KU40

I played golf today, too, and somehow managed to mess up my left shoulder. It feels like a strained muscle. But I did get one birdie, that made me feel good. Even if I was +9 for the day over only 9 holes.

Caught a nice 2+ lb largemouth today, in what is more or less an oversized pond. He fought nice and hard, too. That's a good way to start off the year. Some douchebag came and crowded me. I was on one side of a corner of the lake (on shore) and he went to the other side of the corner and began casting perpendicular but straight out in front of me, well within my casting distance. I was like seriously? Oh well, I wanted to move anyway and where I went is where I caught the fish, within 5 minutes.

What is the voice coil configuration on the subs?

It isn't warming up as fast as I had hoped . I was planning on going golfing then fishing this afternoon. I still probably will, I'd just like it to be a bit warmer than 55 degrees. With a 15 mph wind it gets cut down to 50. At the end of last year's fishing season I was getting frustrated because I wasn't getting any bites. Sure the oversized ponds I was at were probably overfished a ton, but I still figured I'd get something. I even got so frustrated I swore off fishing. But here I am, excited about getting back out there again for the first time this year.

Usually the manufacturer gives displacement to you. For most 15s, 0.15 cubes per sub is adequate.

My dad called me at work yesterday and said that my little brother (16) has been getting into trouble and he was hoping some big brother influence may help, since he doesn't seem to respond to his parents very well. I sent him a 4+ page letter in an email basically telling him my experiences growing up and how I had two best friends in middle and high schools (separate instances) that started getting into trouble and doing drugs, and the choices I made to basically give up my best friends because I didn't want to be a part of that. Then I gave him some of the fun alternatives I did as a kid, like cruising car lots after getting shakes from Sonic during happy hour, chasing girls, etc. And I told him how much easier it is in life if you don't mess it up early and set goals and really strive. My gf read it and thought he wouldn't read the letter because it's too long and sounds like it's coming from a parent, even though I wrote it specifically trying to not sound like a parent. Anyways, he sent a reply email saying he read it multiple times and that some of my stories are remarkably similar to his, and that he's not going to try and change his ways, he IS going to change. That makes me feel really good. It would be amazing if I really had that type of impact on his life. I couldn't turn my two previous best friends around, but maybe I can help my brother.

You know that 4 cubic feet won't be large enough for two ported 15's, right? you need at LEAST 5 cubes after all displacement (subs and port), I'd actually suggest 7 cubes. And with the size of the port you'll need to tune to 30 hz with two 15's, you'll probably need at least an 8 gross cubic foot box. Do you have that much room? They can't tell you length because that's dependent on box size, port area, and tuning. you can find a port calculator somewhere and find out the length you'll need. Just remember that you have to add the port onto the box size you put into the calculator. so if you put 4 cubic feet into the calculator and it gives you a port that takes up 3 cubic feet, your enclosure needs to be 7 cubes total.

Yes.

I brought this up mainly for stability reasons. I'm not too worried about power output. My thinking was that subs obviously present a reactive load and that most of the time their impedance is above the nominal (I thought it was always so until I just read your post in the other thread about the square wave use as a representative of music), so if amplifiers were rated with this in mind, they may be rated for lower than they could actually go with a resistive load for long periods.

I was going to suggest the same thing. With this program you can easily see the differences a box makes on the response. Just note that the responses shown in that program are with the enclosure in an infinitely large room, not a car, so what you get in the car will not be exactly the same. However, it will at least allow you to view enclosures compared to each other and give an idea.

For soft things like the seats that don't really reflect the sound you only need to be as far away as the subs need so that they don't hit the subs when they move. For most subs this is 2" at the most. But I agree with Ryan, in 95% of trunks the subs will be louder facing the rear in that type of setup.

Jacob, Are your amps rated with a reactive (nominal) load or resistive? In other words, are they made knowing a reactive load will be placed on them in normal use? This is brought up due to the number of "impedance rise" and "I can wire the 3000D to .5 ohm nominal because it will actually be above 1 once the sub is wired to it due to the rise" questions and comments. *I am not trying to single your amplifiers out, I just wanted to know in general and since you're on the forum I figured I'd ask you.

Box size varies the way the speaker sounds as well, so you can't look at it purely from a power handling point of view. The power applied won't change the parameters of the sub or how it responds if you change the box size. For instance, a sub moving 20 mm in a 2 cube box with 1000 watts will behave similarly as a sub moving 20 mm in a 2.5 cube box on 800 watts. The sub is moving the same amount in either case but the sound won't change due to power. The difference in sound will be due to how the sub responds to the space behind it in the box and the "springiness" of the amount of air. I don't think it's a bad question, maybe just more technical than some people have an answer for.

Sounds fun, let us know how it turns out.

It's Friday. For being such a slow week at work, this week went by fairly quickly.

I was scared when I saw passives Me too, I was like wait is hell freezing over? Is the underworld merging with ours? Is the outworld dimension merging with our own? What is going on?!?!?! It has been raining all night.

you're using the alpha version, right? The beta version has the mach speed on the inputs pop-up box. If it's green you're ok, if it turns red your port velocity is too high. That's where I was trying to remember the mach speed from. I didn't know the alpha had that in the help menu. I've never read it.

I'm so ready for some more of my smoked pork sandwiches. So hungry!

Digital Design's website says to use 16 sq. inches per cubic foot of box volume. But directly above that they go through a formula that involves the movement of the driver. It says: "A 4" diameter port has about 12 sqin of area. This is about an 8-1 ratio of cone area to port area. If the 12 inch cone moves 0.25", the port must move 2.0". It can handle this, but when the cone is moving 1.0", the port must move 8 inches! Now you've got a leaky sealed box." Which seems contradictory to me. Why would they base the port area on box size when they say themselves how xmax of the driver can affect port velocity?

why did you pick that value? I believe winISD Beta doesn't like you to have a port velocity above mach .14. But that's almost 50 m/s. Maybe I'm misremembering. Oh and I need to correct my units from before. I meant 20-25 meters per second, not feet. Big difference, whoops.

I read that a vegan was turned down for her proposed vanity plate: ILVTOFU Hmm, wonder why. slut!

I'd just get a 4 channel amp and use the front channels for your front speakers and bridge the rears for your sub. An LOC doesn't have any equalizer functions on it. It's simply a way to switch signal from high level to low level (speaker wires from the head unit into RCAs to go to the amp).

I think it's something like 20-25 f/s.

What box size, port, and sub do you have now?

You need as much port area as necessary to not stifle the sub or cause port noise. That's it. It may not be between 12 and 16 sq. inches per cubic foot. As for the port, only the square inches of the opening matter. It doesn't matter if the port is 4" x 5" or 10" x 2", it's 20 sq. inches either way. The length, then, depends on the net size of the box, the size of the port opening, and the desired tuning. Go to the port calculator on SSA's site or download winISD or some other box building program. Then you can see how these things interact.