---
title: "Does US Patent 1,869,178 confirm A.L. Thuras as the bass-reflex enclosure inventor, filed August 1930?"
type: "question"
status: "answered"
date_raised: "2026-07-09T00:00:00.000Z"
date_answered: "2026-07-10T00:00:00.000Z"
tags: ["acoustics","bass-reflex","thuras","bell-labs","patent","verification"]
---


[[claim-thuras-1930-patented-bass-reflex-loudspeaker-enclosure]] carries a
specific patent identifier (US 1,869,178) and a filing date (August 1930), but
those load-bearing specifics currently rest only on a Tier-3 electroacoustics
history site and Tier-4 Wikipedia — below the sourcing floor for a
quantitative claim. The primary patent was never pulled.

## What would answer it

- Pull **US Patent 1,869,178** from Google Patents or the USPTO full-text
  database and confirm: (a) the named inventor is Albert L. Thuras, (b) the
  filing/application date and grant date, and (c) that the claims describe a
  vented/ported enclosure operating as a resonator (Helmholtz-resonator
  behavior), i.e. that it is genuinely the foundational bass-reflex patent and
  not a related Thuras acoustics patent.
- Confirm the coauthorship anchor: **Wente & Thuras, "A High Efficiency
  Receiver for a Horn-Type Loud Speaker of Large Power Capacity," *Bell System
  Technical Journal* 7(1), 1928, pp. 140–153**, via the Internet Archive
  (archive.org/details/bstj7-1-140).

## Why it matters

The Thuras-invented-the-bass-reflex story is well attested in secondary
literature, so this is a floor-clearing verification, not a contested claim.
But the exact patent number and date are precisely the kind of specific that
journalism and history sites garble, and the primary is freely reachable.
Resolving it moves the note off its `flagged` audit status toward
`verified-verbatim`.

## Resolution (2026-07-10, cross-model audit, fable)

Both checks pass, from the primaries.

- **The patent.** Google Patents US1869178A: title "Sound Translating
  Device"; (a) inventor **Albert L. Thuras**, assignee Bell Telephone
  Laboratories; (b) application **August 15, 1930**, patented **July 26,
  1932**; (c) the description covers venting the diaphragm's rear chamber to
  the front through an acoustic passage so low-frequency rear radiation
  reinforces the front output ("This invention relates to sound translating
  devices and more particularly to a method and means for increasing the
  response of such devices at the lower frequencies") — genuinely the
  foundational vented/bass-reflex enclosure patent, not a related Thuras
  acoustics patent.
- **The coauthorship anchor.** archive.org/details/bstj7-1-140 confirms
  Wente & Thuras, "A High Efficiency Receiver for a Horn-Type Loud Speaker of
  Large Power Capacity," *Bell System Technical Journal* 7(1), January 1928,
  pp. 140–153.

The claim-note's `[unverified-quant]` flag is resolved in place, a
`primary_source_url` (Tier 1) added, and its `audit_status` carries the dated
entry; the original flagged wording stays as history.