Hello, my KRK Rokits saturate when I plug them into my Mac with a jack cable, I need a sound card, right?

 

You need a "USB audio interface" such as this one: https://audient.com/products/audio-interfaces/id14/overview/
How much money do you want to spend? Which operating system do you have?

 

No not really, you need level management. Either set the rokits lower in volume on the speakers or your mac lower and the rokits higher. Or you have a wrong cable?.

 

https://www.googleadservices.com/pa...4nyubr8AhVNhFwKHT2rCjEQ9aACKAB6BAgGEBE&adurl= I was thinking about this one, I'm on Monterey

 

Not necessarily. If your Mac has an analogue audio output, it already has an interface, even if its only an onboard soundchip. Which output did you use?

 

It is connected in jack directly to my speakers

 

I have no clue about your mac. But onboard soundcards typically have a speaker out and an unpowered line out. Make sure you try the line-out output or setting. You can't use the loudness control on your mac this way, but there should be no distortion. you could get a passive monitor controller instead of an interface to control the volume of the speakers.

 

How is your gain-staging?

 

I meant the output of your Mac, you haven't used the headphones out accidentally?

 

This Mac has only one jack output

 

The speakers are set to +11.0db

 

And, have you checked in the manual if this is a HP output?

 

I forgot to say it but they only saturate when my Mac's sound is loud

 

They say 3.5 mm headphone jack

 

Which model is this, haven't found one with up to +11dB?

That's why the sound distorts. These are meant for headphones (hence the name ) not to connect to active monitors, that would be called line out.
If this is the only output then you'll need an additional audio interface.

 

No, that's not true. It is absolutely fine to use headphone outputs to connect to line inputs. Headphone amplifiers can usually drive impedances from 32 Ohms up while line inputs usually have an absolute minimum of 600 Ohms, most of the time around 10 kOhms.

What doesn't work is driving headphones with line outputs, as they usually can't deliver enough current.

 

Can something about the problem be said from below specs?

From the KRK Rocket G4 specs:

• Input Impedance
  5.12KΩ Balanced

Specs of MacBook audio output:

• (Playback of 1 Khz tone, full scale, 100kΩ load)
• Maximum output voltage: 2 VRMS (+8.24 dBu)
• Output impedance: < 24 Ω
• Frequency response: 20 Hz to 20 kHz, +0.5 dB/-3 dB
• Signal-to-noise ratio (SNR): > 90 dB
• Total harmonic distortion + noise (THD+N): < -80 dB (0.01%)
• Channel separation: > 75 dB

Note: For best results, equipment plugged into the line/headphone output jack should not connect the audio ground to other grounds, such as the chassis or “green-wire” ground.

 

Not a Mac Expert at all. Not even been a user for years. On PC most 1 output Onboard soundcards let you change the setting for the output from Headphones to speakers etc...
I would be pretty surprised if a Mac would not have such a feature. There should be one setting that puts the amplification very close to line level. For exactly the application @ripkeed has here.

 

They don't offer that functionality. They do however allow one to switch the headphone jack to line IN. That's it however.

 

This is like going to the hardware store and having them spec out a tiny little hammer to nail down an entire roof worth of nails with. In the middle of the hammer aisle.