Siblings in JBL's Studio series, so they share a family sound. It comes down to size, output and price.
| Area | Better | Why |
|---|
| Bass | B | JBL Studio 2 8IW digs deeper - 30Hz against 58Hz. |
| Amplifier needs | A | JBL Studio 665C is more sensitive (90dB vs 88dB), so it goes louder on the same amplifier. |
| Amplifier match | B | JBL Studio 2 8IW is the easier load at 8 ohms. |
| Size | depends | JBL Studio 2 8IW is easier to place; JBL Studio 665C is bigger, which usually goes with fuller bass. Your room decides. |
| Type | depends | A Passive Center Channel against a Passive In-wall - a different job rather than a better one. |
| Cabinet | depends | Ported vs In-wall. |
| Price | A | JBL Studio 665C is cheaper - $400 against $700, about 43% less; arguably a different class. |
A JBL Studio 665C B JBL Studio 2 8IW
depends neither is better in the abstract - it turns on your room, your system or how you will use them. Only specs published for both speakers are judged; anything missing on either side is left out rather than guessed.
Which should you choose?
JBL Studio 2 8IW is ahead, but only on 1 of the measured areas, and it costs about 75% more. That is a lot of money for a narrow margin on paper - JBL Studio 665C looks like the sensible buy unless something else about the JBL Studio 2 8IW appeals to you. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 58Hz anyway, which makes the cheaper JBL Studio 665C much easier to justify. In a large or open-plan room, JBL Studio 665C has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, JBL Studio 2 8IW is the easier speaker to get right.
And remember what a spec sheet cannot show: how each looks in your room and whether the finish suits it, what dealer support and warranty are like where you live, and how they actually sound to you. If you can hear them first - ideally with your own music - that will tell you more than any number above.