The problem has been finding a wall material or materials that allow curved loudspeaker enclosures to be manufactured at mass production levels that has equivalent or better characteristics than wood loudspeaker enclosures.

CHARACTERISTICS

Characteristics can be reduced to two simple concepts:

Look 

Sound Handling 

Product Look... a curved loudspeaker enclosure needs to satisfy the consumer expectations regarding the visual quality of the exterior of the loudspeaker enclosure, no matter if the consumer is in a professional environment such as a recording studio, or, if the consumer is a private individual using the product in their home.  Curved Loudspeaker Enclosures must have an acceptable "look" for it's market compared to standard box's made of wood.

Sound Handling... a curved loudspeaker enclosure needs to match the ability of a wood loudspeaker enclosure to capture and absorb interior sound waves.  Wood enclosure thicknesses vary based on driver sound output and driver designation-- Midbass, subwoofer, tweeter, etc.  Curved loudspeaker enclosures need to match or exceed the sound handling characteristics of wood loudspeaker enclosures for the same application.  For example, if the specification of a loudspeaker requires a 1/2" MDF loudspeaker enclosure wall, then a curved loudspeaker enclosure must also have the characteristics of the density and sound handling characteristics of a 1/2" MDF* enclosure wall to meet this curved loudspeaker enclosure industry specification 

* MDF  Medium Density Fiberboard

REPORTING REQUIREMENTS for this proposed Industry Standard:

The curved loudspeaker enclosure industry needs to report in all their literature, websites, and in all communications with actual and potential clients their enclosure wall in comparison to an equivalent MDF material as a percentage.  Example... "our wall is equivalent to 3/8" mdf".  MDF density per cubic foot or cubic meter is available at multiple sites across the internet, as well as in a number of Engineering handbooks.  Measurements can also be performed using a live piece of MDF in-house.

ALLOWANCES:

If a company manufacturing curved loudspeaker enclosures desires, they can offer two measurements compared to MDF...

(1) with the raw enclosure wall and also
(2) the actual wall after sound absorbent treatments are applied.  If not broken-out, the consumer will assume the figure is after any sound treatments are applied.  

THE SITUATION THAT REQUIRES AA STANDARD:   

A number of curved loudspeakers are currently on the market using extremely thin, concurrently extremely low density enclosure walls that could only be rated against the thinnest possible wood loudspeaker enclosure.  Their products are substandard compared to required MDF wall thicknesses from the manufacturers of the drivers they use and can only hurt the potential for curved loudspeaker enclosures as being accepted as a loudspeaker industry standard.  By requiring all curved loudspeaker enclosure manufacturer's to compare their enclosure walls to MDF will give consumers, both OEM and End-Users, the ability to have a quantitative  measure compared to standard wood boxes.  

REPORTING:

Every manufacturer of curved loudspeaker enclosures must  include this data on all their promotional material including their website and must disclosure it to all potential 3rd-party OEM's as part of their proposal.  Not disclosing this information shall be construed by consumers and business partners that the curved loudspeaker enclosure manufacturer has an enclosure wall that is deficient in construction, no matter what the claims and should be avoided.  Use the following disclosure as an example:

US Enclosure Disclosure:  We have made hundreds of curved loudspeaker enclosures.  All have had a wall thickness equivalent of 1/2" MDF.  A majority have had a wall thickness equivalent of 1" MDF.  We have the ability to produce loudspeaker enclosures with the equivalent of  ~> MDF... unlimited wall thickness.  We also have a proprietary stuffing material that further increases the apparent wall thickness... called SuperStuffing and have used it is many of our loudspeaker enclosures.  We also have a technique for wall dampening called MultiModulus which further adds to the absorption factor of an equivalent thickness of mdf.

SuperStuffing and MultiModulus are both trademarks and protected as a material and a technique using the material for the application in question.

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DISCLOSING DISTORTION FROM LOUDSPEAKER CABINETS

US Enclosure Company is a proponent of all OEM Loudspeaker Manufacturers disclosing the distortion specifications for their loudspeaker cabinets. When measured, loudspeaker cabinets generally have extremely high sound distortion figures.  Unlike electronics with distortion measured in thousands of a percent, standard cabinets measure in the high single digits.  Loudspeaker cabinets color the entire mix.

For comparative purposes, loudspeaker OEM's should provide these specifications to the consumer.  Curved loudspeaker enclosures work to improve the measured specifications.  So does excellent engineered cabinet wall materials.  Combined, the ultimate loudspeaker enclosure is available.

Electronics have very low THD in thousands-of-a-percent, but loudspeaker cabinets have distortion in the high single digits.  Loudspeaker Cabinets COLOR the sound.  Curved cabinets work to improve the distortion levels.  COMBINED... with High Quality Walls, the Ultimate Loudspeaker Enclosure CAN BE Available.

UPDATED 3/27/99