A patch bay (or patchbay) centralises all studio connections in one location using rows of jack sockets. The top row typically connects to outputs (sources) and the bottom row to inputs (destinations). This allows re-routing any signal to any destination using short patch cables.

Normalling creates a default signal path between the top and bottom jacks of a pair without a patch cable inserted. Full-normal breaks the connection when either jack is patched. Half-normal breaks only when the bottom (input) is patched, allowing the output to be multed. Open (non-normalled) pairs have no default connection.

When should I use half-normal vs full-normal?

Half-normal: use for signal paths where you might want to split (mult) the output, like mic preamps to converters — you can tap the signal without breaking the default path. Full-normal: use where you always want an exclusive connection, like insert send/return. Open: use for gear with no default routing.

How many patch cables do I need?

A good starting point is 50% of your total pairs — enough to re-patch a significant portion of your studio. For a 48-point patch bay (24 pairs), 12-15 patch cables is a good start. Keep various lengths: 30cm, 60cm and 90cm.

AudioCalcs

Patch Bay Calculator — Size, Normalling & Cable Requirements

Calculate patch bay size, normalling configuration and cable requirements.

Full-Normalled Pairs

Half-Normalled Pairs

Open (Non-Normalled) Pairs

Patch Bay Type

Patch Cable Ratio

How We Calculate This

Patch Bay Sizing

Total Points = Total Pairs × 2

Bays Needed = Total Pairs / Pairs per Bay

Standard Sizes

48-point (24 pairs, 1U rack) is the most common. 96-point (48 pairs, 2U) for larger studios.

Patch Cables

Estimate 50% of total pairs for adequate flexibility.

Frequently Asked Questions

Related Calculators

Cable Length Calculator

Calculate the maximum cable length before signal degradation for XLR, TRS, TS and other audio cable types. Free online calculator.

Signal Loss Calculator

Calculate audio signal attenuation in dB over a cable run based on cable type, length and frequency. Free online audio calculator.

Cable Impedance Calculator

Calculate the characteristic impedance of audio cables from conductor diameter, spacing and dielectric constant. Free online tool.

Connector Calculator

Reference guide for audio connector pinouts, wiring diagrams and signal levels covering XLR, TRS, TS, RCA and more. Free online tool.

Balanced vs Unbalanced Calculator

Compare noise rejection and maximum cable run lengths for balanced versus unbalanced audio connections. Free online comparison tool.

Last updated: February 2026

All calculations are estimates based on standard formulas. Always verify results for critical applications.