View Full Version : Late Model Lexus speaker size and impedance questions.....

08-02-2010, 08:40 PM
Aite, here's the deal. I have just purchased an '06 Lexus IS350, and would like to upgrade the audio. I have done quite a few systems in the past, but never anything this late model, complicated or high tech.

Here is what I know for sure, the car does NOT have the Mark Levinson sound system upgrade, but it does still have at least 12 speakers in it and a factory amp in the trunk. I do not think I want to run a processor (for now) and deal with bypassing the factory amp, so I am wanting to start with upgrading the speakers.
Now, each door has three speakers in it, a woofer at the bottom, a mid in the middle and a tweet at the top near the glass. With so many speakers (and it being a Lexus) you would think that this would sound pretty good already, but the factory system in my '03 Accord has more of a bass and mid-bass stage than the Lexus.
I know that the "woofer" in each door is approximately a 6 1/2" , and there are even adapter plates available on Ebay which will allow me to run an aftermarket 6 1/2" in the funky factory three mounting hold configuration. There are also brackets available for the tweets. This would lead me to believe that I can run two sets of components and knock out 8 of the 12 factory speakers. What I can't find anything on, is the size of the mids. I would also like to know if anyone has any recommendations for the replacements for the mids.
Lastly, the impedance. I read several forums on Lexus sites, where people have changed factory speakers for aftermarket, only to find that the overall SQ has diminished. In most instances, someone replying to the thread has indicated that the impedence of the aftermarket speakers is not consistent with what the factory amp is set up to handle. While I do find it hard to believe that the factory amp would be unstable with less than, I don't know say 8ohm speakers, I do not want to go through the headache of making the change and having the same result.
As always, and help is greatly appreciated.

Rich B
08-02-2010, 08:46 PM
Go to the Crutchfield website and use their fit calculator to see what sizes of speakers they recommend for your car.

08-02-2010, 09:14 PM
I have done this bro, with other cars and trucks as well, but when Crutchfield sells speakers, they will provide adapter brackets that will allow multiple speaker sizes to fit in the openeing. They do not give a definitive answer as to the factory speaker size. Go there and look up something that you know takes a certain size (2001 Olds Bravada uses an oversize 6.5 in the doors), they will show you that 5.25", 6", 6.5" and 6.75" will work becasue their kit will allow any of them to be used. Great if you are buying speakers from them, lame if you are trying to get a size. Not to mention that people should be PISSED if they bought 5.25" speakers when they could have gone with a larger size........