My '91 Toyota MR2 12inch Sub Box Design --EXPERT OPINIONS PLEASE--

[Nighthawk26]

Not at all. Don't listen to the guy, he's an idiot.

Often times, smaller cabins get louder than larger ones in fact. Resonant frequency can have an effect on a driver's performance in a certain vehicle, but size is not a constant in any such factor.

With 2 cubes tuned that low, you'll have a ton of bass for that little cabin and the size of the car won't effect the driver's sq "performance" noticeably if at all.

Well I would be the idiot!!

I love the internet when it's filled with "knowledgable" people who post and respond most typically without thinking.

All other errors aside i'll stick with the basic and what should be most obvious. That sub is 153mm deep. How would you like him to install that sub when as he mentioned the VERy deepest point is 14"? And thats external measurement. And the taper? Did you bother to read it tapers to about 3"?

Or was your emphatic response supposed to gain some confidence from the readers?

I honestly want him to build this. EXACTLY as you tell him to so he can come back and share his dissapointments with you!

 

[DarkFox 10+ year member]

A. Your a great friend if you want your IRL friend to fail to prove a point to people online....

B. He can change the sub to something that will fit. Shallow mount pioneer 12s for example would work fine. Also, he said 26" high. If he set a regular 12, low in the box, it should still fit. Tapers from 14 to 3 in 26", if he mounted in the bottom half he would have between 14 and about 8 1/2, leaving the basket extending at a angle towards a corner. would probably fit.

C. I have heard people say before about the cabin space not allowing the wave to build in certain vehicles. Lets think about this.

*First, a sound wave (as applies to wavelength) is not woofer dependant and generally alot longer then people think.

***Taken from http://en.wikipedia.org/wiki/Speed_of_sound the speed of sound is 1130feet per second (770MpH)

***A 30Hz wave alternates 30 times in 1 second, its wavelength would be the distance 1 full wave would fill. Sound traveling at 1130 FPS and it alternating 30 times in that second means you simply divide, 1130FPS / 30APS(alternations per second) = 37.66 repeating Feet/alternation(wavelength.)

If you think think that the size of car has to match the wavelength or give it room to build, you are mistaken, no car is gonna give you the space needed on the logic you are using.

Now taking that out of the equasion, lets look at woofer selection. People say 12 is to big in that car, get a 10 for *insert miss-lead infromation here.*

The difference in subs, besided inheritent aspect of larger, being a little harder to move, and slightly prone to lower freq, is Surface area and throw. Size of woofers (all other things equal) is more going to decide pressure (volume.) So if the boxes are = in characteristics (scaled up for relative change in size as you get larger, not the same box with different subs) Sizing up the woofer should make it louder on the same note in the car, as you are increasing surface area of the driver, but maintaing the same tunning freqs.

In short, if boxes are equal, throw is equal, watts are scalled up slightly by size (to overcome added resistance of air with increased surface area) of driver. Larger woofer = louder

When it comes to the sound quality or tone, if all other things are equal, this is decided by the enclosures tunning and match to the characteristics of the sub with a VERY minimal correction for size of vehicle.

 

[ALHII303 10+ year member]

Hmong, i'm wondering how your depth at the bottom is 14" did you cut your storage boxes.

 

[Railrocker 10+ year member]

Well I would be the idiot!!
I love the internet when it's filled with "knowledgable" people who post and respond most typically without thinking.

All other errors aside i'll stick with the basic and what should be most obvious. That sub is 153mm deep. How would you like him to install that sub when as he mentioned the VERy deepest point is 14"? And thats external measurement. And the taper? Did you bother to read it tapers to about 3"?

Or was your emphatic response supposed to gain some confidence from the readers?

I honestly want him to build this. EXACTLY as you tell him to so he can come back and share his dissapointments with you!

Welcome to the forum idiot //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[SuperchargedRS 10+ year member]

nice ride, those are one of the better handling auto-x cars.

 

[PowerNaudio 10+ year member]

hey hmong337 got any more pics of your ride? its pretty sweet. it will be easier for us to help you figure out possible installation methods, if you could provide us with a picture or two of the area you have in mind for these subs to be installed at with the dimensions if possible. video of your ride doing a burn out would help out too. lol

 

[Nighthawk26]

A. Your a great friend if you want your IRL friend to fail to prove a point to people online....
B. He can change the sub to something that will fit. Shallow mount pioneer 12s for example would work fine. Also, he said 26" high. If he set a regular 12, low in the box, it should still fit. Tapers from 14 to 3 in 26", if he mounted in the bottom half he would have between 14 and about 8 1/2, leaving the basket extending at a angle towards a corner. would probably fit.

C. I have heard people say before about the cabin space not allowing the wave to build in certain vehicles. Lets think about this.

*First, a sound wave (as applies to wavelength) is not woofer dependant and generally alot longer then people think.

***Taken from http://en.wikipedia.org/wiki/Speed_of_sound the speed of sound is 1130feet per second (770MpH)

***A 30Hz wave alternates 30 times in 1 second, its wavelength would be the distance 1 full wave would fill. Sound traveling at 1130 FPS and it alternating 30 times in that second means you simply divide, 1130FPS / 30APS(alternations per second) = 37.66 repeating Feet/alternation(wavelength.)

If you think think that the size of car has to match the wavelength or give it room to build, you are mistaken, no car is gonna give you the space needed on the logic you are using.

Now taking that out of the equasion, lets look at woofer selection. People say 12 is to big in that car, get a 10 for *insert miss-lead infromation here.*

The difference in subs, besided inheritent aspect of larger, being a little harder to move, and slightly prone to lower freq, is Surface area and throw. Size of woofers (all other things equal) is more going to decide pressure (volume.) So if the boxes are = in characteristics (scaled up for relative change in size as you get larger, not the same box with different subs) Sizing up the woofer should make it louder on the same note in the car, as you are increasing surface area of the driver, but maintaing the same tunning freqs.

In short, if boxes are equal, throw is equal, watts are scalled up slightly by size (to overcome added resistance of air with increased surface area) of driver. Larger woofer = louder

When it comes to the sound quality or tone, if all other things are equal, this is decided by the enclosures tunning and match to the characteristics of the sub with a VERY minimal correction for size of vehicle.

TO your "A" point, call it frustration as this has acrried over from other boards. I don't want him to do it to fail to prove my point. My statement was more an attempt to show just how confident I am that this setup will not make him happy or give him what he is looking for. I want him to look at things objectively after establishing a solid foundation of knowledge fo rhim to make his decisions and not just keep asking a question till he hears the answer he wants to hear.

I know this car. He knows this car. I know audio, and I know audio in this car. I know the space thats being worked with, and there will be a hell of a lot more in terms of compromise than gains here.

Bottom line is that it's his call.

 

[Nighthawk26]

I will post a pic I have for him. I can tell you without cutting into the car this is the deepest you can go. This is an IDQ10 and with the throw and the seat at about MID position it slaps the back panel of the seat making an annoying sound. The box is ABOUT .65 cf, hard to say for sure with so many curves and this is fiberglass except parts of the side and the back. Should give you an idea of the space beign worked with. That magnet is ALMOST touching the back of the enclosure. WOW I'm bad with uploading. If a mod wants to resize those feel free... sorry guys!

 

[kuijo 10+ year member]

Good God man, You might want to think about resizing those.

 

[Scoobydoo 5,000+ posts]

hmm wouldnt a 30hz note have the same wavelength from a 10" sub as it does from a 12" sub? what does the cone size of a sub have to do with a certain frequencies wavelength?

 

[DarkFox 10+ year member]

hmm wouldnt a 30hz note have the same wavelength from a 10" sub as it does from a 12" sub? what does the cone size of a sub have to do with a certain frequencies wavelength?

this is the shortened version of my post ;-)

 

[Scoobydoo 5,000+ posts]

lol, i didnt read

imo a single decent 12" sub in a sealed box behind the passenger with about 800 watts would be more than enough for an mr2

i wouldnt want the sub pounding the back of my seat non stop whenever i was driving

 

[Nighthawk26]

lol, i didnt read
imo a single decent 12" sub in a sealed box behind the passenger with about 800 watts would be more than enough for an mr2

i wouldnt want the sub pounding the back of my seat non stop whenever i was driving

Already tried that approach. I've sat in the passanger side with the IDQ10, not pleasant.

 

[Nighthawk26]

hmm wouldnt a 30hz note have the same wavelength from a 10" sub as it does from a 12" sub? what does the cone size of a sub have to do with a certain frequencies wavelength?

Valid point!

What I should have emphasized when I started to discuss transfer function with hmong on another board is that it wil increase frequency output at the given cars transfer function. That needs to be established and frankly I have not bothered to do the math on it. He is caught up tuning this box to 32hz or whatever and is not factoring any of the calculations into the car it will go in. All theoretical out of environment design.

And no one has yet to eplain how you're gonna fit a ported box tuned to 32hz in the back of that car. And for TWO subs none the less.

 

[Scoobydoo 5,000+ posts]

Already tried that approach. I've sat in the passanger side with the IDQ10, not pleasant.

who cares about the passenger as long as the driver is happy. the driver is going to be the one in the car 100% of the time, when there is a passenger he can turn it down if needed