What is a cost effective way to level match, for comparing different hifi components?

Over the next little while I am planning on trying out some new DACs in my stereo system, and I know that it is important to make sure that sound levels are carefully matched when comparing. So I would like to ask others here how they do this? I realize that these days we all have smartphones and can download apps to measure SPLs. Is this accurate enough for careful comparisons. I wouldn’t mind getting some ideas from others on how they do this, and what might be the best way.
The only reason I can think of to do something like this is to learn to judge volume. Listen to some music, take your reading, play the next thing at a volume you think is the same, take another reading. When the readings match pretty close you have a good sense of volume. From that point on toss the stupid meter it will only distract you from what really matters which is learning to listen. 
Use a voltmeter you can't level match with a SPL meter. You also need to do the test blind other than that just pick whichever one you think sounds better and don't worry about.
You also need to do the test blind
Do you REALLY need to be blind to judge equipment? I don't see very well. Is THAT good enough? Or do I need to go blind completely in order to assess the sound characteristics? If so, I think I'd opt for just  keeping my old Dac and my vision....or what's left of it. Wow! I never knew it was so demanding to buy audio equipment.

OP strict level matching is essential. Lots of good tools to help with this that IMO should be part of the arsenal. Test tones, SPL meter, DMM, and an RTA with a calibrated microphone ( I use the Studio Six set of tools which run on an IPad )

As you probably already know, the ear brain likes louder and louder is just chasing your tail from a qualitative perspective, unless you can level match. My mentor (RIP) in this critical area and a real stickler for matching to .25 db or better was Roger Modjeski.

and there are measures for speech intelligibility, using a recording of a familiar voice ( instrument, acoustic space, etc ) can be an excellent touchstone- I use a Zoom H-6. There is of course a big and obvious difference between recognizing “ mom” and understanding what she is saying.
of course, Roger really was a genius, creator of lots of legendary high end gear for storied firms including his own Music Reference.

Wow that's a tough one.
If your listening skills are so frail you are deceived by a few dB pack it in, you need a new hobby. 
Post removed 
Level matching is total BS. Play your system where it sounds best for you. Compare the best sound you can get at the level that works for you. No need for scientific measurement, best sound is best sound. Just adjust the volume to YOUR normal/comfortable level. Every system has a different volume level that is the sweet spot. No need to level match apples and oranges. Use YOUR listening volume as the deciding factor.  
The most accurate way is with a voltmeter across the speaker terminals while test tones are playing. I've also used an SPL meter with pink noise (C weighting, slow response) to get a rough level match. Hopefully you have a volume control with small enough steps to make matching levels possible and a readout to make it easy to switch between different settings.
@tomic601 ,
"OP strict level matching is essential."
"As you probably already know, the ear brain likes louder and louder is just chasing your tail from a qualitative perspective, unless you can level match."

A couple of excellent and informative posts.

I don’t even bother comparing different masterings of favourite tracks unless I can level match them first.

Far too many times what, at first listen, seemed like obvious differences mysteriously disappeared into the ether once their volumes were matched. To all intents and purposes, what were quite different recordings all of a sudden became identical.

I’m not sure if I ever managed to get within 0.25db though, but it did really help me to distinguish between different recordings.

To claim that level matching is unimportant for evaluating components (or individual tracks) is either an example of naivety or an attempt at deliberate misdirection.
Hi all

Thanks all for the repsonses. Most are quite helpful. I wasnt intending this to be a debate about whether level matching when doing comparisons is useful, I already believe it is with little doubt. When we listen, our brain is fooled by loudness, thinking it is better.

I agree that playing a system at a comfortable level makes good sense, you want to compare at a volume that is normal for you for how you listen.

And yes I still have old test cds from stereophile etc with test tones, and can probably find similar tones and pink noise from the streaming companies. I was just wondering if a fancy microphone set up is really nexded to do this correctly, the voltmeter idea at the speakers is interesting too.
Cost effective is just using your ears.

I think it is a question of what you enjoy doing. If you get enjoyment out of doing analytical things, and solving problems of how to measure and achieve perfect balance… that is great. I can think of a bunch of different ways of doing it. I have a high quality microphone I had bought about 15 years ago for home theater and other audio measurements… feathering in subs… etc.

I guess I am getting lazy in my old age. My preamp will hold different settings between inputs. So last time when comparing streamers I just used my ears.

Nothing innately wrong with either. Use the approach that you enjoy most. The fate of the world does not rest in the balance on the outcome.
...voltmeter idea at the speakers is interesting too.

The XLO Test CD has a track and instructions for how to test voltage at the amplifier speaker taps.
Yes a decent voltmeter is going to be more accurate than a microphone. While I am a Fluke guy - my Dad programmed me to “ buy Lifetime tools “ , you can get something effective at HomevDepot, etc.

Roger and I had some good back n forth over .25 db.

best to you :-)

i think the op is asking a fair question, a somewhat technical question, he is doing something smart, which is to get his comparison process sufficiently rigorous so as to yield a result he can feel good about, he can trust

i remember as a 19 year old in providence r.i., working for one of the hifi retailers on weekends to make pocket money as a college student ... one of the well worn, ’experienced’ salesmen there kinda sorta took me under his wing, showing me what’s what in world as he saw it - the store had switching panels to connect turntables or other sources, to amps/receivers, to speakers, and then there was a volume adjuster

the guy boasted that he could get most anyone to buy system a over system b, by just making one play a touch louder than the other ... which he then demonstrated on a number of occasions

i’ll never forget that...
Acknowledging the importance of level matching when comparing source components is a sign of a good listener.
+1 @tvad
If you don’t understand the importance of level matching when comparing source components, you need a new hobby!
@jjss49 Yep…… surprised the snot out of them when i picked the Infinity Qb over the louder JBL -50.

and again with the Onkyo A-5 ( class A up to 5 watts ) vs a Nikko

and again with a Denon 790 over a Technics

and lastly the Grado over a Shure.

So while  Albert was pouring over whatever drivel Julian H was pushing, i was busy…listening..

1978, fun
My roommate at prep school had L110… now there was competition….but not for the deserving EMIT tweeter…