<PAGE>   1

            As filed with the Securities and Exchange Commission on July 5, 2001

================================================================================

                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

                                   ----------

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                               SIONIX CORPORATION
             (Exact name of registrant as specified in its charter)

            UTAH                                         87-0428526
(State or other jurisdiction of             (I.R.S. Employer Identification No.)
incorporation or organization)

                               9272 JERONIMO ROAD
                                IRVINE, CA 92618
               (Address of Principal Executive Office) (Zip Code)

        AGREEMENT, DATED MAY 25, 2001, WITH INVESTORS ADVOCATE, LTD., LLC
                            (Full title of the plan)

                                 JAMES J. HOUTZ
                               9272 JERONIMO ROAD
                                IRVINE, CA 92618
                     (Name and address of agent for service)

                                 (949) 454-9283
          (Telephone number, including area code, of agent for service)

                                    COPY TO:
                             ROBERT J. ZEPFEL, ESQ.
                               HADDAN & ZEPFEL LLP
                         4685 MACARTHUR COURT, SUITE 220
                             NEWPORT BEACH, CA 92660
                                 (949) 752-6100


                         CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
==================================================================================================================
Title of Securities     Amount to          Proposed Maximum              Proposed Maximum            Amount of
 to Be Registered     Be Registered   Offering Price Per Share(1)   Aggregate Offering Price(1)   Registration Fee
-------------------   -------------   ---------------------------   ---------------------------   ----------------
<S>                   <C>             <C>                           <C>                           <C>

Common Stock,
without par value      1,000,000                $ .34                         $340,000                 $85.00
------------------------------------------------------------------------------------------------------------------
</TABLE>
(1) Estimated solely for the purpose of calculating the amount of the
registration fee pursuant to Rule 457, based on the closing price of the Common
Stock, as reported by the OTC Bulletin Board, on June 29, 2001.
--------------------------------------------------------------------------------


================================================================================

<PAGE>   2

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE.

        The following documents filed with the Securities and Exchange
Commission (the "Commission") pursuant to the Securities Exchange Act of 1934,
as amended (the "Exchange Act") by Sionix Corporation (the "Company") are hereby
incorporated by reference in this Registration Statement except as superseded or
modified herein: (i) the Annual Report on Form 10-K for the year ended September
30, 2000, (ii) the Quarterly Report on Form 10-QSB for the quarter ended
December 31, 2000, and (iii) the Quarterly Report on Form 10-QSB for the quarter
ended March 31, 2001, and any amendments to any such reports. All documents
filed by the Company with the Commission pursuant to Sections 13(a), 13(c), 14
or 15(d) of the Exchange Act after the date of this Registration Statement and
prior to the time a post- effective amendment which indicates that the
securities offered hereby have been sold or which deregisters all securities
then remaining unsold, shall be deemed to be incorporated by reference into this
Registration Statement and to be a part hereof from the date of filing of such
documents. Any statement contained in any document incorporated or deemed to be
incorporated by reference herein shall be deemed to be modified or superseded
for purposes of this Registration Statement to the extent that a statement
contained herein or in any other subsequently filed document which also is or is
deemed to be incorporated by reference herein modifies or supersedes such
statement. Any such statement so modified or superseded shall not be deemed,
except as modified or superseded, to constitute a part of this Registration
Statement.

ITEM 4. DESCRIPTION OF SECURITIES

        Not applicable

ITEM 5. INTERESTS OF NAMED EXPERTS AND COUNSEL

        Not applicable.

ITEM 6. INDEMNIFICATION OF DIRECTORS AND OFFICERS.

        Under Section 16-10a-903 of the Utah Revised Business Corporation Act
(the "URBCA"), and the Company's Articles of Incorporation, the Company is
required to indemnify a director or officer who is successful, on the merits or
otherwise, in the defense of any proceeding, or in the defense of any claim,
issue, or matter in the proceeding, to which he was a party because he is or was
a director of the corporation, against reasonable expenses incurred by him in
connection with the proceeding or claim with respect to which he has been
successful. Pursuant to Section 16-10a-902 and subject to Section 16- 10a-906,
the Company may indemnify a director for reasonable expenses incurred in a
proceeding. The Company's Articles of Incorporation contain certain provisions
permitted under the Utah Revised Business Corporation Act, relating to the
liability of directors. These provisions eliminate the liability of a director
to the Company or to its shareholders for monetary damages for any action taken
or any failure to take any action, as a director, except liability for: (a) the
amount of a financial benefit received by a director to which he or she is not
entitled; (b) an intentional infliction of harm on the Company or the
shareholders; (c) a violation of Section 16-10a-842 (regarding unlawful
distributions); or (d) an intentional violation of criminal law. These
provisions do not limit or eliminate the rights of the


                                        2

<PAGE>   3

Company or any shareholder to seek non-monetary relief, such as an injunction or
rescission, in the event of a breach of a director's fiduciary duty. These
provisions do not alter a director's liability under federal securities laws.
The Company's By-laws also contains certain provisions permitted under the URBCA
relating to indemnification of directors and officers of the Company. In
general, these provisions permit the indemnification of directors and officers
in certain circumstances if the person seeking indemnification acted in good
faith and in a manner which he or she reasonably believed to be in or not
opposed to the best interests of the Company, and with respect to any criminal
action or proceeding, had not reasonable cause to believe his or her conduct was
unlawful. The provisions also provide for the reimbursement and/or advancement
of expenses to directors and officers under certain circumstances, which
provisions are consistent with the URBCA. Insofar as indemnification for
liabilities arising under the Securities Act of 1933 may be permitted to
directors, officers or persons controlling the company pursuant to the foregoing
provisions, the Company has been informed that in the opinion of the securities
and exchange commission such indemnification is against public policy as
expressed in the act and is therefore unenforceable.

ITEM 7. EXEMPTION FROM REGISTRATION CLAIMED.

        Not applicable

ITEM 8. EXHIBITS.

        5.1     Opinion of Haddan & Zepfel LLP

        23.1    Consent of Cacciamatta Accountancy Corporation

        23.2    Consent of HJ & Associates

        24.2    Consent of Haddan & Zepfel LLP (included in Exhibit 5.1)


ITEM 9. UNDERTAKINGS.

        The undersigned registrant hereby undertakes:

        (a)(1) To file, during any period in which offers or sales are being
made, a post-effective amendment to this registration statement:

               (i) To include any prospectus required by Section 10(a)(3) of the
Securities Act of 1933 (the "Securities Act");

               (ii) To reflect in the prospectus any facts or events arising
after the effective date of the registration statement (or the most recent
post-effective amendment thereof) which, individually or in the aggregate,
represents a fundamental change in the information set forth in the registration
statement;

               (iii) To include any material information with respect to the
plan of distribution not previously disclosed in the registration statement or
any material change to such information in the registration statement.


                                        3

<PAGE>   4

                Provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do
not apply if the information required to be included in a post-effective
amendment by those paragraphs is contained in periodic reports filed by the
registrant pursuant to Section 13 or Section 15(d) of the Exchange Act that are
incorporated by reference in the registration statement.

            (2) That, for the purpose of determining any liability under the
Securities Act, each such post- effective amendment shall be deemed to be a new
registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

            (3) To remove from registration by means of a post-effective
amendment any of the securities being registered which remain unsold at the
termination of the offering.

        (b) The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act, each filing of the
registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Exchange Act (and, where applicable, each filing of an employee benefit plan's
annual report pursuant to Section 15(d) of the Exchange Act) that is
incorporated by reference in the registration statement shall be deemed to be a
new registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

        (h) Insofar as indemnification for liabilities arising under the
Securities Act may be permitted to directors, officers and controlling persons
of the registrant pursuant to the foregoing provisions, or otherwise, the
registrant has been advised that in the opinion of the Securities and Exchange
Commission such indemnification is against pubic policy as expressed in the Act
and is, therefore, unenforceable. In the event that a claim for indemnification
against such liabilities (other than the payment by the registrant of expenses
incurred or paid by a director, officer or controlling person of the registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Securities Act and will be governed by the final
adjudication of such issue.


                                        4

<PAGE>   5

                                   SIGNATURES

        Pursuant to the requirements of the Securities Act of 1933, the
registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Irvine, State of California, on July 5, 2001.


                                                       Sionix Corporation


                                                       By: /s/ James J. Houtz
                                                           ---------------------
                                                               James J. Houtz,
                                                               President

        Each person whose signature appears below constitutes and appoints James
J. Houtz his attorney-in-fact and agent, with full power of substitution, for
him and in his name, place and stead, in any and all capacities, to sign any or
all amendments to this Registration Statement, and to file the same, with all
exhibits thereto, and other documents in connection therewith, with the
Securities and Exchange Commission, granting unto said attorney-in-fact and
agent full power and authority to do and perform each and every act and thing
requisite and necessary to be done in and about the premises, as fully to all
intents and purposes as he might or could do in person, hereby ratifying and
confirming all that said attorney-in-fact and agent, or his substitute or
substitutes, may lawfully do or cause to be done by virtue hereof.

        Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed below by the following persons in the
capacities and on the date indicated:

<TABLE>
<CAPTION>
Signature                                    Title                         Date
---------                                    -----                         ----
<S>                                 <C>                               <C>

(1) Principal Executive Officer


/s/ James J. Houtz                  President and a                   July 5,  2001
---------------------------         Director
    James J. Houtz

(2)  Principal Financial and Accounting Officer


/s/ Robert E. McCray                Chief Financial Officer           July 5,  2001
---------------------------
    Robert E. McCray                and a Director

(3)  Directors

/s/ Joan C. Horowitz                Secretary/Treasurer and a         July 5,  2001
---------------------------         Director
    Joan C. Horowitz


/s/ Rodney Anderson                 Director                          July 5, 2001
---------------------------
    Rodney Anderson
</TABLE>


                                        5

<PAGE>   6

                                  EXHIBIT INDEX

EXHIBIT
NUMBER                     DESCRIPTION
------                     -----------

 5.1      Opinion of  Haddan & Zepfel LLP

 23.1     Consent of Cacciamatta Accountancy Corporation

 23.2     Consent of HJ & Associates, LLC

 24.2     Consent of Haddan & Zepfel LLP (included in Exhibit 5.1)
[{"type": "S-8", "sequence": "1", "filename": "a73934ors-8.txt", "description": "FORM S-8", "secsgml_size_bytes": 15065}]
{"company-data": {"conformed-name": "SIONIX CORP /UT/", "cik": "0000764667", "assigned-sic": "3541", "irs-number": "870428526", "state-of-incorporation": "UT", "fiscal-year-end": "0930"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-64646", "film-number": "1675580"}, "business-address": {"street1": "9272 JERONIMO RD", "street2": "SUITE 108", "city": "IRVINE", "state": "CA", "zip": "92618", "phone": "9494549283"}, "mail-address": {"street1": "9272 JERONIMO RD", "street2": "SUITE 108", "city": "MISSION VIEJO", "state": "CA", "zip": "92618"}, "former-company": [{"former-conformed-name": "AUTOMATIC CONTROL CORP /NV", "date-changed": "19960422"}, {"former-conformed-name": "SIONIX CORP", "date-changed": "19960214"}, {"former-conformed-name": "CORONADO CAPITAL CORP", "date-changed": "19950111"}]}
1

            As filed with the Securities and Exchange Commission on July 5, 2001

================================================================================

                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

                                   ----------

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                               SIONIX CORPORATION
             (Exact name of registrant as specified in its charter)

            UTAH                                         87-0428526
(State or other jurisdiction of             (I.R.S. Employer Identification No.)
incorporation or organization)

                               9272 JERONIMO ROAD
                                IRVINE, CA 92618
               (Address of Principal Executive Office) (Zip Code)

        AGREEMENT, DATED MAY 25, 2001, WITH INVESTORS ADVOCATE, LTD., LLC
                            (Full title of the plan)

                                 JAMES J. HOUTZ
                               9272 JERONIMO ROAD
                                IRVINE, CA 92618
                     (Name and address of agent for service)

                                 (949) 454-9283
          (Telephone number, including area code, of agent for service)

                                    COPY TO:
                             ROBERT J. ZEPFEL, ESQ.
                               HADDAN & ZEPFEL LLP
                         4685 MACARTHUR COURT, SUITE 220
                             NEWPORT BEACH, CA 92660
                                 (949) 752-6100

                         CALCULATION OF REGISTRATION FEE
==================================================================================================================
Title of Securities     Amount to          Proposed Maximum              Proposed Maximum            Amount of
 to Be Registered     Be Registered   Offering Price Per Share(1)   Aggregate Offering Price(1)   Registration Fee
-------------------   -------------   ---------------------------   ---------------------------   ----------------
Common Stock,
without par value      1,000,000                $ .34                         $340,000                 $85.00
------------------------------------------------------------------------------------------------------------------
(1) Estimated solely for the purpose of calculating the amount of the
registration fee pursuant to Rule 457, based on the closing price of the Common
Stock, as reported by the OTC Bulletin Board, on June 29, 2001.
--------------------------------------------------------------------------------

================================================================================
2

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE.

        The following documents filed with the Securities and Exchange
Commission (the "Commission") pursuant to the Securities Exchange Act of 1934,
as amended (the "Exchange Act") by Sionix Corporation (the "Company") are hereby
incorporated by reference in this Registration Statement except as superseded or
modified herein: (i) the Annual Report on Form 10-K for the year ended September
30, 2000, (ii) the Quarterly Report on Form 10-QSB for the quarter ended
December 31, 2000, and (iii) the Quarterly Report on Form 10-QSB for the quarter
ended March 31, 2001, and any amendments to any such reports. All documents
filed by the Company with the Commission pursuant to Sections 13(a), 13(c), 14
or 15(d) of the Exchange Act after the date of this Registration Statement and
prior to the time a post- effective amendment which indicates that the
securities offered hereby have been sold or which deregisters all securities
then remaining unsold, shall be deemed to be incorporated by reference into this
Registration Statement and to be a part hereof from the date of filing of such
documents. Any statement contained in any document incorporated or deemed to be
incorporated by reference herein shall be deemed to be modified or superseded
for purposes of this Registration Statement to the extent that a statement
contained herein or in any other subsequently filed document which also is or is
deemed to be incorporated by reference herein modifies or supersedes such
statement. Any such statement so modified or superseded shall not be deemed,
except as modified or superseded, to constitute a part of this Registration
Statement.

ITEM 4. DESCRIPTION OF SECURITIES

        Not applicable

ITEM 5. INTERESTS OF NAMED EXPERTS AND COUNSEL

        Not applicable.

ITEM 6. INDEMNIFICATION OF DIRECTORS AND OFFICERS.

        Under Section 16-10a-903 of the Utah Revised Business Corporation Act
(the "URBCA"), and the Company's Articles of Incorporation, the Company is
required to indemnify a director or officer who is successful, on the merits or
otherwise, in the defense of any proceeding, or in the defense of any claim,
issue, or matter in the proceeding, to which he was a party because he is or was
a director of the corporation, against reasonable expenses incurred by him in
connection with the proceeding or claim with respect to which he has been
successful. Pursuant to Section 16-10a-902 and subject to Section 16- 10a-906,
the Company may indemnify a director for reasonable expenses incurred in a
proceeding. The Company's Articles of Incorporation contain certain provisions
permitted under the Utah Revised Business Corporation Act, relating to the
liability of directors. These provisions eliminate the liability of a director
to the Company or to its shareholders for monetary damages for any action taken
or any failure to take any action, as a director, except liability for: (a) the
amount of a financial benefit received by a director to which he or she is not
entitled; (b) an intentional infliction of harm on the Company or the
shareholders; (c) a violation of Section 16-10a-842 (regarding unlawful
distributions); or (d) an intentional violation of criminal law. These
provisions do not limit or eliminate the rights of the

                                        2
3

Company or any shareholder to seek non-monetary relief, such as an injunction or
rescission, in the event of a breach of a director's fiduciary duty. These
provisions do not alter a director's liability under federal securities laws.
The Company's By-laws also contains certain provisions permitted under the URBCA
relating to indemnification of directors and officers of the Company. In
general, these provisions permit the indemnification of directors and officers
in certain circumstances if the person seeking indemnification acted in good
faith and in a manner which he or she reasonably believed to be in or not
opposed to the best interests of the Company, and with respect to any criminal
action or proceeding, had not reasonable cause to believe his or her conduct was
unlawful. The provisions also provide for the reimbursement and/or advancement
of expenses to directors and officers under certain circumstances, which
provisions are consistent with the URBCA. Insofar as indemnification for
liabilities arising under the Securities Act of 1933 may be permitted to
directors, officers or persons controlling the company pursuant to the foregoing
provisions, the Company has been informed that in the opinion of the securities
and exchange commission such indemnification is against public policy as
expressed in the act and is therefore unenforceable.

ITEM 7. EXEMPTION FROM REGISTRATION CLAIMED.

        Not applicable

ITEM 8. EXHIBITS.

        5.1     Opinion of Haddan & Zepfel LLP

        23.1    Consent of Cacciamatta Accountancy Corporation

        23.2    Consent of HJ & Associates

        24.2    Consent of Haddan & Zepfel LLP (included in Exhibit 5.1)

ITEM 9. UNDERTAKINGS.

        The undersigned registrant hereby undertakes:

        (a)(1) To file, during any period in which offers or sales are being
made, a post-effective amendment to this registration statement:

               (i) To include any prospectus required by Section 10(a)(3) of the
Securities Act of 1933 (the "Securities Act");

               (ii) To reflect in the prospectus any facts or events arising
after the effective date of the registration statement (or the most recent
post-effective amendment thereof) which, individually or in the aggregate,
represents a fundamental change in the information set forth in the registration
statement;

               (iii) To include any material information with respect to the
plan of distribution not previously disclosed in the registration statement or
any material change to such information in the registration statement.

                                        3
4

                Provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do
not apply if the information required to be included in a post-effective
amendment by those paragraphs is contained in periodic reports filed by the
registrant pursuant to Section 13 or Section 15(d) of the Exchange Act that are
incorporated by reference in the registration statement.

            (2) That, for the purpose of determining any liability under the
Securities Act, each such post- effective amendment shall be deemed to be a new
registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

            (3) To remove from registration by means of a post-effective
amendment any of the securities being registered which remain unsold at the
termination of the offering.

        (b) The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act, each filing of the
registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Exchange Act (and, where applicable, each filing of an employee benefit plan's
annual report pursuant to Section 15(d) of the Exchange Act) that is
incorporated by reference in the registration statement shall be deemed to be a
new registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

        (h) Insofar as indemnification for liabilities arising under the
Securities Act may be permitted to directors, officers and controlling persons
of the registrant pursuant to the foregoing provisions, or otherwise, the
registrant has been advised that in the opinion of the Securities and Exchange
Commission such indemnification is against pubic policy as expressed in the Act
and is, therefore, unenforceable. In the event that a claim for indemnification
against such liabilities (other than the payment by the registrant of expenses
incurred or paid by a director, officer or controlling person of the registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Securities Act and will be governed by the final
adjudication of such issue.

                                        4
5

                                   SIGNATURES

        Pursuant to the requirements of the Securities Act of 1933, the
registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Irvine, State of California, on July 5, 2001.

                                                       Sionix Corporation

                                                       By: /s/ James J. Houtz
                                                           ---------------------
                                                               James J. Houtz,
                                                               President

        Each person whose signature appears below constitutes and appoints James
J. Houtz his attorney-in-fact and agent, with full power of substitution, for
him and in his name, place and stead, in any and all capacities, to sign any or
all amendments to this Registration Statement, and to file the same, with all
exhibits thereto, and other documents in connection therewith, with the
Securities and Exchange Commission, granting unto said attorney-in-fact and
agent full power and authority to do and perform each and every act and thing
requisite and necessary to be done in and about the premises, as fully to all
intents and purposes as he might or could do in person, hereby ratifying and
confirming all that said attorney-in-fact and agent, or his substitute or
substitutes, may lawfully do or cause to be done by virtue hereof.

        Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed below by the following persons in the
capacities and on the date indicated:
Signature                                    Title                         Date
---------                                    -----                         ----
(1) Principal Executive Officer

/s/ James J. Houtz                  President and a                   July 5,  2001
---------------------------         Director
    James J. Houtz

(2)  Principal Financial and Accounting Officer

/s/ Robert E. McCray                Chief Financial Officer           July 5,  2001
---------------------------
    Robert E. McCray                and a Director

(3)  Directors

/s/ Joan C. Horowitz                Secretary/Treasurer and a         July 5,  2001
---------------------------         Director
    Joan C. Horowitz

/s/ Rodney Anderson                 Director                          July 5, 2001
---------------------------
    Rodney Anderson
5
6

                                  EXHIBIT INDEX

EXHIBIT
NUMBER                     DESCRIPTION
------                     -----------

 5.1      Opinion of  Haddan & Zepfel LLP

 23.1     Consent of Cacciamatta Accountancy Corporation

 23.2     Consent of HJ & Associates, LLC

 24.2     Consent of Haddan & Zepfel LLP (included in Exhibit 5.1)