Every tool in Audiophilio, and when to reach for it

There are more tools in here than anyone will use in one sitting, and that is fine. You are not going to measure distortion, align a tonearm, and run an EQ sweep on the same afternoon. The app is built so you can ignore most of it and still get something out of two or three screens. So rather than list features, I have grouped the tools by the job you are actually trying to do.

A note before we start: most of the measurement tools run off the microphone in your iPhone, iPad or Mac. That built-in mic is good for relative work, where you compare one curve against another, which covers most of what is useful early on. For numbers you would trust in absolute terms, you want a calibrated mic. I will flag where that matters as we go, and the Hardware Guide has the details.

The two I open most: SPL meter and RTA

The SPL meter is the first thing most people touch, and it is free. It tells you how loud the room is right now. I use it for the dull but important jobs: matching the level between two speakers, checking how loud I actually listen, and setting a sane reference before I measure anything else.

The Real-Time Analyzer sits next to it. It shows a live frequency spectrum with selectable octave bands, so you can see what the room is doing to your sound as it happens. I treat it as a first glance: is there an obvious bass hump, is the top end rolled off, did moving the speaker six inches change anything. It will not give you a measurement you would publish, but it tells you where to look.

Watching the room decay in time

Most bass problems are really time problems. A note is not just too loud, it hangs around too long. Three tools show you that, each from a different angle.

The Waterfall Plot is the one I reach for first. It draws how bass energy builds and dies away across frequency and time, either as a flat heat map or an interactive 3D view. Watch a room mode ring out, add a bass trap, and watch the tail get shorter. That before-and-after is more convincing than any single number.

RT60 gives you the number instead of the picture: how long sound takes to fall by 60 dB. It is the quick way to tell whether a room is too live or too dead before you start hanging panels. The Spectrogram covers the same ground as the waterfall but laid out flat over time, which some people read more easily.

The energy-time curve goes deeper. It measures the room's impulse response with a log sweep and FFT deconvolution, then shows direct sound, the early reflections, and the gap between them. This is the tool I point people to when they ask which wall to treat first. It shows what no RT60 number can.

The measurement suite

Then there is a cluster of smaller, single-purpose tools. Each one answers one question:

• The Polarity Checker tells you whether a speaker is wired backwards.
• The Delay Finder tells you whether your channels are time-aligned.
• Channel Balance checks that left and right are actually level-matched.
• The Impedance Analyzer looks at how your load behaves across frequency.
• The Distortion Analyzer breaks the harmonics out from H2 to H8, so you can see euphonic even-order distortion separately from the harsh odd-order kind.
• The LUFS meter measures loudness the way streaming services do.

One thing worth knowing: the timing-sensitive tools here, the Delay Finder and the energy-time curve and RT60, care about your signal path. A wireless connection adds latency and will throw them off, so use a wired one. The level-based tools do not care.

Frequency response and EQ

This is the big one, and the tool I would point a serious listener to first. Measure your room or a speaker with a log sweep, and Audiophilio fits up to 32 parametric filters, peaks, dips, and high and low shelves, toward Flat, Harman, a House Curve, or a target you bring in yourself. It reads and writes REW measurement files, and it exports filters to REW, MiniDSP, or Equalizer APO, so whatever you already use to apply EQ, it fits.

Two honest caveats. Boosts are capped, so the app will not let you dial in a huge one that cooks your amp or your woofer chasing a null that EQ cannot fill. And EQ is not a fix for a bad room. Move the speakers and treat the first reflections first, then use EQ to clean up what is left. If you want the longer version of that argument, and how this compares to doing it all in REW, I wrote about that here.

Designing the room before you spend money

The Room Designer is the one tool that does not need a microphone at all. You draw your room, or scan it with LiDAR on a Pro iPhone or iPad, then drop in your speakers and your seat. Turn on the overlays and it predicts what the room will do: standing-wave heat maps, where your first reflections land, toe-in arcs for aiming, and labels for the room modes your dimensions produce. The point is to see a problem before you buy a single panel.

Planning the whole system

The System Builder lets you lay out your signal chain, from source to speakers, as a diagram. On its own that is just a tidy picture. The useful part is the Analyze button: System Intelligence reads the chain and flags the things that are wrong or borderline. A missing phono stage. Speakers with no amplifier behind them. A source that bypasses your DAC. A cartridge and tonearm whose resonance falls out of range. An amp and speaker pairing with an impedance or headroom problem. Each one comes with a specific fix, ranked by how much it matters.

Link a room to the system and the advice starts accounting for size and treatment too. On devices with Apple Intelligence, it will write the whole thing up as a plain-language summary, done privately on the device.

For the turntable crowd

If you spin records, the Turntable Setup Suite handles the fiddly geometry. It works out tonearm alignment for Baerwald, Löfgren A, and Stevenson, draws the null points, and gives you tracking-force and anti-skate references plus a setup checklist. The Wow & Flutter meter is its companion: play a 3150 Hz test record and it grades your speed stability from A to F, with the peak and RMS numbers behind the grade.

Training your own ears

The Ear Trainer is the odd one out, because it works on you instead of the room. Reference mode, which is free, plays the 31 standard third-octave tones from 20 Hz up to 20 kHz, each with a plain note on what that range sounds like and what to listen for. Quiz mode then makes you name a tone from three choices, at an easy or a harder setting, and tracks your best score. Learning to hear "that is a 200 Hz problem" is one of the more useful things an audiophile can do, and it costs nothing to practice.

And the calculators

Finally there is a set of acoustic calculators for the quick math you would otherwise do on paper: room modes, first-reflection points, port tuning, and the rest. Nothing glamorous, but handy when you just need a number.

What's free and what isn't

Since I would want to know this before downloading anything: the SPL meter, the noise generator, the Ear Trainer's reference mode, the calculators, and one saved room and one saved system are free, with no time limit. The one-time $44.99 Premium unlock adds the rest, the full measurement suite, the frequency response and EQ tool, the acoustic overlays, and unlimited rooms and systems. No subscription, no ads, no tracking.

Where to start

If you do one thing, run the guided first measurement. After that, keep the RTA and the Waterfall open while you move a speaker or drop a cushion at the first reflection point, and watch what changes. That loop, make a change, see the change, is where the app earns its keep. The rest of the tools are there for when you have a specific question to answer.

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Sources

Tool descriptions and specifics in this article come from the app itself and its changelog. Software changes over time, so check the app for the current behavior of any tool mentioned here.