Help with audio questions

[cgrantkiter]

I have a new to me 2004 GX470 Non-nav, no ML. I have already installed an Alpine ILX F509 in the dash (love it), and more than anything it has revealed the reality of the condition that the nearly 21 year old speakers are in. I've already ordered some Morel Maximo Ultra 603 MKII's for the front (6.5" 3-way setup with passive crossovers) and Morel Maximo Ultra Coaxial 602's (also 6.5") for the rear doors. I'll sort out the sub at a later time.

My first question is mostly about the signal being delivered to the front doors from the amp under the driver seat.

Is there an active crossover network in the amp? Do the lower woofers get a full range or low pass signal? What about the mid and tweeter? Are there passive crossovers in the doors or does each speaker get it's power directly from the amp independently of the others? If there is an active crossover in the amp or even an existing mid/tweet passive crossover, I may just install the speakers and feed them directly from the existing power leads and leave the Morel crossover out of the circuit until I upgrade the amp in the future. Something else I have noticed is that the balance and fade response seems a bit strange. If I go full front/left (or any other full corner position), I'm still hearing some sound on other speakers. I had Crutchfield prewire the harness, so it was all just plug and play for the install. Only thing I can think is that they have some mismatched wire pairs, but I would suspect I would be seeing other issues as well.

Next question is what are the inputs to the factory amp? FR, RR, FL, RL? I'm considering using these as speaker level inputs for the future amp upgrade if so, but it does leave me lacking a dedicated subwoofer channel that I can tune in the headunit and has me thinking about just running RCA's for all the channels. What is the fuse rating and wire gauge of the power circuit for the factory amp? I'm leaning towards a JL Audio XDM 700/5 (75 x 4 rms into 4 ohm + 300 x 1 rms into 2 ohms) and it calls for (I think) a 60 A feed with 4 gauge power and ground and I would be shocked if the factory amp is using anything approaching that.

Since the rears are coax replacing coax, I don't really have any concerns there.

I did seach the threads and did not find any clear answers to these questions, so if it is out there, I apologize.

 

[McPierson]

I have a new to me 2004 GX470 Non-nav, no ML. I have already installed an Alpine ILX F509 in the dash (love it), and more than anything it has revealed the reality of the condition that the nearly 21 year old speakers are in. I've already ordered some Morel Maximo Ultra 603 MKII's for the front (6.5" 3-way setup with passive crossovers) and Morel Maximo Ultra Coaxial 602's (also 6.5") for the rear doors. I'll sort out the sub at a later time.

My first question is mostly about the signal being delivered to the front doors from the amp under the driver seat.

Is there an active crossover network in the amp? Do the lower woofers get a full range or low pass signal? What about the mid and tweeter? Are there passive crossovers in the doors or does each speaker get it's power directly from the amp independently of the others? If there is an active crossover in the amp or even an existing mid/tweet passive crossover, I may just install the speakers and feed them directly from the existing power leads and leave the Morel crossover out of the circuit until I upgrade the amp in the future. Something else I have noticed is that the balance and fade response seems a bit strange. If I go full front/left (or any other full corner position), I'm still hearing some sound on other speakers. I had Crutchfield prewire the harness, so it was all just plug and play for the install. Only thing I can think is that they have some mismatched wire pairs, but I would suspect I would be seeing other issues as well.

Next question is what are the inputs to the factory amp? FR, RR, FL, RL? I'm considering using these as speaker level inputs for the future amp upgrade if so, but it does leave me lacking a dedicated subwoofer channel that I can tune in the headunit and has me thinking about just running RCA's for all the channels. What is the fuse rating and wire gauge of the power circuit for the factory amp? I'm leaning towards a JL Audio XDM 700/5 (75 x 4 rms into 4 ohm + 300 x 1 rms into 2 ohms) and it calls for (I think) a 60 A feed with 4 gauge power and ground and I would be shocked if the factory amp is using anything approaching that.

Since the rears are coax replacing coax, I don't really have any concerns there.

I did seach the threads and did not find any clear answers to these questions, so if it is out there, I apologize.

I’m posting without certainty on the GX, but lots of experience on an 02 GS…
Based on. Looking for GX470 Wiring Diagram - ClubLexus - Lexus Forum Discussion - https://www.clublexus.com/forums/lexus-audio-video-security-and-electronics/399783-looking-for-gx470-wiring-diagram.html

There is a separate signal to the front woofers and then a signal to the mids and tweets with a passive crossover to separate those two. Probably keeping the OEM crossovers would be best.

There are only left and right signals sent to the amp. Then there is a communications that handles volume, fad, balance, probably bass treble mid too. I’m not sure how Crutchfield handles this, but you need to call them. Their customer service is absolutely the best help you can get. They have the diagrams and will be best able to figure out your fad issue.

 

[cgrantkiter]

I’m posting without certainty on the GX, but lots of experience on an 02 GS…
Based on. Looking for GX470 Wiring Diagram - ClubLexus - Lexus Forum Discussion - https://www.clublexus.com/forums/lexus-audio-video-security-and-electronics/399783-looking-for-gx470-wiring-diagram.html

There is a separate signal to the front woofers and then a signal to the mids and tweets with a passive crossover to separate those two. Probably keeping the OEM crossovers would be best.

There are only left and right signals sent to the amp. Then there is a communications that handles volume, fad, balance, probably bass treble mid too. I’m not sure how Crutchfield handles this, but you need to call them. Their customer service is absolutely the best help you can get. They have the diagrams and will be best able to figure out your fad issue.

Thanks. I did find a video of an install on the non-ML GX, so I have a bit more info to go on now. I think I'm going to run the feed to the 6.5" woofer unfiltered from the amp. The other signal comes to the tweeter first and then goes to the mids. I'm going to take the OEM filter out of the circuit and run the line feeding the tweeter as the input to my Morel crossover and then use just the mid and tweeter outputs to send back to those speakers. I'd like to be able to play with the tweeter biasing using the jumper pins on my crossover, so don't want to run them without it. Back door is easy with a 2 way coaxial.