What I Want

[CBFryman]

OK well Basicly I did have a '96 Blazer and it has audioPAWN Alum 12's in it with 4 sony (also crap) 400w amps rinning them and clarion 2 way 6 1/2" door speakers...sold that crap...and i am now currently looking for a light extended cab truck... here is what i am saving up for to take up that extended cab space...

Subs
RE audio SE 12''s (woofers)
Crystal Audio CAD T600.2 (amp)
Ported 4.25cf enclosure tuned to 40Hz

Mids/Highs
Crystal Audio CSc 50t Componet set (cross overs and all)
Crystal Audio T200.2 (amp)

and im not sure about the head unit yet....

This or
Subs
DD audio DD2512 12''s (woofers)
Pheonix Gold Ti1000.2
Ported 4.00cf Enclosure tuned to 45Hz

Mids/Highs
Crystal Audio CSc 50t Componet set (cross overs and all)
Crystal Audio T200.2 (amp)

Im pretty set on the crystal audio mids/highs...later i may upgrade the midbass woofer to DDw6.5's but that is once i become un happy with the above listed...i was thinking of going with DD3500 series but the amps that thoes puppies deserve to be fed with are way out of my pricerange at the time. I want a head unit that i can turn all the way up and spal thoes RCA cables into an ocilioscope and not see any clipping or distortion....but thoes type units are also out of my price range...if you have any questions/comments/suggestions e-mail me or just reply and maybe i will be able to find it...oh yes and i am a noob to this automotiveforms.com thing but i am not a noob in my stereo knowlage...as you can see i stayed with only the finest woofers in my pricerange....and i do love rock....but nothing pisses off the foges like a nice hard bass line ....which is why i want my stereo to be versitile...i am still deciding on an EQ also....

[sr20de4evr]

Are you going for a SPL-only setup or something? You've got decent subs picked out, but a 40-45hz tune? That's way higher than I would tune for a daily setup

anyway, have you heard those crystals before? I've heard they're nice but the tweets can be a little bright.

[CBFryman]

mostly SQ but i want to have a good 130dB bass line...this will be hard with a box tuned to 25-30Hz...most music doesnt have much audiable sound below 35Hz anyway....

[sr20de4evr]

wha? 130dB isn't hard at all with a good sub or 2 decent subs in a ported box, whether it's tuned in the 20's or not. And if you're going for SQ, you definitely want to tune lower. It's not because songs have a bunch of info that low, it's to flatten out the response. Have you seen a response graph of a 45hz box before? It looks very similar to a prefab bandpass box's response, really really ugly.

You would be going through hell trying to EQ it so that it could sound good with a 40-45hz tune

[CBFryman]

@45Hz the port will be at its peak...it becomes extremely hard for the human ear to detect flats below 35Hz...at which point i dont care about that low anyway....and when i speak if 130dB i am not talking about the supersensitive dB drag mics. mounted on the bottom left corner of the wind sheild...i am speaking of 130dB in the center of the cab...and yes that is extremely hard to reach...i may or may not tune lower...but at hte moment i am going to tune to 40Hz most likely...

[sr20de4evr]

yes at 45hz the sub's excursion will be the lowest (actually slightly above the tuning, but that's beside the point), and you'll also get a huge peak in the response. I'm not talking 1-2dB, I'm talking 6dB or higher. I don't know what you mean by "it becomes extremely hard for the human ear to detect flats below 35Hz", if you have a huge peak in the response you will hear it, I don't care what frequency it's at.

And no it's still not that hard to hit 130dB in the center of the cab, I hit 130dB in the center of the cab pretty easily while listening to rock music with the volume up and I just have a single ported 12 (tuned at 26hz btw) on 800rms (now it's more power, but at the time that I measured this I was using an 800rms amp).

[CBFryman]

a Flat note is what most bass lines in rock and some in rap are...i dont know exact frequincies but one octave of notes is a double in Hz...the 1st octave is 20-40Hz...the notes are 20, 20.5, 25, 27.5, 30, 32.5, 35, 37.5, and 40Hz...flats in the 1st octave are extremely hard to tell from notes...notes are combined to make harmonis...our hears like htoes harmonics...flats our ears only like alone and are the easyest to re create....low flats are hard to hear ad decent listening levels...

[sr20de4evr]

That's fantastic, but I really don't see how this applies to anything. If you tune in the 40's you'll get a HUGE peak in the response and it will be practically impossible to EQ it to a flat response, which is what you need for a SQ setup. If you tune lower, you don't get this huge spike, it's as simple as that.

It would be like putting in a 6dB or larger spike in your EQ at 45hz, or cranking your bass boost up. If you like this that's perfectly fine, just don't say you're going for a SQ setup if you do .

[CBFryman]

you wont get a 6dB spike since with a 100% effency ported enclosure you only get 3dB per port...i dont use Eq's to get a flat responce...i use the Eq for a rock set up...higher from 40-120Hz and then slowly drop off a slightly quieter mid then a slightly louder last 1 1/2 octave (5,000-10,000Hz and 10,000-20,000Hz)

[TheSilentChamber]

CBFryman, stop arguing with people that know what there talking about (and I'm not just talking about this tread either...)

Originally Posted by sr20de4evr

It would be like putting in a 6dB or larger spike in your EQ at 45hz, or cranking your bass boost up. If you like this that's perfectly fine, just don't say you're going for a SQ setup if you do

Agreed.

[sr20de4evr]

Originally Posted by CBFryman

you wont get a 6dB spike since with a 100% effency ported enclosure you only get 3dB per port...

you really don't know what you're talking about do you?

a ported enclosure will give a ~3dB increase over sealed for most frequencies, however around the tuning frequency the output of a ported box is MUCH higher than a sealed box, 6-10dB in many cases. Play around a little with WinISD or any other enclosure modeling program

[CBFryman]

no you really odnt know what yo uare talking about....how are you going to amplify the energy coming form the back of the cone 2 or more times.... @100% effency the back of the cones sound energy being reflected through a columb of air known as a port will have a 3dB jump or in otherwords twice the sound energy of just the front of hte cone moving back and forth...learn some physics....

[CBFryman]

PS
you may have a 6dB jump inside of a vehicle but this is due to sound reflection....in an open air invironment (which is where woofers and enclosure should be tested and rated) where waves can not reflect back to the mic. a 3dB tops at any frequincy above the resonant frequincy of the woffer and above the tuned frequincy of the enclosue...so if the resonant frequincy of hte woofer is 32Hz and the enclosure is tuned to 40Hz and frequincy above 40Hz@100% effency in an open air environment will see a 3dB gain over the same woofer in the same sized sealed enclosure.

[sr20de4evr]

Why do you keep bringing up box efficiency? The box doesn't have an efficiency....efficiency comes when you convert one form of power into another (such as electrical to electrical in an amplifier, or electrical to acoustical in a speaker), the box doesn't convert anything, it has no efficiency. Now it can raise and lower the speaker's efficiency, but who says you can't increase the speaker's efficiency more than 100%? Why can't you raise the speaker's efficiency from 1% to 2 or even 3% by changing the box?

You keep thinking of a ported box in the ideal sense, where it delays the signal coming off the rear of the speaker by a certain amount, so by the time it leaves the port it's partially in phase with the front wave. The thing is, when you approach the tuning frequency, a ported box is not ideal, it doesn't follow this perfectly anymore. Without going into the details of acoustics, since you wouldn't listen to me anyway, here are 2 graphs that I can't believe I wasted my time with since you're just going to ignore them because everyone who disagrees with you is inherently wrong. These are both of the same sub (adire brahma 12), in the same size ported box, and both of these are anechoic responses (no room, no car, nothing). The only difference is the first one has a 24hz tuning frequency and the 2nd one has a 45hz tuning frequency. The red line is the 0dB response, basically if it followed this line you would have a perfectly flat response.

24hz tuning frequency, max .8dB rise at 44hz


45hz tuning frequency, max 9.3dB rise at 49hz

[PaulD]

all I can say is wow ........ I just hope this guy doesn't seriously hurt himself before he wakes up and realizes he really doesn't know much.