Quote:
Originally Posted by 4Rums
Unless things have changed with the latest head units, the signal from the JBL Head Unit is a balanced signal,.....For a full signal, you will need to tap the rear doors. .
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you are correct on this point.
Head unit does sent Left and Right signals to amp with balance as recording/music/source material is recorded/ intended.
User adjustable fader and balance is then done in/at the amp.
OEM wiring
Front door and dash are in parallel with dash having a capacitor to act as hi pass filter. at least that what Tacotunes has told me going to pull the 2019 wiring diagram tomorrow and see if I can confirm that.
even if they are separate signals to the dash /door I only need a single L/R and can pull that form the rear channels.
UPDATE pulls the dash out it s a 2 way coaxial driver and has independent signal going to it and does not appear to be in parallel with the door ( at least the parallel electrical tag is not occurring at the tweeter plug).
Rear door and hatch are in series
or run one of these...
LC6i | AudioControl
All signals out to each location in the rear are ( except sub)
IN FACT ARE FULL RANGE.
Dash and door signal appear to be independently driven from amp with low pass on the 6x9 and a hi pass on the dash 2way coaxial.
any variance in output at each relative location is limited by physical limits of a driver ( EG a 6x9 is just not going to product hi frequencies very well) and tapering off of the low Fq for the 6x9 and 6.5" is just a function of there size power being applied and the fact they are in a door enclosure (" leaky" big box/ free air)
You can physically still feel and see the driver moving aka full signal all the way down to 10Hz ya 10Hz!!!
Acoustic profiles of each location ( near field measurements. RED LINE ONLY ignore the yellow.)
RED line is peak value with sine wave sweep; yellow is real time background noise at the time the data was freeze framed
this Qualitative and not quantitative data
Volume at 30
low/mid/hi all set to center value.
Data recorded at each location in with the fader/balance set to only drive that speaker
On the first graph JBL actually did a decent job of tuning for a relatively flat system response with a bump in the 6k-10k range... measurement taken at clock location.
all other measurements taken right at the speaker/driver.
note on the 6x9 I terminated the test at just over 450hz as the dash driver start to mesh with the recorded level I was recording right at the 6x9 ( despite covering the dash driver as best as I could. . Tells me the cap and or x-over for the dash driver is probably sized/set to be a 550HZ or 600Hz Hi pass at 12db/octave.