SCHEDULE 13D/A 0001755804 XXXXXXXX LIVE 3 Common Stock 09/07/2025 false 0001682149 86633R609 Datavault AI Inc.

15268 NW Greenbrier Pkwy Beaverton OR 97006

Nathaniel Bradley 520-631-9595 48 Wall Street, Floor 11 New York NY 10005 0001755804 N Nathaniel Bradley OO N X1 0.00 19700790.00 0.00 19700790.00 19700790.00 N 16.9 IN Mr. Bradley is Chief Executive Officer and sole director of EOS Technology Holdings Inc. (formerly known as Data Vault Holdings Inc.) and the spouse of Sonia Choi. The shares beneficially owned by Mr. Bradley consist of 4,235,970 shares held directly by Mr. Bradley, 12,289,002 shares held directly by EOS Technology Holdings Inc., and 3,175,818 shares held directly by Ms. Choi. 0001918125 N Sonia Choi OO N X1 0.00 7411788.00 0.00 7411788.00 7411788.00 N 6.4 IN Ms. Choi is the spouse of Mr. Bradley. The shares beneficially owned by Ms. Choi consist of 3,175,818 shares held directly by Ms. Choi and 4,235,970 shares held directly by Mr. Bradley. 0001882356 N EOS Technology Holdings Inc. OO N DE 0.00 12289002.00 0.00 12289002.00 12289002.00 N 10.5 CO These shares are held directly by EOS Technology Holdings Inc. Common Stock Datavault AI Inc. 15268 NW Greenbrier Pkwy Beaverton OR 97006 This Amendment No. 3 to Schedule 13D (this "Amendment No. 3") relating to the shares of common stock, par value $0.0001 per share ("Common Stock"), of Datavault AI Inc., a Delaware corporation (the "Issuer"), amends and supplements the Schedule 13D originally filed by the Reporting Persons with the Securities and Exchange Commission (the "SEC") on January 13, 2025, as amended by the Amendment No. 1 to Schedule 13D, filed by the Reporting Persons with the SEC on June 27, 2025, and the Amendment No. 2 to Schedule 13D, filed by the Reporting Persons with the SEC on August 12, 2025 (the "Schedule 13D"). Except as specifically amended below, all other provisions of the Schedule 13D remain in effect. Capitalized terms used herein but not defined herein have the respective meanings ascribed to them in the Schedule 13D. The information set forth in Item 2(a) of the Schedule 13D is incorporated herein by reference. The information set forth in Item 2(c) of the Schedule 13D is incorporated herein by reference. The information set forth in Item 3 of the Schedule 13D is incorporated herein by reference Item 4 of the Schedule 13D is amended to add the following: 110,909 shares of Common Stock of the Issuer were transferred by EOS Technology Holdings Inc. ("EOS") to a third party in connection with a consulting agreement, dated as of August 19, 2025 (the "Consulting Agreement"), by and between EOS and the consultant under the Consulting Agreement. 10,000,000 shares of Common Stock of the Issuer were issued to EOS pursuant to an amendment and conversion agreement, dated as of September 7, 2025 (the "EOS Note Amendment") between EOS and the Issuer, to the Convertible Promissory Note (the "EOS Note") issued to EOS on December 31, 2024 in the original principal amount of $10,000,000. Pursuant to the EOS Note Amendment, EOS converted (the "EOS Note Conversion") $3,200,000 of the balance of the EOS Note into 10,000,000 shares of Common Stock, at a conversion price of $0.32 per share, and the floor price set forth in the EOS Note was waived and did not apply to the EOS Note Conversion. To the extent required, the disclosure in Item 3 of this Amendment No. 3 is incorporated by reference in this Item 4. Item 5(a) of the Schedule 13D is amended and restated as follows: The percentage ownership of shares of Common Stock set forth in this Amendment No. 3 is based upon 116,701,378 shares outstanding as of September 9, 2025. Item 5(b) of the Schedule 13D is amended and restated as follows: As of the date of this Amendment No. 3, Mr. Bradley beneficially owned 19,700,790 shares, consisting of 4,235,970 shares held directly by Mr. Bradley, 12,289,002 shares held directly by EOS Technology Holdings Inc., and 3,175,818 shares held directly by Ms. Choi. As of the date of this Amendment No. 3, Ms. Choi beneficially owned 7,411,788 shares, consisting of 3,175,818 shares held directly by Ms. Choi and 4,235,970 shares held directly by Mr. Bradley. As of the date of this Amendment No. 3, EOS beneficially owned 12,289,002 shares, held directly by EOS. Except as set forth in Item 4 of the Schedule 13D, the Reporting Persons have not engaged in any transaction with respect to the Common Stock during the sixty days prior to the date of filing this Amendment No. 3. The information set forth in Item 2(a) of the Schedule 13D is incorporated herein by reference. Item 7 of the Schedule 13D is amended to add the following: 99.10 Convertible Promissory Note Amendment and Conversion Agreement by and between the Company and EOS, dated as of September 7, 2025. https://www.sec.gov/Archives/edgar/data/1682149/000110465925088049/tm2525483d1_ex4-1.htm Nathaniel Bradley /s/ Nathaniel Bradley 09/09/2025 Sonia Choi /s/ Sonia Choi 09/09/2025 EOS Technology Holdings Inc. /s/ Nathaniel Bradley 09/09/2025