with round ports using PVC pipe of approprate dia. Was just an idea, how accurate would this be? Polo.. |
Silver Member Username: GoatinU.S.A Post Number: 194 Registered: Jan-06 | |
Gold Member Username: SouthernrebelMonroe, Louisiana USA Post Number: 2059 Registered: Mar-04 | mitchell, how long is the port (if it makes an L in the box, measure it right down the center)? also...is your box 4.7cuft net or gross? (before or after port/sub displacements) |
Anonymous | Polo's kinda talking about box resonance caused by port tuning and cabin gain. Depending on your box tuning and sub, you'll have an increase in spl at a certain frequency. If you model it with a program like WinISD, you'll see what I'm talking about. If you change the port tuning, you'll change the frequency that this occurs at. If you listen to a test tone cd, you will hear it, but it is not the same thing as what your port is tuned at. Now, your vehicle has its own frequency it resonates at. If you compete in spl, you try to get both frequencies the same, so you get a huge spike at one frequency. If you want SQ, you try to get rid of any spikes so all frequencies have the same loudness. |
Bronze Member Username: Teddy21Ann Arbor, MI USA Post Number: 14 Registered: Feb-06 | hey guy, you need to measure the volume of the box then subtract the port volume and the displacement of the woofer, mmmmkay. take this volume and place it in this calculator http://www.carstereo.com/help/Articles.cfm?id=31 guess and check the frequency of the port at the bottom of the calculator and you should get a good idea. |