Diabolik

Ok, I think we got the definition of LOW and LOUD mixed up here. A ported box is a helluva lot louder than a sealed, thats for sure. However, it does not go lower as your own graph demonstrates. Look at the falloff on your ported box vs. sealed. The sealed box clearly goes lower, but the ported box is louder above 20Hz. And look at the cone displacement graph. There's no way that ported sub is producing a clear sound below 20 Hz. I realize that 20 Hz is not used much, but I am just saying that a sealed box will produce it much more clearly than ported, which means it is capable of a lower frequency response. Every sub manufacturer I've ever seen says this in their manuals. I may have been wrong by saying a ported box can't go below the tuning frequency, but I am not wrong in saying that a sealed will go lower without distortion.

For SQ, you want a smooth response, which the ported box simply does not give as well as the sealed. if the opposite was true then a sealed box would never be used for SQ, which it almost always is.

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just a little FYI.. i have been building boxes for over 15 years. and have recently designed a subwoofer box that has broken all the rules for what typically you expect from different types of boxes.
usually a sealed box is the tight accurate box design, ported are known for extended LOW frequency responce and bandpass boxes are known for good SPL but not so good of SQ.
my computer designed subwoofers and computer designed bandpass boxes have combined all 3 aspects into one box. the box happens to be a bandpass but if you ask anyone that has heard it they will all tell you the same thing.. it is simply awesome!
i belive there is are 2 members on this board that will attest to that fact.
thanks for your time.
Kevin

Indeed. Perhaps you can do some things to those boxes you are designing to mess with the physics, many people do that, but all things being equal with boxes built to manufacturers spec, sealed boxes have a better low end (sub 20Hz) response than ported, they are better for SQ because of the smoothness of the response curve, however are not as efficient as ported boxes.

I have ported and would never look back. At least not with my 12L7, that thing is great ported.

-Diabolik

Bass Mechanic

what? at 15 hz? who cares? your nit picking the ported box clearly goes lower look at the graph look where 0 ref is the ported box is making about 5db more than the sealed box at 40 hz and about 4.5 db more than the sealed box at 34 hz (the f3 point for the ported box) how can you say it is not going lower? it clearly shows it on the graph. maybe i should explain it better? the ported box has more output than the sealed box at all frequencies between 15 and 110 hz. that means it will play or emphasize the low frequencies better than the sealed box. to the listener the box will appear to play LOWER with respect to the sealed box. don't try to play on the words to make yourself sound right.

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but the ported box is louder above 20Hz. And look at the cone displacement graph. There's no way that ported sub is producing a clear sound below 20 Hz. I realize that 20 Hz is not used much, but I am just saying that a sealed box will produce it much more clearly than ported, which means it is capable of a lower frequency response. Every sub manufacturer I've ever seen says this in their manuals. I may have been wrong by saying a ported box can't go below the tuning frequency, but I am not wrong in saying that a sealed will go lower without distortion.

yes once again your wrong.. any sub that has less cone movement will have less distortion. but this is only true if the sub goes beyond it's xmax (linear cone travel limit, this is usually defined as the point wich the coil leaves the gap. as long as the coil is moving within the gap the responce is very linear and minimal distortion.) in this example the 2 designs do not match each other untill 22hz. if i redesigned the box i could easily tune the ported box to give a flat responce with no peaks by tuning it to about 20 hz then all the cone movement would be far less and even more controlled until it fell below 12 hz

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For SQ, you want a smooth response, which the ported box simply does not give as well as the sealed. if the opposite was true then a sealed box would never be used for SQ, which it almost always is.

your right about that if your compeating in a SQ contest and are under the watchfull eye of the RTA meter you want a perfectly flat responce. only a sealed box will do that unless you tune a ported box to have a roll off frequency of 45hz (the point at wich most cars produce cabin gain) but in general sealed boxes tend to do this almost automatically no matter what size you build them.
HOWEVER if you have ever listened to a perfectly flat responce i as well as 90% of the people in caraudio will agree it sounds like crap. most people prefer a system with a little more bass or bass heavy. fact is most people like a lot of low bass and that is where ported boxes come in.
there is talk that orginizations like Iasca will be rewriting the rules of SQ contests. people are asking to take out the RTA as well as not allow judges to see what equipment is in the car before judging. too many judges tend to rate the sound of a system based on their opinions of the equipment used as well as the box type and or setup. my point being if a flat responce is only used to make points on a meter what does that have to do with the way the system sounds? people should be allowed to set up their system to where it "sounds good" not what an RTA meter thinks should sound good.
if you like a flat responce then go sealed by all means.
possibly in your experience with ported boxes is that your box is still too small for the sub your using. i went to your webpage and saw your install. it is hard to say from the pic but i know from experience that L7 subs require a very large box to get correct tuning in the ported boxes. yours looks too small and i would not be suprised if it does not go lower than a sealed box. it looks to me more like a SPL box because it would have to be tuned pretty high in that small of a box.

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Indeed. Perhaps you can do some things to those boxes you are designing to mess with the physics, many people do that, but all things being equal with boxes built to manufacturers spec, sealed boxes have a better low end (sub 20Hz) response than ported, they are better for SQ because of the smoothness of the response curve, however are not as efficient as ported boxes.

I have ported and would never look back. At least not with my 12L7, that thing is great ported.

-Diabolik

yes i would agree L7 subs suck in a sealed box i have run several simulations with them and they have a nasty responce curve in sealed boxes. ported is a much better choice with them and it is mostly due to the fact that they have a low BL product (magnetic strength in the voice coil gap) because of a weak magnet power they don't respond well to small sealed applications because the magnet can't produce enough force to move the massivly heavy cone they use and in a small box with so little airspace.

Diabolik

I'm not playing on words dude, chill. I'm just saying that a sealed box can generally go lower than a ported one without distortion. I know it's just 15 Hz, and no one really cares about that, but I'm just saying the sealed will do it. Sure, a ported can do a number of things depending how you port it, but if you tune the thing to 35 Hz like most people, for a balance of SPL and SQ, the sealed will generally go lower. Fvck I can tune my damn box to 20 Hz and it will play the low's well but how many people do that?



As above...



That's true.... The RTA should go. As it is, it doesn't count for much, but should count for nothing. A flat response is not always the best sounding, more often than not it sounds like sh!t, so I guess I see what you're saying there. The problem is that most times the bass in a vehicle is so prominent, it's nice for the SQ guys to have a sealed box because they can keep the low frequency more in control without too much DSP work. In a ported box, there's those spikes that you have to deal with.

As for my box, its great. It's good for both SPL and SQ tuned to 38 Hz. My DSP takes care of any anomalies. That box is actually the Kicker recommended size for 'street bass', whatever the hell that means. I find it a good balance. 2.5 cubes for 1 12" is pretty big, IMO.

According to kicker, 2 cuft is the recommended sealed size. That's big for sealed. I would agree that in a small sealed, L7's would suck.

BTW, what computer program is that you are using? I think I've seen it before.

-Diabolik

Chiuey

heh...u guys helped me more than enuff...imma go with a ported box. they actually make custom boxes for orions at this site.. http://www.custom-car-sound.com/encl...erformance.htm thx

VRGNCD5

Wow, these two guys know their stuff (bass mechanik and diabolik)

seth90dx

DOH!!! why wasnt I here earlier.... BASS MECHANIC.... STFU .... Im takin sides with diabolic... Sure the ported boxes are louder! But who wants to listen to a **** mess of blabering bass, that sounds like total ass? Now mr. bass you say you have been makin boxes for 15 years? Well I hapen to have 2 JL W3V2-D4's and a 500/1 JL amp... I bought a ****load of MDF cause i was curious how much of a diferance there was between ported and sealed boxes.
After me and my brother (A profesianal cabnet maker/woodworker) built 5 boxes 3 ported and 2 sealed, all to the volume posted on the instructions in the subwoofer boxes... We discovered the sealed boxes sound a WHOLE hell of a lot cleaner... Just my 2cents.

Bass Mechanic

thanks for your 2 cents because the way you come off saying STFU to someone you don't know but quite clearly has a lot more experience than you. shows me that you are just some swell headed kid. i would think after being 21 years old you might act a little more mature than this.
i really don't care if you belive what i have to say or not. the fact is one of us owns a very sucessfull business building subwoofer boxes, has his own line of subwoofers and has been building show systems for over 15 years. it is obvious who here has the experience and who dosn't. i think it is quite obvious that between someone with this back ground and someone who lays carpet for a living that there must be some things i know about the subject that you don't.
i came in here to offer information. possibly to teach someone somthing. if there is one thing you need to learn about caraudio it is that no matter how long you have been doing this business you still learn stuff each and every day. for you to come in here and challenge someone who has years more experience than you is a foolish thing to do if you want to learn caraudio. the problem is this industry is it is full of kids like you that think they know everything. when you have this attitude you have gone as far in caraudio as you will ever go. some day when you grow up and realise you don't know it all you might be able to learn somthing. but for now i guess you just have to settle for what you think you know rather than facts that can be proven.

I am removing my subscription from this thread, feel free to flame me all you want. this is the last post i will make in here and i will not be reading anything further in this thread. i have better things to do than sit here and argue with someone that just likes to run his mouth. if i were to continue on this thread it is just going to be an argument and pissing match between you and me. personally the fact that i have had to sink to this level typing this makes me look bad as a professional. but i also felt since you attacked me i have the right to defend myself. i take the words STFU very personally. they may be words you use every day and be common place for you but to others they are offensive.

to everyone else still reading this pointless thread mark my words. if this guy says anything in responce to this post other than
"im sorry i came off like that, and you right"
then my point in this post is proven

seth90dx

Well I may have come off a little harsh with the STFU... Im just sayin it sounded a lot cleaner sealed.... Whats the name of your company? what kind of subs do you make? AKA if I kiss ur ass with you hook me up cheap? I can move some serious audio gear were im at!

Chiuey

Damnit, they dont make custom boxes for the orions anymore...can someone do me a really big favor and tell me what size ported box i should get for an orion xtr pro with dimensions...
XTR PRO 12D
POWER 600 Watts Continuous 1200 Watts peak
Fs 437 Hz
Qts .39
Vas .1.14 cu. ft.
SENSITIVITY 88/ 94 dB
LINEAR EXCURSION 15.2mm
DIMENSIONS 11.25" / 6.5"
Im probabaly gonna go with q logic...but i need to kno the size box! thx

Chiuey

actaully nm i found a site