Image-Source Method Reference
Return the geometric construction and limitations of the room-acoustic image-source method.
Description
The image-source method mirrors a source across room boundaries so specular reflection paths can be represented as straight paths to virtual sources.
The image-source method mirrors a source across room boundaries so specular reflection paths can be represented as straight paths to virtual sources. This reference explains the selected concept and the evidence needed to interpret it.1
The returned values include Source, Statement, Topic. The How section below explains the calculation, input rules and interpretation.
When to use Image-Source Method Reference
Use Image-Source Method Reference when you need to evaluate the supplied records under the calculation and evidence rules below. The basic method assumes specular reflection and geometric acoustics; diffraction, scattering, and wave effects require additional models. This is an introductory excerpt, not the complete standard, a current compliance check or a project-specific calculation.
Choose the measured quantities, units, weighting and measurement basis before entering values. For a reference, select the exact topic. For a catalog lookup, prepare complete source-backed records; for a screen, select an applicable caller limit.
How to use Image-Source Method Reference and understand its results
- Choose the measured quantities, units, weighting and measurement basis before entering values. For a reference, select the exact topic. For a catalog lookup, prepare complete source-backed records; for a screen, select an applicable caller limit.
- Enter topic using the field table and calculation rules, then run the tool.
- Read source, statement, topic. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| topic | Reference topic to return. | string; one of "construction", "order", "caution" | Required |
Choose one of the exact topic values in the table. The tool indexes a fixed, locally embedded reference entry and returns its source label, statement and unchanged topic. It does not fetch the source or update the wording. Topic meanings and all returned entries are shown below.
| Selection | Returned reference entry |
|---|---|
| construction | source: Allen and Berkley, JASA, 1979; statement: The image-source method mirrors a source across room boundaries so specular reflection paths can be represented as straight paths to virtual sources.; topic: construction |
| order | source: Geometric room-acoustics literature; statement: Higher reflection order increases the number of image sources; pruning and time or energy limits control computation.; topic: order |
| caution | source: Geometric room-acoustics literature; statement: The basic method assumes specular reflection and geometric acoustics; diffraction, scattering, and wave effects require additional models.; topic: caution |
selected exact topic → embedded source label, explanatory statement and topic Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| source | Source used for the reference statement. | string |
| statement | Narrow reference statement for the selected topic. | string |
| topic | Selected reference topic. | string; one of "construction", "order", "caution" |
{
"input": {
"topic": "construction"
},
"output": {
"source": "Allen and Berkley, JASA, 1979",
"statement": "The image-source method mirrors a source across room boundaries so specular reflection paths can be represented as straight paths to virtual sources.",
"topic": "construction"
}
}Limitations and assumptions
The basic method assumes specular reflection and geometric acoustics; diffraction, scattering, and wave effects require additional models. This is an introductory excerpt, not the complete standard, a current compliance check or a project-specific calculation.
Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Extremely large text inputs are rejected. Missing fields without a declared default, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Flutter Echo Frequency: Parallel reflecting surfaces can produce a repeated round-trip reflection pattern. An ideal travel-time estimate gives its repetition interval and corresponding frequency. For a complementary task, use FEM and BEM Domain Reference: FEM discretizes the modeled volume and is well suited to bounded domains, heterogeneous media, and coupled structural-acoustic models. This reference explains the selected concept and the evidence needed to interpret it.
References
-
Image-Source Method Reference — tool.io
Similar or alternative tools
- Flutter Echo Frequency
Parallel reflecting surfaces can produce a repeated round-trip reflection pattern. An ideal travel-time estimate gives its repetition interval and corresponding frequency.
- FEM and BEM Domain Reference
FEM discretizes the modeled volume and is well suited to bounded domains, heterogeneous media, and coupled structural-acoustic models. This reference explains the selected concept and the evidence needed to interpret it.