JBL Upgrade w/o Amp

[Blue Bear]

Do your homework on adding 2 ohm speakers. The dashboard and front door speakers are wired in parallel. If all 4 speakers were 4 ohm, the total ohms would be 2.0 due to the parallel wiring.

How do you arrive at your conclusion of 2.0 ohms for four speakers wired in parallel? 1/4+1/4+1/4+1/4=1. The inverse of 1 is, you know, 1. How did you come up with 2.0 ohms?

 

[treadmark]

Did you install an amplifier for the speakers? or just straight plug and play with the speakers?

If you did do an amp - did you find a location for one?

No amp. I relied on the stock head unit.

 

[Onandoffroaddriving]

I’ve got the Audison AP6.5 Prima 2 ohm speakers on order to put in the front doors replacing the 4ohm Hertz C 165. I have learned so much and hope these pair nicely with the JL 350’s I put in the dash. Here is what I got from Grok on the combo:

Sound Characteristics


• JL C2-350x: These provide crisp highs and improved soundstage due to their silk dome tweeters and coaxial design, addressing the stock system’s lack of clarity.


• Audison AP 6.5: These excel in midbass and low-frequency reproduction, with a pure copper voice coil and no crossover filter, delivering controlled, punchy bass. They will complement the JL dash speakers by adding depth to the lower frequencies, which users note is lacking in the stock JBL system.


• The combination should create a balanced soundstage: the JL C2-350x handling highs and mids from the dash, and the Audison AP 6.5 delivering robust midbass and lows from the doors. However, the overall sound may still lack deep sub-bass due to the stock subwoofer’s reported weakness.

I’m stopping by a car audio store Monday to talk about subwoofer replacement. Here is Grok on the subwoofer (edited as I am not looking at anything that isn’t plug and play)

Replacing the stock subwoofer in the 2025 Toyota Land Cruiser's JBL audio system, alongside the existing upgrades (JL Audio C2-350x dash speakers and planned Audison Prima AP 6.5 door speakers), can significantly enhance the system's bass performance, which users often criticize for lacking power and depth.

Here are three viable options for replacing the stock subwoofer, ranging from plug-and-play to more involved upgrades, considering space constraints, OEM integration, and bass improvement. Option 1: Direct Replacement with an Aftermarket 8 or 9 Subwoofer - Description : Swap the stock subwoofer with a high-performance 8 or 9 subwoofer that fits the OEM enclosure in the rear hatch. - Examples : - Kicker CompRT8 8 Subwoofer (2-ohm, 300W RMS, 84.8 dB sensitivity) : Slim design, suitable for OEM enclosures. - JL Audio 8W3v3-4 8 Subwoofer (4-ohm, 150W RMS, 83 dB sensitivity) : High excursion for deeper bass, fits tight spaces. - Rockford Fosgate P3SD2-8 8 Subwoofer (2-ohm, 150W RMS, 82 dB sensitivity) : Punchy bass, robust build.

If anyone is interested, I’ll post my thoughts as I work each solution.

2 ohm door speakers wired in parallel with 4 or 8 ohm dash speakers would combine have a very low resistance (1.3 or 1.6 ohms) that the factory head unit and most amps would be unstable and stressed with as 2ohms stable is often the lowest.

Grok, the processor of internet words, has been very helpful with a lot of research, but does often make mistakes that can be corrected and then it does a better job.

 

[Onandoffroaddriving]

How do you arrive at your conclusion of 2.0 ohms for four speakers wired in parallel? 1/4+1/4+1/4+1/4=1. The inverse of 1 is, you know, 1. How did you come up with 2.0 ohms?

 

[Blue Bear]

View attachment 38445View attachment 38444

I don't need the formula - look at my work and you'll see that's what I did. Rubicon15 said, "Do your homework on adding 2 ohm speakers. The dashboard and front door speakers are wired in parallel. If all 4 speakers were 4 ohm, the total ohms would be 2.0 due to the parallel wiring." That's a 1.0 ohm equivalent resistance.

 

[Thx_1158]

2 ohm door speakers wired in parallel with 4 or 8 ohm dash speakers would combine have a very low resistance (1.3 or 1.6 ohms) that the factory head unit and most amps would be unstable and stressed with as 2ohms stable is often the lowest.

Grok, the processor of internet words, has been very helpful with a lot of research, but does often make mistakes that can be corrected and then it does a better job.

I ended up using an Alpine amp with DSP, a pac module to preserve plug and play and revising my speaker selection. I now have Hertz all around except for the Kicker sub. I use super Grok for work and I'm well aware of how it provided information and how to correct or fine tune your responses from it.

 

[CrayLC]

I ended up using an Alpine amp with DSP, a pac module to preserve plug and play and revising my speaker selection. I now have Hertz all around except for the Kicker sub. I use super Grok for work and I'm well aware of how it provided information and how to correct or fine tune your responses from it.

Where did you hide your amp?

 

[Thx_1158]

Where did you hide your amp?

I didn’t hide it. It’s mounted on top of the sub with a vented custom enclosure. I loose a bit of cargo space..,but it’s no big deal to me.

 

[TX_Landman]

I don't need the formula - look at my work and you'll see that's what I did. Rubicon15 said, "Do your homework on adding 2 ohm speakers. The dashboard and front door speakers are wired in parallel. If all 4 speakers were 4 ohm, the total ohms would be 2.0 due to the parallel wiring." That's a 1.0 ohm equivalent resistance.

I believe he is referring to 2 speakers on the left front channel and two speakers on the right front channel, not 4 speakers on one channel.

 

[Altitude]

I was not fully pleased with the JBL system in my LC LC. I've had worse, but I've had much better, such as in my 17 Golf R. Considering this LC is my first venture into what I consider luxury territory, I was expecting much more. Aside from the sound quality being muddy and lackluster, I was really surprised how much the doors rattled even at neutral bass. So, I decided to upgrade the speakers and add sound-deadening. I also was not really interested in adding amps and thankfully now I won't need to do so. Here is what I used:

• JL Audio C2-350x 3.5" in the dash corners
• Kenwood Excelon KFC-X3C 3.5" in the dash center (there wasn't enough depth for another C2 and I had the Kenwood on hand from a previous Jeep project)
• Front doors
  • JL Audio C2-690tx 6"x9"
  • Metra 82-8246 mounting brackets (they work by drilling two new holes to match the OEM locations)
  • Stinger Roadkill RKFR69 FAST Rings (baffles)
  • I had tried a mid/woofer at first, but then realized a full signal is going to the door. Aside from how much sound was lost with that first attempt, one of the forum members had posted a document from Toyota Japan that showed a full signal to the doors. The JL Audio speakers I ultimately used, really help improve the overall sound quality when combined with the new dash speakers.
• Back doors
  • JL Audio C2-650x 6.5"
  • Metra 82-8148 mounting brackets
  • Stinger Roadkill RKFR6 FAST Rings (baffles)
• Metra 72-8109 speaker wiring adapters for all locations
• Dynamat Xtreme
• Dynamat Dynaliner 1/4"

I'm not an audio expert, but I selected the JL Audio speakers based on:

• Previous experience
• Warm sound and great sound quality
• High sensitivity for working off the stock amp

I took my time over a few weekends and I'm really impressed with the results. It was my first foray in using sound deadening to this extent. I would estimate around up to 25% coverage with the Xtreme and around 30-40 with the Dynaliner. I did not want to remove the vapor liner (in the back doors) or go crazy inside the doors. Here are my key subjective results:

• Significantly clearer sound played with a reduced need for volume. Prior to the upgrade, I listened in the range of 35 to 55. Now I can listen easily from 25 to 45.
• The bass is impressive. I'm still not sure how much the subwoofer in the hatch is doing, but the new speakers in the front doors throw appreciable and solid bass.
• Much quieter while cruising, such that I mainly hear wind noise by the A-pillars.
• I use the surround function enabled now. It sounded harsh/irritating with the OEM speakers, but really fills the space with the improved speakers.

Some other random notes:

• I listen to a wide range of music, including alternative, indie, rock, electronic, industrial, etc. and it all sounds great.
• I bought Kicker 3.5" speakers for the hatch, but there is remarkably little depth for aftermarket speakers and reinstalled the OEM ones. I added sound deadening, while I was in there.
• Taking off door panels in new vehicles always freaks me out the first time. The front and rear doors were fine. The hatch, however, made me feel as though I was going to break something in some areas.
• I didn't bother doing anything with the subwoofer in the hatch. I'm not sure it's doing much, so it wasn't worth upgrading at the moment.
• I did not touch the small tweeters in the pillar or upper back door.
• The OEM speakers look weird (except for the back door ones that seem fairly normal). The front door and dash speakers have a lot of plastic framing in front of the cones. I suppose it keeps them rigid, but seems as though they would block the emission of sound.

All items were purchased from www.crutchfield.com

Apologies if I missed this in the thread - did you replace the tweeters in the A-pillar and the rear doors along with the new speakers there?

Edit: disregard, I see where you answered that question.

 

[Altitude]

I dropped in my JL Audio 3.5” speakers in the dash corners this morning. That is a 1 out of 5 difficulty project and can easily be done in under an hour.

After I’d gotten one speaker in, I decided to pick up my phone and film the second speaker install with some commentary. Maybe this will be useful to anyone else doing this install.

There is nothing challenging about this install at all. For $145 plus an hour of time, it’s an no-brainer upgrade. I immediately noticed better midrange and more descriptive highs. The midrange is what makes the sound pop through the road noise.

I’ll be installing the 6x9s in the front doors next. Not planning to change the speakers in the rear doors; to my ears those are mainly just creating filler sound from the back.

It would be nice to add some more amp power. You can tell the amps in these are a little wimpy. That’s a whole different level of project from a complexity and cost standpoint and beyond my interest at this point.

 

[Dyso]

I dropped in my JL Audio 3.5” speakers in the dash corners this morning. That is a 1 out of 5 difficulty project and can easily be done in under an hour.

After I’d gotten one speaker in, I decided to pick up my phone and film the second speaker install with some commentary. Maybe this will be useful to anyone else doing this install.

There is nothing challenging about this install at all. For $145 plus an hour of time, it’s an no-brainer upgrade. I immediately noticed better midrange and more descriptive highs. The midrange is what makes the sound pop through the road noise.

I’ll be installing the 6x9s in the front doors next. Not planning to change the speakers in the rear doors; to my ears those are mainly just creating filler sound from the back.

It would be nice to add some more amp power. You can tell the amps in these are a little wimpy. That’s a whole different level of project from a complexity and cost standpoint and beyond my interest at this point.

Thanks for going to the effort to film for others. Keen to hear your opinion on stock vs the dash speakers and fronts when youre done

 

[fftfk]

I dropped in my JL Audio 3.5” speakers in the dash corners this morning. That is a 1 out of 5 difficulty project and can easily be done in under an hour.

After I’d gotten one speaker in, I decided to pick up my phone and film the second speaker install with some commentary. Maybe this will be useful to anyone else doing this install.

There is nothing challenging about this install at all. For $145 plus an hour of time, it’s an no-brainer upgrade. I immediately noticed better midrange and more descriptive highs. The midrange is what makes the sound pop through the road noise.

I’ll be installing the 6x9s in the front doors next. Not planning to change the speakers in the rear doors; to my ears those are mainly just creating filler sound from the back.

It would be nice to add some more amp power. You can tell the amps in these are a little wimpy. That’s a whole different level of project from a complexity and cost standpoint and beyond my interest at this point.

Just followed to see the replacement of the door speakers.

 

[Altitude]

Just followed to see the replacement of the door speakers.

Might be a month or two but I’ll post when I do that.

 

[Altitude]

I dropped in my JL Audio 3.5” speakers in the dash corners this morning. That is a 1 out of 5 difficulty project and can easily be done in under an hour.

After I’d gotten one speaker in, I decided to pick up my phone and film the second speaker install with some commentary. Maybe this will be useful to anyone else doing this install.

There is nothing challenging about this install at all. For $145 plus an hour of time, it’s an no-brainer upgrade. I immediately noticed better midrange and more descriptive highs. The midrange is what makes the sound pop through the road noise.

I’ll be installing the 6x9s in the front doors next. Not planning to change the speakers in the rear doors; to my ears those are mainly just creating filler sound from the back.

It would be nice to add some more amp power. You can tell the amps in these are a little wimpy. That’s a whole different level of project from a complexity and cost standpoint and beyond my interest at this point.

I was able to get the front door speakers installed this morning. Here’s the video.

 

[Altitude]

The front doors on the JBL system are not just woofers. I lost a lot of sound when I installed a woofer there. In another thread, someone posted a document from Toyota that the JBL system had full range speakers in the doors, surprising considering the separate tweeter. When I installed the two-way JL Audio C2 6x9s in the doors, the sound appreciably improved along with stronger lows.

I’m sure they just split the output across two speakers in parallel, the front door speakers and the dash corners, and sent full range to both. A crossover there would be expensive and few customers would perceive a difference.

The OEM speaker in the door is a single cone but the signal coming to it is full range. Same with the dash corners.

 

[Thx_1158]

I’m sure they just split the output across two speakers in parallel, the front door speakers and the dash corners, and sent full range to both. A crossover there would be expensive and few customers would perceive a difference.

The OEM speaker in the door is a single cone but the signal coming to it is full range. Same with the dash corners

Yep. If you are going to play with the sound up front, you need tweeters in the pillars, full range in the corners, then a mid bass in the doors. But doing this you have to make sure to match factory impedance or route the signal to an external amp in my opinion.

 

[treadmark]

Yep. If you are going to play with the sound up front, you need tweeters in the pillars, full range in the corners, then a mid bass in the doors. But doing this you have to make sure to match factory impedance or route the signal to an external amp in my opinion.

I put a mid/bass in the door initially and lost appreciable sound . The full range 2-way I ultimately used restored the sound.

 

[Altitude]

I put a mid/bass in the door initially and lost appreciable sound . The full range 2-way I ultimately used restored the sound.

I think it’s in another thread, but my point of view on this is that the stock amp isn’t powerful enough to move a high quality aftermarket 6x9 speaker and it’s possible the stock cone would deliver more output quantitatively speaking. I’ve got the JL 6x9 3-way speakers in there now and they do sound to me like they could use a bit more push.

Since the Beatsonic amp isn’t very expensive and installs quicker than I thought, I went ahead and ordered one. I’ll report back once I get it in.

 

[Thx_1158]

I put a mid/bass in the door initially and lost appreciable sound . The full range 2-way I ultimately used restored the sound.

I think it’s in another thread, but my point of view on this is that the stock amp isn’t powerful enough to move a high quality aftermarket 6x9 speaker and it’s possible the stock cone would deliver more output quantitatively speaking. I’ve got the JL 6x9 3-way speakers in there now and they do sound to me like they could use a bit more push.

Since the Beatsonic amp isn’t very expensive and installs quicker than I thought, I went ahead and ordered one. I’ll report back once I get it in.

yep...you got to do something with the stock Amp. That door speaker is 2 ohm, so if they lost sound, I'd bet it was a 4 ohm mid bass. that would cut volume in half. Messing with that Audio system only had one outcome for me, route the stock signal to an after market amp and fix it right. Anything else is a bandaid.