Go Back   Home > Forums > General Interest > Car Audio

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 13th July 2013, 04:52 AM   #11
diyAudio Member
 
THUMP LUMP's Avatar
 
Join Date: Aug 2007
Referring to an enclosure as being a certain number "order" in NO way describes the TYPE of enclosure and thus should never be used as such. End of story.
  Reply With Quote
Old 13th July 2013, 05:04 AM   #12
OscarS is offline OscarS  United States
diyAudio Member
 
Join Date: Jan 2011
not by itself, and no one ever said that (at least not here on this forum) but when used properly, it can and does describe an enclosure. IE: 6th order bass-reflex, 5th order bandpass, etc. I think you're putting words in people's mouths.
  Reply With Quote
Old 13th July 2013, 05:48 AM   #13
diyAudio Member
 
THUMP LUMP's Avatar
 
Join Date: Aug 2007
Very well then. Name the orders and how they equate to a particular design or type of enclosure. In 25 years of messing with this, I have never heard a reasonable answer to this, nor any consensus among those that have tried.

Change my mind. I'm listening.
  Reply With Quote
Old 13th July 2013, 07:36 AM   #14
OscarS is offline OscarS  United States
diyAudio Member
 
Join Date: Jan 2011
No, it doesn't work that way. I can read between your lines, and you want me to start with a number for the order only, and then describe a single type of enclosure that it maps to. It doesn't work that way. Both you and I know that. [For the mathematically inclined, the mapping for order-to-enclosure-type is not a one-to-one (injective) function ).

Perhaps you are not truly understanding what I am saying. Maybe you are, I don't know, but I'll explain myself, just promise to put the whiskey down a few hours prior to reading my explanation....

The only thing that I am saying is this...I will try to word it as clear as I possibly can...

  • The numerical order along with the enclosure type is a perfectly valid way to describe the overall system.

IE:
  • 4th order bass-reflex (vented): just your normal, standard, everyday ported enclosure, rolls off -24dB/octave below F3
  • 6th order bass-reflex (vented): a vented enclosure with an addition 2nd order filter to further increase the roll-off rate, -24 dB/oct + (-12 dB/octave)= -36 dB/octave
  • 4th order bandpass: single-reflex bandpass (one port tuning) with a natural 2nd order roll-off below F3L, and natural 2nd order rolloff above F3U. 2nd order + 2nd order = 4th order total
  • 5th order bandpass= simply a 4th order BP with an additional 1st order filter on the upper-end to attenuate higher frequencies above F3U. -12 dB/oct on the low-side, -18dB/oct on the high side = -30dB/octave total = 5th order (total)
  • ad infinitum.....


Notice the bold part above. What I am saying, just as the original thread starter did, is state the specific enclosure type along with the order to describe the overall system. Thread starter never said that the numerical order is all that is needed for us to decipher which specific enclosure he needed.(!)



Since the thread starter originally (and specifically I might add) stated his design is to be a bandpass of order 5, it doesn't take a genius to realize that a 4th order bandpass is the lowest order bandpass possible (mechanically) , and since it is to be a 5th order bandpass, it must have an additional -6dB/octave of rolloff somewhere (because the unmodified design is 4th order to begin with).

Now, if he had said 6th order bandpass, then that might be misconstrued as ambiguous because there is a dual-reflex 6th order bandpass (two distinct port resonances), or it might just be a 4th order bandpass with an additional 2nd order filter. But this isn't the case in the original post...


I think you either read the original post incorrectly, or read some post by some numbnuts on some other forum referring to his bandpass box as a "4th order" and perhaps thought that was going on here. Rest assured, it is not.
  Reply With Quote
Old 13th July 2013, 04:34 PM   #15
diyAudio Member
 
THUMP LUMP's Avatar
 
Join Date: Aug 2007
Quote:
Originally Posted by OscarS View Post
[*] The numerical order along with the enclosure type is a perfectly valid way to describe the overall system.
That is exactly what I am saying. Such and such an order is not the same as stating the type of enclosure. People have, and do, interchange the two. To much ambiguity here. To me, it makes MUCH more sense to say "single reflex w/ a 12db LP filter" than to say "6th order". ANY nomenclature that has such a wide area for confusion should not be used, at least not without some clarification. At which point, why bother.



Quote:
Originally Posted by OscarS View Post
Now, if he had said 6th order bandpass, then that might be misconstrued as ambiguous because there is a dual-reflex 6th order bandpass (two distinct port resonances), or it might just be a 4th order bandpass with an additional 2nd order filter. But this isn't the case in the original post...
And this is why, when asked "What enclosure should I build", suggesting a particular "order" can get confusing. Unless the "order" suggested is broken down into enclosure type and additional components used, it shouldn't be used.

Regardless, unless someone has the ability to actually measure the T/S parameters (mfg. spec sheets are notoriously off) of the driver that is intended to be used and the required skills to exactly build the enclosure to specs, they really shouldn't waste the time and money.
  Reply With Quote
Old 2nd August 2013, 01:39 PM   #16
diyAudio Member
 
Join Date: Jul 2013
esayest way i recon with out aiming for perfection is just match the speacker to a like 1 in household cabinated 1 just for esay nice box ive done this an it sounds pretty nice old 1s are best the ole plussey stuff XD cheap but sort of nice
and look at the many boxes used and the old crt tv sound boxes used
some 1 has already done some fancy stuff out thea u just gota find it and clone away also cheak patents on stuff jbl and others will give u some clues XD
but if experimenting try using already in use boxes and making adapotors XD
i have the mintest idea for a sub box i think it mite auctulay cause survre damages XD
  Reply With Quote
Old 16th August 2013, 04:48 AM   #17
diyAudio Member
 
Join Date: Aug 2013
Location: Melbourne
doesn't each order refer to a control element that effects the cross over point? e.g sealed box is 2st order because you have the spring of the air in there enclosure and the mass of the air to control the high pass, ported is that plus the springiness and mass of the air in the port, standard band pass is that plus the spring and mass of the sealed enclosures which is 6th order etc. each added order increases the cut off rate, just like a passive electronic crossover. I could be wrong tho
  Reply With Quote
Old 16th August 2013, 01:41 PM   #18
OscarS is offline OscarS  United States
diyAudio Member
 
Join Date: Jan 2011
Quote:
Originally Posted by ubza1234 View Post
doesn't each order refer to a control element that effects the cross over point? e.g sealed box is 2st order because you have the spring of the air in there enclosure and the mass of the air to control the high pass, ported is that plus the springiness and mass of the air in the port, standard band pass is that plus the spring and mass of the sealed enclosures which is 6th order etc. each added order increases the cut off rate, just like a passive electronic crossover. I could be wrong tho
each order does increase the total cutoff rate, but a standard sealed/ported bandpass is not 6th order, it is 4th order--12 db on the highpass and 12 db on the lowpass.

no need to worry, thump lump was mistaken about the context of the word "order" because it wasn't being used the way he thought it was---the OP was using it in conjunction with the enclosure type to designate the overall system
  Reply With Quote
Old 16th August 2013, 02:59 PM   #19
diyAudio Member
 
THUMP LUMP's Avatar
 
Join Date: Aug 2007
Quote:
Originally Posted by Betrdaz View Post
So I am a carpenter i have all the tools and material i could ask for when looking to build a sub enclosure. Now I need someone much smarter than I to help me design it. I want to build a 5th order bandpass specific to my subs and amp. If anyone has any experience or advice on the subject it would be much appreciated. Ill have to check specific model but I have 2 Polk audio 12's that I believe are 350w rms each. I have a rockford fosgate 700bd1 amp powering them.
Really? I fail to see any other reference to an "order" other than the enclosure.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Enclosure for a Peerless XLS10 needed. Kram Multi-Way 58 20th December 2012 05:39 PM
Enclosure design help needed calem91 Subwoofers 0 22nd September 2012 03:24 AM
Peerless 830845 Enclosure Drawings Needed lancer Subwoofers 3 5th May 2006 01:09 PM
enclosure design help needed skyraider Full Range 5 20th December 2004 08:12 PM


New To Site? Need Help?

All times are GMT. The time now is 08:35 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2