lithium

fucking crossfit..

Watching the first episode of the new Cosmos series. They did a fantastic job on it.

I think you misunderstand the benefits. http://en.wikipedia.org/wiki/Decibel#Acoustics in competition sure you could hope to gain a fraction of a db but you could probably find easier gains elsewhere.

and the answer to your question would absolutely be dependant on the install.

you're also confusing some other topics together. most cars do not have any crossover or processing so replacing the doors speakers with a coax or component set is not a problem. this is completely different than what you're doing when you replace just the tweeter in a home audio design. do you understand this difference?

impious answered that already

First, that mechanical sound is probably the subwoofer's coil bouncing off the back plate. This is very bad for the woofer and you're likely damaging the subs. Good news is you can recone the woofers(which means you replace all the softparts) unlike other brands. The reason you're damaging the subwoofer is likely due to using that enclosure and playing the subwoofer below tuning without a subsonic filter. when playing a subwoofer is playing below tuning the sub can "unload" which means the cone will travel beyond the mechanical limits (move too far in and out). When you're using a ported enclosure you must set a subsonic filter just below the enclosure's tuning frequency. This filters out the signal below that point. The enclosure, like most pre fabs, is probably tuned rather high and you lack of subsonic filter allowed the sub to damage itself. The first thing you should do is figure out the tuning frequency of the enclosure and set the subsonic filter properly. If you're happy with that than you're set. But its likely that the enclosure will perform like shit and you should build a proper one. also, assuming you wired the woofers up correctly to 2 ohms. it's impossible to wire them to 1 ohm. but that difference in power wont be noticeable so dont worry about it.

It's probably fair to say that a lot of the head units have gone down hill for some companies. look at alpines line. consistently downhill and i'm not sure if they even have a single din unit anymore. in fact the 9835 is more expensive than the 9855 which came after (probably because people hate the glide thing..). You got a pioneer 80prs on the way right? that will do 99% of everything you need it to do. Any anything else can probably be addressed with the install itself. the old processors like the dqdx are just that, old. However, there are plenty digital processors, not sure why you cant find them. Audison, helix, rf, soundstream/ppi (minidps design), alpine, jbl, etc.. And no, you shouldn't buy any of these. just like you probably shouldnt bother with a dqdx or minidps when the pioneer will do the job just fine. I'm not sure why you think more features will improve your results.

any electric works

explain what your goals actually are and someone could point out which to go with.

a bandpass enclosure wont net you anymore spl than a regular vented enclosure design

Not sure what exactly you're trying to cook up but just stick to something simple like a set of 6.5 components. sell the rest

Even in that example, multiples don't nessarily help increase SPL at higher freq. For Midbass and lower you can successfully use multiple drivers under certain constraints

i'd start out with bcae1.com if you're looking for a free resource that isn't terribly technical. then move on to the cookbook.

I would say the vast majority of installs in car audio are complete shit. It takes some understand of acoustics to explain why two speakers playing the same information is a bad idea. So if you google constructive and destructive interference you could read about whats happening. In a very basic sense it means that if two sources are reproducing the same information it will result in peaks and troughs at various frequencies at your ear. Even if you dont understand any of that, think about why it would be a good idea to buy 2 sets of cheap speakers vs 1 set of good speakers. which would you think would sound better?

if the insulator isn't punctured through to the copper I'd say its ok. but 1/0 welding wire is cheap if you need to replace it.

yes you might have to fiberglass the door trim but the drivers themselves should never be mounted to the door trim. I dont know exactly what you're planning to do with 2 sets of speakers in the doors. sounds like like a horrible idea. seriously look into methods for properly installing speakers.

so if i set the balance all the way to one side that will damage the amp? no, leaving channels disconnected or otherwise can't hurt an amp.

what so hard about making a baffle attached to the door panel?

they're still attached to the door trim instead of the door panel.

its a heat sink. the fins create lots of surface area.

A rta graph is a great way to show off the install in a sense. but its not the whole story. its just amplitude vs frequency. is that peak at 100 hz from the driver or a resonating panel? i cant tell from here.

well that was strange. switched to my laptop till i figured out whats up with my pc. coming up with a better solution that doesn't cost a lot more more would be difficult. perhaps just mlv cut to the shape of the opening and attached with some kind of adhesive. For those of us doing this as a hobby Don's methods are probably the best we have to work with in terms of using the bare minimum mount of material per dollar and getting the best performance. I think you've worked with his stuff before.

Thanks for posting Bing. I understand where you're coming from on the business side of things. Though most of us here are doing our own installs and have significantly more time to invest, so our methods will be different. Also the OP, ncc, works at a shop that doesn't even bother to use wooden baffles, let alone sound deaden the door so maybe you're installs would give him a better idea of what professional installers are doing. I'll be referencing Don's site, here. But, feel like i might be regurgitating Don's descriptions so maybe I or someone else can link other sources if you don't find his arguments convincing. You're right that ccf is a decoupler but you're wrong about its ability to act as a barrier. Its simply too light to block sound and too thin to absorb. Is it blocking or absorbing anything? sure, but probably frequencies much higher than the mid is actually producing. An actual product capable of acting as a barrier like MLV or lead sheet have specific qualities. Don's mlv for example: note the mass/area of 1lb/ft^2, this is the important specification for barriers. here is a link to a lead soundproofing application, http://www.acousticalsurfaces.com/noise_barrier/acousti_lead.htm The goal of sealing the holes is to isolate sound produced by the rear of the driver. If you agree with the physics than ccf cannot accomplish this. Lets take your example with a sealed enclosure. Lets say we build an enclosure with a speaker installed in it. Next replace one of the sides with ccf. I guarantee sound will pass through. Now replace the ccf with mlv. Significantly less sound will pass through. Replace the mlv with steel or concrete, etc and you see where this is going. Lets be clear, a 6.5 driver in a car door is practically IB so i dont understand what you're saying about the speaker being underdamped, etc. When we're talking about isolating the front and rear wave we are talking about interference. I think i answered your other questions above. But, to simplify, if the front and rear of the driver are not isolated the midbass will suffer. Test it with the door panels off (also test with and without ccf). I run Peerless SLS 8s as dedicated midbass in my doors and have done this test. Midbass was significantly better with the holes sealed with fiberglass, and improved again with mlv installed between the door panel and door trim. yep but you're ears will do a better job. edit: there are some things an rta wont show you but you're ears will. a panel vibrating due to excitation at 100 hz is just some extra amplitude on the rta.

if you have an android phone download funcgen and play test tones at 30, 40, 50, 60, 70 hz and compare the relative loudness at each of those points. you can download these tone somewhere else or if you have an iphone there is probably another app. so if you see that 40hz, for example, is louder than lower and high frequencies (or a peak in the subwoofer's frequency response), eq it down.