{"uid":"cap_xdDJ62dVt3cCkOVoQ0q1V","slug":"audio-calc-spl-distance-af7c590f","name":"Audio Calc SPL Distance","description":"Sound level at another distance (inverse-square law; line sources fall 3 dB per doubling), or the distance for a level.","url":"https://audio-calc.x402tookit.com/spl-distance?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["level"],"properties":{"level":{"type":"number","description":"Sound pressure level in dB measured at refDistance"},"source":{"enum":["point","line"],"type":"string","description":"point (default, 6 dB per doubling) or line (3 dB per doubling)"},"distance":{"type":"number","description":"Distance in metres to find the level at (use this, or targetDb)"},"targetDb":{"type":"number","description":"A level in dB to find the distance for"},"refDistance":{"type":"number","description":"Distance of the measurement in metres (default 1)"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","properties":{"asOf":{"type":["null","string"]},"source":{"type":["null","string"]},"levelDb":{"type":["null","number"]},"reasons":{"type":["array","null"],"items":{"type":"string"}},"summary":{"type":["null","string"]},"verdict":{"type":["null","string"]},"changeDb":{"type":["null","number"]},"degraded":{"type":["boolean","null"]},"distanceM":{"type":["null","number"]},"spreading":{"type":["null","string"]},"disclaimer":{"type":["null","string"]},"notChecked":{"type":["array","null"],"items":{"type":"string"}},"pressurePa":{"type":["null","number"]},"dbPerDoubling":{"type":["null","number"]},"intensityWPerM2":{"type":["null","number"]},"levelAtReferenceDb":{"type":["null","number"]},"referenceDistanceM":{"type":["null","number"]},"soundPowerLevelPointSourceDb":{"type":["null","number"]}}}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.02","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.02/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_ZE5YOFYtdj7KZyrCTx8rn","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.02","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Calculates sound pressure level at a new distance or finds the distance for a target dB level using the inverse-square law (6 dB per doubling for point sources, 3 dB per doubling for line sources).","exampleAgentPrompt":"If a speaker measures 94 dB at 1 metre, what will the SPL be at 25 metres away, assuming it's a point source?","exampleUseCases":[{"title":"Venue PA speaker coverage planning","prompt":"My PA speaker puts out 100 dB at 1 metre. What will the sound level be at 30 metres and 60 metres for a point source? I need to know if the back of the venue will be loud enough."},{"title":"Road traffic noise at property boundary","prompt":"There's a busy road that produces 75 dB at 5 metres from the carriageway. Treating it as a line source, what SPL should I expect at a house 40 metres away?"},{"title":"Finding safe distance from loud machinery","prompt":"An industrial machine emits 110 dB at 1 metre. How far away does a worker need to stand for the level to drop to 85 dB? Assume it's a point source."}],"resultDescription":"Returns the computed SPL in dB at the requested distance (or the distance for a target dB), along with the change in dB from the reference level, pressure in Pascals, intensity in W/m², dB per doubling, spreading type (point or line), sound power level for point sources, reference distance, and a plain-language summary.","failureModes":["Missing required 'level' query parameter returns an error","Neither 'distance' nor 'targetDb' provided — endpoint needs at least one of these to compute a result","Negative or zero distance values may produce invalid or undefined results","Extremely large distances may yield physically implausible results below noise floor without warning"],"whenToPreferThis":"Use this endpoint when you need to apply the inverse-square law (or cylindrical spreading for line sources) to predict how sound level changes with distance, or to find the distance at which a source reaches a target dB level. It is the right choice for acoustic planning, noise impact assessments, PA system design, or safety distance calculations. Prefer this over manual calculation when you need physical output quantities like pressure in Pascals or intensity in W/m² alongside the dB result.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-30T00:35:23.478Z","isFirstParty":false,"canonicalSlug":"audio-calc-spl-distance-af7c590f"}