Alpha Sound Lab

The workflow

Nine stages, in the order you actually work

Take a measurement or import one. Align the ways. Set the crossovers. Fit the correction by hand or automatically. Listen to it. Export it. Then measure again and see whether it did what it promised. Each stage shows you its result before you move on — there is no button that does everything, on purpose.

1Import
Smaart, REW, or any file with frequency, magnitude, phase and coherence columns. Mic calibration is applied once, and the tool records who applied it.
2Measure
Take your own, with an interface, a microphone and a loopback cable. Swept sine, several sweeps averaged, a level meter before the measure button rather than a warning after it — and an impulse view that shows when the sound arrived, in milliseconds and metres.
3System
Sub, low, mid, high. Delay, polarity and gain per way, with the alignment worked out from where the ways actually overlap.
4Target
Flat, tilted, shelved — the curve you are correcting towards, owned in one place.
5FIR Design
Windowed-sinc and linear-phase Linkwitz-Riley legs, with the delay and polarity carried in the taps.
6IIR / PEQ
Parametric bands by hand, with Q and bandwidth in octaves side by side.
7Auto Fit
Levenberg-Marquardt fitting that prefers few bands to many, and refuses to correct what it cannot see.
8Audition
Hear the correction on your own material before it goes anywhere near a rig.
9Export
Coefficients, processor presets, and the settings sheet.

The part nobody else does

A page you can type into any processor

Every FIR designer assumes the job ends with a coefficient file loaded into a FIR-capable box. Most boxes in the world are not that, and the engineer standing in front of a DriveRack is not going to buy a rack to use a measurement tool.

So the tool prints the numbers instead: crossover points and slopes, delays in milliseconds and samples and metres, polarity, gain, the band list with Q and bandwidth both, and the limiter settings for every way. A system set up from that sheet and a DriveRack gets the alignment, the crossover and the EQ. It gives up only the linear phase.

Prints, emails, or survives being photographed on a phone
Readable six months later without this program installed
States what it does not model, so nobody treats it as a guarantee

================================================================
  SYSTEM SETTINGS SHEET
  Main hangs - 4-way line array
  48000 Hz    343 m/s assumed for distances
================================================================

  WAY 4   High 1.4" horn
----------------------------------------------------------------
  Crossover      high-pass  1.60 kHz  Linkwitz-Riley 24 dB/oct
                 (no low-pass - this way runs to the top)

  Delay          4.104 ms   197.0 samples   1.408 m / 4.62 ft
  Polarity       normal
  Gain           -4.5 dB

  RMS limiter    threshold  -1.72 dBu   -3.94 dBV   0.635 V
                 attack 0.62 ms      release 100 ms

  Working        driver 80 W AES / 8 ohm  ->  25.30 V
                 amp 700 W / 8 ohm, 32.0 dB gain
                 timing from one period of 1600 Hz
                 at the threshold the driver sees 80 W

Limiters

The same rig. Thirteen decibels apart.

An 18″ sub and a compression driver on one system want completely different limiter thresholds, and a single setting is wrong for both. The threshold is arithmetic — the driver’s rating referred back through the amplifier’s voltage gain — so the tool computes it per way rather than leaving you to guess.

18″ sub · 1600 W AES · 4 Ω

+8.28dBu

+6.06 dBV · 2.010 V
attack 33.3 ms, release 333 ms

1.4″ horn · 80 W AES · 8 Ω

−1.72dBu

−3.94 dBV · 0.635 V
attack 0.62 ms, release 100 ms

Give the horn the sub’s number and it sees

13.01dB too much

which is 10 × log₁₀(1600/80), exactly.

Three units, always, on the same line

Processors disagree about whether their threshold field means dBu, dBV or volts, and dBV sits exactly 2.2185 dB below dBu. Reading one into the other’s field is 2.2 dB hot — which a sub shrugs off and a compression driver does not. So every threshold is printed in all three and nobody converts anything at one in the morning.

And it refuses to guess

No driver rating, no suggestion. Thermal time constants, excursion below box tuning, and what a real amplifier does into a real load are named on every sheet as not modelled, because a threshold presented without them is a number people treat as a promise.

Several positions

What EQ can fix, and what it cannot

A measurement taken at one place describes one place. Part of what it shows is the loudspeaker, and EQ fixes that everywhere. The rest is the room, and EQ “fixes” that at the microphone while making every other seat worse. One measurement cannot tell them apart — not because it is a poor measurement, but because the information is not in it.

Measure the same source from several seats and the tool separates them. What is the same everywhere is the loudspeaker; what moves as you move is not.

Six seats, one loudspeaker — the example set that ships with the tool
Frequency	What it is	Spread across seats	Coherence	Verdict
94 Hz	port tuning	2.1 dB	0.97	EQ it
331 Hz	reflection null	20.8 dB	0.97	leave it
1804 Hz	horn dip	6.4 dB	0.97	EQ it

Coherence is 0.97 at all three. Coherence tells you how good the measurement is, not whether the thing it measured exists anywhere else — a 20 dB null in one seat can be a flawless measurement. Without the position check, a fitter would happily correct all three.

Pricing

Measuring is free. Correcting is what you buy.

Finding out what a system is doing costs you nothing and has no time limit. Designing the correction is the part that was paid for.

Free, permanently

Measure & Align

No cost, no account, no expiry

Everything up to the filter

Measurement, with your own interface and microphone
Measurement import and microphone calibration
Multi-way system tree with per-way delay and polarity
Alignment, and how exact it has to be
Several-position analysis
The settings sheet
Saving and reopening your projects

One edition

Suite

USD 349 or PHP 19,900 within the Philippines

Everything above, plus the correction

Target curves and FIR design
IIR / parametric fitting
Auto Fit
Per-way limiter and compressor thresholds
Coefficient and processor preset export
Every future 2.x update, at no further cost

Bought once. Yours permanently. It does not lapse, it does not phone anywhere, and it keeps working whatever happens to us.

Buying one

PayPal internationally, GCash within the Philippines. Email masterpro0115@gmail.com with the name the licence should be issued to and you will be sent payment details and, on payment, your key. Keys are issued by hand, by a person, usually within a day.

The name becomes part of the key and cannot be changed afterwards without a new one being issued. If the licence is for a company, send the company name.

Support is by email as well, and there is no public issue tracker to file into. You are answered by the person who wrote the program, and there is no queue in front of you.

There is no money-back guarantee. That is exactly why the free half exists and why it has no time limit: measure your own loudspeakers, with your own microphone, in your own room, before you pay anything. Nobody should buy a measurement tool on a promise when they can buy it on a measurement.

Download

Try all of it for sixty days

The demo is the whole program, unlocked, for sixty days. When they are up it does not shut down and does not take your work away: measuring and aligning stay free permanently, saving included. Only the correction — the filter design half — asks for a licence.

Download for Windows Read the manual

Windows 10 1809 or later, 64-bit · 30 MB installer
This program is not code-signed, so Windows SmartScreen shows a “Windows protected your PC” notice on first run. Choose More info → Run anyway. A certificate costs more each year than it would be worth to the people this is for, and it is not planned.

What we would like back

Every calculation in this tool is checked against a closed-form answer — the hashes against their published test vectors, the crossover summation against the algebra, the limiter thresholds derived twice by different routes.

The timing has since met a tape measure: a microphone at a hand-measured 76 cm read 2.31 ms of propagation, which the program put at 0.793 m of air — closer than the error in assuming 20 °C for the speed of sound. So the loopback really does remove the sound card’s latency, and what is left is air.

What has not happened yet is the part only you can do: nobody has taken a filter this program designed, loaded it into a processor, played it through a real loudspeaker and measured the result on a rig we do not own. Timing is one claim; the magnitude response is a different one, and it has no such check.

You can now do that inside the program. Measure, design, load the filter into your processor, and measure again — Verify names the worst deviation and where it is. Send that number back. It is worth more than any amount of arithmetic, and it is what this tool should be judged on.

Design the filter.Then print the pagethat goes in the rack.