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Silver Member Username: Safa19Post Number: 238 Registered: Apr-05 | 1)is a fiberglass box as affective as MDF wood? 2)what does it mean to tune a box? 3)are rounded ports better than rectangle? 4)is it better to run 2 power lines for 2 amps or to run one with a distribution block? 5)finally when is it appropriate to use a cap? thanks to everyone who can answer any of these questions |
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Silver Member Username: Dustin3Tigard, Or U.S. Post Number: 231 Registered: Oct-05 | no size of port yes run 2 sperate when ur alternator can handle the extra power |
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Anonymous | omg noob^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^bassman3 stfu |
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Silver Member Username: MixneffectOrangevale, Ca. USA Post Number: 747 Registered: Apr-05 | 1)is a fiberglass box as affective as MDF wood? Fiberglass is used in applications where you want to mold a box to a non square opening such as a glob or like a trunk, kick pod, etc... Fiberglass does not sound as good as MDF because it resonates. The fiberglass is too thin and it adds extra sound, therefore it is not recommended unless it is strictly used for show. MDF is better because it is a denser material and it resonates less than fiberglass. MDF is almost as good as it gets. There are better materials out there, but they are not cost effective. 2)what does it mean to tune a box? Tuning a box means to adjust the way it sounds. You know the knobs on a guitars head? They are used to fine tune the way each string sounds. If you loosen it, then the string sounds lower. If you tighten the string it sounds higher pitched. The tuning knobs are also used to tune the strings as a group, not just by themselves. Tuning a box is similar. To tune a box, you need to adjust the air pressure in the box. A higher pressure will make the speaker cut off at a higher frequency than a lower pressure box. In a sealed box, the larger the box, the lower the air pressure, the lower the bass will be able to be reproduced, otherwise known as a lower frequency cutoff. The smaller the box, the higher the air pressure, the higher the frequency cutoff. In a ported box, you may use a vent (port) to change the air pressure. This will allow you to get a lower pressure by just changing the length of the port, without changing box size, but this will not make that big of a change in air pressure by much, only slightly. If you want a lower frequency cutoff, then make a bigger box. You will still need fine tune the sound by using a port (just like the guitar strings). 3)are rounded ports better than rectangle? Round ports are smaller than rectangle ports because they allow the air to travel a lot smoother and therefore help the air pressure flow. Rectangle ports are preferred by others because they eliminate port noise. Port noise sounds like wind. It is due to the fact that the port is too small in diameter. For example if you use a 2" diameter PVC port you may need to have a 14" long port, but if you use a 3" diameter port, you may need a 22" long port. This is due to air pressure. 4)is it better to run 2 power lines for 2 amps or to run one with a distribution block? When it comes to power sources, it is always better to have an efficient supply. This means that if you have more than one electrical equipment, you will need more current draw. So to make sure that you have enough, you will need a bigger wire. A distribution block allows you to run a thick wire to it from the battery, and then a normal wire to each source thereafter. The drawback is that if there is a short circuit, then all of the sources are affected. Running separate power wires is better because it eliminates complications in case of an error. 5)finally when is it appropriate to use a cap? Some people believe that a capacitor is helpful when an alternator does not put out enough amps to supply the electrical current draw your entire car's needs in order to function sufficiently. A capacitor stores electrical energy under normal conditions. It supplies electricity when a larger amount of current draw is required for a limited time, such as a temporary congestion of heavy bass in a recording. Bass requires more current than higher frequencies because it must create larger air waves or wavelengths. Capacitors are also dangerous, and almost useless. Capacitors require that they are charged with power before they can release power to other sources behind it. They are very in-efficient. Most people will agree that a high output (HO) alternator be used instead. This will definitely supply the power needed in real-time without setbacks. |
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Silver Member Username: Safa19Post Number: 239 Registered: Apr-05 | wow thanks mixneffect i was going to build a box with all the sides out of mdf and only the one side that the subs are mounted of fiberglass, if i use fleece with polyester resin first and then 2 layers of fiberglass mat will that be close to being as good as mdf? also this is for 2 alpine type R's (500watts rms each) would it be loud enough sealed or should i port it? its for every day driving so it doesnt have to be extremly loud but i want it to def be noticable. the specs for port would be 12" x 1.25" total of 15" how would that compare in a diameter of a round port? like 2.5 inches? as far as tuning it i wouldnt know how to to much so i will just go with the specs that came with my subs, also i will run 2 power lines (because i already have one for one of my amps) and no cap Thanks for the help!! |
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Gold Member Username: CarguyPost Number: 5135 Registered: Nov-04 | Go to www.bcae1.com and read up on "basic enclosure design." Do not run 2 power wires. Instead run one heavier gauge and use power distribution block. |
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Gold Member Username: InsearchofbassPost Number: 4153 Registered: Jun-04 | I think the reason isaac said dont run two power wires compared to one just one is because that would create two potential fields that could cause interference since power in a power wire travels on the outside of the wire contained inside the insulation |
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Gold Member Username: InsearchofbassPost Number: 4154 Registered: Jun-04 | oh i missed your last part isaac...I think im right in application though...the more power wires you have the more potential for interference |
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Silver Member Username: Safa19Post Number: 240 Registered: Apr-05 | ok so what about the fiberglass part? will that still sound good? and should i get a port or not bother? |
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Silver Member Username: N2audioLawrence, Ks USA Post Number: 202 Registered: Mar-04 | Sean, skin effect is a high frequency AC problem, not DC, besides, the magnetic fields created by amp powerwires don't oscillate enough to produce audible EMI, and if they did - it would have to be during high current demand which would also be during high volume - no way you'd be able to hear it. I would suggest running one large wire to a d-block simply for the sake of not having to get 2 large wires safely through the engine compartment and firewall. Common sense wise it's just the thing to do. |
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Gold Member Username: 54danny54Betsy layne, Kentucky.. USA duh Post Number: 1486 Registered: Nov-04 | joe...if u going fierglass...make it pretty thick...it will resonate less |
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Silver Member Username: MixneffectOrangevale, Ca. USA Post Number: 749 Registered: Apr-05 | "if i use fleece with polyester resin first and then 2 layers of fiberglass mat will that be close to being as good as mdf?" No. To get the same results or even close to an MDF, you would need to make your fiberglass thicker than just two coats and fleece. You may need to make it thicker than MDF just to break even. "this is for 2 alpine type R's (500watts rms each)" Also, think how those subs are going to pound on that fiberglass baffle. Even in a ported box where the air pressure will be less, you will have a lot of stress on the fiberglass baffle. Those subs are also heavy. I dont think that your design would be strong enough to support the weight of those subs. |