KU40

Well if you want to try it, go ahead. I can't tell you for sure that it will have port noise. Have you thought about upfiring?

I don't think you can use aeros with only 3" of height. I think that even 2" aero ports are 4" total diameter on the flare. A slot port is likely the better solution. You could make it 3" tall and 4-5" wide.

You are comparing the long narrow port to the wrong thing. You don't want to compare it to 20 3" square ports as that adds even more resistance because that's a lot more perimeter wall. None of us would recommend 20 3" square ports over a single rectangular port. Again, a 3" x 60" port has 126 inches of perimeter. 20 3" square ports have 240 inches of perimeter. However, a 13.5" square port (which has approximately the same 180 sq. inches of area) has only 54 inches of perimeter. If you want to find out if air has similar resistance properties than water, find a bunch of straws and stuff them in your mouth and breathe through them. then take the straws out, and find another straw or pipe that's as large in diameter and length as all of those smaller straws, put it in your mouth, and breathe again. See which one is easier.

3" wide slot port and 3" round port are waaaaay different things. If you know about air or water movement through an opening or channel you know that the air on the outsides moves slower than the air in the middle due to resistance against the wall. If you have a 10" square hole, there is a lot of room in the center of that, away from the walls, for the air to move quickly through and not be affected by the slowdown caused by the walls. In a narrow port, by the time you get away from one wall's resistance you're almost to the next wall and running into its resistance zone. Since there's more perimeter area around a long rectangle than a square of the same area, there's more resistance by the walls. Any port velocity calculator only takes into account the overall area of the port, not any characteristics caused by port shape. So it may show you that the port area is enough with your long and skinny rectangle, but in the real application it will not be.

Who knows. It's the full potential of the subs that you should be worried about. The 3000D will deliver that. If you're worried about getting the full potential of the amp get a 2000D. Also, do not make two different threads with basically the same ideas. You could have put both the Q and BL in the same thread. For some reason merging the topics won't work right now though so I guess it'll have to stay.

I had a similar problem in an amp that would come to life only when I turned the volume up quite a ways, then would later fade out or cut out sometime. The amp is toast. I believe when I opened up the case a couple of the mosfets were a little burnt. I tried replacing those but it didn't fix it, so there must have been something else wrong but I wasnt' skilled enough in amp repair to diagnose it. If channels 1-4 work, I'd just use those channels and then get another amp for the remaining speakers you need to power, unless you want to send it in for a refurbishing. If it's not under warranty, however, open it up and see if you see anything wrong.

Any sub(s) can handle any amp as long as you're smart with the volume and gain knobs.

I love sexy black tires. I think I have used black magic a few times myself. I'd recommend not using any kind of tire shine. It causes weather cracking faster.

If it's blinking in rhythm with the bass but that's "ok," then either the indicator isn't accurate or the guy is lying. Having it turn solid before clipping makes no sense because music is dynamic. The peak that's being clipped IS when the bass hits. So if the light is supposed to represent when the signal is clipping, it would come on exactly when the bass hits. If it stays lit then you're basically sending a square wave because that's the only time a signal could be clipped continuously enough to leave the light on.

I used to have that amp. Decent amp, though won't do any more than rated. At any rate, I wouldn't run it below one ohm with two D2 subs. My suggestion, if you really want those subs, is to either wait until you have enough dough for 2 of the D4 coiled subs at the same time so that you know you get two, or be prepared to sell your amp for something 2 ohm stable when you get D2 subs.

A single 4" port would probably only be sufficient for subs with relatively minimal xmax capabilities. If you want to know what xmax that would be, look at the sub and see how far it's moving right when the port noise starts.

I've always thought that my ears are a good enough O-scope.

An actual home amplifier like the one Impious linked to would be a lot easier. Plus I'm not sure I'd trust a $20 power supply for that much power.

Congrats on a job well done!!! Gotta love the feeling. thanks Nice work. What topic? thanks, it was about competitive markets and their characteristics etc. etc. Have you learned about the situation where two firms agree to keep prices the same but earn more if they cheat on the contract? Basically I learned it using two gas stations in a situation where a price war may occur. The two stations agree to keep their price at, say, $2.50. This gives each station 50% of the profitability of the town. However, if one station cheats and lowers their price to attract more customers, they increase their intake to 70% of the overall profitability in the town, while the other station only gets 30%. Basically what it comes down to in the end is that both will cheat because they don't want to be the one with the 30%. It's not a riddle, but rather supposed to be more of a real-life scenario.

That port opening is going to be bad. 40 square inches per 18 is not sufficient for no port noise in a "good" slot port, let alone one with a ratio such as that. I would suggest maybe switching to some round ports if you are having this problem. You calculate tuning using any box building program or any of the tuning equations on the net. But I get the tuning to be about 25 hz with a 10.25 cube box with 2x40 port x 25" long.

Just because they're in separate chambers doesn't mean you can't wire the subs together. I assume that's a 2 ohm stable amp in mono operation? If so, then Jay-cee's posted diagram is correct.

Finally my Firefox remembered my cookies and kept me signed in. First time in a month. I guess that upgrade to the newest version yesterday helped.

It will be fine.

I ordered an amp from there. No problems.

How can you hate Peyton? It's because he's one of the greatest isn't it? Yeah, I don't know how anybody could hate him. He just works hard and is smart and not a jackass. He's like Joe Montana. And yeah definitely no ego that I've ever seen.

You must not have read the sequels very well then, ha. I believe it was in the second one where his sister started her philosophical bombardment of the internet and many people agreed with her ideas and then took them to the government to implement. It has been a couple years since I read them so I'm not exactly sure on all of it, but I'm fairly sure that's the gist. Also, the squirrel is significant because their littlest brother, I forget his name, was a cruel kid and would slaughter squirrels just to watch them die. He later became the Hegemon. I get all that. I guess the humor was in that idea actually working, but, I believe it could work given the parameters of the book. You get someone to say persuasive, and I don't care who they are, they can have power. *cough*Obama*cough*

With only 300 watts you could clip the hell out of that amp and never blow the sub. Anything that has resistance and gets power applied through it warms up. That's it.

Are you going to be able to actually use all of that space? That's about 11.5 cubs net volume for a box, you could port two 15s. I guarantee that'll be louder than four sealed 15s.

If you want loudness, get fewer subs and go ported.

You must not have read the sequels very well then, ha. I believe it was in the second one where his sister started her philosophical bombardment of the internet and many people agreed with her ideas and then took them to the government to implement. It has been a couple years since I read them so I'm not exactly sure on all of it, but I'm fairly sure that's the gist. Also, the squirrel is significant because their littlest brother, I forget his name, was a cruel kid and would slaughter squirrels just to watch them die. He later became the Hegemon.