KU40

You can't have a 12" tall port in a box that's 12.75" tall outer dimensions. Did you give us internal dimensions?

Yes. Stop it.

Been a while since I've been in here. Just too busy.

If you tell us exactly how much room you have, that would help our recommendations. For the record, I once built an optimum sealed box for 4 12s, then later tried porting it to 40 hz. They metered the exact same. Granted the port cut down on box size a little, I think it went from 4 cubes net to about 3.5.

Try a different amplifier

If you would have put that information into your first post it would have helped. All you asked about were sound differences. However, there should be very little change in box size unless you use aeroports and use less port area. 40 sq. inches of round port and 40 sq. inches of slot port will have the same length, and thus the same port displacement. The only difference is that with slot port you have a little extra displacement from the 3/4" board used to make the port. Will it make a difference? Maybe .2 cubes or something, definitely not something I'd make a whole new box for. But aeroports allow you to use perhaps 60-70% of the port area needed for a slot port, thus port length will be shorter and port volume lower. However, if this makes a large difference in overall box volume is dependant on the box you have, port area, tuning frequency, etc. You'll have to figure out the volume savings and if it's worth it to you. I didn't see you said flared round ports in your first post (and not even until halfway through this post) or else I would have mentioned the less port area needed and possible space savings. My bad.

Oh also, make sure and give each component set their own crossovers. Don't just put the new speakers on the same passive crossover as the other set. Each individual speaker set (mid + tweet) needs its own passive crossover or else you will mess with crossover points and a host of other things.

There is an explanation of the flatwind coil on Fi's site, I believe in the tech section.

Don't need two threads on the same thing.

Right.

Hmm, proprietary maybe?

Don't confuse impedance and resistance. They are not the same thing and it happens quite often. The impedance is a nominal number and will constantly fluctuate when playing. When in doubt always go higher than the amp's lowest rated impedance.

96% of trunked cars with systems in them have the back seats up. It will be fine.

Nothing wrong with setting the gain by ear. I do it. As has been said, you have to troubleshoot. Try hooking up a different amp, then a different sub, measure the resistance of the coils on the sub, etc. But there was a time when my music would cut out completely, and if I turned my head unit volume nearly to the max I could play it at safely (where I set my gains), the sub system would all of a sudden turn on and start hammering away just like normal. The amp was bad in that case.

Just leave it alone. If you put round ports in instead of the slot ports and tune it to the same frequency it would sound the exact same as it does now. I don't know why you would do that since there is no point or benefit.

Yeah, leave as much clearance as you can under the sub. Obviously you'll need to leave at least as much as xmax, but an extra inch or two or three is better. Otherwise no real problem.

62* on Thursday, snowed 4" Friday night and Saturday in 25*, back to 60* today here.

Right. You'll just need to make some adapter plates to convert the 6x9 to 6.5.

There's no problem with running the other sub free air for a while to see if it's the amp. You just have to realize that the power handling will be drastically reduced. So if you keep the power to the sub down there's no problem. It could run free air forever with the correct power.

Yes. They sucked, just never got it together on either end of the floor. Quite disappointing. Then again it is my opinion that Northern Iowa should have never been a 9 seed. 5 seed would have been more like it.

You may as well maximize the output of that amp and run it at 1 ohm (I assume it's 1 ohm stable). You can always turn the gain down to limit the output power. You just don't want to be in a situation where you're trying to get extra output from the amplifier at 2 ohms by cranking the gain or bass boost beyond clipping levels.

85% efficient doesn't mean the amp will put out 85% of rated power. It means it will only output 85% of the power it consumes. So it would actually draw 2588 watts from your electrical system. 2588 * 0.85 = 2200. Don't run it at .5 ohm unless you want to buy a new one.

Make your box the 50x16x16, and make each port 14.5" tall x 2.25" wide x 35" deep. That'll give you 4 cubes @ 33 hz. Or, the two boards that make up the L-shaped port will probably nearly come together at the back of the box on the inside. Just make sure the opening between them is 4.5" (2.25" x 2). You can just end the boards so that they're 4.5" apart. If that means your ports are only 34" long each or whatever, that's fine. It'll only raise your tune about .5 hz, and that's in between your 33-34 hz still anyways.

or anywhere else that managed to escape the real estate bubble for that matter Like most of Kansas. My mom just bought her 5br/2ba house for 114k. I think my dad's 5br/3ba is appraised at 130k or so, and he bought it for 60k about 15 years ago. Both with full basements. One of my friends just bought a 3br/2ba 2 story + basement for 160k in a KC suburb, and I think here in Lawrence that type of house would be about the same.

Just FYI, having an enclosure too large lowers power handling above tuning as well. So it would have been easy to overexcurt the sub even with a higher subsonic filter setting because with that size of enclosure you probably could have broken the sub at any frequency with that power.