New Head Unit

[Dan_Harris]

Ok guys just picked up my lex at the weekend (thanks again to scorps), looking at getting a Pioneer P80BT for it, this is double din which i'm right in thinking shouldn't be too much of a problem to fit?

-My only checks are how easy/hard is it to remove the old headunit?

-Will the cd changer work fine with this headunit, also will I need any extra cables for this?

-Anything else I should be carefull and cautious of?

Thanks

Dan

[Parthiban]

-My only checks are how easy/hard is it to remove the old headunit?

-Will the cd changer work fine with this headunit, also will I need any extra cables for this?

-Anything else I should be carefull and cautious of?

Not difficult to remove the old headunit, there's a few walkthroughs on here of how to get it out, on my car with satnav I think it was 6 screws and the whole centre lot was out, not sure on cars without the nav screen at the top.

Which CD changer? If you're talking about the Lexus one, it's built into the headunit so once you lose the headunit, you lose the CD changer, but please forgive me if I've totally misunderstood! :shutit:

I'm assuming it's an SE or Sport? If so, you'll need the amp bypass cable available on eBay (or build one yourself) to be able to put the sound through the car's OEM speakers........or are you replacing all the speakers as well?

Make sure you mask up the dash very carefully, it scratches very easily and the corners of the stereo can easily make a mess of it

[Dan_Harris]

I have just realised how dumb I have made myself look *runs and hides* , but yes I will be running a seperate headunit through the OEM speakers, so I will need a bypass cable for this? For ref I have a is200 sport.

[Parthiban]

I have just realised how dumb I have made myself look *runs and hides* , but yes I will be running a seperate headunit through the OEM speakers, so I will need a bypass cable for this? For ref I have a is200 sport.

Lol, no worries matey, yep you'll need a bypass cable, the SE and Sport models have an external amp behind the glovebox so you'll need the bypass cable.

It's a pain in the a$$ to remove the cable from the amp though so be prepared for some scraped knuckles and a lot of swearing!

[Dan_Harris]

any guides on how to do this?

[TigerFish]

I'm assuming it's an SE or Sport? If so, you'll need the amp bypass cable available on ebay (or build one yourself) to be able to put the sound through the car's OEM speakers........or are you replacing all the speakers as well?

I thought the bypass cable essentially just patched the ins and outs of the amp together to bypass it. Without it you would need to do it yourself i.e. it doesn't do anything as far as impedence goes and is just allowing you an easy way to use the speaker cables already installed in the car. Nothing to do with the speakers themselves? or is there some jiggery-pokery going on in the bypass cable too?

[Parthiban]

I'm assuming it's an SE or Sport? If so, you'll need the amp bypass cable available on ebay (or build one yourself) to be able to put the sound through the car's OEM speakers........or are you replacing all the speakers as well?

I thought the bypass cable essentially just patched the ins and outs of the amp together to bypass it. Without it you would need to do it yourself i.e. it doesn't do anything as far as impedence goes and is just allowing you an easy way to use the speaker cables already installed in the car. Nothing to do with the speakers themselves? or is there some jiggery-pokery going on in the bypass cable too?

I actually have no idea, know you need the cable but not really sure of the reasons why - although people have done without it so I assume it can be wired yourself if you know what you're doing..........

One of the others who knows what they're doing (Geoffers/Wozza ) could probably explain what needs to be done :)

With regards to guides, Wozza's guide to replacing the headunit is quite a good one :winky:

[DJ Wozza]

To clear this up, the bypass cable actually is mis-named.

It actually goes from the ISO at the back of the new Head Unit to the back of the amp.

The other cable in the back of the amp actually stays there and supplies the speakers.

All the "bypass" cable actually does is match the outpust of the New Head Unit,

to the input section of the amplifier. There is in fact no bypass.

The amplifier still does all the splitting of signals and impedence matching.

Instructions should come with the lead re-fitting, just remember to carefull cut the cable ties to the cable

you need to remove from the amp as it will make removing it easier. There is a keyway that needs to

be pushed on the connector to remove the plug from the amp.

To get to the amp in the first place, open the glovebox and pull the sides of the glovebox towards the middle.

The glovebox will now flop down (spilling it's contents on the floor if you didn't empty it first).

If you have difficulty, the glovebox is mounted on 2 plastic pins in a hinge. they are easily removed by pushing

the outisde of the pins towards the centre of the glovebox. Replacement is the reverse of removal.

The amp is on the left bulkhead and the cables are connected into the amp from the back.

You can also give yourself a tiny bit more room, but unbolting the front amp bot and then with the bit of movement in

the amp mount you are left with, should find it slightly easier.

Job done :D

[Dan_Harris]

wozza you have just earned yourself some milk and cookies :)

[DJ Wozza]

or a cold beer @ JAE :winky:

[Parthiban]

Cheers for sorting that Woz, I actually removed both bolts from the amp to completely free it and I still couldn't get the damn cable out!

Obviously I can't guarantee yours will be as strong as mine so do this at your own risk, but I had to use the blunt end of a screwdriver to push the cable out of the amp as it simply wouldn't move at all :duh:

[Dan_Harris]

or a cold beer @ JAE :winky:

haha, JAE may have to take a back seat. As funds are low seeing as I've forked out for the car + insurance this month! Will probably be at the next meet though :)

[aztecbandit1]

any guides on how to do this?

Dan have a look here mate as i did a quick walkthrough on the amp bypass cable fitting yesterday as i was bored :D CLICK ME

[TigerFish]

To clear this up, the bypass cable actually is mis-named.

It actually goes from the ISO at the back of the new Head Unit to the back of the amp.

The other cable in the back of the amp actually stays there and supplies the speakers.

All the "bypass" cable actually does is match the outpust of the New Head Unit,

to the input section of the amplifier. There is in fact no bypass.

The amplifier still does all the splitting of signals and impedence matching.

Sorry for going off topic

I am more confused about the bypass lead now after reading this bit and aztecs great walk through. In that thread, stav mentions removing the other connector and taking out the amp altogether. Sooo, that leads to the question "what is the lead actually doing and what is the amp doing in Wozza's quote above?". Looking at the pics on Aztecs thread, the bypass lead looks like it is plugging straight into the outputs of the amp, and therefore it is "bypassing" the amp. Anyone got a circuit diagram for the Stereo wiring to check the colour codes? I'm interested in seeing how the bypass cable is matching impedences and stuff assuming the wire colours match up to the speaker wire outputs of the amp.

[madmikedrivesanis200]

i have just replaced mine. the walk thru guide to getting the old unit out that wozza provided was top notch so get that.

the hardest bit is indeed getting the cables out the amp. we removed the bolts on the amp, ended up removing some of the door trim as well to get it out. Took us over an hour to do that and about 15 minutes to do everything else =D

the "bypass" cable comes with full fitting instructions off eBay as well.

[chrisis200]

Tiger Fish I could be wrong but I thought this so called bypass lead was just infact a extension lead really. Power from the Battery now goes to the HU direct, rather than through the amp an from the amp to the HU. Ofcourse I could be very wrong I'm no expert an have had mine happily fitted for years :D

[TigerFish]

Tiger Fish I could be wrong but I thought this so called bypass lead was just infact a extension lead really. Power from the battery now goes to the HU direct, rather than through the amp an from the amp to the HU. Ofcourse I could be very wrong I'm no expert an have had mine happily fitted for years :D

Yeah, I'm guessing that is part of it mate. Although the outputs of the new head unit must go somewhere. This is where the question of the original amp removal comes into it. If the stock amp can be ditched, it can't be doing anything as far as impedence matching goes ( through the stock amp). in which case, either the cable has some trickery going on in it or there is no impedence matching. If it can't be ditched, then how does it take high level speakers outputs from the head unit and feed them through the low level inputs that the stock head unit would've had?

[Jon557]

Hi, I just fitted my bypass lead and have the same question as TigerFish, can I unplug the small connector aswell and take the amp out of the car as its now dead weight?!

It looks like all the speakers now go straight past the amp into the bypass lead and into my new headunit.

Cheers, Jon

[Parthiban]

I'm confused now too, the way Wozza explained it made sense and agreed with what I did when I fitted a phone mute into the standard setup - all you are doing is unplugging the cable from the back of the amp that used to go to the OEM headunit, and plugging in the new bypass cable in its place that has the standard ISO on the other end that plugs into the new headunit. Otherwise everything else is unchanged.

Is that not correct?

[DJ Wozza]

Sounds to me like maybe there are different "bypass cables" available, or someone is telling porkies.

I was told by someone who is very experienced in IS200 Sound & Sat-Nav, that all the bypass cable does,

is go between the new Head Unit & Stock Amp.

The impedence matching is done inside the stock amp, not in the bypass cable.

If this is incorrect, maybe someone else who has fitted one recently will correct me & provide the instructions that came with their cable.

The only time the Stock Amplifier is removed, is when speakers in the car are being replaced, and the new Head Unit or seperate Amplifier

is powering them.

[Jon557]

Ok, must be different cables then.

I fitted the power cable for my new sub but I am having trouble getting it in the boot because its an annoying saloon! It almost fit the other day, but I have discovered a few new angles I will try tonight. A word of warning, anyone thinking about getting a 15inch sub needs to be careful, in my case the box is a funny shape. I thought I could take the seats off and put it through that way, but oh no there is a large metal back to the seats so screw that lol.

How annoying, might have to downgrade to a 12inch. lol

Jon

[DJ Wozza]

Hi Jon,

I think 14" is the maximum gap for a box to get through the opened boot aperture mate.

I had to have the box for my JL Audio 12W7 specially redesigned so the internal volume

& port dimemnsions were correct as the recommended specs were for a box 15" high.

[84Stoney]

I'm not sure on this one. I was told (by maker and seller of "by pass" cables) that my standard speakers would sound better, as they would be getting 4x52w output from my headunit and the stock amp was only 4x25w. When I asked about impendance etc, he told me something about the headunit still seeing the same total impendance from the speakers and that it would be fine.

At the time I didn't think anything of it. But now you have go me thinking...

That would certainly imply that the amp was no longer being used at all. Also, a couple of treads recently on fitting by pass cables have said that you can remove the amp completely, (which i have now done, but not relevent as also have external amps). But several people have done without problems.

I have to disagree with Wozza, but at the same time agree totally:

Sounds to me like maybe there are different "bypass cables" available, or someone is telling porkies.

I don't beleive you are telling porkies, and I know that I am not!

I think we can conclude that there must be more than one design of "by passs" cable.

[Jon557]

Lol, do'h!! Well all the boxes are different slightly, so I have taken its rubber edges off and will take the plasic edges off the boot and possibly the floor because my box is quite triangular and might fit at an angle. But there is plenty of room in the actual boot for it, just this darn enterance, I will try it tonight when it is dark and so I dont look like an idiot lol.

I will let you know how I get on. haha

Cheers, Jon

[Jon557]

I DID IT! I took some photos and will make a new thread just to share what I had to do. The sub is VIBE's Evo Active 15" (complete in enclosure), see here http://www.vibeaudio.co.uk/products/evoactives/

Jon