more beat with less space

You guys realize that larger the speaker the longer the wavelength of sound is produced. 12" subs in a truck cabin are too large, you will hear more bass outside of the vehicle than inside. If all you listen to is rap/ hiphop then this is probably fine due to the low frequency bass but if you listen to a wide range of genres 10" is the way to go. Bigger isnt always better!

 

I'm going to have to say you are wrong on the part about hearing the sub outside the car than inside with 12's. You can BARLEY hear my sub standing 3 feet away from the cab with the windows up. (Alpine Type-R 12 shallow mount) You can hear my mids/highs clearly from over 25 feet away with the windows up (Focals), but still can't hear the sub until you walk up to grab the door handle. The only thing from the subs you can hear on the outside is the box rattling against the metal skin of the cab wall and that even isn't that loud. I haven't added fatmat yet or secured the box fully so that will go away as soon as I do that. Inside you get some serious tight clean bass. It makes your chest thump and shakes the piss out of your mirrors if you want it too. I run a sealed box a .60ft of air with 3/4lb of loose polyfill. On the inside it hits very hard and low and works great on rap to rock. Fast tight bass notes will never miss a beat and the low bass is there just not shaking the frame of your truck apart and pissing off the car next to you.

If you take your time and do it right you can have a very hard hitting sound system with any size subwoofer and not drown out your mids/highs with bass. Most people just get giant subs, put them in ported boxes that are not tuned for SQ (or not even the right box for the sub), then push the gain all the way up on the amp and distort the shit out of the woofer while saying 'It sounds amazing right?'.

 

Most people dont do things correctly! However, there is a direct relationship between speaker size and wavelength of the sound produced, its a scientific fact! I dont care what type of box you put a 15" sub in or how much deadening you use, if the room the speaker is in is too small, the frequencies heard wont be what you want.

With regards to your smaller speakers being heard further away its due to a the higher frequencies produced by those speakers. Like how a gunshot is heard very far away, very high frequency noise.

The point im trying to make is bigger isnt better when it comes to subwoofers installed in a vehicle.

 

To the guy asking about my box, it's 31" wide, 15" 3/4 tall, 15" deep. The port is 7" 1/2 tall by 2" 3/4 wide. And mekanism is correct about his sound waves and frequencies statement. Just sayin.

 

No. There is a lot of BS in this post.

It is a "scientific fact" that a certain frequency, produced from any size driver, is the same frequency.

To bring this down a notch...

A 50hz tone from a 15" driver is the EXACT SAME TONE as a 50hz tone from a 8" driver. If it changed in wave length, it wouldnt be a 50hz tone, now would it?

This link may help you:

http://www.engineeringtoolbox.com/sound-frequency-wavelength-d_56.html

 

Either you made that up or you got trolled HAAAAAARD by your physics teacher.

 

I'm also flagging that post for removal since it's factually incorrect and also so you'll also have a chance to repent.

 

Joooo neeeeeeeed to give me mod powers. I can police this shit. I'd be good at it.

 

BbBbbbbuuut....stupidity is rampent around here. I need to be able to tame the beast.

 

No need to call me stupid or get nasty! Im definately no physicist and didnt properly explain above and use the correct terminology. For that I apologize!

We all can agree that a larger subwoofer is designed more for producing lower frequencies right? Some can produce a wider range than others depending on driver quality and the cabinet. Can we all agree that the lower the frequency, the longer the wavelength?

If this is true, which im pretty sure it is, then there is a point at which it becomes pointless to go with a larger subwoofer as you wont hear those lower frequencies correctly... because by the time the wavelength completes a cycle it will have passed through or reflected off the medium causing phase cancellation and odd resonances .

The sub is basically over pressurizing the room/cabin and all you will hear is muddy inaccurate noise.

Why spend more money and use more space on 15" subs when much of that low end will be wasted anyway!

 

You're getting there. Larger subs will produce more bass across the entire range which makes people think they produce lower bass. I ran 20Hz through a tweeter once and it played it, not very loudly, for about 10 seconds before the 1000 Watts I had on it cooked it.

There is a point in all cars where the sub is doing nothing more than pressurizing the cabin. The smaller the cabin the higher that frequency is. A standard cab Tacoma would probably be in the 80Hz range. As long as you can move enough air to pressurize the cabin then you don't NEED to go any larger. Larger subs are, however, more efficient.

 

Woah woah woah....let's slow down here. Let's start from the beginning.

A speaker makes sound by moving in and out. If a speaker moves in and out 5,000 times a second that's a 5,000hz note. If it moves in and out 20 times a second that's a 20hz note. The difference is whether there is any audible output at the frequency being played.

Look at the graph below. It's a model I did of two 6.5" Tang Band subwoofers in a ported box. The top graph shows that the speakers in that ported box provide USABLE output down to about 28hz. After that it takes a nose dive. It's only about -3db from 28hz to 80hz. That's really damn flat! Will the system play a 20hz note? You bet! But you aren't going to hear shit!



The second graph under the first one shows how far the cone is moving in and out. The red line is the physical limitation of the speaker itself before it breaks. The port tuning of the enclosure is set to 30hz so we get good output down to that area and the cone movement is kept in check. Below tuning the cone movement increases DRAMATICALLY and we don't want to try and play it down there with any large amount of power. It will die.


Now let's stop and take a second to comprehend what I just showed you. Those were two 6.5" subs. Like, subs smaller than your door speakers.

So clearly we don't need a big cone to get the job done. Yes, a bigger cone will help but not for the reason you might think. Did you notice something special about the second graph? As you go lower and lower in frequency the cone moves more and MORE. Basically, we're needing to move more and more air for lower and lower frequencies. How do we move air with a speaker? You move the cone. The amount of air displaced can be calculated by taking the effective area of the cone and multiplying it by how far it moves. So you can move more air by using a bigger cone or moving the cone farther....or both. Those little subs above have a small cone but they have 13mm of throw which is quite a lot.

Now onto the last point....you can't get low bass in a small space because the wave length is longer than the distance from the speaker to your ear. Well an 80hz note has a wavelength of about 14feet. Not likely that you've got an extra 14ft in the car you can play with. But you still hear it clear as day right? RIGHT. Sound reflects off of objects as it travels and this helps. Also, you don't have to have a full wavelength before your ear to hear a sound. I think it's been said that quarter wavelength is all that is needed. Not 100% sure on that last part.

 

soo what tones would sound good in a small car like a single cab truck? or up to.

say 80-30 hz for subs?

this is just a guess and asking.

 

my sub makes noise

 

They'll all sound good. As mentioned above, your brain only needs 1 quarter-wavelength to be able to "complete" a particular frequency. Realistically, don't worry about it. Pick your sub size based on the output you need and be done with it. The enclosure (type and location) will have a larger affect than the sub size anyway. As long as your sub moves enough air for your listening habits, you're good.

I tend to cross my subs to my midbasses between 80 and 100Hz. This is greatly dependent on the sub though since any decent midbass driver will play to 80Hz without even trying hard.

 

^Is right....

When I pick a subwoofer I want something that hits the output I want and is controlled. Distortion rises as you reach the limits of a subwoofer. So the more controlled it is the better it will sound. I've been building subwoofer enclosures for years and I've never once toasted a coil. I'm way more concerned about bottoming out the sub. That's why the FR and XMAX graphs are my primary concern. They tell me how loud at what frequency and whether or not I'm about to lose control of the cone.

 

thanks man