<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2022-07-05</periodOfReport>

    <issuer>
        <issuerCik>0000923601</issuerCik>
        <issuerName>SINGING MACHINE CO INC</issuerName>
        <issuerTradingSymbol>NASD</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000896493</rptOwnerCik>
            <rptOwnerName>BitNile Holdings, Inc.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>11411 SOUTHERN HIGHLANDS PARKWAY</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 240</rptOwnerStreet2>
            <rptOwnerCity>LAS VEGAS</rptOwnerCity>
            <rptOwnerState>NV</rptOwnerState>
            <rptOwnerZipCode>89141</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>false</isDirector>
            <isOfficer>false</isOfficer>
            <isTenPercentOwner>true</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2022-07-05</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1300</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>7.7785</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1652300</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Digital Power Lending, LLC</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The common stock was purchased by the reporting person in open market transactions on the transaction date, with a volume weighted average purchase price of $7.7785. The range of purchase prices on the transaction date was $7.76 to $7.8421 per share. The reporting person undertakes to provide, upon request by the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares purchased at each price.</footnote>
        <footnote id="F2">Digital Power Lending, LLC (&quot;DPL&quot;) is a wholly-owned subsidiary of BitNile Holdings, Inc. (&quot;BH&quot;). Mr. Ault, the Executive Chairman of BH, is deemed to have voting and investment power with respect to the securities held of record by DPL.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Milton C. Ault, III, Executive Chairman</signatureName>
        <signatureDate>2022-07-07</signatureDate>
    </ownerSignature>
</ownershipDocument>
