Hi

May seem like a silly question but I'm only mixing and mastering not recording

Would I need a professional soundcard ?

 

Well a decent soundcard can produce more accurate frequencies so you can hear how you sound sounds well more accurately so yes you need one if you plan to release the music more seriously usb cards are decent, for recording an good card is a must good low noise and high sensitivity is good card

 

You should be asking yourself if you need professional monitors if you are mastering, are you relying on pc speakers?

 

No, you need good monitors and a well treated room to make good decisions. And experience and a good ear and for mixing also some talent (since mixing is a creative process too).
Converter quality is really the last thing to worry about.
But if you want pro/perfect go for a RME ADI2 dac. It is for playback and mixing only and will not record, hence cheaper then the RME ADI2 pro.

 

I'm using presonus HD 9 studio headphones
Directly into my laptop.

Issue I'm having is the sound is completely different when I mix down using cubase 10.5
And listening on other devices like car or phone

So I'm not sure if it could be my headphones and I'm not sure if it could be the soundcard

 

Studio headphones

 

Using only headphones has some problems:
1) Volume balancing is way trickier.
2) They sound too different from real speakers moving air in a room. This is going to affect a lot of your creative and technical decisions.
3) You must know really well their frequency response. It's practically not possible to correct their curve because it needs specialised equipment.

I know only one mixing engineer who claims to have mixed with headphones only (Scheps), and no master engineer ever using just headphones. If you want to do any mixing/mastering even as a hobby you need monitors as a top priority. Look at the JBL or Mackie lines for the cheapest decent ones.

 

Get a RME... anything...
You're all set

 

Laptop integrated soundcards are useful only for Zoom calls: if you are dealing with audio production -yes- you definitely need a dedicated audio interface. Generally speaking, the higher your budget, more quality and features you’ll have in the product, also notice that a good interface from a respectable brand, is a futureproof choice (you won't need to buy a new one every season)
What’s your budget?

 

I'm looking to get the DT 770 pro 250 ohm what soundcard should I get with it

 

Would recommend anything from Audient depending on your budget. I have an iD4 and it's been brilliant. Amazing preamps too

 

I want to be a formula one racer, do I need a race car? is there any tutorials on youtube to learn how to drive ?
If you do not know if you need a soundcard, maybe is not time to mix . . . and of course, neither to mastering.
Mastering really is only for people with 20 years or more mixing and lot of experience with lots of analog and expensive gear in big studios.
Put L2 and a eq from the brother site in 2bus is not mastering, is a child game . . .
Yes, you need a good room for mastering, not in a home or flat, maybe in a specific isolated structure for mastering.
You need 2 o 3 loudspeaker systems, you need a serious amp, callibration for profesionals (the room, the speakers, the amp) . . . an then . . . you need a soundcard and computer . . . but this is not so important for mixing or mastering.

 

That is the question @abbas786 needs to answer. It is all about the budget. You can spend $250 for a run of the mill converter or $5000 and up for "mastering" converters.

 

Best A/D in class - Antelope Zen Go
If you mix and master this is the one for under a 1000 bucks.... it´s native USB 3.1 on a USB C connector .... don´t get mislead by the "Flash Icon" it´s only USB not thunderbold.
More dynamic range equals more detail - more detail, better mixes/masters...