Non-JBL speaker / audio upgrades

There doesn't seem to be a non-JBL audio thread going for this topic, so let's start one. Linking the JBL thread for reference: https://www.tacomaworld.com/threads/4th-gen-jbl-replacement.830793/

To start down this path, I'd like to upgrade the front dash speakers which are 3.5" units.

These speakers are closest to ear level and reproduce midrange frequencies which humans are best at perceiving, so these are the biggest bang for your buck in terms of improving clarity.

I pulled one of them off the dash with a panel pry tool and 10mm socket and wrench (clearance to the windshield is tight). Very easy. I discovered the speaker has a 4-pin socket because it has two wires coming in from the headunit (positive, negative) and two going out which continue on to feed the front door speaker. The stock 3.5" midrange has a small capacitor wired into it. I think the label reads 70uF, I'd have to pry it out of the glue to be sure.

Is this wired up as a high-pass filter (e.g. allowing only high frequencies to reach the 3.5") or a low-pass filter (e.g. blocking high frequencies from reaching the door speaker so that it only has to deal with low frequencies)?

 

I dont have the answer but if filtered, think its being done through the amp, doesnt have inline capacitor style crossover "choke"...

 

I believe it is a high-pass filter, filtering out low frequency. I replaced mine with a 4" Polk speaker, without any filters.

 

You sure it's not going to a tweeter?
That's how many OEM speaker setups are, use a cap on the mid that feeds back to a tweeter

 

There's no dedicated tweeter in the base audio system: 3.5" in dash, 7" in front door, and 6.5" in rear door. All are single-driver speakers, no coaxial tweeters etc.

I will do some more research, but right now my theory is it's a low-pass filter, sending only low frequencies to the speaker in the front door (with the 3.5" outputting a full-range signal). That's how Toyota wires their JBL systems in some of their vehicles based on personal observation.

 

Dose anybody know if the tweeter up grade done to the 3rd gen will work on the 4th gen ?

 

You’ll be better off adding 4 inch speaker coaxial will give you a nice fill over the dashboard
This the Audison prima I used

 

A single capacitor is a 6dB high pass filter. It could also be it is intended to go to a tweeter, but your trim of truck doesn't have the tweeter

 

I pulled out the speaker on the other side to get a better look at the label on the capacitor: it's 10uF, not 70uF. I measured the DC ohms of the 3.5" at around 6.4 ohms, which I estimate would be about 7.3 ohms in AC resistance (audio is AC). Maybe 8 ohms nominal.

A crossover calculator like this one suggests that this combination would create a high-pass filter of about 2200hz, which is plausible if Toyota was trying to prevent the 3.5" from getting low frequencies it can't handle.

From what I can tell, the front door speaker and dash speaker is wired in parallel so the ohms presented to the headunit is 8+8 = 4 ohms using Ohm's law. Replacing the dash midrange with a 4 ohm unit would bring it down to 2.67 ohms which is probably risky for the headunit. The midrange would also output much louder than designed for a given input relative to the door speaker.

 

Ive only seen like 3.5 inch middler that takes care of all high frequencies, when I added the 4 inch coaxial speakers I had no issues
I would not add just a tweeter though, and I didn’t seem to need any kind of filter either

 

Posted this in the JBL thread, figured I'd cross post it.

Installed morel maximo ultra 603s and needed a bracket for the mid drivers in the dash.

Here's the link to the file if anyone needs it. Happy to print and mail if needed.

 

This is an interesting point.

So can the dash and door speakers not be replaced without adding an amp? If the dash speaker becomes 4 ohms and door speaker becomes 4 ohms, then it would be 2 ohms at the headunit. I suspect that would be an issue.

Hmm. Maybe amp and speakers need to be done together?

 

Does this help sort out the series vs parallel?

Also there were molex adapters in between the door and the cab. I was not able to run speaker wire through the doors. Had to cut and splice into the factory wiring behind the kick panel.

 

I can't read that diagram at that zoom level, it's too tiny. Can you share where you got that page? I'm 99% certain the non-JBL has the midrange and front door speakers wired in parallel. I ordered a midrange harness today from a certain Tacorito "tunes" shop so I can play around with it without cutting up my stock midrange speakers.

I think the simplest solution would be to replace the midrange with another 8-ohm unit. They're not very common on the market, but Dayton makes about a half dozen different models. I might go with this one: https://www.parts-express.com/Dayton-Audio-RS100-8-4-Reference-Full-Range-Driver-295-352?quantity=1

 

Even the upgraded JBL audio system in the Tacoma sucks. It sounds like a standard base system to me.

 

https://techinfo.toyota.com/ is best (paying) source.