Sound as Art. Technology as the Bridge
As an emerging brand in pro audio, Eyou Acoustics approaches the art of sound with deep reverence. Step by step, we are laying a solid foundation — starting with precision DSP algorithms and professional filtering software. We will never settle for the present, and we dare to challenge the future.
Professional Filter Generation Software
The complete path from a loudspeaker measurement to a ready-to-load FIR filter.
What it does
One project file carries the measurement, the target, every filter stage and the export settings.
📥 Measurement front end
Load one or more measurements and average them (AVG). Working sample rate, import gain offset, 1/1–1/48 octave smoothing (power or complex), polarity flip, and delay entered in samples, ms or millimetres with a Find Peak helper.
🎯 Composable target
Build the target from four stackable components — a tilt/slope Curve with LF shelf, a
Magnitude section, a Phase section and an imported File. Save as a
reusable .fgt preset.
🎚️ IIR stage with Auto IIR
Parametric, low-shelf and high-shelf bands with a brand-flavoured coefficient model and Q or bandwidth entry. Auto IIR fits up to N bands inside an F min–F max window under a gain ceiling and tolerance, so the biresonances are gone before FIR work starts.
📐 FIR Mag Adjust
Hand-placed magnitude bands — Flat-Top and Parametric — each switchable between linear and minimum phase, with a selectable order. The Mirror & Adjust view overlays what you are drawing on the target-weighted required curve.
🤖 FIR Auto Mag
Automatic magnitude correction over one or more frequency windows, each with its own smoothing. Optional coherence weighting keeps the fit from chasing unreliable data, and the result can be rendered minimum phase or linear phase.
🌀 Phase correction
Allpass sections (2nd/4th order, Max or Min type, with angle and inversion) for surgical work, plus FIR Auto Phase to flatten phase across a window automatically — useful for crossover regions and driver alignment.
📤 Export you can trust
Choose tap count, delay, window (Cosine Tapered / Kaiser with α), DC normalise, export sample rate, gain and polarity. The window and the windowed impulse are drawn live, and the app warns you before coefficients exceed ±1.0 FS.
🔊 DSP Audition
Audition the whole chain before you export: pick the output device and L/R channels, play a WAV or the built-in signal generator, and bypass IIR, FIR magnitude or FIR phase individually to hear exactly what each stage did.
💻 Native on both platforms
One native build per platform — macOS and Windows — with no runtime to install. Projects and presets move between platforms unchanged.
The workflow
Each tab hands its result to the next one, and every tab shows a before/after pair, so you always know which stage created which change.
Import the measurement
Load your measured response (average several positions if needed), set the working sample
rate and octave smoothing, remove bulk delay with Find Peak, and check the
impulse response before going further.
Define the target
Stack a slope-based curve, a magnitude section, a phase section and an optional imported file into one Total Target Response. Everything downstream is expressed as "required, target-weighted" — the distance between where you are and where you want to be.
Take out the coarse errors with IIR
Let Auto IIR fit the low end and other high-Q trouble spots first. Cleaning up
here means the FIR stage only has to deal with what IIR cannot solve, which keeps the tap
count and the coefficient peak low.
Shape broad regions with FIR Mag Adjust
Draw the remaining broadband trend by hand — this is where Flat-Top earns its keep — and decide per band whether it should be linear or minimum phase.
Let FIR Auto Mag finish the detail
Set an F min–F max window and a smoothing value, and the automatic correction closes the remaining ripple. Coherence weighting keeps it from over-correcting noisy data.
Correct phase
Use allpass sections for a specific crossover region, or FIR Auto Phase to
flatten the phase reference across a whole window.
Audition, then export
Listen through DSP Audition with per-stage bypass. When it is right, pick taps, window and delay in Export, watch the clipping warning, and write out the coefficient file for your processor.
In focus: the Flat-Top filter
Flat-Top is the filter type in FIR Mag Adjust that most people reach for once they have tried it. It is what a parametric bell is not: a correction with a flat middle and defined ends.
A constant-gain plateau instead of a peak
A parametric band is a bell. Its maximum gain exists at exactly one frequency, and everything either side of that frequency gets less. When the error you are correcting is not a resonance but a region — a presence range sitting 5 dB low, a waveguide passband tilted the wrong way — a bell is the wrong shape. You either overshoot the centre to satisfy the edges, or you stack three or four overlapping bells and inherit their ripple and their combined phase.
Flat-Top solves that directly. It applies the same gain across a whole band, then transitions back to 0 dB on both sides at a rate you choose. One band, one gain figure, edges exactly where you put them.
The four parameters
| Parameter | What it controls | In practice |
|---|---|---|
| Freq | Centre of the plateau. | Place it in the middle of the region you are correcting, not at the deepest point of the dip. |
| Q | Width of the plateau. Lower Q → wider band. | Q 0.30 around 2.5 kHz covers roughly 700 Hz–10 kHz. Set the width first, gain second. |
| Gain | The constant level applied across the plateau, in dB. | Read it straight off the required curve — no need to over-aim as you would with a bell. |
| Order | Steepness of the two skirts leading into and out of the plateau. | Order 2 for musical, gradual edges; raise it when the band must line up tightly with a crossover point. |
Like every band in FIR Mag Adjust, a Flat-Top can be rendered linear phase (no phase change, pre-ringing traded for phase accuracy) or minimum phase (the phase behaviour a conventional EQ would produce).
Why it makes a measurable difference
- One band replaces three or four. Fewer overlapping sections means less interaction ripple in the result and a correction curve that matches what you intended.
- Lower coefficient peak. A bell that has to hit +5 dB at the band edges peaks far higher in the middle. A flat correction holds +5 dB and no more — which is what keeps you below the ±1.0 FS clipping warning at Export, and keeps headroom in the processor.
- Defined ends, unlike a shelf. A high shelf runs all the way to Nyquist. A Flat-Top comes back to 0 dB, so correcting the presence range does not silently lift the top octave with it — the octave where FIR boost is most expensive and least useful.
- Cleaner hand-off to Auto Mag. Remove the broad trend with Flat-Top first and FIR Auto Mag is left with small ripple only. Its correction stays gentle, the impulse stays short, and fewer taps are needed to hold the result.
- It reads clearly on the plot. In the Mirror & Adjust view the green Flat-Top overlay should sit level through the middle of the blue required curve. If it does, the band is right; you can see it at a glance rather than inferring it from four bell curves.
Where it fits best
- Restoring a broad presence or HF region that sits several dB low across octaves.
- Flattening horn and waveguide passband tilt without touching the crossover edges.
- Level-matching one driver's passband to the rest of the system.
- Voicing — adding a deliberate, gently bounded house-curve lift with ends you control.
Specifications
| Platforms | macOS · Windows |
| Version | Ver 2.0.0 |
| Import | Measured frequency response with magnitude, phase and coherence; multi-measurement averaging; import gain offset; delay in samples / ms / mm; polarity flip |
| Smoothing | Fractional-octave from 1/1 to fine resolutions, power or complex; optional coherence weighting in Auto Mag |
| Target | Curve (slope table + LF shelf), Magnitude, Phase and File components combined into one
total target; saved as .fgt presets |
| IIR filters | Parametric, low shelf, high shelf; Q or bandwidth entry; brand-flavoured coefficient model; Auto IIR with frequency window, gain ceiling, tolerance and band-count limit; table copy/export |
| FIR magnitude | Flat-Top and Parametric bands with per-band order and linear/minimum phase; automatic correction over multiple frequency windows |
| FIR phase | 2nd and 4th order allpass sections (Max/Min type, angle, invert); automatic phase flattening over a frequency window |
| Export | Selectable tap count and delay; Cosine Tapered and Kaiser (adjustable α) windows; DC normalise; export sample rate, gain and polarity; text coefficient output; over-full-scale warning |
| Audition | Output device and channel selection, WAV playback, sine/signal generator, per-stage and global bypass, live DSP chain preview |
| Project file | .fgp — measurement, target, all filter stages and export settings in one
file |
| Licence | Lifetime, one activation per machine, tied to a Machine ID |
Get FIR Generator Pro
FIR Generator Pro
The complete workflow for optimising system phase and magnitude response with advanced DSP algorithms.
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🆓 Free to download — and clear about what is locked
The download is free, with no time limit and no card required. Install it, load your own measurement and see how the software reads your system — the unlicensed build is a look at the front of the workflow, not a full working copy.
| Available without a licence | Part of Import, Target and IIR Filters — enough to load a measurement, see your response against a target, and get a feel for how the program works. |
| Requires activation | The remaining functions in those three tabs, and every stage after them: FIR Mag Adjust (including Flat-Top), FIR Auto Mag, FIR Phase Adjust, FIR Auto Phase, Export and DSP Audition. |
In short: without a licence you cannot generate or export a filter. We would rather say that here than have you find out after paying. If you want to see the FIR stages working on your own measurement before you decide, send it to [email protected] and we will run it through and send you the result.
This is a single-machine licence. Run the software once to get your Machine ID, then submit it in the Account section together with your invoice reference — and please check you are on the machine you actually intend to work on, because the binding is permanent. Codes are issued by a person, not a robot — normally within a few hours, and always within 24 hours. Your code arrives by email and also appears under “My licences”. Upgrading from an earlier version? Ver 2.0.0 needs to be reactivated — email your Machine ID to [email protected] and we will sort it out.
1. Create an account in the Account section below, then click Purchase Licence to check out. Paddle emails you an invoice with a reference number.
2. Download, install and run the software to obtain your unique Machine ID.
3. Return to Account and submit the invoice reference and Machine ID together.
4. We issue your activation code — normally within a few hours, always within 24 hours. It appears under My licences and we email you when it is ready.
Frequently asked questions
What is the difference between Flat-Top and a high shelf?
A shelf changes level from its corner frequency onwards and never comes back — it runs to Nyquist. A Flat-Top has two skirts: it rises into the plateau and returns to 0 dB after it. Use a shelf when you genuinely want everything above a point lifted; use Flat-Top when the correction should stop at a defined upper edge.
Should I use linear phase or minimum phase?
Minimum phase behaves like a conventional EQ and adds no pre-ringing, so it is the safe default for correcting minimum-phase behaviour in a driver. Linear phase leaves the phase response untouched, which is what you want when magnitude and phase are being corrected by separate stages — at the cost of pre-ringing and latency. FIR Generator Pro lets you choose per band, so a broad Flat-Top can be linear phase while a narrow resonance fix stays minimum phase.
Why does Export warn me about ±1.0 FS?
Because the generated coefficients would clip. It usually means too much boost has accumulated — most often a wide band with a large gain. Reduce the boost in FIR Mag Adjust or FIR Auto Mag, or apply negative gain in the Export tab so the whole filter is scaled down. Export is still possible; the warning tells you that the result will not be clean as it stands.
How many taps do I need?
It depends on the lowest frequency you are correcting and on how much correction remains after the IIR stage. Doing the coarse work with IIR and the broad work with Flat-Top means the FIR only has to hold fine detail, which usually lets you get away with a lower tap count — important when the target processor has a fixed budget.
Which processors can load the exported filter?
Export produces a text coefficient file at your chosen sample rate, which most DSP platforms accept directly or after a trivial reformat. If you need a specific format for your hardware, email [email protected] and tell us the processor.
How long does it take to get my activation code?
Normally a few hours, and always within 24 hours of you submitting your Machine ID and invoice reference. Codes are checked and issued by a person rather than generated automatically, which is why it is not instant — but it also means a human sees every request. Your code appears under My licences when it is ready and we email you. If 24 hours have passed and you have heard nothing, please chase us at [email protected] — that is a mistake on our side, not a queue you need to wait in.
How many computers does one licence cover?
One. The licence is a single-machine licence: it is bound to the Machine ID you submit, and it stays on that machine. If you need to run FIR Generator Pro on a second computer, that is a second licence. Please make sure you submit the Machine ID of the machine you actually intend to work on — check it before you submit, because the binding is permanent. Any questions before you buy, ask us at [email protected].
Is there a trial? What can I do before I buy?
The download is free and never expires, but it is a limited build rather than a full trial. Without a licence you get part of the Import, Target and IIR Filters tabs — enough to load a measurement and see it against a target. Everything from FIR Mag Adjust onwards, including Export and DSP Audition, needs activation, so you cannot produce a finished filter without a licence. If you want proof on your own system first, send us a measurement and we will process it and send back the result.
Hardware
The same standard we hold our DSP to, applied to the equipment around it. Eyou Acoustics supplies high-quality professional audio hardware across six product lines — from the microphone at the front of the chain to the amplifier at the end of it, and the servers that run your plugins in between.
Wireless Microphone Systems
无线话筒系统
Enquire nowHandheld, bodypack and headset systems for stage, house of worship, conference and broadcast use. Selected for clean RF behaviour and predictable multi-channel coordination — the things that decide whether a show runs quietly or becomes a problem in the middle of it.
- Handheld, bodypack, headset and lavalier options
- Multi-channel coordination and antenna distribution
- Rack, charging and spares packages
Live Performance Peripherals
专业演出周边设备
Enquire nowThe supporting equipment a touring or installed system depends on and nobody notices until it fails: DI boxes, splitters, stage boxes, cabling and looms, monitoring and rack hardware. Built to survive load-ins, not just to pass a bench test.
- DI boxes, splitters, stage boxes and looms
- Monitoring, patching and rack infrastructure
- Custom lengths and configurations to order
Audio Processors
音频处理器
Enquire nowLoudspeaker management and matrix processors — crossovers, delay, limiting, routing and both IIR and FIR filtering. This is where the filters you design in FIR Generator Pro end up, so we will tell you honestly whether a given processor can load your tap count before you buy it.
- Loudspeaker management and matrix processing
- FIR-capable platforms, with tap budgets stated plainly
- Networked audio and remote control options
Power Amplifiers
功放
Enquire nowTouring and installation amplifiers, with and without onboard DSP. We size them against the loudspeakers they will actually drive rather than against a headline power figure, and we will say when a smaller model is the right answer.
- Two, four and eight channel models
- Optional onboard DSP and network control
- Amplifier-to-loudspeaker matching advice included
Custom Waves Servers
Waves 定制服务器
Enquire nowPurpose-built SoundGrid servers for Waves plugin processing and LV1 systems. Every machine is assembled and burned in for audio duty — component choice, thermal design and BIOS settings all chosen for stable low latency under a full plugin load, not for benchmark scores.
- Specified for a stated plugin count and latency target
- Burn-in tested under sustained full load before shipping
- Redundant / mirrored server configurations available
LiveProfessor Audio Servers
LiveProfessor 音频服务器
Enquire nowTurnkey machines for running LiveProfessor as a live plugin host — VST racks, snapshots and show control, on hardware configured and tested for the job. Delivered ready to work: audio interface, driver stack and system tuning already done.
- Configured and tested for live VST hosting
- Audio interface and driver stack set up before delivery
- Show file, snapshot and control integration support
How we work
We would rather sell you the right item once than the expensive item twice. Tell us the venue, the loudspeakers, the channel count and the budget, and we will come back with a specification and a quotation — including the parts you do not need. Distributor and integrator enquiries are welcome; write to [email protected].
Account
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Forgot password?Community
Questions, feature requests, bug reports and tuning notes. Posts are public and use the same account you registered for your licence — no separate sign-up. For anything private (invoices, activation codes, order problems) please email [email protected] instead.