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View Full Version : Bandpass builders: I need your help!



1ndatrunk
12-07-2009, 06:52 PM
Since nobody seems to want it, I'm gonna try my hand at building a 4th order for my XXX. Its going in a trunk, and I already know its gonna be huge, but can some body give me the dims for the sealed and ported chambers, as well as the port area/tuning?
Thanks

misfit138
12-07-2009, 06:53 PM
Since nobody seems to want it, I'm gonna try my hand at building a 4th order for my XXX. Its going in a trunk, and I already know its gonna be huge, but can some body give me the dims for the sealed and ported chambers, as well as the port area/tuning?
Thanks

Wouldn't it be easier to flat out ask for a design?

1ndatrunk
12-07-2009, 06:57 PM
Wouldn't it be easier to flat out ask for a design?

Ok, can somebody give me a design for one?

marcotheclepto
12-07-2009, 07:01 PM
prolly gonna have to pay for a design for bandpass, 80INCHES iamamp3pimp mobieous galacticmonkey... THUMPPER << spelling? any of them should be able to help you out...

1ndatrunk
12-07-2009, 07:22 PM
Not a prob, just need to know if it'll even fit, since the regular ported box for this thing is so freaking big. My trunk has a stupid shape too, so I have issues

Dr. Hertz
12-10-2009, 11:04 PM
I seldom have built a band-pass for a woofer that I loved the first time around. I use bassbox pro, and even then some trial and error is necessary. I just went through my files on bbpro, and have no RE XXX BP box diagrams....If I have time in the next few days, I'll design one for you-don't hold your breath too long. One thing I learned is to have the sealed side and the vented side an octave apart.

mobeious
12-10-2009, 11:09 PM
I seldom have built a band-pass for a woofer that I loved the first time around. I use bassbox pro, and even then some trial and error is necessary. I just went through my files on bbpro, and have no RE XXX BP box diagrams....If I have time in the next few days, I'll design one for you-don't hold your breath too long. One thing I learned is to have the sealed side and the vented side an octave apart.

prolly dont know what ur doin if ur using BBP that program is horrible for bandpasses and it calculates for HA use anyhow so the graph means nothing


i have never had a box i didnt like or didnt sound like i wanted ....

Dr. Hertz
12-11-2009, 02:27 PM
prolly dont know what ur doin if ur using BBP that program is horrible for bandpasses and it calculates for HA use anyhow so the graph means nothing
It is for BP, but I do say trial and error is necessary. Pretty sure I know what I'm doing, I've learned from some of the best (RTTI instructor/creator Mark Lowe), I'm sure you're the whip at whatever you do, all I have to do is ask you!

i have never had a box i didnt like or didnt sound like i wanted ....
That is proof you've not made a BP box right, made very few boxes, and don't know what sounds good! Does it say prefab FTW in your sig? You may jock yourself as boxbuilderextraordinaire, but that comment screams arrogant prick.

mbrooky
12-11-2009, 03:40 PM
this is what mobieous wrote about a 15" Nightshade...NS has a fs of 41hz i believe the xxx15 is around 37hz so specs should be close:



The nightshade has a fs of 41ish hz so u really want to dampen anything under that so considering how much power u are going to have u could go 1.25-1.75 sealed and then if u want high output then the ported section should be in the 3cube area and for a less peaky box around 2-2.5 and i would tune around 45hz if u want a low end monster

mobeious
12-11-2009, 04:47 PM
edit

iamamp3pimp
12-11-2009, 07:12 PM
not a good thread for me.

:)

galacticmonkey
12-11-2009, 07:16 PM
I started messing around with it a little bit, but your shape makes it tough. If you could get another 1" height you could fit it most likely. Its just that one sub that is so huge where it would have to be facing up or down wouldnt work too well.

PV Audio
12-12-2009, 11:49 PM
prolly dont know what ur doin if ur using BBP that program is horrible for bandpasses and it calculates for HA use anyhow so the graph means nothing


i have never had a box i didnt like or didnt sound like i wanted ....
Not even Robert Bullock, Neville Thiele, Richard Small or Joseph D'Appolito have never NOT built an enclosure they don't like. Some humility works, because it's impossible to know what good is if you haven't heard bad.

80INCHES
12-13-2009, 01:43 PM
pm sent to thread op

80

boogeyman
12-13-2009, 05:21 PM
box 1.....front 2.642 cubic ft. NET....rear 3.3 cubic ft NET......port in front chamber 6 inch round port 20.19707 inches long....tuning frequency 34.25....passband frequency 20.57 hz- 57.02 hz...........very narrow passband but very efficient......Box 2....front 1.835 cubic ft. NET.....rear 2.015 cubic ft.NET.......6 inch round port 20.20532 inches long......tuning frequency 41.09....passband frequency 23.47 hz- 71.93hz.....I would personally go with box 2........if you want to use slot ports someone here can help you convert my round port suggestion to a slot port..........Im about to go eat good luck.

80INCHES
12-13-2009, 05:30 PM
box 1.....front 2.642 cubic ft. NET....rear 3.3 cubic ft NET......port in front chamber 6 inch round port 20.19707 inches long....tuning frequency 34.25....passband frequency 20.57 hz- 57.02 hz...........very narrow passband but very efficient......Box 2....front 1.835 cubic ft. NET.....rear 2.015 cubic ft.NET.......6 inch round port 20.20532 inches long......tuning frequency 41.09....passband frequency 23.47 hz- 71.93hz.....I would personally go with box 2........if you want to use slot ports someone here can help you convert my round port suggestion to a slot port..........Im about to go eat good luck.

both designs r a no go

80

boogeyman
12-13-2009, 08:23 PM
what exactly are you looking for

mobeious
12-13-2009, 09:14 PM
box 1.....front 2.642 cubic ft. NET....rear 3.3 cubic ft NET......port in front chamber 6 inch round port 20.19707 inches long....tuning frequency 34.25....passband frequency 20.57 hz- 57.02 hz...........very narrow passband but very efficient......Box 2....front 1.835 cubic ft. NET.....rear 2.015 cubic ft.NET.......6 inch round port 20.20532 inches long......tuning frequency 41.09....passband frequency 23.47 hz- 71.93hz.....I would personally go with box 2........if you want to use slot ports someone here can help you convert my round port suggestion to a slot port..........Im about to go eat good luck.

:crazy::wow:

marcotheclepto
12-13-2009, 09:31 PM
:crazy::wow:

looks like it was fed straight outta a calculator

power-fanatic07
12-13-2009, 09:33 PM
in most 4th and 6th orders ive seen the front chamber is almost always considerably larger than the rear

mobeious
12-13-2009, 09:42 PM
in most 4th and 6th orders ive seen the front chamber is almost always considerably larger than the rear

This is the "by the book way" for a flat responce but lacks in overall output


say u have a box that is 1cube sealed and .6 ported at 55hz that is going to yeld a roll off around 34hz and 59hz and the box will be flat from those 2 roll offs but with a overall output of -2db well lets keep the 1cube sealed and bump up the ported section to around 2cubes and lower our tuning freq to around 49 what that does is through a big peak in the graph u still roll off at say 34 and 59 but u have say a 8db peak at 45hz and still -2db at roll off points so u get a overall louder responce between the roll off points ... and if u play with the numbers just right u can flatten that out and keep the + gain in DB

robertoyoung08
12-13-2009, 09:50 PM
i need a bandpass design too!
any takers?!

mobeious
12-13-2009, 09:51 PM
shoot me a PM

PV Audio
12-13-2009, 09:53 PM
box 1.....front 2.642 cubic ft. NET....rear 3.3 cubic ft NET......port in front chamber 6 inch round port 20.19707 inches long....tuning frequency 34.25....passband frequency 20.57 hz- 57.02 hz...........very narrow passband but very efficient......Box 2....front 1.835 cubic ft. NET.....rear 2.015 cubic ft.NET.......6 inch round port 20.20532 inches long......tuning frequency 41.09....passband frequency 23.47 hz- 71.93hz.....I would personally go with box 2........if you want to use slot ports someone here can help you convert my round port suggestion to a slot port..........Im about to go eat good luck.Please stop, because you don't know what you're doing.

PV Audio
12-13-2009, 09:54 PM
both designs r a no go

80Thank you, I don't even design BPs but I know enough about their theory that that is a ludicrous design and that he didn't even think about it and instead just plugged it into a computer.

bubbagumper6
12-13-2009, 09:55 PM
So what's a good program to model bandpasses in then? WinISD?

boogeyman
12-13-2009, 10:07 PM
pv audio what is so ludacris about it....smart ***

boogeyman
12-13-2009, 10:16 PM
let me tell you something pv audio Ive been doing this since YOU were two years old still shitting in diapers so dont tell me I dont know what Im doing...I have forgotten more than you even Know LIL BOY

bubbagumper6
12-13-2009, 10:18 PM
let me tell you something pv audio Ive been doing this since YOU were two years old still shitting in diapers so dont tell me I dont know what Im doing...I have forgotten more than you even Know LIL BOY

Your only 12 years older than him...meaning when he was "shitting in diapers" you were still in junior high :rolleyes:

mobeious
12-13-2009, 10:20 PM
let me tell you something pv audio Ive been doing this since YOU were two years old still shitting in diapers so dont tell me I dont know what Im doing...I have forgotten more than you even Know LIL BOY



ok lets see what ya got .. 2.4 cubes 32hz single 12 Kerfed port

post up ur design and prove ur point

boogeyman
12-13-2009, 10:34 PM
okay lets see what you got design an ...Isobaric quasi eighth order series tuned dual reflex bandpass enclosure....can YOU handle that MOBEIOUS

mobeious
12-13-2009, 10:40 PM
okay lets see what you got design an ...Isobaric quasi eighth order series tuned dual reflex bandpass enclosure....can YOU handle that MOBEIOUS

i can if u would like but no car woofers these days would really benifit from that type of enclosure

bubbagumper6
12-13-2009, 10:41 PM
Cat Fight!!!

galacticmonkey
12-13-2009, 10:47 PM
box 1.....front 2.642 cubic ft. NET....rear 3.3 cubic ft NET......port in front chamber 6 inch round port 20.19707 inches long....tuning frequency 34.25....passband frequency 20.57 hz- 57.02 hz...........very narrow passband but very efficient......Box 2....front 1.835 cubic ft. NET.....rear 2.015 cubic ft.NET.......6 inch round port 20.20532 inches long......tuning frequency 41.09....passband frequency 23.47 hz- 71.93hz.....I would personally go with box 2........if you want to use slot ports someone here can help you convert my round port suggestion to a slot port..........Im about to go eat good luck.

Are you ******* high? Thats impossible to read.


So what's a good program to model bandpasses in then? WinISD?

I could eyeball a better bandpass than a program could design. All these calculators **** for bandpass.

bubbagumper6
12-13-2009, 10:49 PM
I could eyeball a better bandpass than a program could design. All these calculators **** for bandpass.

So if I ever go with a bandpass I'd be better off just asking for help instead of designing it myself?

mobeious
12-13-2009, 11:01 PM
okay lets see what you got design an ...Isobaric quasi eighth order series tuned dual reflex bandpass enclosure....can YOU handle that MOBEIOUS

here ya go just a little quick something i threw together for a JBL GTO 12

http://i7.photobucket.com/albums/y290/mobeious/4thiso.jpg

bubbagumper6
12-13-2009, 11:03 PM
here ya go just a little quick something i threw together for a JBL GTO 12

http://i7.photobucket.com/albums/y290/mobeious/4thiso.jpg

wow that's a weird design...

mobeious
12-13-2009, 11:05 PM
Isobaric quasi eighth order series tuned dual reflex bandpass enclosure

exactly what he asked for

80INCHES
12-13-2009, 11:21 PM
i like it mobes...

80

PV Audio
12-13-2009, 11:25 PM
pv audio what is so ludacris about it....smart ***


let me tell you something pv audio Ive been doing this since YOU were two years old still shitting in diapers so dont tell me I dont know what Im doing...I have forgotten more than you even Know LIL BOY
Without being arrogant or elitist, I can say with pretty much 100% certainty that I have a greater understanding of enclosure theory than you do. The difference is that while you sit here and type, I am sitting here and reading volumes from like likes of Bullock, Thiele, Riley, Klippel, D'Appolito and Small trying to enrich my knowledge, then I ask questions on here to people who know more when I don't fully understand something.

The simple fact that you posted numbers directly from a calculator; numbers that aren't possible to achieve in the real world anyway, proves that you don't have the intuition to design properly. A calculator is a tool, and especially for bandpasses, the designer knows what to do in the first place then uses the computer to get the exact numbers, not the other way around. That's why I had a design contest to weed people out. Over 9 entrants were so poorly designed that I didn't even bother to list them because they listed things like 2.000344483728 cubic feet when in fact the enclosure would have been more suitable for a laboratory rat maze.

It's when people like you come on here spouting out information as though you know what you're doing when in fact you just opened up a computer and punched in some numbers that I try and help others who might not understand why that isn't true. People like 80, mobes and imamp3pimp are some of the best BP designers on this forum, and you will never see them give a customer numbers like that because they aren't made for a person, they were made in a computer without even considering someone's vehicle, input power, driver, extraneous effects or personal preference. That's what it comes down to.

If you want to debate me on enclosure or loudspeaker theory, please, feel free to do it another time because I don't want to come off as arrogant since it makes me feel badly and I have studying to do, but I don't particularly like being told that I don't know what I'm talking about when out of all of the car enclosure designs I have made, all of them have been original and over 3/4s have been repeat customers.

I used to be like you: thought I knew everything, got mad when someone said I was wrong, and tried to argue against them without actually having the knowledge to back it up. I learn new things every day. Hell, I learned some interesting stuff today that I already posted about somewhere on here. So please, if you know how to design BPs, then fine. Posting random numbers and assuming that they are of any use to anyone is simply, as I said, ludicrous. :)

PV Audio
12-13-2009, 11:28 PM
okay lets see what you got design an ...Isobaric quasi eighth order series tuned dual reflex bandpass enclosure....can YOU handle that MOBEIOUSGood lord you're obnoxious. Throwing around enclosure terms as though that proves that you know something people don't. Not only is that sort of enclosure entirely useless, it only proves that you are striving to show that you are somehow better than someone who already proved himself to be one of the most accurate designers on here, and did it while being the most creative. Just stop, please.

PV Audio
12-13-2009, 11:31 PM
wow that's a weird design...
It is also incredibly useless, would sound atrocious and would never be used in industry. There are infinite numbers of enclosure variations that you can use. That doesn't mean that you should use them. Boogeyman is just getting into a pissing contest with mobes to prove that he's somehow more knowledgeable when in fact all he's doing is picking random words to make an enclosure that has zero useful features.

galacticmonkey
12-13-2009, 11:32 PM
So if I ever go with a bandpass I'd be better off just asking for help instead of designing it myself?

You can design it yourself. I dont know 6th orders well enough to design and build one for myself and be sure of how it will sound... But 4th orders arent that complicated.

Its 2 chambers and a single port. Alot of the time, bandpasses are easier to design than regular ported boxes. In my truck, I went as small as possible on the sealed, and as big as possible on the ported, then got a decent sized port and made it deep enough to fit a big horn in it... Which happened to tune it to 47-48hz. Thing sounds awesome and I couldnt be happier.

Be one with the box. :fyi:

robertoyoung08
12-14-2009, 12:39 AM
**** ..
we havnt seen boogymans design
=(

this went from a helping thread to build off.
haha

HighTQCummins
12-14-2009, 01:26 AM
Im glad there are regularly available measuring systems that can measure down to 8-9 decimal places. With accuracy like that, you are better off working for nasa and such, if that makes sense.

I clicked on this thread because i too am trying to learn a little bit about 4th order BP's and their workings, however once again all I got was someone who thinks they know everything, and other people, who do know a lot about it, getting into arguments.

boogeyman
12-14-2009, 10:11 AM
mobeious nice work, But with all due respect anybody can draw a box, I was talking more along the lines of, volumes of chambers, port area and length, tuning frequency, usable passband, 3-db down point, gain, s-factor, qbp, power handling, port velocity, linear x-max, and other IMPORTANT factors.

HighTQCummins
12-14-2009, 10:24 AM
hey hold on a second, let me open up an online dictionary of BP terms, i'll throw them out there too.

boogeyman
12-14-2009, 10:50 AM
pv audio Im glad youre reading intellectual literature, but whose to say I am not or have not? Certainly not you.People CAN NOT say if a box is undesirable until they build it and place it in the listening environment and listen, In order to ACCURATELY predict an enclosures response before construction, One must take accurate measurements of the vehicles "transfer function". So for everyone who said my enclosure designs fail who has not took an in depth measurement of the vehicle in questions transfer function, Your negative assumption of the enclosures performance can ONLY be UNPROVEN AT BEST.

boogeyman
12-14-2009, 10:58 AM
You should not have to open an online dictionary, You should know these, if you dont know these, Wich is obvious you need to go sit on the bench.

PV Audio
12-14-2009, 11:12 AM
indatrunk, PM mobeious, 80INCHES, imamp3pimp, galacticmonkey, THUMPERR or anyone else who has shown talent in bandpass design. This thread has been derailed as most do when people start arguing. I apologize for being a part of it.

HighTQCummins
12-14-2009, 11:37 AM
You should not have to open an online dictionary, You should know these, if you dont know these, Wich is obvious you need to go sit on the bench.

u mad?

mobeious
12-14-2009, 02:23 PM
mobeious nice work, But with all due respect anybody can draw a box, I was talking more along the lines of, volumes of chambers, port area and length, tuning frequency, usable passband, 3-db down point, gain, s-factor, qbp, power handling, port velocity, linear x-max, and other IMPORTANT factors.

alot of those characteristics depend on 1 other thing and i bet u cant name it

PV Audio
12-14-2009, 03:05 PM
alot of those characteristics depend on 1 other thing and i bet u cant name itI would just let it go since while he may know a lot, he's too arrogant to be of any use. I know that because I was the exact same way except that I really didn't know a lot. :(

Savag3
12-14-2009, 04:54 PM
here ya go just a little quick something i threw together for a JBL GTO 12

http://i7.photobucket.com/albums/y290/mobeious/4thiso.jpg

this looks sik ! , how would it perfrom

SicAudio
12-14-2009, 05:12 PM
http://dbdynamixaudio.com/60/4th-order-bandpass-enclosure-calculator/

design ur box yourself and experiment the experience will be a great teacher.

mobeious
12-14-2009, 07:30 PM
this looks sik ! , how would it perfrom

lets just say it wouldnt go in my truck... very limited bandwidth and no cone control really dont know why u would use that design... he just went to the12volt.com and got the most complex lookin one on there

Blue Fury
12-14-2009, 07:53 PM
Is boogieman and this other boogie related? Both seem to get the same approval for their input..
the other boogie (http://forum.realmofexcursion.com/enclosures/64485-anybody-needs-design-help.html)