Killahertz Acoustics

 

Domestic audio and acoustics – a collection of practical and accessible articles and  tools.

 

Room Treatment.

 

Practical Domestic Room Acoustics.

 

This is a practical and approachable article concerning the application of acoustical treatment in a domestic environment. Primarily concerned with 2-channel stereo reproduction, and rooms of shared domestic function, the article describes the need for, and use of, low-impact OEM and domestic-equivalent room treatment.  

 

Practical Acoustics

 

(This is a Microsoft Word document that will open in your browser window – 266kB)

 

Practical Acoustics (zip)

 

(This is a zipped version of the article available to download in zip format – 118kB)

 

An Introduction to Room Acoustics Theory.

 

A comprehensive introduction to the subject of room acoustics. Introductory but comprehensive theory complements illustrated practical DIY room treatments. From modal room response to specular reflection response and calculation. Includes a Microsoft Excel spreadsheet, which calculates axial room modes – and analyses their effect, giving a visual indicator of potential room mode problems. The spreadsheet also includes a section on room treatments formulae, allowing for easy calculation of DIY treatments.

 

Room Acoustics

 

(This is a Microsoft Word document that will open in your browser window – 138kB)

 

Mode Calc

 

(This is a Microsoft Excel spreadsheet that will open in your browser window – 129kB)

 

Room Acoustics (zip)

 

(This is a zipped version of the article and spreadsheet available to download in zip format – 96kB)

 

[PLEASE NOTE THAT THE ‘MODECALC’ EXCEL SPREADSHEETS USES MACROS – THEY ARE ESSENTIAL FOR THE CORRECT OPERATION OF THE SPREADSHEET. THEYARE GUARANTEED VIRUS-FREE AT THE TIME OF UPLOADING]

 

Helmholtz Resonant Absorber.

 

A two-page article (including illustrations and embedded test results) – hosted by Audioholics – regarding the theory, practical design, and in-room tuning of an Helmholtz Resonant absorber. An interesting (and readily replicable) DIY project regarding this demonstrably effective narrow-band bass trap. 

 

Helmholtz Resonant Absorber

 

(This is a link to the article on the Helmholtz Resonant Absorber, which is hosted on the Audioholics website)

 

Loudspeaker/Subwoofer Design.

 

The Fundamentals of Transmission Line Enclosure Design.

 

An introduction to the theory and design of Transmission Line Loudspeaker/Subwoofer enclosures. Including numerous illustrations, formulae, and guidelines borne of design experience, the article is approachable to all levels of experience, including novice designers. Yet, whilst introductory in nature, all aspects of design are covered. This not only enables reasonably complex design (without recourse to additional information or modelling software), but serves as a grounding for further study.  

 

TLdesign

 

(This is a Microsoft Word document that will open in your browser window – 340kB)

 

TLdesign (zip)

 

(This is a zipped version of the article available to download in zip format – 256kB)

 

Audio Principles.

 

Crossovers and Filters.

 

A two-part introduction to the theory and design of passive crossovers. Including numerous illustrations and formulae the article will guide the reader through the theory behind, the application, and the design of high, low, and bandpass filter designs up to a practical 2nd order (12dB/Oct).

 

Filters

 

(This is a Microsoft Word document that will open in your browser window – 113kB)

 

Filters (zip)

 

(This is a zipped version of the article available to download in zip format – 33kB)

 

Equalisation.

 

An introduction to the theory and application of graphic and parametric equalisation. Includes useful information on ISO octave spacing (10, 15, and 30 bands), and an illustrated explanation of the theory and application of filter Q. 

 

Equalisation

 

(This is a Microsoft Word document that will open in your browser window – 83kB)

 

Equalisation (zip)

 

(This is a zipped version of the article available to download in zip format – 29kB)

 

Tools and Calculators.

 

Cable Design Calculator.

 

A comprehensive Microsoft Excel spreadsheet designed initially to debunk audio cable mythology. In doing so, however, it naturally has use in cable design where parameters such as inductance, capacitance, characteristic impedance, skin effect, etc, are considerably more valid. Other calculations include resistance, cable area, volt drop, velocity of propagation, etc.

 

 **please note that the calculator is under almost constant revision with reference to accuracy and content – email any questions/points**

 

Cable LRC

 

(This is a Microsoft Excel spreadsheet that will open in your browser window – 139kB)

 

Cable LRC (zip)

 

(This is a zipped version of the spreadsheet available to download in zip format – 38kB)

 

[PLEASE NOTE THAT THE ‘CABLECALC’ EXCEL SPREADSHEETS USES MACROS – THEY ARE ESSENTIAL FOR THE CORRECT OPERATION OF THE SPREADSHEET. THEYARE GUARANTEED VIRUS-FREE AT THE TIME OF UPLOADING]

 

Links.

 

Noteworthy audio forums and sites.

 

Talk Audio …....The UK’s leading car audio forum.

 

Hifi Wigwam …..The UK’s leading home hifi forum.

 

AV Forums ……The UK’s leading home cinema forum.

 

RPG Europe …....UK-based arm of RPG, OEM acoustical product manufacturer and retailer.

 

Audioholics …....An excellent resource for objective hardware reviews and technical audio and acoustic articles.

 

Art Ludwig …….An excellent resource for audio and acoustic science articles.