Advanced Discussion

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.

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 .

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

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

Welp guys.... The install im doing i would like to incorporate the sub between the amps [amp][amp] If I make the enclosure 14x14x14 i have the perfect amount of space. Just enough for the sub and just enough to fit between both amps. The box will be polyfilled, but should I do the 14x14x14 cube ? Its not like the kid needs as much SPL as he can get, just something with a lil umph.

Got my hands on a FLUKE TiR thermal imager for the day so I figured I do a little testing on the heating and cooling of my subs/amps. So Playing my system full blast for about 4 1/2 minutes (usher-daddys home off decaf's zip 14) The main frequencies peak at 39hz, 38hz, and 26hz. Subs just starting to get stinky(clipping a tad to see how hot I can get them) Subs are in a 17C.F C-pillar wall after displacement, tuned to roughly 28hz. Subs are (2)18" AA Mayhem D1, amps are (2)Colossus XXV clamped at 2,800 RMS each. First image was taken within seconds after turning down the volume to 0. Shows the center(dustcap area) of the sub being roughly 132 degrees, and just next to…

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Hey all, I've built plenty of enclosures and done 1 wall that I was able to build outside and slide in through the hatch but my next build I need to go as large as possible so build inside, and thats quite a change from slapping screws in, flip the box, drop more in. Can I get some links to build logs that have good pics of this please... I have been searching and found almost none that really help. Thanks! Krypto

well my budget is almost together to rebuild my system I have a alpine 7998 deck. I don't listen to my music very loud usally but I still want good clean sound. I need new amps (and subs but they can wait). Should I go with a higher power amp 100-150+ watt per channel and use the passive crossovers or sould I get a 40-60+ 4 channel and bi amp them with the deck 3way Xover. I have MB Quart 6.5 comp. rated @50-120. If there is a better option I am open to suggestions. I have 50 watts going to the passives and it is close to loud enough but I want more bass and more head room for when I get new subs.

Ok, I got this idea from looking at Decware's planar speaker design they have up, LINK and was wondering if this could be scaled up for a home subwoofer type setup. My thinking was with the large radiation area could make up for using a smaller driver due to the fact that the displacement of the airmovement is going to be pretty dang big. What I am wondering is if anyone knows of anything like this that has been done before. I think if it could be pulled off with reasonable degree of sucess it would look really cool with maggies, plus I think it'd be a challenge o build something like this too. Does anyone have an idea as to what size of panel area I would need for …

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…

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

I have an 02 monte carlo. the factory amp has an internal crossover to the door drivers and seperate tweeters. if i buy new component system do i discard new external crossover. i have 4 wires in factory harness and am adding an amp to power new componts. i am keeping my stock head unit for now and there are no pre amp outs.i know that new crossover should be installed wity new spkrs. but the wiring has me stumped.thanks for any help i can get.

My HU it a JVC AVX830. I have the option to change the q on my lows and mids in the eq. Now I've noticed when I change the q to a lower setting the speakers seem to play "louder". What does this do? Is this based off the qts of the driver? How should it be adjusted. Right now I can't seem to get the tuning right. It either sounds hollow and muffled or the highs drown out the words. Could someone enlighten me?

Ok so i have two motors that need reconed,i had Rusty(DC) do one for me and the coil rubbed. How do i get the measurements i need for the right coil? I do not have either coil that originally were in either sub,i do have a set of digital calipers. So what do i measure to get the correct coil? Thanks.

I've grown concerned about something that I see all over the audio forums: People stating that tuning a ported enclosure has nothing to do with the woofer. Couple of quetions / points to discuss: How many here believe this? For those that do, why? By that, I mean, because someone else told you so or because you've done some reading somewhere? If so, where... Wouldn't it make sense that the woofer acts upon the port by nature? Considering displacement, excusrion, fs, & emf properties... I'm under the impression that a woofer will interact with the port design, not act independantly. For reasonable / average installations this isn't a big concern I suppose... as the mec…

Hi everyone, new guy here. I'm a mechanical engineering student/intern at the moment and have had a passion in audio for nearly a decade now. I took it upon myself to design an enclosure for a pair of Demon 10"s for my civic hatch. I'm pretty happy with the punchiness, but the lower end is lacking pretty significantly and sounds "blown out" or "not really there" instead of "deep". I'm hoping to get some insight on where I went wrong with my design. As you can see, this is a non-traditional enclosure where the port effectively shares 4 walls with the enclosure on the outer sides. The design was done this way to maintain a specific outer dimension that fits like a glove in …

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…

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

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

hey guys i have a quick question. what is the benifit of tuning your box closer to the res. freq of the car instead of to the sub? in spl competitions?

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

I have been building boxes for sometime and I notice that a lot of boxes have the same concept but are built a little different. When I build a ported box for two subs I normally direct the air out of the front (depending on the application) of the enclosure with a divider between both chambers. I have seen some enclosures with no divider coming out of the front, just a big hole. Does adding or taking away a divider give off a different sound? I also add one in the middle just to make the box more rigid. I am building two ported boxes for a van. Would it be better to port it in the front like I have been doing or to go another way. I would think that by porting it out the…

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.

So Ive been looking at numbers, maybe im way off. its .078ohms/1000ft ohms/1ft ------------ 12v 14v------------ 12v Amps--- 14v Amps 1-/0 0.00078 ------------ 12v 14v------------ 15384.61538--- 17948.71795------------ 205.1282051 205A is at 75ft which is close to 250likemost charts say with the 1ft values are high as hell though. This looks more reasonable. 1/-0 ------------ Ohms ------------ ------------ Amps 350A ------------ 12-- 14 ------------ ------------ 12-- 14 50ft ------------ 0.034285714---- 0.04 ------------ 350-- 350 25ft ------------ 0.017142857---- 0.02 ------------ 700-- 700 12.5f…