JBL Upgrade w/o Amp

[uraniumrich]

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?

 

[uraniumrich]

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.