The correct size spade connector for speakers is determined by the width of your speaker or amplifier’s binding post. The most common documented sizes are 4.8 mm and 6.3 mm, but the exact size must match the post to create a secure connection, as a mismatch is the main failure point.
Common speaker spade connector sizes
Spade connectors are available in several documented sizes, each suited to different binding posts. The table below lists the sizes and where they typically appear. | Documented size | Typical use |
|---|---|
| 4.8 mm | Negative terminal on some speakers; common general speaker terminal size |
| 6.3 mm | Positive terminal on some speakers; also listed as a 1/4 inch fit |
| 8.3 mm | Fits binding posts up to 8.3 mm or 5/16 inch |
| 8.9 mm | Fits binding posts up to 8.9 mm or .35 inch |
| 2.8 mm | Found in mixed assortments for smaller terminals |
| 5/16 inch | Common binding-post size equivalent to about 8.3 mm |
How to find your speaker's correct size
- Check the speaker or amplifier manual for the binding post size. Some manuals specify separate sizes by polarity: positive (+) may use 6.3 mm while negative (-) uses 4.8 mm. One official speaker manual documents two spade sizes by polarity: positive (+) uses 6.3 mm and negative (-) uses 4.8 mm.
- If you do not have the manual, measure the diameter of the metal binding post with a caliper or ruler. The connector fork width must match that measurement exactly.
- Note whether your speaker uses different sizes for positive and negative terminals. If the manual gives separate sizes, follow that exact pairing.
Matching wire gauge to your spade connector
Spade connectors are rated for specific wire gauges, and you must ensure compatibility. Some products pair connector size with specific wire ranges such as 10-18 AWG, 10-12 AWG, 14-16 AWG, or 12-18 AWG. Common wire ranges include 10-18 AWG, 10-12 AWG, 14-16 AWG, and 12-18 AWG. Check the connector’s specifications to confirm it accepts the gauge of your speaker wire. Using a connector rated for a different wire size can result in a loose fit or poor electrical contact.
Frequently Asked Questions
What size spade connector do most speakers use?
These two sizes cover the majority of consumer speaker binding posts.
Can one spade size fit all speakers?
No. The size must match the binding post exactly. Some speakers use 4.8 mm, 6.3 mm, 8.3 mm, or 8.9 mm posts, and using the wrong size can prevent a secure connection.
How do I know which one to buy?
Measure the diameter of your speaker’s binding post or check the manual. If the manual gives separate sizes for positive and negative terminals, buy connectors for each size. Also confirm that the connector is rated for your wire gauge.
Is this a setting I can change on my phone?
No. Spade connector size is a physical hardware match, not a phone software setting. No official iPhone or Android menu path, carrier option, or app setting exists for choosing spade connector size. This is unrelated to wireless audio connections.
