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New member Username: AdyWest Yorkshire UK Post Number: 1 Registered: Apr-05 | Hi folks, I'm new to the site, and could do with a bit of info please. I've decided to re-install my audio system into a new car i got recently. The car is a lot smaller than my last one, and i'm trying to design a new enclosure for my 12" sub which matches the ergonmics of the boot (trunk?) a bit better. I worked out the volume of my current box to be 64 litres, and then found out that this is the volume for a ported box. I've been stupidly using it as a sealed enclosure in the past and now realise that i'm not getting the full potential from it. I'd like to have a smaller box (sealed is 28 litres) as there would be more room in my boot, but i'd rather have the sub working at its best and if it means a ported box, then so be it. So my question is which box would you recommend, sealed or ported. I listen to varied music like rock, jazz, sometimes ballads, but i don't play rap, rave, house stuff, or anything like that. Thanks for listening to me rant on, and thanks in advance for any suggestions you might have. Ady |
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Silver Member Username: TheelfkeeperStockbridge, GA USA Post Number: 211 Registered: Feb-05 | you'll get more output from a ported box, but it won't be as deep as a sealed. either will work, its just up to you whether you wanna try and tune ports or not |
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Silver Member Username: AraknidBOCA , FL U.S. Post Number: 375 Registered: Nov-04 | are you looking for SQ(sound quality) or SPL(sound pressure level or more plainly loudness)? |
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New member Username: AdyWest Yorkshire UK Post Number: 2 Registered: Apr-05 | Is it a real saga to tune the ports? And from your post, i assume there is more to working it out than i thought. Obviously i want good sound quality, but what exactly is the 'sound pressure level' and how does it change the sound? Is it better to include or exclude this property in working out which type of enclosure to use depending on the type of music i will be listening to? There's a lot more to a sub, and its box design than i thought!! Thanks again. Ady |
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Gold Member Username: James1115Wilton, Ct Post Number: 2120 Registered: Dec-04 | yup there sure is. SPL is the pressure levels inside the car kinda like the bass you feel in your body if you know what I mean. What sub are yopu running exactly? You can build a ported box and tune it low and you will get better SQ then a selaed and greater output as well. Ported boxes are more efficient at lower volumes as well. it takes alot of power to get the same output from a sealed box then it does from a ported box. Sealed boxes handle more power also. Let me know what sub you are running. what do the manufacturer specs say to tune a vented enclosure to? |
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New member Username: AdyWest Yorkshire UK Post Number: 3 Registered: Apr-05 | My sub is a JBL GT2 12 rated at 450W (250RMS), powered at the moment by a Legacy LA630 amp using two channels bridged to give 300W (150RMS). Nothing fantastic, i know, but it'll do for me. I am considering getting a different amp, but that depends on my available funds. I can't find any info about manufacturer specs on tuning the ports. Going on what you guys are suggesting, it sounds like a ported box will give me a better result in the long run, but i'll need to know how to 'tune' the port. Is there a standard wavelength for each size of sub, or does it depend on the size of car its going to be working in? I looked on JBL website, and they say that 64 litres is the correct volume for a ported box. Is this right? Or does it depend on the size of the port? I kinda like the sound of the SPL, and being able to 'feel' the bass as well as hear it. I could a bit before, but if there is a way to enhance that, it'd be great!!! So many questions, i know, but thanks for your time Ady |
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Silver Member Username: SolacedagonyNew Jersey US Post Number: 337 Registered: Oct-04 | The size of the port for a specific tuning is based on the volume of your enclosure. So the port size to tune a 1.5cf box to 30hz will be different from a 2.0cf box to 30hz. |
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New member Username: AdyWest Yorkshire UK Post Number: 4 Registered: Apr-05 | Is there a specific wavelength which works best? To take your example of 30hz, is this standard? How do you work out what size and depth of port to use? For example, the box i would make would be 64 litres (which is 2.275cf). What size port should i have in a box this size? |
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Silver Member Username: ByrumjrPost Number: 183 Registered: Jan-05 | Here is a good link to find out port leinght. http://www.the12volt.com/caraudio/boxcalcs.asp |
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New member Username: AdyWest Yorkshire UK Post Number: 5 Registered: Apr-05 | Thats well cool! Thanks a lot for that link. Can anyone suggest an optimum frequency to tune my port to? In the example above its 30Hz. I've seen you guys talk about Fb. I assume thats the musical note Fb? Is Fb pitched at 30Hz? Thanks again. |