I’ve continued to experiment with audio upgrades little by little on this vehicle. I’ve caught up in my understanding with a few of you who went all-in on a complete system replacement and come up with a few of my own observations, specifically about the Beatsonic amp application in this vehicle.
The JBL audio system makes the Land Cruiser a very poor subject for audio upgrade tinkering. This has become more and more apparent to me the deeper in I get. This mostly because there is a very complex audio control module/amp between the head unit and the speakers that does all sorts of things, known and unknown. For sure, it is where the amp is for the JBL system speakers. It receives a signal from the head unit and processes that into parsed and crossed-over signals for the various speakers across the system. What I’m still not sure about is how the vehicle alert tones and other non-entertainment information processes - my suspicion is that the head unit does not originate this stuff (like, for example, a Porsche PCM unit does); instead it comes from some other source and feeds directly into the JBL processor, which then combines it with the MMI signal and sends it to the speakers. This, alone, makes it very challenging to upgrade the system meaningfully as removing or bypassing the JBL control unit would have unintended effect on this group of signals. You might stop hearing the parking sensor alerts, for example.
As goes signal crossover. It appears that the JBL unit sends a full-range signal to the front stereo channels, which include the front door speakers and the dash speakers. For this reason, it can be reasonably effective to upgrade those speakers. From what I can tell, the OEM speakers are 2-ohm speakers but very inefficient. So you can replace them with much more widely available 4-ohm speakers that are more efficient and see an increase in output and sound quality. I see no reason not to upgrade the front speaker group if you are inclined. It’s easy to do and will sound better.
The rear door speakers appear to have a high-pass filter applied in the JBL control unit. This means that the door/tweeter set receives a signal where some of the low end has been attenuated or removed. There is another crossover at the tweeter that is visible when you remove the door card - this removes much of the remaining low end sent to the tweeters and sends that low-end, such as it is, to the door speakers. But there is little “bass” frequency in the signal that reaches the tweeter crossover to begin with, so upgrading the rear door speakers bears little or no return. If you choose a more sensitive speaker, it might be a little louder, but it is still a midrange function that will not be notably improved upon by an aftermarket speaker
What makes this strange is that, presumably, JBL did it this way because there is a subwoofer in the back hatch and they wanted that sub and the rear door speakers to operate as a unit. If true, the execution is dismal because the subwoofer provides so little output that you pretty much have to sit or stand next to it with your ear to it in order to hear anything. It might as well not be there. You can’t adjust the balance or level - the JBL control unit calls the shots there. So, there’s not much you can do with the rear channels (including the sub) that does not involve major surgery.
Now onto the great mystery, which is the Beatsonic amp.
This is an aftermarket amp marketed as an upgrade to the OEM amp in the Land Cruiser, among other vehicles. The installation places it immediately downstream of the MMI head unit with the JBL control module (which is under the driver’s seat) between it and the speakers. Here is what that means:
The Beatsonic is a 45 WPC amp, and possibly a very good one - but you will never know if you install it in your Land Cruiser. It receives a signal from the head unit, which I believe to be an amplified speaker-level signal, converts that into a line-level signal, runs that signal through its own gain stage and amplifier, then sends its output to the JBL unit downstream.
From there, there are only two ways this could work, electronically.
Way #1 is that the JBL amp splits that amplified signal across multiple channels and sends it to the speakers, along with whatever other processing it does to the signal. This is almost certainly NOT happening here, as there are many more output channels from the JBL unit than input channels. There’s the front speaker set (including a center channel), the rear doors, the subwoofer, and those little fill speakers in the hatch near the sub. I’m 99.99999% confident that the Beatsonic amp is not designed to be stable across the total resistance load, which would be exceedingly low, for all of those channels.
So Way #2 is probably what is happening - which is that the JBL unit does the same thing the Beatsonic amp did. It accepts a speaker-level input, converts it to line level (leaving behind the 45 WPS amplification the Beatsonic added), re-amplifies it, processes it variously, and sends output to the speakers. This means that the Beatsonic amp is basically doing nothing, except potentially sending a higher gain signal to the JBL unit that results audibly into a slightly louder output. If you run the Beatsonic amp, like I do, you are still hearing the OEM JBL amp, not the Beatsonic amp, whose work is being discarded within the JBL unit.
Now - I do think my stereo sounds better than it originally did. I have JL Audio 6x9” door speakers and 3.5” dash speakers in the front, Hertz 6.5” woofers in the rear doors, and the Beatsonic amp. All of those speakers are of substantially better quality than the OEMs, and seem to be more sensitive. That alone makes the system seem more assertive. But if I am right about my diagnosis above, Beatsonic is being a bit disingenuous about the advantage of their product. It may be amplifying the head unit signal, but we never hear that. I have not done an A/B with and without the Beatsonic in place to listen to how my aftermarket speakers sound - and I’m not likely to based on how hard the Beatsonic amp is to reach - but I wonder if it would sound any different or much different.
A few of you apparently figured this out before I did and you found a way to bypass the JBL control unit entirely. You may or may not have run into any unintended loss of non-MMI material in the output along the way. That upgrade approach is more $$$ and time than I’m willing to commit right now, myself.
I’m annoyed by the “premium system!! 15 speakers!!” marketing for these upgraded stereo systems. I’ll take a four channel head unit output, a nice four channel amp, and two sets of 6.5” or 6x9” separates any day. Unfortunately the system is much more complex, and harder to hot-wire, than that in these Land Cruisers.
The JBL audio system makes the Land Cruiser a very poor subject for audio upgrade tinkering. This has become more and more apparent to me the deeper in I get. This mostly because there is a very complex audio control module/amp between the head unit and the speakers that does all sorts of things, known and unknown. For sure, it is where the amp is for the JBL system speakers. It receives a signal from the head unit and processes that into parsed and crossed-over signals for the various speakers across the system. What I’m still not sure about is how the vehicle alert tones and other non-entertainment information processes - my suspicion is that the head unit does not originate this stuff (like, for example, a Porsche PCM unit does); instead it comes from some other source and feeds directly into the JBL processor, which then combines it with the MMI signal and sends it to the speakers. This, alone, makes it very challenging to upgrade the system meaningfully as removing or bypassing the JBL control unit would have unintended effect on this group of signals. You might stop hearing the parking sensor alerts, for example.
As goes signal crossover. It appears that the JBL unit sends a full-range signal to the front stereo channels, which include the front door speakers and the dash speakers. For this reason, it can be reasonably effective to upgrade those speakers. From what I can tell, the OEM speakers are 2-ohm speakers but very inefficient. So you can replace them with much more widely available 4-ohm speakers that are more efficient and see an increase in output and sound quality. I see no reason not to upgrade the front speaker group if you are inclined. It’s easy to do and will sound better.
The rear door speakers appear to have a high-pass filter applied in the JBL control unit. This means that the door/tweeter set receives a signal where some of the low end has been attenuated or removed. There is another crossover at the tweeter that is visible when you remove the door card - this removes much of the remaining low end sent to the tweeters and sends that low-end, such as it is, to the door speakers. But there is little “bass” frequency in the signal that reaches the tweeter crossover to begin with, so upgrading the rear door speakers bears little or no return. If you choose a more sensitive speaker, it might be a little louder, but it is still a midrange function that will not be notably improved upon by an aftermarket speaker
What makes this strange is that, presumably, JBL did it this way because there is a subwoofer in the back hatch and they wanted that sub and the rear door speakers to operate as a unit. If true, the execution is dismal because the subwoofer provides so little output that you pretty much have to sit or stand next to it with your ear to it in order to hear anything. It might as well not be there. You can’t adjust the balance or level - the JBL control unit calls the shots there. So, there’s not much you can do with the rear channels (including the sub) that does not involve major surgery.
Now onto the great mystery, which is the Beatsonic amp.
This is an aftermarket amp marketed as an upgrade to the OEM amp in the Land Cruiser, among other vehicles. The installation places it immediately downstream of the MMI head unit with the JBL control module (which is under the driver’s seat) between it and the speakers. Here is what that means:
The Beatsonic is a 45 WPC amp, and possibly a very good one - but you will never know if you install it in your Land Cruiser. It receives a signal from the head unit, which I believe to be an amplified speaker-level signal, converts that into a line-level signal, runs that signal through its own gain stage and amplifier, then sends its output to the JBL unit downstream.
From there, there are only two ways this could work, electronically.
Way #1 is that the JBL amp splits that amplified signal across multiple channels and sends it to the speakers, along with whatever other processing it does to the signal. This is almost certainly NOT happening here, as there are many more output channels from the JBL unit than input channels. There’s the front speaker set (including a center channel), the rear doors, the subwoofer, and those little fill speakers in the hatch near the sub. I’m 99.99999% confident that the Beatsonic amp is not designed to be stable across the total resistance load, which would be exceedingly low, for all of those channels.
So Way #2 is probably what is happening - which is that the JBL unit does the same thing the Beatsonic amp did. It accepts a speaker-level input, converts it to line level (leaving behind the 45 WPS amplification the Beatsonic added), re-amplifies it, processes it variously, and sends output to the speakers. This means that the Beatsonic amp is basically doing nothing, except potentially sending a higher gain signal to the JBL unit that results audibly into a slightly louder output. If you run the Beatsonic amp, like I do, you are still hearing the OEM JBL amp, not the Beatsonic amp, whose work is being discarded within the JBL unit.
Now - I do think my stereo sounds better than it originally did. I have JL Audio 6x9” door speakers and 3.5” dash speakers in the front, Hertz 6.5” woofers in the rear doors, and the Beatsonic amp. All of those speakers are of substantially better quality than the OEMs, and seem to be more sensitive. That alone makes the system seem more assertive. But if I am right about my diagnosis above, Beatsonic is being a bit disingenuous about the advantage of their product. It may be amplifying the head unit signal, but we never hear that. I have not done an A/B with and without the Beatsonic in place to listen to how my aftermarket speakers sound - and I’m not likely to based on how hard the Beatsonic amp is to reach - but I wonder if it would sound any different or much different.
A few of you apparently figured this out before I did and you found a way to bypass the JBL control unit entirely. You may or may not have run into any unintended loss of non-MMI material in the output along the way. That upgrade approach is more $$$ and time than I’m willing to commit right now, myself.
I’m annoyed by the “premium system!! 15 speakers!!” marketing for these upgraded stereo systems. I’ll take a four channel head unit output, a nice four channel amp, and two sets of 6.5” or 6x9” separates any day. Unfortunately the system is much more complex, and harder to hot-wire, than that in these Land Cruisers.
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