Software for Room Correction?

There are a lot of options here. As for a mic the most popular options I’ve seen and used are the MiniDSP UMIK-1 and the Dayton Audio mics available on Parts Express. 

What are you using for your digital playback chain? Are you using a laptop/computer direct into a DAC or preamp? If so you can use REW (Room EQ Wizard) which is free or Dirac Live. If you have a streamer/server you can look into a number of DSP solutions with room correction, like MiniDSP. 

If you can list the components in your system you will get better guidance to the quality of the DSP solutions that will best match it. 

I use an Innuos Zen 3 Streamer

Uptone Audio Etherregen

An ANK 4.1x DAC

Pass Labs INT25

Fritz Carerra 7BE Speakers

REL T5X Sub

Balanced Power Transformer

Truth be told I experienced this effect recently

with a pair of Buchard S400 Mk2s at someone's home.

They went from Okay to Jaw dropping.

 

Maybe my jaw dropped because I knew how they

sounded in two other rooms and was shocked by the

improvement.

What gear were they using?
Finding out what your acquaintance was using would be where I would start.

So who uses this gear and what do I buy???

Your choices are a built in unit that does a lot for you, or a unit that has more of a DIY approach for tuning.
And at a kindergarten level, one has choices of more of a PEQ approach for frequency response, and more of the DIRAC for phase correction.
So there is a bit to consider.

Some ideas/examples to bound the field include:

• MiniDSP FLex using DIRAC
• Lyngdorf TDAI 3400 integrated.

With an integrated amp it might get harder, as the DSP usually sits between the preamp and the amp.
If one only has a digital source then it could sot between the DAC and integrated.
i.e. :

Balanced Power Transformer

I use an Innuos Zen 3 Streamer

Uptone Audio Etherregen

An ANK 4.1x DAC

It probably needs to go here for a full spectrum solution.

Pass Labs INT25

Fritz Carerra 7BE Speakers

But it could go here for a sub correction only DSP 

REL T5X Sub

I would probably suggest you just get the microphone and REW. You will need the same UMIK mic for many systems (like all the MiniDSP), and a lot of processors that do it for you come with their own microphone… but having a mic is not a bad start.

What you are looking to do is use the Roon DSP with a convolution filter. Roon has a great post on how to do. I had a person come in and do it for $400 but if you change anything you have to redo. I got the UMIK 1 mic and looked at REW which is free and many have used but I went with Focus Fidelity instead. $250. It was super easy. I can now redo my filters in about an hour or less. 

This only goes to show you how some companies like to tighten the screws into your back when yo think you are buying all of their product.
My brand new NAD came with the MIC. Though it is the same mic that they provided with my old T748 it is probably sufficient to do the job. on the other hand there is the issue with the software. NAD only provided the DIRAClive lite and that might be sufficient BUT... In my case living as an apartment dweller and 70 yr old My hearing is definitely less discerning. The lite version of the software probably covers enough of the frequency band to tune my room, On the other hand for those who don't want crippleware, the extra $100 for the full version of the software, is not too exorbitant a price.
Also I can use the included mic with my phone and the 'Decibel X' software on it. to watch my music at a finer resolution.
I must agree that activating diraclive was a jaw dropping experience for me.

I thought this article was a good read about DSP philosophy from a leading manufacturer: 

http://www.audiodrom.net/en/special-edition-reviews/57-accuphase-dg-58

I have the DSP function of Roon for a couple of years. A year ago I bought a Lyngdorf TDAI 3400 and I am using Roomperfect now. Roomperfect makes it possible to use DSP also while listening to my turntable 😎