j-roadtatts

This topic is to discuss test box alignments and tuning for a 6.5"-7" midbass. I am planning on testing quite a few mids in different alignments. MY GOAL IS TO achieve tight accurate dynamic midbass down to 63Hz, with overhead in the output. I am after a very open natural crystal clear sound. I am NOT after punchy colored thick sluggish midbass. My current set up is the Seas U18 in an IB (deadened doors). They are crossed @63hz 24db slope presently. I am running two 15" Icons sealed, crossed @50hz 24db slope. The U in its current alignment handles these frequencys, but has what I believe to be cone edge resonance once at reference level. Plus has no overhead left for dynamic peaks. They are only on about half power currently... but will be fed full, if not double once dialed. I know this will help with the dynamics, but is not the topic at hand. Also worth noting is I will be adding an H701 DSP before testing, for greater control of the fr. I understand a heavy and/or ridged cone and and stiff surround will control cone edge resonance, so a few choices are in that direction. Otherwise these are all picked for large voice coil, high xmax, and high suspension compliance. Also must play high enough accurately to reach the tweeter. Mids picked so far: Evil Seas U18 Seas CA18 Seas ER Scan speak 18W Dayton rs180 The test boxes being considered: IB/deadened door sealed for a .5 Q sealed for a .7 Q ported tuned to 50Hz ported tuned to 63Hz I understand the effect the ported box has on cone excursion vs output. I understand the trade off of the ported box is either gain efficiency or drop the fs. I see that tuned to 50Hz gives the reach and 63Hz output. Here is modeling of the 18W black 63Hz red 50Hz green .762 qtc blue .505 qtc First few questions. Am I approaching this correctly? How does cabin gain play into this? Should I my model in Leap? Or is it something I can eq out? Am I overlooking anything? Any other input on the topic appreciated and thank you in advance.

WOW is all I can say!!

WOOT WOOT!!!! Party at Casey's house!!!!!

...or the mustang!!

Will add is WAAAY to flashy for my taste. Would rather be driving my old beat up truck.

Haven't needed the warranty and runs like a beast. Can't say is what I would of bought, but that's what the W picked when I sent her car shopping.

Honestly better that way if it works, as a computer will repeatedly turn the alternator on and off depending on load. Which will cause wierd voltage drops with a high-powered stereo.

Dude I'm super jazzed for you to hear this!! Think I miss read your alternator situation on the last page. If you don't mind a check engine light you should be good just hooking up the two wires. Once you can figure out which ones are field and stator. I could be wrong and the computer won't let the car start. But would be crazy enough to try anyway.

Volvo XC60 perhaps.

About 500 dollars worth of fertilizer.

Check your local welding shops. You should probably go there though, instead of call. They will usually have a scrap pile you will need to look through yourself. They might have sticks in stock too, but generally that kind of stuff is order as needed.

I spent a few hours at a grow expo yesterday. I ended up winning the grand prize in the raffle. lol

Grand Cherokee Summit or SRT. Base models suck, but the fit and finish on the Summit and SRT are stellar. Harman Kardon tunes is a nice bonus. The SRT is the Hemi version!! But the V6 in the summit is plenty powerful. I cant say 0% interest and lifetime warranty suck either. I would think they might as well be considered a European company at this point. lol I saw a X3 yesterday and damn that thing is ugly for a beamer.

I did the math at the time and there was minimal volume comsumed. Each inch of brace is .562 cu in (3/4"x3/4"x1") ...so like 200ish inches is only .06 cu ft. Your 2x2 equals 2.25 cu in per inch (1.5"x1.5"x1")... so 200ish inches is .26 cu ft. still not enough to lose sleep over.

Labyrinth bracing would be ideal. In your case though I would say a combo of both styles previously mentioned would create a similar effect. This is my box^. I will note that the braces are symmetrical, and that is technically a no no. As it will fuck with the waves in the box.. As you see in the guitar pic, the right side is asymmetric, which would be correct way for any bracing.

The extra wire on the alternator most likely is a feed from the (more advanced) computer. The other two are field and stator wires. The one I did required a 47 ohm resistor on the extra wire... then I believe it was hooked to the power wire. Would need to confirm all that to make for sure. Is to tell the alternator to charge. Iirc the resister stepped it down to 5 V, same as the computer would send to it.

I might have come up there and show you guys how to ride a sled. :D

I feel you. We have been getting college letters on the weekly for my youngest. I'm really feeling the empty nest coming on. Is even crazier hearing all these guys talk about their kids still doing soccer and such. It was literally just yesterday.

Wait till your kids are teenagers you guys will know all the code. It will be lit! Lol

Don't know if I'd mentioned it. I scored a mountain of 1x12 on CL for about 30 cent on the dollar. Has been fun trying to use it all up. lol

Finished up this project yesterday!! Before^ After!!

And DAMN that is a SEXY amp!!!!!! I love the industrial/utilitarian look!!

Ribs like the left side in the pic^^^. Flat on which ever wall you are mounting the amp. Generally for an SPL box I believe you want a little flex, so don't go crazy and do them on all the walls. Besides the ribs could start to create turbulence inside the box, so just where needed.

Nope. The "I" in the "T" shape would be a brace... the part that protrudes into the box. The top of the "T" is wall of the box. Google T beam or T beam webbing. Think about the tall skinny part that hangs down from a bridge, that's what gives the thin road surface structure. Make sense?

Ouch that's a long time without tunes dude. loOks like you getting close! Almost time to start hooking up equipment!!