RCA coaxial cables?

Do you mean for carrying a line-level signal, or powering passive speakers?

Coaxial cable is good for signals because of its shielding.

Just for audio signal. Speakers are active.
They are very bulky and long. So I want to see if I gain any advantage by using them. If not, I will stick with a short 3.5mm aux cable and 1 "snake" xlr cable that connects both speakers

Regular RCA cables arenn't that bulky, or expensive: https://www.amazon.com/C2G-40464-Va...&qid=1624734298&sprefix=6'+rca,aps,189&sr=8-3

If at all possible, I would return them and just use a normal pair.

Can't return them, bc I got them for free
So I should stick with AUX 3.5mm cable ?

Does your source only have a 3.5 mm stereo output jack? Most cables that use those have to be thin (high gauge) to fit in the plug. If you can use lower gauge cable, it is probably better.

Be specific, show your audio source options. If you have options on hand to try different ways of hooking things up, try them and use what sounds best. Even if you can't hear a difference, I would use the more robust cable if it is good quality. The cables you show are RCA to RCA, if you can use those, why not? Your source must have left and right RCA outputs. I hate mini phone plugs but they are necessary on some things.

Source has 2 RCA outputs and 1 AUX output.
Speakers have 1 AUX input and 2 XLR 6.35mm inputs.
With the RCA cables I need to use a 6.35mm plug on one end.

Lovely dog & even an healthier pair

ank88 said:

Source has 2 RCA outputs and 1 AUX output.
Speakers have 1 AUX input and 2 XLR 6.35mm inputs.
With the RCA cables I need to use a 6.35mm plug on one end.

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There is no point using XLR connectors, your source is unbalanced. 6.35 mm = 1/4 inch. You can use RCA to 6.35mm cable. I assume you mean AUX = 3.5 mm. Use the best cables and connectors you can, I doubt that is anything with a 3.5 mm stereo plug.

I did try a lot of combinations and hear no difference in quality.
There is a difference in volume tho, with the RCA cables volume is louder for some reason.

ank88 said:

I did try a lot of combinations and hear no difference in quality.
There is a difference in volume tho, with the RCA cables volume is louder for some reason.

Click to expand...

The source output voltage is probabljy higher via the RCA outputs.

Stick with the RCA cables. You can even order RCA-to-TRS (1/4") cables from Amazon, and they don't cost much at all, if you don't want to bother with extra adaptors This is what I use for my external amp for my Atmos channels: https://www.amazon.com/Hosa-CPR-202-Stereo-Interconnect-Meters/dp/B000068O17/ref=sr_1_3?crid=17U3DK1ZRH0QF&dchild=1&keywords=rca+to+trs+cable&qid=1624817633&sprefix=rca+to+trs+cable,aps,188&sr=8-3
As @Rex Anderson mentioned, we have no idea about your gear. If you are able to give us this basic info, it might go a long way to help us in assisting you.

This looks like a continuation of a previous thread that contains more information about the devices being used:

Yes, these are two bluetooth adapters that I tested:
17.99US $ 20% OFF|UGREEN Bluetooth RCA Receiver 5.0 aptX LL 3.5mm Jack Aux Wireless Adapter Music for TV Car RCA Bluetooth 5.0 3.5 Audio Receiver|Wireless Adapter| - AliExpress (rca & aux)
9.39US $ 53% OFF|Baseus Aux Bluetooth Adapter Dongle Cable For Car 3.5mm Jack Aux Bluetooth 5.0 4.2 4.0 Receiver Speaker Audio Music Transmitter|Bluetooth Car Kit| - AliExpress (only aux)

With first one, on the phone bluetooth settings it shows AAC.
With second one it shows SBC.
I did not notice difference in sound quality

The RCA-TRS adapters are these:

Why is it so difficult to reveal your gear? We're just throwing darts blindly here...

But I did. What information is missing?

ank88 said:

But I did. What information is missing?

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The make and model of the device you're using to provide signals for the powered speakers, and the powered speakers themselves.

That would make it easier to provide precise recommendations. If you're unfamilar with the details of the various interfaces, it would be helpful not having to go back and forth with you.

If that excites paranoia in you, don't tell us.

ank88 said:

But I did. What information is missing?

Click to expand...

You most certainly have not revealed any of the gear.

All of the information is missing.