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A few people on this board have asked me about group delay, I mention it from time to time. Here is a good primer Dan Wiggins wrote about it: http://www.audiodesignguide.com/Sub/SIGroupDelay.pdf Hopefully this will help some of you! -Mike

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

just a small topic that always seems to be explained without being explained. --------------------------------------------- amplifier Gain and DMMs. Most guides that talk about gains and DMMs are a bit simplified. you may want a higher or lower gain. Obviously to set the gain you would need to ask yourself what you are trying to accomplish by setting the gain! but this is overlooked in most guides. --------------------------------------------- ** most guides assume you want maximum undistorted power output from the amp ** Q -- What's wrong with that??? A -- you may not want maximum power. ---------------------------------------------- When you wouldn't want maximum powe…

I'm working on a project for a buddy of mine and I've come across a bit of a hold up. I'm more than familiar enough with circuit design, crossover components and such to build crossovers. I've been doing it for quite a few years with results that I felt were what I needed. I've come across something different with this as my buddies tweeter is significantly louder than the midrange or the woofer in his 3 way floor standing speakers. The speakers haven't been used in several years and when we hooked them up to test and tune the system for his mom's upcoming birthday party that we were going to DJ ourselves the old tweeters didn't work. Instead of waiting for me to hel…

I am trying to fit this 10" under my seat in my 08 silverado ext cab, But this seems like an impossible task because its so much bigger than most 10s, i havent read or seen anyone do anything about this and im wondering if i even can and if anyones done it short of taking out a seat?

I need to know exactly what mechanical failure is to a sub woofer. I know this is a rookie question, but I need some technica answers as I think it's the reason for my sub's death. Or can a sub even break due to this. I am 110% sure it wasn't because of thermal failure. The voice coils look brand new when I took it apart. Yes I took it apart and ordered a recone before asking. I know part of it was due to playing freq. lower than box tuning and using bass boost. What part of the sub breaks or what does the coil look like when it dies mechanicaly + 1,000,000 other questions I have but i'll start w/these. Thank's.

First off I have two alpine pdx 600.1amps each amp is producing over 700 watts I want to buy 2 fi ssd 12s run 1 off each amp anyway here's the questions when ordering I'm asked about flatwind coil yes or no copper coil yes or no and bo power. Could someone explain this to me and what I should do to answer these questions thanks

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check the linky>>> db calculator

Bl/Mms is constantly turning up everywhere to describe the "acceleration factor" of a driver. This is totally wrong! The "acceleration factor" or "speed" of a driver is determined only by the bandwidth of the driver and nothing else. In reality the "fastest" driver or the one with the quickest rise time is one that can play the highest frequencies! Here we will use a picture to help explain the situation. In the following we show time from left to right, and amplitude from top to bottom. - Picture courtesy of Cool Edit 96 - www.syntrillium.com We have 3 complete sine wave cycles showing with a period of silence between each. The first one we shall say is 20hz, t…

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 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…

I'm not sure if this is in the correct forum or not, because this isn't quite as technical as the other topics I searched through, but hopefully this one will do. I've got a friend from work who's son has an amp that is not working. I don't know a whole lot about amp repair, but I know how to check diodes, transistors, and simple stuff with a meter (no oscilloscope at my disposal unfortunately), so I am just taking a look at it for him. I dont have a whole lot of description about what the amp is doing, but from what he tells me, the amp will come on, won't go into protect or anything, but the subs will pop and them hum continuously. The first thing that came to my mind i…

please people, i am working on an assignment that require that i compare two amplifiers( Velleman K4004 amplifier vs Amplimo A120amplifier) the task is to determine between the two amplifiers the one with better SOUND OUTPUT.i hav the following equipments to work with, true RMS multimeter,oscilloscope,function generator,variable resistor,the two model of amplifiers mentioned above i have chosen the following specs from a range of online research i have conducted as a means of determining which is better btw the two 1. gain 2. frequency 3. linearity 4. noise 5. bandwidth 6. output dynamic range 7. input and out impedance 8. damping factor please my problem now is how to us…

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…

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Ok I've been trying to do a lot of reading about the more technical side of audio. I was thinking about different styles of port and how they effect the output of the box. So on to my main question. What if you had a circular port that started off small and grew into a larger diameter. Say it begins as a 3" port and ends up say a 10" port (pulling numbers out of my butt) What advantages or disadvantages would this have?? If you think about it wouldn't it make it louder?? When you helling into a cone your louder, or when you cup your hands around you mouth your voice is louder then without. Wouldn't the same apply for car audio applications??? Any informative incite would …

Aside from LEAP's capabilities, is there any software out there anywhere than can graph, plot, or otherwise visually show a person what happens to the response curve (from a 0dB reference line) when they would apply say an 2.5khz LWR LPF -12dB filter, or even a 3.5khz HPF -6dB filter, or perhaps have 5 bands of parametric EQ each with the frequency, Q, and level to show what the effect those settings have on the baseline. My thoughts is that it might help to show and understand exactly what those adjustments are doing, how much they're affecting, and maybe to help get a healthier understanding of the interaction between all the settings by being able to see it without s…

Does anybody have any good suggestions on Car Audio Books. More advanced stuff.

this might be on another thread, someone direct me if it is please. im very interested in building a t line for a 12 i will be getting. what are the pros and cons of a t line and how do you figure out exactly how to build it for a specific subwoofer. thank you

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.

Okay, now everything has a resonant frequency. At this point, the most energy will be on the object correct? If this is the case, wouldn't it be wise to find the resonant freqency of a particular meter in your intended application and mounting location, measure it, and then design for your peak to be at that point? Wouldn't that produce the highest reading? I'm sure this has been thought of, but I'd like some input. Sean, Neil. . .

Lil while back I'd tried a TL in my grand am. Kind of just to do it... I don't recall the exact specs on it, though it is still in the garage, so I could measure as need be. It twas not very large. I ran it with a Vega Vega 12" at the time. Very clean nice sound, not so much extension... but I believe the line was too short. The reason I stopped running it was that with higher musical notes (low 40's - upper 50's), the woofer would bottom out. Only in this enclosure had I ever had this thing bottom out. I tried a Visonik 126S4 that I'd had laying around, similar wattage (250rms actual), and very similar results. Point of the thread: What kind of EBP or mechanical propert…

Your site bitpusher has malware? Congress up on many of my checkers... Just a heads up Love the site and wanted to make sure it stays working well