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Dezzy FN Baybee

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Posts posted by Dezzy FN Baybee

  6. 4 DD3518s 20,000 watts

    in Subwoofers / Enclosures

    Posted · Edited by Dezzy FN Baybee

    finishedbox-1.jpg

    Here's a little sketch of what's going in my van sometime during the next few weeks, after it warms up some. I over compensated a little for the bracing I might add. Which will take anywhere from .5 - 1.5 cubic feet. So my enclosure volume may go up and tuning frequency may drop but its going to be between 35-36 Hz and 24.11-25.xx cubic feet net.

    [box] Outer Dimensions

    Height: 41"

    Width: 52.75"

    Depth: 35"

    [Port] Inner Dimensions

    Height: 39.5"

    Width: 14"

    Length: 20"

    Equipment

    Subs: (4) Digital Designs 3500 series 18s Dual 2

    Amps: (2) Hifonics XX Maxximus 10,000 rms @ 14.4v

  7. Can someone explain the science behind ported boxes?

    in Subwoofers / Enclosures

    Posted

    A ported box is a HP filter, 12dB/oct. Notice how ported boxes roll-off at around 24 dB/oct instead of the average 12 for sealed boxes. Imagine the cone of the speaker as a weight, imagine the suspension as a spring, and now hang the weight from the spring and you have a resonant system. Compliance, resonance, it's all there. The port is essentially a smaller spring and a smaller weight attached to the first one. The port itself is similar to a helmholtz resonator. At a certain frequency, depending on tuning, the port will resonate. The energy providing this continued resonance is the backwave of the speaker. At port resonance, the speaker motion is resisted and the cone barely moves. At tuning, I think the port is 90 degrees out of phase with the sub, no biggie. As you go down in frequency, the sub unloads and it might as be free-air. Above that, the port and speaker are close enough in phase so that the response adds.

    So, a vented enclosure extends the response of a speaker by adding another lower resonance powerred by the speaker.

    This is one level of understanding of vented boxes. It can get more complex and does.

    Ok now it all makes sense to me. My last ported box was tuned to 45Hz and my car peaked at 57Hz. So basically I needed to tune my box to about 55Hz to get the full benefit of using a vented enclosure(in an SPL sense). So if I were to tune to 25Hz with the exact same box I would have the same score as the 45Hz box because of the fact that my car liked 57Hz anyway. Please correct me where I'm wrong.

  8. Can someone explain the science behind ported boxes?

    in Subwoofers / Enclosures

    Posted

    29 hz would take away because the higher the frequency the easier it is to get loud. Your box will work better with your vehicle at a higher fq assuming it would be closer to the resonant frequency of the vehicle

    idk if that whats ur lookin for either?

    this here is exactly what i'm asking to be explained. The science behind the port says that at frequencies around the tuning frequency of the box the subwoofer will have less excursion resulting in more subwoofer control. But it doesn't explain why tuning to 40hz will give you a higher score than 30Hz

  15. Anyone run amps rated at 14.4v on 16v batteries?

    in General Audio - Can't find a category for your question? Ask here.

    Posted

    I would invest in a good alternator of atleast 300-350amps.(bigger=better)

    i think those amps didn't like voltage below 11.5-12v or above 16.

    SO if you don't have a voltmeter yet in your car, get one for 20-25 dollar.

    I have a DMM. I know it wasn't smart but I hooked it up the over the weekend and played with it for an hour or so. Using 4 gauge power cable from my old RF Amp kit, the Kinetik HC2000 and a Duralast 1000 CA battery I borrowed. The Maxximus has 4 hots and 4 grounds I kept each connection no longer than 8 inches in length directly to the battery. No alternator just those 2 batteries in the trunk played the whole time without dropping below 12.2v

  16. I finally made 150db sealed

    in Member Videos - Host 'em & Post 'em! System Vids / Off Topic

    Posted

    what type of meter is that

    its a new AC mic lol. I know whats comming next ITS NOT A TERMLAB lol but its what we use in alaska. I was told the new AC were equall to the TL's.

    AC is usualy 3-5db higher than TL numbers from my testing. But hey if its what you use up there than good job

    Not even close I did a 149.5 on the AC sealed. Then did 143.4 from the headrest at MECA the next weekend. Headrest scores higher with the door open I believe. So I'm thinking it would have been something like 139 on TL. But good score bro, you'll be maxing out that meter in no time. Ask Questions!!!

  17. Anyone run amps rated at 14.4v on 16v batteries?

    in General Audio - Can't find a category for your question? Ask here.

    Posted

    Wish I could have stayed to chat but I had to go to work. otherwise i have no money to dump into this. I'm not a complete noob nor do I have 20+ years of experience. I'm going on 21 in about a month I started competing in 2008. I do my research and I just try to learn as much as I can because I love the sport. I'm not the type of guy to pay someone to do everything for me I do my own installs and take pride in my work. My first competition I did 139.9 in MECA's M4 class, last month same class I did 143.4. My highest official score at a show is 147.3 @ 57hz legal. I had the 2 3518s in the same box mentioned with 2 Power Acoustik OV1-5500D amps strapped. Now I've upgraded to the XX Maxximus, which brings me to this topic.

  23. Anyone run amps rated at 14.4v on 16v batteries?

    in General Audio - Can't find a category for your question? Ask here.

    Posted

    Are you planning on running a 16 volt alternator and then running a step down module?

    No I was just going to run the batteries together in the trunk. 6 or 7 batteries directly to the amp

    Do us all a favor, and stick with 12V... If you get 16V batteries, and don't get some sort of external regulator, you'll fuck them up. If you do run an external regulator, and think your car will be fine, you'll fuck it up... Best advice I can give you is to READ... Read lots of stuff... Its all right here... Learn and then make your decision...

    thanks. I just wanted some opinions. the previous owner said it would take 16v all day long in those exact words. But mike from maxxsonics said its not 16v stable. what about the 14v batteries? still too risky?

  24. Anyone run amps rated at 14.4v on 16v batteries?

    in General Audio - Can't find a category for your question? Ask here.

    Posted · Edited by Dezzy FN Baybee

    Some competitors do that and then charge it later. Thats fine if you arent giving long demos. But why not just go with 12 volts and run more batteries and still have a solid electrical?

    are you burping only?

    well I have been doing demos when I had my crappy Power Acoustik 5500. I had a kinetik 2000 wired to my starting battery and a 20 fared cap. But I paid all this money on a amp and I just want to get all of what i paid for. I really want to put up some numbers so I was looking to try 14v or 16v batteries

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