Amp upgrade questions

Hi all, have some questions about potentially upgrading the JBL amp in my 05 dbl cab tundra.

When I got the car, the previous owner had an old pioneer HU with an axxess module (GMOS-05?) to retain the factory amp. I bought a

$220 BOSS Audio Systems Elite BE7ACP-C Car Multimedia Player with Apple CarPlay Android Auto - 7" Capacitive Touchscreen, Double Din, Bluetooth, No CD/DVD, USB, SD, AV In, AM/FM, Backup Camera Included

BOSS headunit (has a pre-amp). I did not understand what the axxess stuff did at the time, so I wired the new HU by matching the wire colors to the axxess amp harness. It worked fine. A few months later, I turned on my car and got an extremely high pitched screeching sound. I assumed it was coming from either the amp or the axxess, so I bypassed both with the

$33 Metra 70-8117 Factory Amplifier Harness for 2004-Up Toyota Vehicles with JBL Sound System

metra bypass harness.

Ive been riding with this setup for a few months now, but Im not happy with the sound quality (it f*cking sucks) as the head unit I got doesn't have a built in amp, and its trying to push a lot of JBL speakers on its own.

Questions:
- Is it possible to upgrade the factory amp and keep the JBL speakers? Is this recommended? What kind of amp would I need?

- Does it make sense to rewire the factory amp? (aka how likely is it that the amp itself is what caused the screeching and not the wiring?) Im assuming ill need the

$11 Metra Electronics 70-8113 Amplifier Integration Harness for Select 2000-2004 Toyota Vehicles

metra 70-8113 for this option?

- Any ideas where the screeching audio could have come from? When I turned on my car, the speakers put out the loudest, most high pitched tone I have ever heard. I say "screeching" because it was so loud that it was painful. I probably lost some hearing because of it. Has anyone experienced this before?

 

YES.

• Amp bypass harness.
• New aftermarket amplifier to mount under the seat or in a cubby, somewhere, or behind the head unit if you go with the Alpine ilx-w650 head unit with piggy-back amp kit.
• New amp wiring kit, with at least a 10awg or 12awg fused wire thru the firewall, to the new amp.
• RCAs from the head unit to the amp
• Speaker leads on the amp bypass harness will be used for the amp output to the speakers

Highly doubt the amp is screeching. I suspect it's your install job, or the shit-tastic BOSS head unit you installed. They make garbage audio equipment, and have long been the laughing stock of the custom car audio world.

But you really need to get the exact model of Axxess unit you're using - it'll be printed on it somewhere - so we know whether it's for steering wheel controls retention, or JBL amplifier integration.

NO. At least, probably not. It clearly states that's for 2000-2004 Tundras (see next reply section for info). You have an '05. Please read this. Once you finish reading it, come back here and post which setup you have. i.e. JBL amplified or non-JBL amplified. Also, what cab type you have, since that's critical to udnerstand compatibility.

If you need harness info, or to understand what others are typically using, read this.

Not a clue where it came from, but if you suspect somehow the Axxess unit is involved, simply unplug its power and see if the problem continues.

You may want to read the "Audio and audio upgrades..." section of this sticky post.

Compatibility of that harness is as follows and instructions to install are here if you need clarity:

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PS - you'd be wise to check for loose grounds and loose wires. That could cause some pretty raucous noise if a ground came loose somewhere too...

 

Hey! You helped me fix my rats nest of wiring back in November. And funny enough...

Your post is using the photo in my thread of my wiring setup before I rewired everything haha

I have the Axxess ASWC-1 for steering wheel integration, along with the steering control harness. The previous owner installed the TYTO-01 (which I no longer have) for amp integration with his old pioneer. I'm currently setup with:

• Boss headunit (because it has android auto)
• Axxess ASWC-1 + harness
  
• Metra 70-8117 amp bypass harness
  
• Bypassed JBL amp in the rear, sitting unplugged

Now that you know my previous wiring was pretty wild, I think its probably likely that the screech was from the wiring and not the amp.

Amazon is notorious at having incorrect titles/years for car parts. I usually just read the reviews to confirm if it fits my make/model, or match the part number exactly. Heres the same harness from Crutchfield correctly showing its for 2000-2007. I didn't see anything about using a new HU with rear JBL amp in the harness info you posted.

What is the difference between the Metra 70-8113 and the tyto-01? Or it seems like i would need both in order to use the preamp on my headunit + the JBL amp in the rear?

Also, thanks for your help

 

Ah! You're right, I did reply on this. Sorry, I have selective memory on things. I just treat every audio post as a new one.

Yes, scAmazon sucks on compatibility, hence the image at the end of my last post, which clearly shows compatibility:
-- Tundra 2000-2003 (select models)
-- Tundra 2004-2005 (AC, RC only, not DC)

I see in the other thread, you have the JBL amplified system in a Double Cab. That Metra part you linked, per Metra, is not compatible with your '05 because wrong cab type. I also see the install sheet is pretty much garbage.

$33 Metra 70-8117 Factory Amplifier Harness for 2004-Up Toyota Vehicles with JBL Sound System

Metra 70-8117 should be the correct amp bypass for your system. You'd be plugging that in at the amp, then chasing the speaker and power cables up to the dash for repurpose with the BOSS unit. I highly doubt the harness is your problem: It's just a collection of wires. Problems come into play if you don't attach them correctly, or don't use proper fittings, or don't hook up some essential wire.

I hate pulling out my stereo to check wiring, therefore I hate asking people to pull their stereo to check wiring. There are technically a couple things we could do to test whether it's the Boss system causing probs, possibly.

You may try reattaching the amp bypass, then fading the BOSS unit all the way to front, then all the way to rear, just to see if the screech continues. You may repeat this step fading full-left to full-right to see if the screech continues. These steps could isolate whether it's tied to a specific channel. You may also try muting the stereo to see if it persists.

Look, I'm not shy about being critical of BOSS equipment. My first inclination is, "you got a defective head unit". But I've seen so much stupid BS caused by BOSS hardware over the years, far more catastrophic than you're dealing with. They are the bottom-barrel of the audio world. You'd be better off with Kenwood or Jensen (same company nowadays). Hell, I'd almost put more faith in the cheapo ATOTO mass produced hot garbage, but I don't trust them any farther than I can throw them.

It's also possible it's the wiring, but not being able to see the current wiring with my own eyes, it's hard to say. And to show the wiring, you gotta pull the head unit ... and I don't like asking for that

 

Just to clarify... My screech is already gone. I've already bypassed the amp using

$33 Metra 70-8117 Factory Amplifier Harness for 2004-Up Toyota Vehicles with JBL Sound System

Metra 70-8117. The screech was a problem I had before I installed the bypass. Im assuming it was from the previous wiring job.

Now my issue is poor sound quality. Understandable it sounds bad considering

• I'm bypassing the amplifier
  
• I'm not using the built in pre-amp on the new headunit
• the new headunit is boss

Can I utilize the preamp outputs on the BOSS unit in conjunction with the 8117 bypass? What would I need to do that?

 

AAaaaahhh.

Holy shit, I totally missed that point. I must've misread, I thought the post was about active screeching, and poor sounding audio.

The BOSS low level outputs are likely only to be used with an external amp; re-using your factory JBL amp would be somewhere between tedious and impossible, unless you want to return to using the Axxess JBL amp integration kit, but wire it up correctly, not with the haphazard shit the previous installer had setup.

The BOSS likely has shit for built-in amplification, hence the poor audio output; but if I were you, I'd test other inputs just in case it's actually a problem with CarPlay signals specifically. Does the audio suck with radio stations, for example? Does it suck if you link your phone via Bluetooth and play audio via Bluetooth? Sometimes sound quality problems can be fixed with firmware updates, BOSS may have an update available for your head unit.

The only other solution would really be installing an aftermarket amp OR a better quality head unit with better internal amplification. My Alpine (referenced above) has audio superior to the amplified OEM, for example. But there's no reason you couldn't go with, say, a compact external 4-channel amp (or better yet, 5-channel if you intend to ever add a sub!) to fill that void.

Some of what's out there is really small! Like, I mentioned the

$280 ilx-w650 digital multimedia receiver with carplay and android auto compatibility

ilx-w650 has the add-on piggyback amp available. Model number KTA-450 at around $225 I think. It actually bolts onto the back of the ilx radio like this, but it's only 4 channel @ 50w/channel I think:

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Sorry, I have more questions than answers first

Do you have the stock JBL speakers? If so, have you looked at them to make sure they are not blown (very common problem)? Secondly, they are 2 ohm speakers so it could be frying your head unit slowly. Thirdly, the JBL speakers up front are 3 way and your stereo doesn't have a way to decipher 3 way.

You've already done the hard part of bypassing the amp. I would replace the front speakers with components and use the crossover that comes with them. I went cheap-ish on my double cab and used the sound ordnance from crutchfield for the fronts and Memphis audio coaxial in the back. Sounds pretty good. Crtuchfiled sells the speaker brackets you'll need.

If that doesn't get the sound you want, you can add an amp easily just run the RC pre outs to the amp wire the speakers from the emtra bypass kit to the amp. I'm personally not a fan of amps for the speakers though because to me they make the speakers sound a bit harsh. I'm sure someone with knowledge could tune that out, but I'd rather spend my money on better speakers or a head unit than an amp. I put the ATOTO A6 in my son's car and I've been really impressed with it for a Chinese stereo.

$190 ATOTO A6PF Android Double-DIN Car Stereo, Wireless CarPlay, Wireless Android Auto, Mirrorlink, 7" Touchscreen in-Dash Navigation, GPS Tracker, WiFi/BT/USB Tethering, HD LRV, 2G+32G, A6G2A7PF

https://www.amazon.com/ATOTO-Android-Navigation-Stereo-Bluetooth/dp/B07B3T59TX

https://www.crutchfield.com/p_777P65CB/Sound-Ordnance-P-65CB.html?tp=105

https://www.crutchfield.com/p_953SRX62/Memphis-Audio-SRX62.html?tp=105

 

I can't speak to the JBL system having 2ohm speakers because I had non-JBL, but I had just as many speakers in the doors (Pics of mine here), and I had the same number of channels on the OEM Fujitsu amp as the JBL, mine were 4ohm (edit: well, two were. Read my next reply below). It'll usually tell you on the magnet of the speaker what the impedance is BUT you can change the impedance the radio sees based on how the speaker is wired up! So that value on the rear of the speaker has limited importance by itself, it's how it's wired that truly matters.

Even if @rock climber is correct, and the JBL speakers are 2ohm, if the Y-cable Toyota uses to wire up the front door actually puts the speakers in series, that would produce a 4ohm load, which wouldn't overload your integrated amp. There's no way they'd wire them up in parallel, creating a 1-ohm load. They also may add a resistor in that Y-cable to increase/decrease load, I'd hafta rip my old ones apart to know for sure.

If you want to know what load your amp is seeing, you can measure the resistance across the gray/gray-black strip OR the white/white-black strip wires to verify if that's even a possible issue for you. I'd also be interested to know the result. It could help us with making suggestions here.

I always recommend JBL components for a myriad of reasons. They typically aim for 3ohm impedance on their components to eek a little more out of your amp.

 

Actually, I just noticed two of the mids are 6ohm on my OEMs. I'm going to guess those were the fronts, and the tweets may've been 6ohm too, and they may've been running in parallel to get them down to 3ohm up front, or using other methods to dumb the impedance up/down.

 

Im not an audiophile, as long as its good enough, its fine with me. At this point, Im either going to buy new speakers, or buy the TYTO-01.

Cost of the speaker setup you recommended is $150.
TYTO is $62 on Amazon.

How much better is the sound quality of your new setup versus the stock speakers and amp? Do you think its worth $87 (speakers - TYTO)?


PS yes I have stock JBL speakers and they are 2ohm, which is the issue with my sound quality. They are not blown... yet .

 

My 06 Limited had a JBL 6 channel amp and three speakers in the front doors. The subwoofer, mid range speaker and tweeter. I think the front door speakers were 2 ohm and the tweeter was on a separate channel than the sub and mid. The rear door speaker were 4 ohm. So 4 channels to front doors and 2 channels to rear door.

I have an older single DIN Alpine head unit with a 5 yearish old Alpine 4 channel amp. The early version of the KTA-450 Shifty linked. The older Alpine amp I have did fit inside the dash behind the single din head unit. I zip tied it to something in the dash.

Front door sub and mid speaker

 

I used the TYTO in my daughters car and it's ok, but not great. If you can swing for the new speakers, I'd go that route. You can always start with the front only.

My stock speakers were blown when I got it so I can't speak to sound. My Sequoia has the JBL setup with the same speakers and they sound pretty good. Those were blown also so I replaced just the woofer with this and have been happy with them.

$57 PowerBass OE-700 (L2-700) OEM Replacement 7'' Midrange 2Ω Speakers (Pair)

https://www.amazon.com/Powerbass-L2-700-Midrange-Speakers-2Ω/dp/B00EYR4AJM

 

Haha, I don't doubt it; already had to return the first one I installed in January. Crutchfield replaced it and shipped me a different unit for free. The CarPlay cable intermittently failed and then totally failed and, while the Bluetooth function still worked, the audio over BT was a mess. Other than that though it pushed my OEM speakers just fine, and giving me access to front and rear cameras and all the other goodies? Sold. I just can't justify spending 400-500 dollars for better-known brands entry-level head unit models.

Also, Crutchfield really has outstanding customer service.

 

It's not necessarily the speakers that will blow. When you're forcing the integrated amplifier inside your head unit to handle a 2-ohm load while most are typically expecting a 4-ohm load, the amp is having to work significantly harder to push the speakers. You can blow your speakers if the amp can't keep up and introduces a shitload of noise trying to keep up, while you're cranking it. Power doesn't destroy speakers nearly as fast as power+distortion does. That little amp doesn't have the heft, circuitry, and cooling to support the extra strain.

You can also really screw shit up if you managed to, say, bridge the front 2ohm door speakers and push things down to a 1-ohm load. I don't specifically know how the amp bypass kit is working with the JBL setup if the system is running two separate channels for each front door, one for the tweeter, one for the mid - I posted the wiring breakout from Crutchfield below.

The amp bypass harness I used for my truck only had 4 speaker inputs off the bypass harness using the standard colors: white pair, grey pair, purple pair, green pair. Are you pairing up any wires, tying two bypass speaker wires into one speaker wire at the head unit?

Once again, I'll say it: I'd like to see the actual wiring to diagnose if that's the root issue. I could easily see someone mixing up the green/red or green/white wires for green and/or green/black. Or even the white/red with white and/or white/red. There is this warning w/Crutchfield also:

They are really good like that.

And FWIW, I got my Alpine head for $279 if memory serves, on sale, at Crutchfield. It's a hell of a lot of bang vs. buck and can be had all day for $300. I paid $30 more than the OP for mine. I see a couple of sellers right now at $300, so $50 more. Several of us have it, and it's Alpine quality for like 10-15% more? No-brainer to me.

Pic for my other reply above:

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