Advanced Discussion

Sorry my drawings are a little crude, but I'm taking an auto electrical class and some of our discussions got me thinking. I did a search and found nothing on it, but would like some input. I figured this would be a better place to post it than ca.com With series wiring, once power has passed through a load, there is a voltage drop depending on all 3 factors, Voltage, amperage, and ohms of resistance. With parallel wiring, each leg of the circuit gets the same voltage, only amperage and resistance fluctuate (they SHOULDN'T fluctuate differently in an audio setup, but if all coils are identical, theoretically, they all do the same thing) Remember, these are all theory, …

Hey all , I've got this AA mayhem 15 inch dual 2 ohms wired to 1 ohm , now BBpro6 tells me that the minimum impedance under load will be 2,05 ohms in the box its playing in , is this what the amp will see or will the amp still see the Re of 0,7 ? thanks in advance .

http://www.hotrodders.com/forum/alternative-lizard-skin-103610.html Micro ballons http://www.heatshield-r20.com Anyone had experience with it? It looks interesting.

I need help with design enclosure for BMW trunk, i need to get bass to cabin. Maximum height 16" Maximum width 35,2" Check this topic to see what i have there right now: HERE Subwoofer: JBL GTO 1514, 15 inch.

My buddy recently bought a 94 Cadillac Seville, and the radio wiring was so ghetto rigged so he went to rewire everything. While wiring, something shorted and now his instrument cluster will not work at all. We pulled the dash apart and tested the power leads and the would get power right before the fuse blew and all the accessories worked fine without issues. So we figured theres a short in the factory wiring. We bypassed all the factory wiring and and gave it constant power right off the ignition and fused it the same as the factory fuse size. Still blowin fuses. The problems arose when messing with the factory radio. The radio would cut out at medium volumes. We took a…

Hey guys. I used to have a nifty little excel sheet based off of JL's equation, but my computer died and poof went that. Does ANYONE have this document? The original was removed by the poster. Please help me out here guys. That thing was the key to me making any enclosure. Thanks!

I've been toying with the idea of using a horn in a spl application (one note wonder, as efficient as possible) for a few weeks now.. Instead of a regular wall, with the woofers and port on the wall, me and a friend had the idea of using a horn, with the opening as the whole front of the wall. It would be a front loaded horn, exponential, loaded with some sort of efficient pro-audio woofer, not the "horns" that have popped up in the car audio scene. Apart from the difficulty of fitting a horn (around 22ft long for the woofer I'm thinking about, should be shorter for a very narrow bandwidth), any problem with using it in such a small space ? Or any sort of other problem…

Ok so I have basic knowledge of rear/front waves and all that mess. My basic question is this: I have a subwoofer enclosure with the port firing to the side and the sub firing upward. Theoretically, which way should I "point" the port to get the loudest result? I can fire it in four different ways You can look at this vid to get a good idea of how much room it has etc. So to get the least amount of canceling or whatever, what do y'all think? I will probably test all four different ways on the TL, but I am just wondering what your theories are... Thanks! PS - pic is as though you were looking down on the car. The red square is the TL mic.

i've been trying to figure this out for a while now.. in a ported enclosure, how would you determine the phase of the sound emanating from the port at any given time? e.g. you have a 4cu.ft box tuned 40Hz.. and you play 3 tones, 35Hz, 40Hz and 45Hz.. will the phase of the port ever be in-phase with the sub? or will the tuning of the box and tone being played determine the phase of sound coming from the port? or would the distance between the back of the woofer and the port determine it?? i know the phase of the sound coming directly off the woofer's cone is 0 deg.. what i want to get is the phase of the sound coming from the port to match that coming from the sub at the d…

so many of you get that you need a pretty big amp for a pretty big woofer, but intuitively this makes little sense right? a big motor should in fact be more efficient! bob explains this pretty well why this is not true... http://www.sunfire.com/pdf/woofwhiteall.pdf

I had some kick panels made for my car a few months ago to house my 8" midbass. I had some issues fitting them into the door so I went this route. Even with only a 3/4" spacer, the door panel would not fit back on. Anyhow, the kicks look great, but I think are a bit too small, causing a peak in certain frequency bands. This problem is most noticable with male vocals. I tried filling the kick panels with polyfill...it helped a bit...but did not totally fix the problem. Other than that the system sounds awesome. Staging is fairly high and centered in the driver seat. So I'm opted to try once again to put the midbass back into the doors, and the 3" dome midranges back into …

Hi everyone, I have a dual 2ohm that is 1200 wrms and 2000 peak. Can I run a 800wrms amp or more on each vc? the sub is PG titanium elite (proven power hogs). How common of a practice is this? The reason I ask is because it seems like that application would use the woofer to the fullness of its potential. Later everyone

can someone please explain these concepts of on axis and off axis to me.

So Im tryin to come up with a design for my 18's and im stuck.. I can either have 122.5 inches of port at 5.5 cubes at 34hz or 70inches of port at 7.4 cubes at 28hz im leaning towards the 1st one or i can have even more space and just use aero ports thoughts?

Both 12V batteries. but is mixing them going to cause a conflict at all?

I'd like to start a topic regarding the technical aspects of sound absorption and how it relates to improving the quality of sound in our vehicles. First, I think we need to hammer out the technicalities of the term "absorption" as there seems to be a ton of misinformation floating around on the forums. What does it really mean to "absorb" sound? How is it accomplished? Second, we should transition from theory to practice and discuss the merits of using this acoustical phenomenon in a vehicle. When should we use sound absorption in our cars? Where should we use it? And perhaps the most valuable question of all: Why should we even try to absorb sound in the first place??…

I'd like some knowledgeable input on this topic. I have been told to o-scope amps with no load but am wanting to know if any of the following i've been told is true or not. Do not have a load as the amp output from the amp could fry the oscope. Do not have a load as the reading may be off. Well, i've always o-scoped amps with no load. I've o-scoped class d and class ab amps like that with no problems. Today, i attempted to o-scope this class d amp and it got damaged immediately. I contacted the manufacturer and was told it MUST have a load on it or it will do what it did. I ask why and it is due to the amp seeing 0 ohms... Wouldnt the amp go into protect? I dont understa…

Here is a test we did a few years back... Always surprises people... http://forum.carstereos.org/clipping-test-...41.html?t=47441 -Mike

ok, see if you can follow me, to create a sonic boom an object has to travel 720mph rite? A driver displaces air to make sound rite, so if I had a sub that would displace air at 720mph could I create a sonic boom in my car? Or would it create an ungodly amount of db's? Also, how loud is a sonic boom? Or is speed and sound not relative to pressure? Or would the sub make no sound at all since it would be traveling faster than the speed of sound or would it just be delayed? would the car explode? just trying to keep those good minds working. lol

I tried to read the threads on how to make a slot port and etc. etc. I tried to use the ones on the net, but people keep saying they are off. So if you happen to have microsoft excel, you can use this on and plug and chug some numbers in to get your required port length. This is based off the equation on JL Audio's site and it also takes into account End correction. If anyone has any input or if the JL Audio equation is wrong, then let me know, I just wanted to do my port right. http://www.uploading.com/files/CFXVZ5QA/Sl...ulator.xls.html

If i build my wall do i have to deadedn the whole car, or can i just deaden the doors and half the cabin and spray the back half with sealer or specdrum

What kind of tones do you guys use ? 0dB, -3dB, -6dB ? I've used the 0dB tones a few times. Worked ok with the gain setting for my mids but when I used it for the subs in 2 installs I had to turn up the gain (after setting it) just to blend the sub in with the front stage. I read everything here http://www.soundsolutionsaudio.com/forum/i...?showtopic=4256 but except Jmac's post I don't think I could draw a conclusion for myself. By ear is good enough for my car ( I just need the sub to blend in) but when it comes to getting the full output on music, 0dB tones haven't worked

Hey guys, just wondering what your input was about passive radiator boxes used in car set-ups??? I used to have a set-up of 2 12" VMax(the red older surround version) with 2 AE speaker 1050g PR's and its lows were pretty amazing. However, I had to have a pretty large box to utilize them like I did. Are there any advantages to me trying to use these PR's in say a SQ set-up or are there better alternatives out there? Let me know what your thoughts are! thanks

I see all these vids of people playing 10 or even 5 hz test tones, and i dont really understand how. If you have it tuned to 35, you set the SS at 30 give or take. Then how is it that the sub can play a 10hz tone. Doesn't the box constrict it, and wouldnt it be unable to control the sub below 30 hz or so if tuned to 35? This may sound noob as hell, i dont care lol. Thanks for reading, Mitch

a subs ability to play lower frequencies loud and well? I'm talking about around 30-40 hz. Ive been told that the big factor is in fact not the box's tuning like I thought it was, so what exactly affects the subs performance at those frequencies?