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poorfish88

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  2. Impedance Problem

    in DC Sound Lab - Big Bass on ANOTHER LEVEL!

    Posted

    Thanks for all the input guys. I decided to get in touch with DC audio and they stated more than likely one of the coils was burnt as a result of my box being too big so I'm going to have them repair it. Also I did have my infrasonic filter set to the 'on' position but I'm not too sure what frequency that is really set to. But anyways seeing as this is my second time blowing this woofer I'll probably just have to be more attentive to the recommended enclosure size to avoid the headache in the future.

    WCA Rusty, that already posted In this thread, owns DC Audio. FYI

  4. (2) xl12's box as backseat port help

    in DC Sound Lab - Big Bass on ANOTHER LEVEL!

    Posted

    Not sure what the Sundown subs you mentioned have to do with DC Xls he's going to use.

    I was quoted 9-12 areo for 12 xls from DC. I agree with you that more port might give more output, but how will the afffect daily?

    I picked the Sundown sub as an example because Sundown is one of the few companies that gives an actual port area recommendation, not just the typical "x sq in of port area per cube".

    I picked the Zv.4-12 because its a roughly equivalent sized sub in terms of RMS power handling. I know it's not a perfect comparison, but 14 sq in of port area (using one 6" port for two subs) isn't anywhere near the 40 sq in Sundown recommends for their sub.

    This isn't the only information I'm going off of for my recommendation either. I'm also going off of my experience, and I also use box modeling software to see what kind of port velocities the OP is going to get. With a single 6" aero velocities peak at almost 80 m/sec, above 33 m/sec is when bad things start to happen and lower is better. Even if software is off by 25% (which I doubt) port velocity will still be way, WAY too high.

    The reason this affects daily use is primarily, you aren't getting what you pay for. If you lose 5 db to port compression, you are paying for a 4000 watt system, but only get roughly 1500 watt performance, if that even. Also there is a really good chance you will get port noise like crazy, so not only are you not getting the performance you paid for, you get some really annoying port noise you didn't want.

    Now the 5 db loss is just a number, I can't tell you exactly how much output is going to be lost to port compression, I wish I could. I do think that 5 db probably isn't unreasonable though.

    Thanks for the knowledge.

  5. (2) xl12's box as backseat port help

    in DC Sound Lab - Big Bass on ANOTHER LEVEL!

    Posted

    If I did that it would be over 20 square inches of port per cubic foot and my ports would have to be like 6 feet long. Remember how small this box is everything I've seen says 1.5-1.75 per xl12.

    Your box is a perfect example of why "port area per cube" rules don't always work out. I've built plenty of boxes with over 20 sq in of port per cube, it all depends on what the application requires. You are going to be putting 4k watts into this box, that's going to move some air and you need to facilitate that or your output is going to suffer significantly.

    To put things in perspective, Sundown recommends 40 sq in of port area per sub for their Zv.4 12"s. A single 6" aero port is 28 sq in, so you have 14 sq in per sub. Does that sound like a recipe for success?

    I know there are other people here who are saying they've run similar setups with a single 6" aero, but here's the problem, how do you hear the output you aren't getting because your port is too small? You can't. Port compression isn't always audible, but you would sure as hell hear the difference if it wasn't there.

    Not sure what the Sundown subs you mentioned have to do with DC Xls he's going to use.

    I was quoted 9-12 areo for 12 xls from DC. I agree with you that more port might give more output, but how will the afffect daily?

  17. What version SA-8 do you have ?

    in Sundown Audio - GREAT Amps/Subs! GREAT Customer Service!

    Posted

    I got 2 sa8v1.5 dual 4ohm, and have been wondering what the diff was between 2 AND 1.5.

    Thanks a ton that clears it up for me.

    Off topic, but I aquired these from my friend, who I had installed them under the seats of a Nissan Tittan.

    He didnt like the way they made the truck rattle on the low bass, so he put his flat Kenwood 8s back in.

    I tryed to explain to him he's missing so much bass with the Kenwoods, and to sound deaden to fix the rattles.

    Lulz, now the are dust catchers in my closet.

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