To boost bass, the best options are adding a subwoofer or upgrading speakers. However, for more bass from 6.5-inch speakers alone, try these:

• Adjust your stereo’s equalizer for more low-end sound
• Incorporate noise reduction materials around the speaker
• Encase the speaker with a rubber seal

The only distinction is size – 6 speakers are six inches in diameter, while 6.5 speakers are 6.5 inches. Both offer comparable sound, with one size potentially better fitting your vehicle.

The optimal size is contingent on the space you have. Common selections include 6.5-inch and 6×9-inch speakers, which offer excellent sound, superior high- and midrange quality, and even a bit of bass. Typically, 6.5-inch speakers are perfect for door installation, whereas 6×9-inch speakers are suitable for the back seat.

Indeed, there are ways to enhance cheap speakers:

• Choose a prime location for better sound quality
• Add an equalizer or inline capacitor to reduce unpleasant frequencies
• Incorporate an amplifier matching your speakers’ RMS output

Your choice hinges on your personal taste and the type of content you’re consuming. For many, setting the midrange to 0, with bass and treble at +4 and +5, makes music sound better.

A 5-inch hole opening is typically needed for most round speakers that are 6.5 inches in diameter. If replacing the old 6.5-inch speakers, the new ones should fit the same hole. If cutting a hole for new speakers, use a 5-inch hole saw.

These speakers excel in providing good high- and mid-range sound. They fit well in car doors and complement 6×9-inch speakers or a subwoofer.

Speakers like the JBL GTO629, JVC CS-J620, and Polk Audio DB6501 are excellent choices if you want deep, nuanced low-end.