Thanks for all of the updates. You inspired me to check out the 8 channel amps and I think I have decided on the Audison Forza C8.14bit. Full power at 2 ohms is 34 amps, but I will not be running it that hard, will be using all nominal 4 ohm speakers. Should not ever pull more than 25 amps, so I will use a 30 amp fuse on the rear battery. Going to use an active three way setup in the front (channels 1-6) and save channels 7 & 8 for the sub/subs. Will use the factory head unit to drive the rear speakers.
Upgrading speakers on 1958
- Thread starter Rubicon15
- Start date
The Forza line looks very good.
I was first looking at 6 channels, but 8 includes a sub, or two, in the DSP as well as the center dash option which I hear adds a lot to vocals.
A three way speaker setup should sound great. I read today about recommendations to have the rear speakers at lower volume that the fronts to help the "soundstage," so that factory powering the rears could work well. One question that does come up about rears outside the DSP is they won't be time alignment adjustable. When I set that on the speakers with the Infinity DSP, it made a big difference. The distinct music notes arrive at the driver's ear at the same time even from those far right speakers. Maybe the Audison has a way to for the fronts to be time aligned to the factory rear sound used as a starting point? But even then the two rears would not be matched together for the driver. I'm a complete newbie to DSP, but having noticed a big difference with only time alignment and crossover, that's something I'd study over.
It looks like the Audison has outputs that could send direct line signal to a powered sub, or separate sub amp. Maybe that's a good option? Seems a sub outside the DSP maybe simpler to tune to the DSP as the frequencies are so low and nondirectional.
Or, Audison has the 12 channel- bridgeable. 6 front, 2 rear, and 4 remaining that can be bridged for subs. The signal specs are slightly different, but the 12 channel looks to actually have less total electrical draw at a 45A : 55A ratio, ~20% less. The 12 channel powers 60w instead of 90w at 4 ohm. Depending on speaker choice, 60w could be more ideal. What is the optimal wattage for the 3-way speakers are looking at? I did read that the super high watt numbers are mostly suited for convertibles or competition sound systems. Then again, I did see some high end speakers having those higher watt numbers...
I tried to find out as much as I could about how much power draw the LC can handle, but didn't find much definitive. JBL tech support did after study email that their DSP4086 would work fine with the LC. Crutchfield had set a lower bar at 30A fuses, but then recommended a powered underseat sub to go along with an amp adding up to 35A. It's a real truck with a hybrid battery. One might suppose its electrical is robust. My amp on a 30A fuse and the sub is 15A. I imagine a multimeter could measure the battery voltage with LC off, then record it's charging voltage with LC turned on, and then turned on with music playing and see if there is any measurable dip in charging voltage while on with music. Crutchfield writes in an article that systems with less than 1000w RMS rarely need electrical upgrades.
The 1958 trim has that factory EQ in line with the existing speaker wiring. 60w per channel may be within its limits, 90w less likely. I was glad to be able to use the factory speaker wiring for the door speakers, but maybe putting new wiring into the doors is less of a challenge that I might think. Bypassing the EQ seems doable with perhaps even a prefab connector. Crutchfield advisor had said factory speaker wire is good up to 50w, then a tech said newer cars are generally good to 100w. One could caliper measure the wire diameter, but is it all copper?
Are you planning to run all new speaker wire?
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One of the pro shops I went to talked about putting 3-way JL Audio in my front doors/ dash on my 1958. 6.5" in the doors, a 3" mid in the dash, and then tweeters in the A-pillars. There'd have to be some good DSP/crossover in that setup, though, as all three speakers would be on entirely different axes. Woofer aiming at your knees, mid aiming at the windshield, and tweeter at your face. Which is why I'd personally probably leave that to a pro to handle, and would definitely run new speaker wire as I'm not sure the stock wiring and crossovers would know what to do with that.
Anyway, from an audio standpoint, I know all high-end home audio (not home theatre, but just home audio) is 2-way. Just two speakers in front of you, left and right. That doesn't work as well in cars, though, as you need some rear speakers to create a little more sonic "space" and create an atmosphere. That said, I think you are spot-on about the speakers in the front needing to be louder to create a soundstage.
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That’s why I went with an Alpine 8 channel DSP, Hertz tweeters, replacing the JL 350’s in the dash corners with hertz 70mp mids Monday, hertz C165’s in the doors, and a kicker powered sub. I would imagine you would have issues with tweeters and cross over points. I’m ditching the JL’s for that very reason. Seperate and dedicated speakers to each frequency range.
My current plan is to run the amp off the front channel inputs only, so I could just use the factory fade to the front if needed or just disconnect the rears. In the past I have run car audio systems with no rear speakers with good results. However there is a lot more cabin to fill with sound in the LC. Want to keep the total amp draw to a minimum, as I plan on adding additional exterior lights to the LC. I was originally looking at the Morel Sensus 63 speakers. As my LC is a 1958, I need to order the JBL A pillars from Toyota to see what tweeter will fit. I have a feeling it will be a 20mm tweeter. The Helix Ci7 tweeter might be a good option. I will tap in the same way you did, but run all new speaker wire to the front stage so I will not have to worry about the factory EQ. Thinking about taking out the plastic storage unit directly behind the rear seats and building the amp rack and sub enclosure in its place, will not lose any storage and be completely stealth. I really started off as wanting to keep it simple, just a factory speaker swap and now I will have to rip half the interior out. The hardest part is finding the time.
Did they want you to run the new JL Audio C6-653 3-way component speakers, they look to be well built and should sound fantastic. The Audison Forza amps do have time alignment delay and fully adjustable crossovers. In my home 2 channel system I use two Rel Subs using the High level inputs with my Dynaudio speakers, IMO makes a substantial difference in the sound quality over just the two speakers.
That looks like a very fine setup!
Bringing in the JBL A-pillars is an excellent solution for the tweeters and having the dash for midrange.
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