Ported Loudspeaker Enclosure Modeller

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Documentation

See the accompanying note for a discussion of the differential equations and the numerical method used here.

Driver Data: Fundamental and Thiele-Small parameters

Primary parameters

portedboxresponseX2a_2.gif

Secondary parameters

portedboxresponseX2a_3.gif

Derived parameters, reported for convenience and checking data consistency

Note: Due to rounding errors most of these computed parameters will differ slightly from actual values.

portedboxresponseX2a_4.gif

Tips

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Clicking on the + icon at the end of each slider reveals an input field for that parameter.

Enclosure Data

Primary parameters

portedboxresponseX2a_5.gif

Derived, reported for convenience

portedboxresponseX2a_6.gif

Automatic Optimization

Estimate best box

This computes values of VboxVas and ƒbƒas that result in either a third-order quasi-Butterworth alignment, a fourth-order Butterworth alignment, or a fourth-order Chebyshev alignment. Lport is adjusted to achieve the resulting ƒb, leaving the already specified Ap unchanged. So it may be necessary to change the setting of Ap in order to get a feasible value of Lport. For a discussion of the method, see the accompanying note.

Minimize portedboxresponseX2a_17.gif

Adjusts Lport to minimize ƒ3.

Sources

[1]  A. N. Thiele, “Loudspeakers in Vented Boxes,” Proceedings of the IRE Australia, 22, August 1961 pp. 487–508. Republished in J. Audio Eng. Soc., 19(5&6), 1971 pp. 382-392 & 471-483.

[2]  R. H. Small, “Vented-Box Loudspeaker Systems,” J. Audio Eng. Soc., 21, June 1973, pp. 363–372; July/August 1973 pp. 438–444; September 1973 pp. 549–554; October 1973 pp. 635–639.

[3]  W. Marshall Leach, Jr., Introduction to Electroacoustics and Audio Amplifier Design, 4th ed., Dubuque IA: Kendall Hunt, 2010.

 

Examples

Driver data are from Parts Express. (I cannot vouch for their accuracy.)

Dayton Audio RSS210HO-4 8" Reference HO Subwoofer      portedboxresponseX2a_25.gif

portedboxresponseX2a_26.png

Peerless 830452 10" XLS Subwoofer     portedboxresponseX2a_29.gif

portedboxresponseX2a_30.png

 

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