Amazon Basics 3.5mm Stereo Aux to 2 RCA Audio Cable Adapter for Sound, Connecting Amplifiers, Speakers, Smartphone, Tablet with Gold-Plated Plugs, 4 Feet/1.2 m, Black

Something like this if your receiver has the small headphone jack (like mp3 players or older phones): Headphone-RCA or if it's the bigger 1/4 inch headphone jack Headphone(.25inc)-RCA I also want to mention, I can't tell in the pic how your cables are run from the cassette deck, but the OUT on the cassette deck should plug into the AUX on the receiver. The SW is for subwoofer so unless you have a subwoofer, leave that unplugged. So, the cables go like this: Headphone > RCA > In/REC tape deck Out/Play > Aux on receiver Then, obviously, when you want to play something on the tape deck, switch the receiver to Aux on the input. The only bad thing that might happen, some receivers won't output a speaker signal if a headphone is plugged in. Sometimes it's an option to output both speaker and headphone, sometimes the receiver does it by default, and some don't do it at all. Best test is to just plug headphones in and see if you can get sound while the speaker is still playing.

And does this look like the right cord? Compatible with the speakers I linked above? https://a.co/d/01mdOgAY

Setting amplifier gain with an lc2i To answer your other questions Any bass knob you’re using should be connected and set to max before setting gains. Set your radio eq to flat, bass boost and loudness off, and subwoofer level either to 0 (not boosted or cut). You can see bass roll off using your multimeter, you set it to ac voltage and connect it at either the signal coming into the lc2i, the output of the lc2i or the amplifier speaker output, all three locations will show it, make sure you have accubass level and threshold all the way down when testing for it. Play your 40 or 50hz test tone. You will see one of three things, as you turn the volume up the voltage will either continue to rise as you turn volume up all the way through max volume, or at some point (maybe 2/3 max volume) you will see the voltage stop rising as you turn volume up (it may rise slightly but not nearly as much as it was at lower volume adjustments, or lastly, voltage will actually decrease as volume turns up. If your voltage continues to rise, you do not have bass rolloff and probably would not want to use accubass. If your voltage stops rising you can use accubass but personally I do not like it, to me it sounds like a bass boost applied at high volumes which makes volume adjustment not very smooth, you will have low bass at lower volumes and all of a sudden it will turn on and suddenly have a lot more bass. Personally in this situation I just adjust the gains to achieve desired voltage at the volume that the voltage on the test tone stops rising. If you have the third situation where voltage actually starts lowering, this is where accubass shines. Adjust the threshold to turn on just before the volume that bass rolloff starts. The subsonic filter should be set to half an octave below the enclosure tuning frequency. That enclosure is tuned to 34hz according to Skar’s website so set it to around 24hz. Below the enclosure tuning frequency your ported enclosure loses the benefit of the air inside the enclosure acting as part of the subwoofer’s suspension and risk blowing it, the subsonic filter helps by lowering output below that frequency. For an RTA you can get a UMIK-1 and download REW (room eq wizard) for free. There is a lot to learn about REW so prepare to spend some time figuring it out. To see the signal itself you can get a line out converter connected to your input signal and then connect an rca to 3.5mm cable and plug it into your microphone input. You may be looking for an oscilloscope though for what you’re trying to do which will let you see the sine wave and help show you when your signal is clipping. You can find cheap-ish ones on Amazon. Hope this helps a little.

$110 Douk A5 Pro 48v amp and a $9 Apple USB C DAC and $8 3.5mm stereo to RCA cable

awesome <$400 2.0 stereo system your phone/laptop>>$9 Apple USB C DAC>>$8 3.5mm stereo to RCA cable>>$111 Douk A5 Pro 48v amp>>$25 14ga speaker wire w/banana plugs>>$245 Polk Audio XT20 speakers used/like new

With such small basic low cost entry level speakers an analog wired input or digital wireless is not going to make much or any difference since it's the basic low cost speakers that are the sound quality bottleneck. However it looks like the Sony CMT-SBT20 has 3.5mm AUX input on the back. So pass on paying $50 extra to have the basic Bluetooth transmitter in the turntable. AT-LP70X $195 AT outlet sale >>> RCA To 3.5mm audio cable >>> Sony CMT-SBT20. ------- Or get a better turntable with a better and adjustable tonearm: AT-LP3X $279 black https://outlet.audio-technica.com/catalog/product/view/id/8515/s/at-lp3xbt-bk-cr/category/1111/ AT-LP3X $279 white https://outlet.audio-technica.com/catalog/product/view/id/8516/s/at-lp3xbt-wh-cr/category/1111/ Or a better manual turntable with a better and adjustable tonearm and a better motor and a better stylus: AT-LP120X https://outlet.audio-technica.com/turntables/at-lp120xusb-bk-cr AT-LPW40 https://outlet.audio-technica.com/catalog/product/view/id/8613/s/at-lpw40wn-cr/category/1111/ ------- Also instead of the basic Sony stereo with the tiny basic 3" drivers consider an upgrade to better quality larger 5.25" or 6.5" speakers. 6.5" Dayton B65A $129 black or wood finish https://www.parts-express.com/Dayton-Audio-Classic-B65A-Powered-Bookshelf-Speaker-Pair-Black-300-260?quantity=1 5.25" Neumi BS5P $219 https://www.amazon.com/75-Watt-Powered-Bookshelf-Speakers-Bluetooth/dp/B08LV4SMH9 6.5" Dayton M6 $299 black or white https://www.parts-express.com/Dayton-Audio-M6-Powered-Speaker-Pair-Black-300-462?quantity=1 Or passive speakers and an amp and you can later upgrade one part at a time: Fosi $81 mini amp https://www.parts-express.com/Fosi-Audio-MC101-Bluetooth-Stereo-Amplifier-100W-x-2-235-268?quantity=1 6.5" Dayton B65 $79 passive speakers in black or wood finish https://www.parts-express.com/Dayton-Audio-Classic-B65-Bookshelf-Speaker-Pair-Black-300-254?quantity=1 Speaker Placement • Intro to Home Stereo Systems • Turntable and Speakers Setup Guide • Record Cleaning • Audio Guides