Decode Racquet String Tension in Hz and Dial Paddle Tungsten Stability Without Bench Hardware.

CourtHz pairs an on-device Accelerate FFT acoustic string-bed analyzer for Tennis, Squash, and Badminton with an exact parallel-axis tungsten inertia calculator for Pickleball, Padel, and Tennis frames.

Acoustic String Ping Frequency452 Hz

Head Size

String Pattern

String Gauge

String Material

Fresh Job Reference52 lbs (23.6 kg)

Weekly Court Hours5h / week

Restring Cycle

Every 16h / 3.2 weeks

Dynamic String-Bed Tension

38.4 lbs

17.4 kg · 1.69 g/m linear mass

-26.2%

vs 52.0 lbs fresh

360 Hzf0 Peak: 452 Hz660 Hz

Dead Poly: Restring Now

Severe plastic tension loss detected. Notched strings transmit high impact shock to wrist and elbow.

Two Distinct Physical Engines Built for Strung Beds and Solid-Core Paddles

Strung racquets and honeycomb or EVA paddles obey completely different mechanics. CourtHz never conflates solid-core pickleball paddles with vibrating string membranes.

Vibro-Acoustic String Bed Resonance (Tennis, Squash & Badminton)

When tapped, a strung racquet bed vibrates at a fundamental modal frequency governed by head area, string pattern density, filament diameter, specific gravity, and flexural stiffness. On iPhone and iPad, CourtHz samples 4096-point Hann-windowed audio via Accelerate vDSP and interpolates peak pitch to within 0.15 Hz.

Fresh Tour Poly: 535 Hz / 52 lbs
Dead Poly Alert: 452 Hz / 38.4 lbs
Squash 77 sq in: 628 Hz / 27 lbs
Badminton 0.66mm: 1142 Hz / 26 lbs

Parallel-Axis Tungsten Inertia (Pickleball, Padel & Tennis)

Pickleball and Padel paddles use polymer honeycomb, thermoformed carbon, or MultiEVA foam cores rather than strings. Their sweet-spot forgiveness depends on polar Twistweight about the centerline, while hand speed at the kitchen line depends on Swingweight about the 10 cm handle pivot.

Stock Joola Perseus 16mm TW 6.15 kg*cm2

+3g Strips at 5&7 + 3&9 7.08 kg*cm2 (+15.1%)

Resulting Swingweight 119.5 kg*cm2 (+3.5 pts)

How CourtHz Compares to Legacy String Apps and Pro-Shop Consoles

Players should not have to choose between a broken 1.89-star legacy mobile app, clunky desktop spreadsheets, or a $3,500 diagnostic machine bolted to a pro-shop counter.

Equipment diagnostic comparison across CourtHz, stringster 2.0 (App Store 1.89* average), and desktop/bench alternatives
Diagnostic Capability	CourtHz (iOS + Web)	stringster 2.0 (1.89*)	Desktop Web / RDC Bench
Instant Zero-Login Testing	Yes: live simulator dial + mic FFT with zero account wall	Forced registration & rigid preset gates before testing	Manual spreadsheet cells; zero mobile audio capture
Acoustic FFT Precision	4096-pt Hann FFT + parabolic bin lock (+/- 0.15 Hz)	Frequent false octave reads & mic permission hangs	$350 to $4,500 physical hardware required
Pickleball & Padel Tungsten Lab	Interactive 5&7, 3&9, 10&2, 12 Twistweight + Swingweight	None (racquet strings only)	Desktop-only calculators unusable courtside
Dead Poly Arm-Safety Alerts	Live % tension drop vs fresh job + restring cadence	Limited legacy string catalog updates	Requires manual logbook math
Annual Cost	$29.99/yr (7d free trial) or $69.99 lifetime	Recurring per-racquet / subscription friction	$3,500+ Babolat RDC / Briffidi hardware

Built Native for iPhone and iPad with Transparent Tour Pricing

Every acoustic FFT calculation, tungsten setup, and Gear Bag tension curve runs 100% locally on your device with zero cloud audio uploads.

Annual Tour Pass

7-Day Free Trial

$29.99 / year ($2.50/mo)

Full access to live AVAudioEngine racquet ping diagnostics, unlimited Gear Bag frames and paddles, tension-decay history charts, and perimeter tungsten maps.

App Store SKU: com.studio.courthz.annual

Weekly Pass

$3.99 / wk

Ideal for tournament travel weeks, fresh string testing, or dialing a new paddle setup.

com.studio.courthz.weekly

Lifetime Unlock

$69.99 once

One-time bench license for home stringers, coaches, and multi-racquet gear tinkerers.

com.studio.courthz.lifetime

Frequently Asked Questions

Does CourtHz measure string tension on Pickleball or Padel paddles? +

No: Pickleball and Padel paddles do not have strings; they use polymer honeycomb, carbon-foam, or EVA cores. CourtHz uses the Acoustic String Frequency Analyzer strictly for strung racquets (Tennis, Squash, and Badminton), and provides the Parallel-Axis Tungsten & Lead Inertia Lab to calculate Swingweight, Twistweight, and Balance Point on Pickleball paddles, Padel rackets, and Tennis frames.

How accurate is acoustic frequency tension measurement compared to a stringing machine? +

Immediately after stringing, dynamic string-bed stiffness settles below reference pull tension due to friction at main/cross intersections and frame relaxation. Pinging your racquet fresh off the stringer establishes a baseline Hz fingerprint, allowing CourtHz to track exact percentage tension loss (-8%, -15%, -26%) across court sessions with +/- 0.15 Hz spectral repeatability.

Where should I place 3g tungsten strips on an elongated 16mm pickleball paddle? +

Applying symmetric 3g strips at Throat (5 & 7) and Belly (3 & 9) expands lateral Twistweight by roughly +15% (for example, lifting a Joola Perseus 16mm from 6.15 to 7.08 kg*cm2) to stabilize off-center blocks while adding only ~3.5 points of Swingweight so hands stay fast at the kitchen line.

Is microphone audio ever uploaded or stored on external servers? +

Never. Audio buffers are processed transiently in device RAM using Apple Accelerate vDSP to locate the string-bed peak frequency in Hertz and are discarded immediately after each frame.