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someone should do this with a voice coil and make the sub-woofer super efficient!!!

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'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??…

Alright. I've got to get this perfect. I'm LOVING the Bravox CS60K's. The output, mid-bass authority, and overall quality of sound is fantastic. They're truly a great set for the price I paid. The problem I'm running into with them is very common with speakers/components in their price range however and that is either beaming or break-up. Not sure exactly what the difference is just yet, though I do have a pretty good idea, but somewhere in the 4k area it's almost ear piercing on CERTAIN songs. It seems some of the songs have a lot of material in that range 2-5k that just causes them to nearly make your ears bleed, or so it feels. Then other songs couldn't be smoo…

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 was just thinking of this the other day and my general knowledge of physics dosnt lead me anywhere. Extreme DB levels seem to be in the mid 170's and slowly getting a little bit higher. Would it be phyically or humanly possible to make a subwoofer that moves air fast enough to create a sonic boom? It just moves faster and faster until the air it is displacing breaks the sound barrier! In which case I think that would be able to be higher than 170's, though im still not sure. What do you guys know about something like this? Im sure there is some sort of law of physics that would completely disregard this theory.

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)

Ive had my 1 rfr3110 in a regular square-ish prism shaped ported box no polyfil and at first all I wanted was boom. At higher volumes, theres a noise that I dont know how to describe, but I think its just reverb from within the box or something. Now im tired of boom and really want smooth bass, just LOUD smooth bass. By the way, its in a chevy lumina trunk, stock battery, will have 200A alt, 1x dub8001 (i know, not the best by far...). I have another sub (same kind) and amp (same as the amp im using) and im just saving up for an alternator, so in the meantime Ive been thinking of boxes that will help boost sound quality and eliminate standing waves. The point for this top…

I actually have a few questions. I have two different box ides. If I build a box with the sub facing UP, and fire the port into the car, will i lose spl? And as well, if i build a box with the Sub facing UP, and the port facing up, will I have a greater, or same as the bass response from firing the sub to the rear of the trunk. In other words, will facing the port in a different direction then the sub, affect the spl factor of the sub.

I think this will be the best place to post this as I am not ready to buy anything for a bit, but I do want to know what to buy when I am and be better informed. What I would like to know is what limits us from getting down to verry low Hz in speakers with any real force. I know the basic design doesn't allow us to get to .0000001hz mechanicaly and such but what factors contribute to this and what should someone look for in trying to acheive this? I don't think I am asking the question correctly because I don't have a strong grasp on the lingo enough to use it properly, but I usualy understand technical jargon when used or I can look it up, so I'll give you the applicati…

Hey guys I remember years back, when we wanted to build a "premium" subwoofer enclosure we would use birch plywood rather than particale board. Back in the late 1980s and early 1990s we mostly used particle board, not MDF, at least not at the shops I worked at. I don't know if it was because MDF wasn't widely available, or if it was more expensive, or if we just didn't know about it. So, my question is: What are your thoughts on using birch plywood for a subwooder enclosure? How do you think the enclosure would handle flex and can you comment about its tonal qualities? What brought this question to my mind is that MDF really is not a great material for holding fasteners (…

I'm confused as to how a subwoofer can have a Resonant Frequency of say 18 hz, but a frequency response that only goes down to 25 hz. If the sub only responds to 25 hz, how can you know the fs is lower than that. The new Soundstream T5's are an example of this. I just don't understand. -C

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…

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.

looking for a box design to fit behind seat of s10 that is the right cubic feet for a sundown sa8 top of box can be 5 inches deep and bottom can be 7 inches deep anyone got any designs ?looking for sealed

Okay so the other day i noticed my system was not playing the same. It seems to be playing at half of its potential! So i waited and didn't listen to it for one day.. didn't even drive the truck. I just now took it for a ride and its true... something is wrong! I pulled into an empty parking lot and played it at full tilt with the truck running in park, i was steady at 14v.. MY system is not suppose to be steady at 14v, i hit 151.8 dBs parked and the voltage dropped to low mid 12s and it was at the same volume as it was when i hit 151.8 It seems like the subs are only getting a couple thousand watts of power. No i am not getting use to it.. I checked all 0gauge connect…

pretty much my truck is telling me no to this system. I installed my box, wired my subs, wired the amp, fired it up... nothing amp comes on, zero output to subs. I do hear a whine through the door speakers if I rev the engine. -installed new RCA's -I have a 1/0 copper wire running to the frame as my ground. and after no sound I grinded the frame down to bare shiny metal. -checked all the fuses. -checked all the wires. -Rechecked all fuses and wires. -moved and jiggled the whole length of RCA -took the remote wire out and jumped a wire from the power to the rem When I turn the volume up on the HU as soon as a hard not comes through, the amp hits the subs once then goes int…

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

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've noticed that a lot of people suffer from the same misconceptions about the same topics in the world of car audio. This seems a befitting place to dispell those myths. Amplifiers Amplifiers do not magically create power. They simply convert existing power from your car's electrical system (amperage and voltage) to amplify a source feed (usually RCA or Line Level input). Just because your amplifier says it puts out "1000w RMS" doesn't always mean that your electrical system will put out enough power to actually achieve this rated power. In fact, 9 times out of 10, it won't. Even if your electrical system will support the amplifier's needs, it isn't constantly putting o…

I'm looking for anyone near Sioux Falls with a Term Lab. I won't be going back to Dashboard by Karl's, so I'll need to travel.

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

would someone like to try to explain the effects that I am starting to notice with the serious increase in humidity and temperature? I have a faint Idea, but I was curious to hear from more experienced SPL'ers

It's kicking my ass. Who will help me understand it better?

I thought I’d share this here. The writer goes through great length to explain the why’s and how’s of time alignment in a stereo system. He explains comb filtering, phase issues and alignment, crossover settings and so forth. Plus he does it in a manner that pretty much anyone with just a little bit of background or experience on the subject can understand. http://www.audiofrog.com/community/tech-tips/time-alignment-part-one/ http://www.audiofrog.com/community/tech-tips/time-alignment-part-2/ http://www.audiofrog.com/community/tech-tips/time-alignment-part-three-delays-and-crossovers-for-tweeters-and-mids/ http://www.audiofrog.com/community/tec…