[Quasar]

I started off with an OEM JBL premium sound system in a 2011 Prius. I replaced the head unit with a Joying to get CarPlay, but that just threw me down a rabbit hole when I discovered how tightly integrated the whole JBL system is and I couldn’t get a proper sound from the factory amp with the Joying’s line output (super low line output voltage).

I ended up with a JBL DSP4086 amp/processor to take advantage of the high-level inputs and some Infinity Reference 3 1/2”co-axial speakers to replace the factory dash drivers. I now have it all installed but am confused on how to set my crossovers for the new dash drivers that theoretically should have a wider range than the OEM.

Infinity claims the speakers go as low as 85hz but they also say:

Crossover: The included 270 microfarad capacitors are 1st order high pass crossovers (6 dB/octave); the crossover point is approximately 196 Hz. One capacitor is wired in-line with the positive input of each speaker. For best results, solder speaker wire terminated with quick slides to both ends of the capacitor, then insulate the assembly.

So if I’m reading this correctly, the capacitor is high-passing the speaker to 196hz at 6db/octave, correct? Would I be best to leave the capacitor in place and try to match this point with the door 6x9” mid-bass drivers? Would I be better off removing the capacitor and dial in a different frequency with the amps active crossover?

I don’t currently have a microphone to do advanced measurements. Thanks for any feedback or education on this matter!

 

[gijoe]

Leave the cap in place, and set a HPF about an octave above where the cap is, 400hz or higher. The 6x9 can easily play up to 1.5khz, so you don't want to push the small dash speakers too low and get a bunch of distortion, but you do want them to play low enough to keep as much information at the dash level as possible. I would start around 400hz-500hz and see how they handle the volume level you need. Leave the cap there as a protection device to prevent them from damage if you play them too low too loudly.

 

[mzmtg]

I high-pass my JL 3.5s at 1000Hz. My mids are 6.5" JBL GTOs.

 

[Quasar]

I would start around 400hz-500hz and see how they handle the volume level you need.

I set them to 400hz with 24db slope on both the dash and door speaker. Sounds awesome! Much better soundstage. Thanks for the feedback
🤜🤛

 

[My_Rav4]

I high-pass my JL 3.5s at 1000Hz. My mids are 6.5" JBL GTOs.

1000 Hz seems too high. Try lowering it to 500 Hz and hear how it sounds.

 

[mzmtg]

1000 Hz seems too high. Try lowering it to 500 Hz and hear how it sounds.

1000 is working better for me than 750 was when I started.

 

[gijoe]

Turn off the midbass speakers and play just the JL 3.5's. Turn up to a volume level that would be about your max listening volume for a particular song while driving. Set the HPF to around 1khz, and lower it until you hear distortion, or until the cone is moving excessively. I don't know the particular speaker, so I can't tell what the ideal setting would be, but start high and work your way down.

 

[mzmtg]

Turn off the midbass speakers and play just the JL 3.5's. Turn up to a volume level that would be about your max listening volume for a particular song while driving. Set the HPF to around 1khz, and lower it until you hear distortion, or until the cone is moving excessively. I don't know the particular speaker, so I can't tell what the ideal setting would be, but start high and work your way down.

I understand your approach. However, my goal is not to get every driver to play as low as possible. I work to get each driver playing in its passband and let the bigger driver play as high as is practical before handing it off to the next. My 12" sub can play 80Hz way better than the 6.5, so I let it. The 6.5 can put a lot more power into 900Hz than a 3.5, so I let it. My system sounds different with lower crossovers on the 3.5s, but it's not really "better" that way.

I have an MS-8 to sort out the mess for me and it sounds great!

 

[gijoe]

I understand your approach. However, my goal is not to get every driver to play as low as possible. I work to get each driver playing in its passband and let the bigger driver play as high as is practical before handing it off to the next. My 12" sub can play 80Hz way better than the 6.5, so I let it. The 6.5 can put a lot more power into 900Hz than a 3.5, so I let it. I have an MS-8 to sort out the mess for me and it sounds great!

I'm not saying you should play it that low, but it's helpful to know how low that can go.

Agree with your approach to not push any driver higher than necessary, or lower than necessary, and when pairing a 3.5" and a 6.5" you have a good deal of overlap compared to a 6.5" and a 1" tweeter.

 

[mzmtg]

I'm not saying you should play it that low, but it's helpful to know how low that can go.

That's a good point.

JL quotes the frequency range for the C2-350X as 130 - 20k. This leads me to belive the Fs is 130Hz. They don't publish a full set of t/s parameters.

Maybe it can be high passed as low as 250 or 300.