Advanced Discussion

Maybe this should be stickied... Impedance cannot be measured with a DMM. Only DCR can be measured with a single DMM, and this isn't impedance. There is no such thing as "Impedance Rise". There is an impedance curve, but this both rises and falls..... The system impedance will always be higher than the DCR of the driver under any condition. Many factors affect impedance, the biggest being the enclosure. Until you measure your complete alignment at all frequencies in it's operating range, you have no idea what the impedance is. Impedance changes do not change driver power handling, they change how much current you amplifier puts out at a given voltage.. Nobody owns a .7 …

I'd just like to bring up a certain point to the every raging debate whether cone size plays a role in a sub's "quickness." At a certain frequency and excursion, any sub's cone will be traveling the same speed. No argument there. But what about the transitions from rest to that frequency and from one frequency to another? I'm looking at the Force = Mass * Acceleration equation here. If both a large sub and a small sub have the same motor structure, I believe it is safe to assume the force is constant. Therefore, an increase in mass has to lead to a decrease in acceleration. Are these differences in acceleration large enough for us to hear? Am I missing some other pa…

I have a f150 std cab and im about to do a blow threw .. i only have room top to bottom for 12's but if i ever wanted to go bigger i have a idea how i could make it work. I just have not seen many people or any one ever build a box like this. Now t-lines work off of 1/4 wave and a 6th order is like a ported box with ports on both sides of the sub.. what would happin if i built a box and made it were there was port on the front and back of the sub like a 6th order but the ports were all 1/4 wave like a t-line just front and back.... the box would be huge because of the simple fact that each port would be around 9 feet long lol but hey i got a long bed truck so it dont m…

Does anyone know the factory raido wire color codes for a Lincoln navigator 2006 with navigation...

I am not running all of these at once, but I have the option of choosing any combination. I am running 2 vifa Vifa BC25SC06-04 and 2 DDC6.5"s I have a sony xm-4045, 4040 and 6020. I have a cache cloc'd, pac SNI-35, pac sni-15 and fierce FILC20V2 I just picked up an american bass ABX-3.1A crossover which I will be using to replace an older optimus 3 way crossover, and I will be using it for the mids and tweeters. I will level match (to my liking, which will leave the tweeters a little brighter than the mids) on the crossover. My question on that is what the output knob does. It doesn't show any db so I'm guessing that with the knob maxed out, it's simple not…

OK SO IM TRYING TO FIND THE BEST WAY TO GET THE POWER AND QUALITY WITH OUT GETING A DIVORCE.! LOL IVE GOT ROOF MOUNT, DOOR MOUNT, DASH MOUNT, REAR DECK LID AND I HAVE A SPACE BEHIND THE REAR PASSANGER SIDE WINDOW WERE ID LIKE TO PUT THE ROCKFORD FOSGATE PUNCH PRO 6" 4 OR 8 OHM MIDRANGE. IM REALLY NEEDING A GOOD AMOUNT OF HELP IV DONE THE FIBERGLASS MYSELF AND IM VERY INTERESTED IN COMPLEATING MY PROJECT. THE HELP I REQUIRE IS SUCH: 1. I NEED TO KNOW THE BEST SPEAKER TO CHOOSE FROM EITHER THE PUNCH PRO 6" 4 OR 8 OHM MIDRANGE , BOTH HAVE THE SAME MOUNTS BUT IM OPEN TO SUGGESTIONS OF OTHER BRANDS BUT DEPTH MAY NOT EXCEED 2.26" 2. I NEED TO KNOW THE BEST AMP OR AMPS TO DO THI…

I'm going to be starting a 4th order blow through my rear deck soon and had a few questions. One being when I port through my rear deck would it be best to fallow to window angle to port straight up into it?

hello everyone fist post .i really need your guys help with eq and crossover setting stopped doiing spl and entered the aq seen bud never knew how difficult it will be .got an alpine 9887 dlsr6a s inthe front doors with baffles and jbl coaxil in the back running of an jl xd600/6 2 jl 10w3v3 running of an jl600/1 all active can enyone please recoment good eq and crossover settings any help will be aprecuated thanks

I've been looking around at some different subs, trying to decide what I want to do for a summer project. I want to do my own work, i.e., build my own box, replace door speakers, etc. I've been looking at subs on Parts Express, like Dayton and Tang Band. I've been all over their websites, but can't find any recommendations for box sizes or types (ported, sealed, etc). So, my two questions are: 1) How do you calculate box size requirements using the specs that are provided? 2) How can you tell what type of enclosure a sub will work best in? I'm specifically interested in very small applications, as I'd like to try and run multiple subs (three or more) and try to retain s…

Active 2-way with Full Range driver for the top end? This is not meant to be a pick my driver for me topic. My new dilemma is because of Adrian, he put the full range bug in my ear and I am starting to question my plans. I am not as versed in full range drivers as many others are on this board, so why not use the knowledge base. Setting: car - Mazda Protege5 wagon original front stage plans - Bravox CF603CF's power - many to choose from, so not an issue mounting location - FR's or mid/tweet would have to be at the base of the A-pillars (small manual car with no real room in the foot wells) Now where I am questioning my plans is that I have not had a passive set up in y…

I remember reading about this somewhere, but I can no longer find the information. I'm wondering if any of the EEs we have can give me some insight as to the benefits other than cost and how to implement them into my system. This will mainly be used for control of alarm accessory channels. Thanks!

Hi guyz... Happy New Year, all the best, keep safe and healthy. On to the topic. I would like to know if an amp @ 4 ohm pushing 600 watts will draw the same (amperage) as opposed to the same amp pushing 600 watts but at @ 2 ohm (hope that is english lol) Not sure if it has been answered before. Thanks for the help. Kelvin

i made a comment on a post on facebook, and tony d'amore said he would be happy to come to SSA and talk about the amp dyno , he actually told me there would be no debate because its science , so here is the topic. where he and we may discuss .. i mean .. talk about science

Hey guys, I am having the following issue with my amp: The protection light comes on as soon as it powers up and it stays on. If I leave the amp on for a minute or so I can feel it getting really hot on the corner where the fuses are located on the bottom. The side of the amp is where it is getting hot and it looks like maybe a transistor over there (you can see if by looking in past the fuses). I have a Kicker amp that works just fine using the same power, ground, and remote wires. Memphis quoted $175 to fix it. I think it could be an easy fix if its just a bad transistor. I know how to solder and I've taken an amp out of its heatsink before to work on it but ended u…

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.

I was thinking about speaker and amplifier resistence with all these RMS threads and Iron laws going around........I remember once checking the ohms of my driver which was a dual 2 ohm driver.......it was 2.12 ohm in the box and 1.97 out of the box...........when the sub was hooked up to the amp (amp shut off and no music) the resistence was like 2.75 or 3 ohms............why would this be? J

This passed weekends comp got me thinking. In BBP6 and WinISD the F3 for my NAR (Amplitude Responce) is 50.8hz, so at the comp I expected somewhere over that to be my "loudest" tone. When I did the sweep, why was 37hz? Could it have to do with the cabin of my truck? Next question, the New SI's F3 per BBP6 is [email protected] cu.ft. Wouls the "loudest be even lower then before or again does the "resonant frequency" set around 37 for the "loudest" tone. I am at a loss. My knowledge of these things is very limited and I always want to learn more

Ok I was watching Mythbusters last night and they were making a wind tunnel. They used a "honey cone"effect by using straws to help the air transition to the tunnel from the fan (or blower) better. I was wondering if this could be put to use in the car audo world??? Make a regular slot port and fill it with straw (like) tubes to the proper length. Very little surface area per straw and lots of straws. I was just wondering about that last night and figured I'd see if anyone here has ever tried or thought about it??? Your incite is appreciated... Jon

I despise "Which brand/driver" type threads but unfortunately, in helping my son, I am hitting just that. 2004 Pontiac Grand Am. Waiting on HO alternator. 3 Die Hard Platinum batteries. 2 runs of 1/0 positive 1 run 2/0 as a negative connected to frame in 3 spots System layout: 2 ea. JBL GTO14001 amplifiers each driving a DD9012 sub in a ported enclosure. Each sub in it's own chamber each sub wired to achieve a 4 ohms DCR at the amp. JBL GTO1004 4 channel amp 100X4 Image dynamics wave guides acoustic open cell foam inserted in the throat to cut down on some of the screechiness. Really helped! Crossfire compression drivers and the crossfire passive/frequency shaping cr…

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.

I have a pair of 8 ohm MJ18s. I am designing a Zobel for them at the moment and cannot find the published Le of these anywhere. I also don't have access to my Suncor LCR meter at the moment.... Does anyone know off-hand what it is?

Ok before I get flamed I know I'm retarded for what I did to this amp.. Ok here is the deal I tried using another brand of bass knob so I had a clipping light.Well long story short it worked for about 5 seconds and blew the inline fuse. I tried reconnecting the AP knob and a new fuse it blew right away as soon as it powered up. Then same thing With no knob connected I checked inside the amp everything looks and smells ok did a few more test with a small fuses and used speaker wire as a jumper i can't get the power light to even come on for a secondbut the amp is turned on by the remote.. the top lights up just not the power or protect led's The amp is **** near new just w…

Do any of you notice how if you look at rims on a car rolling down that street while playing a song with a high frequency that you can actually see the individual spokes almost like its slowed down. Its a trippy effect. Sometimes people rims will also look like there jumping up and down on some bass notes. I also get this similar effect when i play a 50 hz and up frequency while looking at led lights ( xmas lights, BMW spoiler Brake lights) these lights also move to the bass..It is an awesome effect very entertaining! I was wondering what is causing this and does anyone else experience this?? I think it has something to do with our eyes moving at the same frequency as whi…

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…

Im trying to get the TEST SPL tuning for a box in a 01 Grand Am, 2 door. The box is going to be 4 cu ft for a SSA Icon . I'm trying to design a SPL box for a competition coming up on July 8th so any info anyone can help me with would be awesome. I was told that the best SPL tuning would be 5 hz below the resonance frequency of the vehicle, not sure how to spell resonance, but hopefully nooe gets too confused. Thanks Dustin