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                                                                   EXHIBIT 10.20

                              AMENDMENT TO WARRANT

Reference is made to that certain Warrant, issued as of October 24, 1997 by
Digital Theater Systems, Inc. ("DTS") to Comerica Bank-California, a California
banking corporation, successor-by-merger to Imperial Bank ("Comerica"), granting
Comerica the right to purchase up to 40,000 shares of the Common Stock of DTS
(the "Warrant").

For good and valuable consideration, the receipt and sufficiency of which is
hereby acknowledged, DTS and Comerica hereby agree as follows:,

1.       The definition of "Excluded Securities" contained in the Warrant shall
be amended and restated to read in its entirety as follows:

         "Excluded Securities" means (i) the Company's warrants to purchase an
aggregate of 608,238 shares of Common Stock at $.53 per share issuable to
Universal City Studios, Inc. and Forth Investments, LLC (collectively "Universal
and Spielberg Warrants"), (ii) warrants to purchase an aggregate of 59,435
shares of the Company's Preferred Stock issued to Hambrecht & Quist, LLC (the
"H&Q Warrant"), exercisable at $2.019 per share, (iii) warrants to purchase an
aggregate of 4,253,327 shares of Common Stock at $6.057 per share issued to
certain of the Company's Common Stock holders (the "Offering Warrants"), (iv)
options to purchase an aggregate of up to 4,142,102 shares of Common Stock
issued or issuable under stock option plans approved by the Company's Board of
Directors from time to time (the "Incentive Stock Options"), (v) an aggregate of
5,943,536 shares of Series A Preferred Stock issued at $2.019 per share (the
"Series A Preferred Stock"), (vi) warrants to purchase an aggregate of up to
5,943,536 shares of Common Stock (the "Purchaser Warrants") exercisable at $.01
per share, issued in connection with the sale of the Series A Preferred Stock,
(vii) an aggregate of 1,857,355 shares of the Company's Series B Redeemable
Preferred Stock (the "Series B Preferred Stock") issued at $2.019 per share,
(viii) warrants to purchase an aggregate of up to 3,714,710 shares of Common
Stock ultimately issued in connection with the sale of the Series B Preferred
Stock (the "Series B Warrants"), exercisable at $.01 per share, (ix) warrants to
purchase up to 65,728 shares of Common Stock at an exercise price of $.01 per
share issued pursuant to a settlement agreement between the Company and one of
its stockholders, and any shares of Common Stock issuable upon exercise thereof,
(x) any shares of Common Stock issued upon exercise of the Universal and
Spielberg Warrants, the H&Q Warrant, the Offering Warrants, the Series B
Warrants, the Incentive Stock Options or the Purchaser Warrants and (xi) any
shares of Common Stock issued upon conversion of the Offered Series A Preferred
Stock or the Series B Preferred Stock."

2.       No adjustment to the exercise price of the Warrant or the number of
shares issuable under the Warrant shall be made as a result of the provisions
contained in subsections 6(b), 6(c) or 6(e) of the Warrant with respect to any
event that takes place following the earlier of the date upon which the Company
shall (i) merge, consolidate or effect a share exchange with another entity, or
shall sell, transfer or otherwise dispose of all or substantially all of its
assets or (ii) complete an initial public offering of shares of its Common
Stock.

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3.       The parties acknowledge and agree that effective as of the date of this
amendment, the Warrant is exercisable for a total of 40,000 shares of Common
Stock at an exercise price equal to $2.019 per share.

         Except as amended hereby, the Warrant shall remain in full force and
effect.

         This Amendment to Warrant is made as of this 13 day of March, 2003, by
and between Digital Theater Systems, Inc. and Comerica Bank - California,
successor-by-merger to Imperial Bank.

                                    DIGITAL THEATER SYSTEMS, INC.

                                    By: /s/ Jon Kirchner
                                        ---------------------------------------
                                        Jon Kirchner
                                        President & Chief Executive Officer

                                    COMERICA BANK - CALIFORNIA,
                                    Successor-by-merger to Imperial Bank

                                    By: /s/ Judy Tu
                                        ---------------------------------------
                                        Judy Y. Tu
                                        Vice President