Hey, I've got a 73 240z and after doing some spelunking it turns out the previous owner had the rear MSA speakerbox setup in the car, and at some point they removed it, and just left the speaker wire in the back.

I want to install a pair of speakers in the back, and like the cleaner look of mounting them behind the interior panels with matching mounts on each side, similar to how the original speaker was mounted, but was curious if anyone had any experience on what the sound quality of the speaker behind the panel was like? I can't imagine it's particularly great, but wanted to check.

If that doesn't work, I'll probably move forward with fabricating my own speaker box similar to the MSA setup.

Thanks!

I would go with an MSA style box if sound matters to you at all. The factory location is pretty poor.

Agree with Mr [mention=22019]Patcon[/mention] - the factory location on my 260z (just behind the seats on the sides with tiny speakers) isn’t great for sound. Let alone anything in the luggage area behind strut towers!
 
BUT, this little baby (USW10) under the passenger seat transformed things to an “acceptable” standard. The sub volume controller is hidden under the ashtray and very useful to have for easy tweaking. Shockingly great bass from such a little thing! Incidentally, I refuse to put more holes into my car than the factory did, so I used industrial Velcro to hold it down. A total no no for sub woofer mounting, but it works exceptionally well and didn’t have a detrimental affect.

https://amzn.eu/d/4M8AstJ
 
Then having gone through the effort, I found myself just listening to the engine [emoji14]
Seriously though, in my experience as a car audio-holic in my younger days, what I’ve found is that with speakers, the “cavity” and its solidity / sealing was everything when it comes to decent bass and some mid range.

In a car environment it’s hard to beat a decent (and discrete) pair of 2 way speakers at the front with separate tweeters up high - ideally at dashboard top height but maybe at visor height in a Z to keep things looking clean?

Finally, MLV sound deadening is vital on the car panels behind / around the speakers - especially if open cavity. My high end 6x9s on a custom heavy arse shelf sounded amazing in one car. But the same set up transferred into a hot-hatch French car with panels made of Cornflake packets sounded like $10 speakers. The paper thin panels just absorbed everything but treble!

 

If you move the sub woofer under the driver seat you can feel the music even if you cannot hear it over the exhaust. 

33 minutes ago, Jeff Berk said:

If you move the sub woofer under the driver seat you can feel the music even if you cannot hear it over the exhaust. 

I'm too old for all that now!!

I get mostly engine/exhaust sound and mine sounds like a burbly V8 due to the performance cam installed in the 80s

I might actually try grabbing some 6x9's and see if I can put them behind the panels and see if that sounds good enough, and if I want something better I can at least swap them over to a custom box at the back. I think 6.5s might be too big and not sure if 5.25s would be a bit small.

 

If you move the sub woofer under the driver seat you can feel the music even if you cannot hear it over the exhaust. 

You know, my MR2 in the 90’s had a sub behind both seats from the factory and it was stunning in operation! Didn’t shake the cars around me, but in the car it shook your bottom nicely!