1. What's better? Dynamat, Peal N Seal, or Raam Mat?
2. Anyone ever heard of RE (Resonant Engineering)? thats what I'm gettin and it's amazing, I'd recommend it to anyone. The bottom of the line sub easily compares to the JL W7
3. Is just a plain, square, Q-Logic box alright, or is there any reason I should stay away from them?

 

1. Raam Mat, peel & seal loses its grip when it gets hot, dynamat is over priced.
Personally id suggest SecondSkin STFU-80 or dampilfier v2.

2. Yes ive heard of them, if your getting them but havnt heard them yet how could you recommend them saying they are amazing? Sounds like some1 had been hyping these up for you. They are great subs, but still not a W7

Which ones are you planning on getting? RE, SE, HC or the XXX? im gonna guess your spaking of the XXX if your comparing to a W7.

3. 20% of how a sub sounds id from the sub, 80% is how the box is built. Stay away from Q-logic and have a custom box made. Reason you should stay away...I have yet to see one pre-fab box thats perfectly sealed.

 

if you do get a prefab box you can always just seal up the seams anyway just in case. but if your getting a supersub id make my own box too.

 

1) Second vote for Damplifier
2) If you are going to spend that much money on a sub you should put it in a good home.
3) Do not build a perfect cube. There is a possibility that a perfect cube will intruduce excessive standing waves in the enclosure. True or not I have always stayed away from them.

XXX needs lots of power and a very sturdy enclosure.

 

what do standing waves do negatively in terms of performance? i hear about it but dont seem to understand it.

 

This is a "sealed" term which I have done no research on so I too would like a detailed explination. From my understanding its bass waves that cancel each other out causing a loss in output but id like a more specific explination.

 

well i agree wit hitman, only the XXX series can compete with the W7, i just bought an HC, yay! also, yeah, i would make yourself a box out of AT LEAST 3/4" MDF . Q-logiv sucks

 

would polyfill take care of some of the standing waves?

 

Actually, im guessing it should make it worst. If I understand correctly bass waves are obviously long & slow but in a cube box (one thats large enough anyway) they might meet and cancel each other out. I still doubt its any1 would have a problem unless they make a HUGE cube box were the waves actually have time to meet. Im still new to this logic but thats what I personally see it as, Dan...what do you have to say about this...

 

see i talked 2 a tech guy at pg and he says they recommened polyfill in the boxes to get rid of standing waves. who knows.

 

Thats the thing, I dont want to contradict any1 but I really am not 100% sure as for what this is, I've heard the term a few times but I dont use sealed so I was never interested in finding out what it exaclty is and how its created. I can PM on of the guru's over on the audio forums, but I'll save that for a last resort thing

 

polyfil only slows down the waves inside the box, giving the sub, or any speaker for that matter, the appearance of being in a larger box because the waves take a tiny amount longer to travel.

standing waves in a box, im not too sure about...what i do know is even ultra high end speakers for the home are built in a rectangular shape...i think it has something to do with the ratio of the size of the sides.

 

can we also throw brown bread up there on the list of sound dampening thats cheaper than dynamat?

 

Why not, dont 4get edead.

 

According to Vance ****ason, you can eliminate standing wave modes by using fill. There is also a widely held conception that standing wave modes can be minnimized by using the "golden ratio" of 2.6/1.6/1, that is height/width/depth. He goes on to explain that the effects of enclosure dimensions isn't nearly as good as using fill, his personal favorite is 100% R19.

I think the issue is that if all of your dimensions are the same you will have the same frequency standing waves (either 1/8, 1/4, 1/2, or 1 wavelength). therefore, their effect will be additive. I could be wrong, though.

 

hmm. so using polyfill helps this. now what about polyfill increasing temperatures inside the box and causing maybe a slight loss in power handling?

 

All about compromise. Are you after SQ or SPL. The standing waves will give you odd bumps in the frequency response, bad for SQ. The best solution is to try and avoid a perfectly cubed box and use 50-60% poly fill maybe more or maybe less depending on how you want it to sound.

 

my box dimensions are 13.5x28x13.5. this is for 2 10's. im thinking polyfill would help get rid of some of the standing waves because for each chamber its close to a cube shape. http://bigdogaudio.com/proddetail.asp?prod=BIG102SQR
do you think polyfill would be worthwhile?

 

You can try it. It depends on how much you like taking the subs in and out of the box, but I ususally mess around with the fill level a few times before I decide. I also use R19 insulation from Lowes instead of poly fill but both will work.

 

yeah frankly im tired of playing with my subs. have you deadened the trunk yet? i think im gonna do it very soon and i was wondering what is the best area to deaden? i was gonna do the trunk lid and the area where the lid meets the trunk. do you think doing the area where the spare tire is located is worth while? i have a piece of plywood underneath the carpet to keep my box level and i wasnt sure if deadening there would help.

 

Man, have I. The stupid thing still rattles like it's coming apart. I think the best place to start adding dampening is the rear deck I think that is where most of the rattles come from. But yeah, I have added brown bread to just about everywhere on this car and it still hasn't fixed all my rattles.

 

yeah i put a ton of foam on the rear deck. has the road noise decreased at all due to the damping?

 

Yeah, that it definately helped with.

 

You aint the only one To perfectly sound deaden a maxima is pretty much impossible IMO. That stupid rear deck I have 2 layers of STFU-80 on it, some foam cutouts were I could stuff it and more stfu-80 all over. I should have gone as far as taking the seatbelts out and stuff some in there too but oh well. Im not going to take it all apart again for that.

To fix all the rattles id have to do that, then take apart my interior and do the roof, doors, trunk lid (another layer or two and it wont even open). Not sure how but I was to do the inside of the trunk lid as well. Too much empty space IMO. Id have to remove the rear bumper and fill that thing, as well as...ahh crap I could sit here and name every peice on the damn car...how about this, I need to take the whole car apart and SD the whole thing...twice...and hope it does the trick. What a pain in the @ss.

 

We'll see how bad things get when I put the second Brahma in

 

Thats totally unnecessary and you sir are nuts

 

Hey, my 2 12s sealed will probably still fall short of your 1 15 ported. Now I just need to figure out what to do about amplification.

 

I thought you were going to port them. Your right the 15 ported will outdo it, ive modeled up a pair of B15's sealed with 1200 going to each it it pretty much matched my current setup, the 12's should fall slightly short of that, but your still going to be within a few db (over 140, thats 4 sure) so its still going to be stupid loud

Amplifcation...hmm...how about 2 Hifonics BX1000d's You could fit one under each seat w/o any problems. Some1 here locally has one under his driver side and could easily add one more to the other side. I would say go with the 1500's but its not really necessary IMO, once you pass the 1Kw mark with each sub the extra 500w to each sub ist going to gain you much but its sure as hell going to put an unnecessary strain on your electrical system. They dont cost a bundle either.

 

Yeah, I ma going to use the SubZero dual B12 box for now. I really don't have the facilities to build my own box anymore and the quality is better than what I would get from any of the local shops. So I am looking at 1.25 ft^3 per sub. When I model it I only need about 800W per sub to reach Xmax at 20Hz. I figure the amp I have now will put out around 1000 into 2 Ohms. i am really looking for a good clean unmodded MMATS D300HC. It would be perfect, about 1750W into 2Ohm, fit under the seat, and run forever. I also recently upgraded to a Battcap 400, hopefully that along with my 1/0 power and ground will help with the electrical.

 

SubZero is better then most every pre-fab so thats cool. Id still make sure its perfectly sealed though, I know you know that but just saying...
1.25ft^3 is gonna be tight as hell, one things for sure, your going to have insane SQ. Thats setup is going to very nice.
800/sub to reach xmax with 1.25ft? you should still have over 10mm to go at 20hz with 875 to each sub, so you should be nowere near its limit IMO.

If it was one 12, in a 2.5ft box with 875 going to it, then yeah it would hit xmax at about 20hz but you got a while to go man.

Goodluck finding that amp man Battcap 400...mmmmm...a cap that actually does something...

 

What are you using to model. I'm using LspCAD and it is still showing numbers more in line with mine than yours. With 1000W to both voice coils in series I have a max cone excursion of 61mm at 20Hz, well past the 55mm that I actually have. Now at 1 ft^3 I have 56mm at 20Hz. This also seems more consistant with what the guys at Adire told me, that the B12 will reach Xmax with about 900W in a 1ft^3 box.

I'll ask the guys up there next week. Gotta make sure I'm not short changing myself

 

Im using WinISD . Ill have to use the one at work (more updated) and get a better setup demo but Ive been playing with that one for months and they seem on be pretty much accurate. Im not going to try to say its better then what adire uses but there is always the benafit of the doubt

I was actually exagertaing when I said it would reach xmax at 20, on this diagram it show it to reach the full 56mm stroke at about 18.37hz. Atleast thats what this thing is showing me anyway