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Hi guys, i am writing a paper about the behavior of woofers tied in with resonance, tuning and such, the behavior of a woofer under stress (i.e. during use) and a detailed diagram of all the parts of the average woofer. i am focusing on these main topics: A) resonance/tuning 1) movement at and around the tuning frequency 2) the uses and benefits of diferent tunings, uses; musical and competitions B) Behavior under stress 1) impedance rise 2) thermal compression 3) box rise + the effect of tuning on it C) mechanical parts 1) Moving parts 2) suspension/soft parts, and effects of different styles of suspension materials 3) cooling technologies Thanks for taking the time to r…

I wanted to ask this question because I understand about them through extensive physics classes, but I wanted to ask on a clearer run down on how to deal with them in the car audio world say for example a normal SQL for the everyday street beater and then the SQ competitor and then wackos like me who are building massive boxes to stupid loud numbers (I understand the flow and movement of the air as controlled by the box designer, in my box case dave edwards is the genious behind it, but I wanted to start this for all members)

Hey, I just bought a Velleman HPS10 oscope a couple days ago. Im trying to configure it, but am stuck on one step. I cant set up the x10 measuring probe. I set the scope and probe to the 10x position. I also set the voltage/division to 1v and time/division to .1ms I think I set it to AC mode too. Does the "~" sign symbolize AC mode? When I touch the "Probe Test" point on the back of the scope, the screen of the oscope doesnt appear to show a signal because its blank. The directions say to adjust the trimmer. What exactly is the trimmer? Also, should the negative probe be grounded in this step? If so, what should it be grounded to? Thanks in advance for the help.

I have 4 4 ohm 10's in my car now, wired to 1 ohm for my saz-1500d. I am thinking of upgrading to 4 12's. The 12's I am looking at only come in dvc config, so to get 1 ohm, i need to get dvc-2's. My question is should I wire the coils on each sub series and then wire the subs parallel, or vice-versa? Would it make a difference to the amp? I would end up with a 1 ohm load either way. Any help would be appreciated.

I need to replace four of these, but cannot figure out the vales to find the part. Help?

I'm curious on what type of aluminum people use for bus bars and such? I will be making some to fit my post batteries because I can't find any terminals I like. Plus making my own will cost less, because I need four.

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 found this pretty relevant and interesting audiopulse`s site... enjoy SUBWOOFER MYTHS # 1 Subwoofers have an RMS rating Speakers actually have a very complex thermal compression relationship and certainly can not be quantified by just one or two numbers typically called RMS and Program or Peak. Because voice coils in traditional drivers are inherently resistors, any amount of voltage generates some amount of heat which then adversely changes the resistance and properties of the speaker. This is the principle of thermal compression: As the voice coil heats up, the resistance changes and the efficiency and performance of the driver decrease until the point of maxim…

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, …

just something i was looking at today. The basic highpass filter will allow for higher peak voltages then the input has. basically -- if you put in a 1V peak square wave, you can get peaks of 2V from a highpass filter. this is easy to show with RC circuits such as a simple cap inline with the speaker. Square wave goes to 1V. cap charges to 1V. square wave goes to -1V, cap is still charged to 1V. voltage across speaker is now -2V. cap will charge to -1V, square wave chages to +1V, speaker sees +2V. note that RMS power is lower, but peak power is higher. ----------------------------------------------------------------- This brings up two issues: 1.) the peak values c…

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 …

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So within a few months I will be getting the '13 Fusion and I want to do an active setup. I really don't know much about the speaker choices, best crossover points, processing so I'm relying on you guys to help me get a good front stage. Right now I want to start planning; don't want to rush it when the time comes. So what will I need? amp, speakers (2 6.5 mids and 2 tweeters), minidsp? I will keep the stock hu and use a LC2i. My budget as of right now is undetermined as I want to see prices of everything then see what I should spend. My goals really are simple. I want it to be loud enough to hear vocals over the bass when the subs are high and I want the mid bass t…

http://www.sciencedaily.com/releases/2007/06/070603225026.htm we can we expect to see these in amplifiers? and how much more efficient would they be if 30% or more of the heat was turned into electricity? what about lining sub boxes with piezoelectric crystals to make electiricity from the sound subwoofers produce. and have that electricity go back to the amplifier/capacitor.

http://ampguts.com/forum/atomic-36/atomic-5000-1d-1901/ Same board as a couple other amps, RD, Cactus blew a fet or 2 or 3 lol. Got all the screws out and cant pull this board out, its like wedged in or something. and the heatsinks look like they have to be bent up, but if i bend them up not sure if they are going to be able to bend back down.

found this article via CYV forums!

My box is 36w x 19 d x 15.5h Port is 5.5x14 and 13.75" long I burp at 49hz, which I have found is the loudest in testing. Initially, I had the subs wired to 1 ohm, and the total rise came to about 3 ohms. I then strapped the amps, and wired the subs together, to get a load of .25 to each amp. I went up about a db and a half from doing this. I want to get my rise lower, but have no idea where to start. If you guys have any ideas to help me, any would be appreciated.

I need to build a new test enclosure and in the process prefer to use a removable baffle. In the past I have used something like this: http://www.madisound.com/catalog/product_i...products_id=768 I am also curious if anyone has any specific implementation recommendations on bolt spacing, overlap of the gasket, better gasket materials, and so on.

Hey everyone, I'm having issues designing an all purpose (SQ while being loud) ported enclosure for my RE '06 XXX15 sub. I had a ported enclosure built. Its approx. 3.5ft^3. It has a rectangular L port with a port area of 60in^2. At the time when I designed the enclosure, I hadn't discovered WinISD or any other similar programs and just used the RE L Port calculator. This enclosure was supposed to be tuned to 35Hz. In short, its a mess. There is alot of port noise and it barely reporoduces anything under 35Hz. So I went back to the drawing board and learnt how to use WinISD. From what the program is telling me, it can't be tuned to 33Hz (which I want to achieve) unless th…

I am burping my loudest freq below the tuning of the port. My only question is, how much lower should I tune the port to? I burp the loudest at 47, port is tuned to 52 Would tuning it at 45 be okay?

I have not put to much though into this but I was just wondering if this would be a great charging system for car audio. The way a hybrid vehicle works is it runs off battery power at low speeds and at idle. The only way gas is used is when the voltage drops past a certain level to charge the batteries. This would be ideal for competition use as the charging system is geared toward the idle to low rpm range. There are multiple batteries in a hybrid setup and I am sure that the charging system would have to be pretty beefed up to charge a hybrid vehicle. A regulator could be used to change the voltage at which the charging system kicks in. If you were to have a high power…

Just looking around and thought this video might be interesting to some.. http://blog.edesignaudio.com/?p=244

Just curious why no speaker manufacturer uses dual tweeter setups? I see multiple mids on a single speaker all the time, but I have never seen dual tweeters on a single speaker. What would be the cons and pros of using two tweeters per speaker (four total for stereo)?

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 need subwoofer box building software......I wanna start designs for my 2 15's NOW!!!1 Anyone got any help?? FREE is really helpful!!!! J