02 Rx300 -is Sound Eq'd Before It Gets To The Speakers?

shovel99 · February 11, 2008

Hi Folks,

I have an '02 RX300 Navigation and the sound system sounds like turds. It is the "Lexus Premium Sound"... Feature that! There is absolutely no sound starting around 300hz... all vocals and most instruments completely gone between 300-2khz and then screaming, hissy midrange peak that hurts my ears so bad I can't listen to it. I literally bought a portable CD player and it is much better than this trash. There is voluminous puffy, distorted, boomy midbass (no real bass: nothing below 100hz that I can detect). On the radio, I have to push down the bass 3 or 4 clicks to just listen.

I got great instructions on how to get the speakers out at www.carstereoremoval.com removed and tested the 6.5 inch front door woofer on my computer cad speaker design and testing system (20hz to 40,000 hz capability at + - 1/2 dB). When I pulled the tweeter out of the dash and measured it with the lab quality system, the tweeter put out nothing below 10,000 hz with its crossover (one capacitor) connected! Just one sharp nasty peak at around 14,000 hz! I disconnected it altogether and that side sounded better.

Then I used carstereoremoval.com's instructions to remove the front door woofer and tested it on my test setup. It rolled off steeply at 100hz ( read: NO REAL BASS)... then the response was fairly flat up to around 2000 hz... at which point it shelfed up 6 dB (read: increased in volume by quadrupling) ... and then continued at that punishingly loud level for midrange to about 6000 hz, then dropped back the 6 dB to the previous level.. and rolled off at around 10k.

The plateau from 2 k to 6 k explains the searingly screamy scratchy highs. But where is the really puffy midbass coming from in the system?

Here is my question: what I have described is the response of the speaker itself, in a test box, out of the car. Where is the huge, puffy midbass coming from when it is hooked up?

Has Lexus put incredibly crappy cheap speakers in this car and then EQ (equalized by adding subtracting bass, treble, mid, etc.) the terrible speakers from inside the head unit or amplifier? Preventing us from fixing cheap speakers with good cheap speakers? It sure looks that way. And worse... it is operated by a proprietary navigation system.

Sucks a bunch.

Hope someone has some answers.

Maybe I'll buy a Ford that I can put a $200 radio and $60 speakers in and have real sound.

shovel99