What is the best enclosure for sub woofer speakers?

Question

What is the best enclosure for sub woofer speakers?

Answer 1

If you know the speaker characteristics, you could calculate the box volume, and port dimensions. It requires a great deal of knowledge to do this (if you want a good sounding sub-woofer). Do you really want to try to do this yourself when you could buy one for just a few dollars?

Answer 2

I would have to say a ported box. Even with a low wattage subwoofer and amplifier, you can still feel the bass coming out.

Answer 3

In general there is no single, universal “best enclosure” type for subwoofer systems. You will find excellent results amongst a wide variety of subwoofer designs. If you would like (or intend) to build your own subwoofers then you may be interested in the following information.



Low-frequency moving-coil loudspeaker drivers (aka transducers) are characterized by their Thiele-Small Parameters. It is these parameters that will largely determine which enclosure type is best suited for a given driver model.



Richard H. Small derived a simple ‘rule-of-thumb’ equation known as the Efficiency Bandwidth Product (EBP), which may be used to quickly determine the best match of any given low-frequency loudspeaker unit to the appropriate enclosure type.



              Driver Free Air Resonance Frequency

   EBP = —————————————————

              Driver Electrical Q Factor



              Fs

   EBP = ——–

              Qes



An EBP of approximately 50 or less indicates a closed-box enclosure would be more suitable, while an EBP of approximately 100 or higher suggests a vented-box enclosure would be more suitable. (An EBP between 50 and 100 will require additional driver criteria to be considered in order to choose the most appropriate loudspeaker enclosure type.)



In addition, low frequency drivers designed for use in closed-box systems are typically characterized by a low free-air resonance (Fs) and high-compliance suspension (Cms), a relatively high total moving mass (Mms), a high total Q factor (Qts), and a long—often overhung—voice coil. Low frequency drivers designed for use in vented-box systems are typically characterized by a higher free-air resonance (Fs) and lower-compliance, i.e., stiffer, suspension (Cms), a relatively low total moving mass (Mms) and a low total Q factor (Qts).



Generally speaking, low frequency drivers with a total Q factor (or Qts) of approximately 0.35 or higher are best suited for closed-box loudspeaker designs and drivers with a Qts below approximately 0.35 will often be best suited for a vented-box loudspeaker design. Unfortunately one cannot always rely upon the loudspeaker driver manufacturer for accurate Thiele-Small parameters for their drivers.



Whenever possible, for the best results you should carefully break-in low-frequency drivers and then perform your own measurements to obtain accurate Thiele-Small parameters. The alternative is to take your chances by trusting the manufacturer’s specifications. That said a closed-box enclosure design will accommodate a greater margin of error when it comes to the accuracy of a loudspeaker driver’s Thiele-Small parameters. Likewise, a closed-box enclosure design of sufficient size will be the best option if the Thiele-Small parameters are unknown and you lack the tools or equipment to measure them.



Personally, I favor active equalization, aka assisted, subwoofer enclosure designs over conventional passive designs. I also prefer bandpass subwoofer enclosures in general due to the design’s inherently better balance of acoustical impedance on the driver(s) as well as the ability to acoustically control the passband gain, during the enclosure design phase, of the subwoofer system.



######## RESOURCES ########



Wiki: Thiele/Small

http://en.wikipedia.org/wiki/Thiele/Smal...



Discussion: Qts = closed or vented?

http://www.diyaudio.com/forums/showthrea...



Ported/Vented Box Design Calculator and Formulas

http://www.ajdesigner.com/phpsubwooferve...

Closed/Sealed Box Design Calculator and Formulas

http://www.ajdesigner.com/phpsubwoofercl...

AJ Audio Subwoofer Box Enclosure Design Software

http://www.ajdesigner.com/speaker/index....



Loudspeaker Design Cookbook

by Vance Dickason

http://www.audioxpress.com/bksprods/prod...



Siegfried Linkwitz - Publications

http://www.linkwitzlab.com/publications....



Klippel GmbH Know-How

http://www.klippel.de/background/default...

________________________



WinISD Pro (freeware)

http://www.linearteam.dk/default.aspx?pa...



mhSoft Online HiFi Speaker Design Tools

http://www.mhsoft.nl/spk_calc.asp



Free Audio Software and On-Line Enclosure Design

http://www.audiogrid.com/audio/



LspCAD Software

http://www.ijdata.com

(A free demo download is available)

LspCAD U.S. Distributor

http://www.audioxpress.com/bksprods/SOFD...

Drawings of popular loudspeaker enclosure designs

modeled by LspCAD software:

http://www.libinst.com/LspCAD.htm



BoxCAD and SoundEasy Software

http://www.interdomain.net.au/~bodzio/

I recommend downloading and reading the

BoxCAD V4.00 Manual.



SPEAK Loudspeaker Modeling Software

http://www.gedlee.com/speak.htm

The only loudspeaker design software to include

Acoustic Lever™ design simulation

________________________



United States Patent 6,223,853

Loudspeaker system incorporating acoustic waveguide filters and method of construction

http://patft1.uspto.gov/netacgi/nph-Pars...

- or -

http://www.pat2pdf.org/patents/pat622385...



“New Low-Frequency Enclosure Configuration”

Huon, Graeme; Cambrell, Greg

AES Preprint Number: 4038; Convention: 5r (March 1995)

http://www.aes.org/e-lib/browse.cfm?elib...



Whise Acoustics Ltd / Whise Technologies Pty Ltd

Reviews of PAM Technology (esp. Profunder 624 Subwoofers)

http://www.whise.com.au/reviews.htm



“Subwoofer Performance for Accurate Reproduction of Music”

Fielder, Louis D; Benjamin, Eric M

J. Audio Eng. Soc., Volume 36 Number 6 pp. 443-456; June 1988

http://www.aes.org/e-lib/browse.cfm?elib...

AES Preprint Number 2537

http://www.aes.org/e-lib/browse.cfm?elib...

 

Answer 4

Is this for your car or home? If for the home just buy a sub complete. Goto Parts Express and get a titanic sub you have to put together. You can purchase boxes put together also.