ShagggDiesel

Why are you going with Q's if you're competing? I'd probably go with the SA series or BL's you stated at the beginning if you're going to be chasing numbers as well.

I have a buddy that I built a box for and installed two SA-8's. He bought both of them used, one from Darren Francis, the other from a local guy. Anyway, with the subs wired in series/paralell for a 4 ohm load, one of the subs gets extremely hot after only about 3-5 minutes of play. If the sub hasn't been played and is cool, there is no scratching when pushed in, but when it's been played and gets hot, it has a little scratching noise when pushed in. Anyone know why this would be happening to only 1 sub? The other sub stays completely cool and plays fine. It is possible that one of the coils could be blown on the bad sub? I did a quick test with a DMM on the subs wired together and got a reading of 5.5-6 ohms. Anyone have any ideas? I haven't been able to go back to his house to test each coil independently yet. The subs are being amped by an Alpine MRD-1000. No bass boost on the amp or HU.

This stuff doesn't really add weight.. it doesn't weigh any more than paint does. It's not thick like you see on some restaurant tables where it's raised almost a 1/4". I guess it could be if you spent a month adding about 25 coats. But 3 coats is plenty sufficient for a great finish.

So, I tried the fiberglassing idea.. it was a fail. The PU does not dry hard/thick enough on material surfaces that arent solid such as wood or plastic. However, I did manage to put 2 more coats on a scrap piece of MDF with a good bit of sanding between each coat. The results were very nice.. a very smooth shiny finish, and hard as a rock. And just for fun, I left the piece outside overnight during a rainstorm. Checked it the next morning, and the PU'ed part of the wood was in perfect condition. Beat it against the corner of my metal fence pretty hard, and barely a dent. So, this could even be used for potential waterproofing if you have a leak in your trunk or using wood somewhere that moisture could get in contact with the wood. This stuff works great. It dries very evenly and the finish is glasslike if applied correctly. I'd suggest a foam brush or something of the likes. My next experiment will be with birch as stated above. Stefan, I also thought about doing the same idea you have with the paint underneath. I say go for it! Looks like this stuff would work great for it.

No, I'm not 100% positive. I did check the wiring 3 times before putting them in, but there could still be error. This is how I SHOULD have them wired: Each sub has a wire from + on one coil to - on the other, then the two remaining + and - running in paralell to the other sub.. + to + and - to - on the free terminals on the other sub. I guess the only solution is to take them out and check again.

Could you explain how a direct short works with a speaker? The sub still plays fine and keeps up with the good sub. Wouldn't a short cause some odd effects to the performance of the speaker even though it's only 1 coil?

You'll have to let me know when this becomes available. I'm about an hour and a half south of you. I think you actually helped Phi design/build my box for my 12" BTL a while back. Had the teardrop internal kerf.

Save the T-Line to try out for yourself if you're the one curious about it. Then you can see if the design and labor really pays off as opposed to a simple ported enclosure. Chances are, if you don't know much about T-Lines, your first one isn't going to be pleasant. Everything is worth a try though.. I just personally wouldn't try something I don't have any experience with for a customer. If he feels that he is going to be satisfied with that Lanzar, chances are he's not going to be too worried about a perfect flat response. Build a ported box, make him go boom, he will be happy.

Will definitely post pictures. I think I'm going to build an enclosure for a single ported 12 or something and use the PU on it to see what the results are (inside and outside of the box). Another note about PU: I'm not sure how pricey fiberglass materials are for I've never dealt with FG, but a quart of PU is roughly $10-12 which supposedly covers 125sqft. To me, that isn't bad at all. And it looks much easier to work with.

Well, I went to Lowes a picked up a quart of some oil based gloss PU to test out on some scrap MDF. The results after one coat and 24 hour cure was pretty neat.. It left the natural wood a dark tint, very smooth, and hard as a rock. I haven't tried sanding and mulitple coats yet. The only problem I saw with it, is that it makes the MDF swell up about 1/8" or so. The swelling seemed to be even across the wood, so no bubbles or anything of that sort. So I don't really a problem there as long as all pieces are assembled completely before covering with PU. Note: The fumes that this stuff puts off is STRONG. I'd advise anyone else who tries it to use a mask and a very open and ventilated area. The product still has a pretty strong smell after 3 days of curing on the wood.

Are you even competing? If not, why are you chasing 150? Measure the output and satisfy yourself with the actual sound, not a number. You're listening to this system with your EARS. Use that as your measuring device. Actually hearing how loud something is can be much more impressive than seeing a number. 140db can sound louder to the ear than 150db depending on the install. Just food for thought. If you are wanting to reach 150db for competition, then disregard my comments.

I built a box for 2 SA-8v1's yesterday. 1.68ft^3 tuned to 30hz. Sounds damn good for 8's and only 125 watts each.

And to enjoy the personal listening experience of course, right?

Anybody have any experience with polyurethane in car audio? Box building etc..

Maybe it's saying to set the gain in the opposote way you normally would. Set the "input level" all the way up, turn your HU volume to your max listening level, then adjust the subwoofer level control to set the output voltage to the amp. You'd be using the subwoofer level to set the gain as opposed to setting the gain on the amp after setting the subwoofer level first. You could do it either way.. I'm just assuming that's what the manual is trying to say.

Build the box to Fi specs, for they know what the driver performs best in. You can always add polyfill if you need to.

Definitely try porting the Type R first. If you are not satisfied with those results, then worry about upgrading the sub.

Example of Polyurethane on MDF. http://media.photobucket.com/image/polyurethane%20mdf/jeeposaurus/Picture9-1.png

I remember a year or two ago going through the "Pound That Sound" section watching all of his box builds and being so fascinated by his craftsmanship. What ever happened to that guy/company? I was off the forum for quite a while, and when I came back, I was sad to see that the section wasn't there anymore. :sadface:

What a shame. The guy had such amazing talent. I'd love to just see all of his old builds. Especially the box for the 2 15" Xcons in the truck. That was a one of a kind.

Since I already had the speakers and the materials, I decided to go ahead and try my idea. I decided if I didn't like it, I would go a different route. I built the enclosures to .25 ish cuft tuned to 45hz with 1" PVC. These are similar dimensions to the studio monitors I use in my recording studio. They aren't the prettiest things in the world, but that wasn't my goal. They sound much better than I expected.. Plenty good to satisfy me for what I needed. Overall, I'm impressed. It also makes the listening experiece that much better knowing that I made the enclosure. The only real issue I've seen, is that the tweeters leak air through them from the woofer. Doesn't seem to affect the sound, and it's not audible, so I don't see that to be a real problem. It worked out great for something to listen to music with while working in the garage. Thanks for the replies. I'll keep the Dayton's in mind for future reference.

I'm thinking about doing something that I've only see Steve Meade do, on a much larger scale. I want to build a small setup to just listen to music in the garage with. I have a cheap set of Pyle component speakers that I can use.. I'd like to build a ported enclosure like this. They would be ran off of a really old 100 watt 2 channel Pyramid amplifier. I do not plan on adding a subwoofer to the setup, just this set of components. Since this old amp doesn't have any sort of SSF, HPF, or LPF, it's playing a full range. I will have a crossover for the tweeter, but the woofer will be seeing even subsonic frequencies. I'm thinking about using 1" PVC for a port tuned around 40hz or so.. What are your guys' suggestions? Would this be even desirable? Or would I be better of just having them mounted somewhere IB? Remember, I'm not looking for audiophile quality here.. just something decent to listen to in the garage while working. If I do go throigh with this, they will go in a 7w/10h/10/d studio monitor style enclosure. Woofer mounted on the bottom, tweeter on the top, and port either inbetween or in the bottom corner. Thanks in advance for input!

I had this problem with a 10" Dcon I built a box for. I cut all the pieces, including the sub cutout with a CNC router, so the cuts were perfect. When I went to put the sub in, the spokes on the basket were too large. Had to do a good amount of heavy sanding to get it to fit. Even then it was very tight and nearly impossible to remove.

It sounds to me as if you're thinking of the subwoofer level as a "bass boost", in which case would be a bad idea to turn up. However; it is just a level control. Set the level to Max, set the gains on the amp with that setting, and let that Dcon wang.

If he has his amp setup up correctly now, then he needs to asdjust the sub level control. Regardless what has been said, most units require the use of this to be off of zero to produce voltage. Yes, and that makes sense, but... If the HU doesn't produce any voltage at 0, then why would it go into the negatives all the way to 15? You can get any less voltage than 0..