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RE: Sub boxes and Subs and Amp....help

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Old Sep 26, 2001 | 02:21 PM
  #1  
highspeedfreak's Avatar
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From: Streamwood, IL
RE: Sub boxes and Subs and Amp....help



Hey Jim - thanks for the input!!! (Under the Kicker Speakers post)!!!
I saw your link to the sub boxes!!!
So here is another question - well actually let me tell u what/how/where.....

Ok i went to this audio store - hoping that i would get a little more knowledge from them. So i asked about subs and amps - the guy suggested i go with 2 12" (kicker - the round ones) and a 4 channel amp (phoenix 400.4 - i think)!!!
He said it wouldnt be wise to spend moeny on boxes and the square subs cause the camaro rear could do with a board!!! Now im not expert but ive heard ppl say that putting a board over the well is not worth it!!! He said it would be added weight too. He kinda had his mind made up about stuff - like he wanted to get rid of old stock or something!!!
Now i dont mean to **** ppl of by saying i never heard so much about phoenix amps - are they worth it!!!
I get the impression he just wants to make quick money of me!!!

So finally - could u guyz tell me - if boxes are the way to go - or boards if done properly are good enough!!! And does he know what he is doing???

I really like the square kickers - and i dont mind going with the process slowly (spending extra money - which he quite doesnt understand) - so if u guyz with the sqaure subs would be greatly be appreciated for any input!!!

By the way - ppl in the Northwest region of chicago could suggest other places for me - this store was - ACTION INSTALLERS on I-19 - Streamwood IL.

Thanks again
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Old Sep 26, 2001 | 02:45 PM
  #2  
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From: Stillwater, OK
Plates are not very good for reproducing sound,because it's a freeair seup. If you like the L7's, do a 10" in a vented enclosure, and it will rock just fine. In the post you did earlier, the outlined IX405D would be a great amp to get,so you only have to run one power wire,ground,etc.
Plus, you get the EQ and crossover built in, as well as a Class D to that 10".
That amp you mentioned is a good amp also.
You could swap out the stock speakers, run them off the headunit and still run that or a similar amp to the sub. The L7's do work fine in sealed enclosures, but really come alive in vented. You stand to gain a few db's by doing that.

Hope this helps.
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Old Sep 26, 2001 | 03:18 PM
  #3  
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From: Streamwood, IL


Ok fine ill ask him for that - cause thats what i want - but he is stuck on a board over the well!!!
Ill mention it to him and see!!!
Thanks
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Old Sep 26, 2001 | 03:37 PM
  #4  
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From: Readsboro, VT
Car: 85 IROC-Z / 88 GTA
Engine: 403 LSx (Pending) / 355 Tuned Port
Transmission: T56 Magnum (Pending) / T5
Axle/Gears: 3.42 / ?
Let me repeat my most famous of all statements:

Plates suck.

I've never heard a salesman (circuit city idiots don't count) say that plates are anything better than garbage.

I'd find a shop with smarter salesmen if I were you.

------------------

The IROC Homepage
<A HREF="http://www.rit.edu/~jli4307/camaro" TARGET=_blank>
View the restoration of an 85 IROC</A>
Custom Thirdgen Subwoofer Enclosures
"I didn't know a bored out Ford could go so slow" -Shenandoah
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Old Sep 26, 2001 | 08:17 PM
  #5  
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From: Streamwood, IL


OK i dont mean to disagree with u!!!

But it would be nice trying to get it thru his (seller) thick skull that there might be other ways to do things (boxes and not boards)!!!

So could someone give me the nitty gritty details as to why boards are not good - so i can tell him!!!

Thanks
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Old Sep 27, 2001 | 08:11 AM
  #6  
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From: Readsboro, VT
Car: 85 IROC-Z / 88 GTA
Engine: 403 LSx (Pending) / 355 Tuned Port
Transmission: T56 Magnum (Pending) / T5
Axle/Gears: 3.42 / ?
In order for a speaker to propigate sound, the rear wave needs to be blocked from blending with the front wave and cancelling it out. This is extremely easy with high frequency drivers because their physical size is larger than the wavelength of the signal they're producing. Unfortunately, wavelengths get much larger with lower frequencies.

Wavelength = Speed of sound (in air) divided by frequency, or WL=1120/f.

So, let's take a 15khz signal. WL=1120/15,000 = .07466 feet, or .9 inches. Since the diameter of the tweeter is bigger than this, it would block the rear wave. Of course, virtually all car-audio tweeters are sealed domes anyway, so it's basically a moot point.

Let's try this with a subwoofer playing, say, 50hz.
WL=1120/50 = 22.4 feet. So, unless you have a plate that extends at least 22.4 feet, the rear, out of phase sound wave is going to blend with the front wave and cause some level of cancellation. But, let's consider that some music actually has bass that extends all the way down to 20hz.
WL=1120/20 = 56 feet. Good luck fitting a 56 foot plate in your car.

So now your next question is why do ported boxes work? A ported box needs to have the port tuned to a very specific frequency in order to interract with the driver properly. There's no way that I'm getting into the physics of it here (Suffice to say that they're complicated enough that I'd sound like a babbling fool without looking it up first), but the long and short of it is, the proper length tube will provide output in a narrow frequency window that is in phase with the actual driver's output.

So, on with the sermon. Let's put a plate in the car. We spend time cutting it to make sure that it fits perfectly. That way no air leaks around it. But guess what? It's surrounded by a bunch of cheap plastic panels that are FAR from airtight. Some of them fit so poorly you can stick your fingers between them. So, let's say that you spend ridiculous amounts of time sealing them airtight. Oops, they still don't seal tightly with the floor. But, somehow you smear 5 cans of silicone around down there to seal it up. Well, the fact is, those cheap plastic panels, along with the thin tin body are not well enough damped to stop the propigation of the soundwaves, so you're going to have to substantially reinfoce all of the interior panels. By the time you do all that crap, you could have just built a box and been better off.

------------------

The IROC Homepage
<A HREF="http://www.rit.edu/~jli4307/camaro" TARGET=_blank>
View the restoration of an 85 IROC</A>
Custom Thirdgen Subwoofer Enclosures
"I didn't know a bored out Ford could go so slow" -Shenandoah
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Old Sep 27, 2001 | 09:44 AM
  #7  
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From: Streamwood, IL


Thanks Jim!!! Didnt know the technical stuff - but kinda figured about the sealed bit and material around there!!!

Ok - i saw your website - and didnt find the material u actually made the boxes out of!!!
So if u could let me know - then maybe ill mail u with something i have in mind - then ofocarse u tell me if its possible!!!

But its for sure gonna be revolving around kicker solo barics - dont quite know the specifics!!!

Thanks
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Old Sep 27, 2001 | 01:18 PM
  #8  
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From: Readsboro, VT
Car: 85 IROC-Z / 88 GTA
Engine: 403 LSx (Pending) / 355 Tuned Port
Transmission: T56 Magnum (Pending) / T5
Axle/Gears: 3.42 / ?
My prices listed on the site are for MDF or particle board, depending on how much you want to pay, but as soon as I update the site the particle board stuff is going to disappear. I hate working with that junk, and I get LESS money for the boxes. MDF is the ONLY way to go. It's exceptionally solid, and a joy to work with.

------------------

The IROC Homepage
<A HREF="http://www.rit.edu/~jli4307/camaro" TARGET=_blank>
View the restoration of an 85 IROC</A>
Custom Thirdgen Subwoofer Enclosures
"I didn't know a bored out Ford could go so slow" -Shenandoah
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Old Oct 22, 2012 | 05:50 AM
  #9  
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From: Wisconsin
Car: 1991 Camaro RS
Transmission: 700R4
Re: Sub boxes and Subs and Amp....help

I happen to be the owners son if where talking about the same Action installers.
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Old Oct 22, 2012 | 06:06 AM
  #10  
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From: Wisconsin
Car: 1991 Camaro RS
Transmission: 700R4
Re: Sub boxes and Subs and Amp....help

Actually your defiantly talking about us because thats where we were in 2001. Technically it was Hanover Park since we were on the same street but right across the border. My grandpa owned it And was the sales person and my uncles and dad worked on the cars in the back. We moved around 10 or 11 years ago to Woodstock,IL now my dad and my uncle own it. if anybody needs work done of ANY KIND message me, inside the car or outside the car or body work or wiring or ANYTHING and we could get any part you need and if you want a box we could get it and if you want a plate we could get it. Trust me we are professionals ether way it would be done right! My dad can fix what other places say can't be fixed or unrepairable.

Last edited by V8Broski; Oct 22, 2012 at 06:10 AM.
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Old Oct 22, 2012 | 08:44 AM
  #11  
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From: Wisconsin
Car: 1991 Camaro RS
Transmission: 700R4
Re: Sub boxes and Subs and Amp....help

Actually thinking about Action Audio didnt change are sign till like 3 months after we left so you might have been dealing with them not Action Installers.
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