I am unsure what kind of design i should make for my car, i know a little bit about Pa audio but not cars, im looking for max performance, if i was to make a dual 12" bandpass speaker box would that sound better than say a dual 12" box? using Type R alpine 12's?
Richie
It depends what you're looking for. What do you mean by max performance? are you after sounds quality, or volume? My 15" is mounted in a sealed enclosure and offers excellent response, but is not as boomy as some 15"s that I've heard. However, some ported setups that I've heard seem very monotone, and a bit droney at times. Though I've never heard a bandpass setup, the foreman installer at work tells me that they can sound very loud, whilst still acheiveing a decent level of response across a given frequency band. The only drawback is the amount of time you'll need to put into box design and construction.
I agree with some of the info but it still is a bit wrong.
It has been shown that ported boxes are louder (spl) then there sealed counterparts.
Where a sealed boxed sub has generally tight bass reproduction (depending on sub) ported can sound a little boomy if not designed correctly.
I've had two bandpass enclosures and one was indeed with alpine 12" subs. It is what I measure everything to as it provided the best sound quality of all my systems.
Bandpass boxes are great for quality and inbetween a sealed and ported box for outright spl.
Saying this though a bandpass box is an exacting art, needing a great deal of experience in building and designing enclosures.
If you want an opinon on your situation, build a ported box for you 2 12" alpine subs and roll around in both the detailed and deep bass they provide :mrgreen:
yeah good point Jet-6, thats why you need to spend a great deal of time (backed up with knowledge) to make your bandpass boxes. And VK - Turbo, you didn't say anything contrary to what has already been said.
Woops, meant to add it but it was already pretty long (the post hehe).
Bandpass is more efficient meaning louder with less power needed.
So for high output use a bandpass box.
Also if setup right, both bandpass boxes and ported boxes sound far from monotone as they can play more then one tone or frequency even without a box (just playing).
I actually rather bandpass and proted box designs as although they can be a bit larger and harder to design, then sound is excellent.
My fav and suggestion is a 4th order as they are a little easier to get right then a 6th order.
Did you know that with a proper designed 4Th order you get a natural low pass of 12db/oct and with a 6Th you get a 24db/oct lowpass and @ 12db/oct highpass. pretty cool.
Some original photos have not been recovered yet.
We may have to agree to disagree here dude, cause i'm firmly embedded in the belief that a sealed enclosure can provide a smoother frequency response from lower down to higher up than any other box configuration. Thing is, you then have to use external filters. It just depends on whether you want your sub to gow low or loud.
Thats not saying that I don't like bandpass, 'cause I do. I guess it's the closest thing to the best of both worlds. But for me, it's too hard and sometimes too big.
It was my understanding that bandpass is designed to only play well in a certain frequency range and outside of that range i thought they were meant to sound like utter crap?
With this info if you're going for loudness for entering comps, ie playing tones, go for bandpass ( as long as the box is made to exact calculations else tuning will be off) if you're going for better sounding loudness for music go ported, and if u want good quality, good punchy sounding bass across the frequency curve go for sealed.
PS. this is a generalisation and results may differ in different circumstances
I have built many bandpass boxes and ive only ever had good comments from the customers. I also run one in my car and it the best box ive ever made, sound great in every way.
I feel some of you need to understand a little more what exactly the Subwoofer and it's enclosure is for.
1. A subwoofer is only suppose to play a "CERTAIN FREQUENCY" band.
2. It's sole purpose is to reproduce "SUB" frequencies.
Saying this, they are all usually meant to reproduce 2 octaves, from 20hz to 80hz. thats it. This is why the Bandpass design works so well.
A tuned bandpass can reproduce a section of the frequency more efficiently then almost all other designs, and easily top a sealed and in most cases a ported setup.
80hz is about as you really need/should go as above this is the region of the mid bass speaker and all good component speaker systems cover this area better with a faster attack and better response then a subwoofer.
bandpass boxes will have a natural effect of highpass and lowpass filters at certain crossover points... hence the name 'bandpass'. If you design the box in accordance with what your front end is capable of (in terms of midbass, as VK says) you'll get a near seamless crossover in a very efficient box. This efficiency is why subs play so loud in bandpass boxes. And trust me, going lower in frequncy than 20hz is pointless unless you have SERIOUS cone area, loads of power, and don't mind going infinite baffle. Even then, the sound you pick up will still tend to be inaudible and you'll have trouble picking up any serious vibrations.
i dunno where you got going below 20hz from, but yeh what you said, and the fact that u wont find many subs with an Fs of lower than 20hz and tuning below their Fs is not advised at all
True. Everyone is true and has a valid point. As to the topic, go into a reputable Car Audio dealer and listen to some of the subs on display. They should have at least the same sub in either a sealed and a ported enclosure. This is the only way you will be able to hear what each sound like.
As for the Bandpass, I'd leave his design untill you can get a pro to design and build it for you.
It shouldn't cost any more then $800 fully built and covered, or you could by a generic 4th order bandpass enclosure and get the store to set the correct port sizes before you install it - I have seen these from $350.
Also if you can afford the 2 x 12" alpine R subs, thats a fine choice.
