Line Out Converter Question

[MXracer115]

I'm installing subs and a amp on my 2007 Toyota Tundra with the factory JBL Nav and amp. I know I need a LOC, i'm trying to find the best one for my application. With the factory amp, I can tie into the sub output with the LOC or the rear speaker output. Which one would be better? All of the LOC's out there and two channels, and i'd only be using one channel if I used the sub output on the factory amp, any help on this would be appreciated.

[eskateboarding7]

It's not going to matter if you grab sub or rear output. The only benefit I can see from grabbing on the sub out would be sub control from the JBL unit. Since you will be using the LOC as a mono channel, you can tie the left and right channels of the LOC together.

[t3sn4f2]

Don't Toyota JBL systems have balanced output into the factory amp?

[MXracer115]

why would a balanced output make a difference?

[VP Electricity]

The Toy JBL systems I have tested the last few years - which do NOT include this specific vehicle - have a low-voltage balanced output from the HU to the amp.

BUT - the amp has the preamp in it, and the voltage of the HU's output does not change with volume. I don't think the HU has F and R outputs either. There is a data line that controls the preamp inside the amp.

The reason you care is that all the JBL processing happens in the amp. If you use the balanced signal, it is flat and full-range and needs no de-processing. Much better potential SQ.

You would need a volume knob, though. I would buy a Zapco SLB-U and a volume knob for it and use that, myself.

That truck has a single sub? Many Toy JBL systems use the F 6x9 in the door as subs in stereo.

I won't comment on your LOC needs other than to say most passive LOCs suck.

The best way to answer your question is with a pink noise test cd and a RTA setup.

[MXracer115]

I've been told my a few people that all i'd need is a LOC, they do make LOC's with adjustability, I'm def keeping my stock NAV, what do you think is the best way to add some RCA's so I can hook up my amp and subs?

[VP Electricity]

Would you explain your system and what amp and such you are using? That would help me.

Most people who tell you what to do with OE interface don't actually know what they are talking about.

[Andy Wehmeyer]

Buy an amplifier with speaker level inputs and connect it to the OE amplifier's subwoofer output--orange and grey wires. Amp is under the passenger's seat. If you already have the amp and it doesn't include speaker level inputs, scheck to see if the inputs are differential and check to see what the maximum signal input voltage is. If it's c. 6V, hooking up to those wires directly is fine too.

If not, use a basic passive LOC. It'll work fine.

If you hook your sub to the output of the radio, the volume of the sub will remain constant, no matter the position of the volume control. If you use a powered LOC with a volume control, you'll have to adjust the level of the sub AS you adjust the volume of the system. That sounds like a big PITA to me.

[MXracer115]

I'm putting in two RE SL 12s and powering them with a jl 1000/1. Does this amp have what I need?

[Andy Wehmeyer]

Yes, read the manual--you'll need an RCA cable or an RCA terminal to input the signal, but you don't need a line-out-convertor.

[MXracer115]

Ok thanks. So I just need to convert the sub wires to RCA and I'll be good? Also how would I go about setting the speaker level inputs?

[MXracer115]

Never mind I found the info I need, I just need a speaking wire to RCA adapter, and the the JL amp has two settings, high input and low input, I just have to set that on high input, you say that the gray and orange wires with be a 6 volt input right?

[VP Electricity]

Originally Posted by Andy Wehmeyer

Buy an amplifier with speaker level inputs and connect it to the OE amplifier's subwoofer output--orange and grey wires. Amp is under the passenger's seat.

Andy certainly should have more info available on this system than anyone.

Originally Posted by Andy Wehmeyer

If not, use a basic passive LOC. It'll work fine.

It will pass signal, certainly. The EMI it might pick up will most likely be inaudible through the subs.

But JBL Toy systems employ a high-pass filter to the sub signal, don't they? That HP is not a 20 hz "subsonic", but higher in corner freq, to protect the OEM drivers?

So if you stack the OE high-pass filter and the substantial LF rolloff of most inexpensive LOCs, the OP is in danger of losing substantial LF information, isn't he?

If he is planning on using large drivers and looking for LF info, wouldn't this be a problem? I've seen it be a problem, and so I avoid it.

By the way, I certainly didn't want the OP to have two volume controls. I was just hoping he was upgrading the entire system.

[VP Electricity]

Originally Posted by MXracer115

Never mind I found the info I need, I just need a speaking wire to RCA adapter, and the the JL amp has two settings, high input and low input, I just have to set that on high input, you say that the gray and orange wires with be a 6 volt input right?

No, he said measure it But the JL amp will work fine ()switchable for H or L voltage), and you don't even need an adapter, you need a cheap short twisted-pair RCA which you chop in half.

[MXracer115]

Well the jl can do up to 8v input, hopefully it won't be more than that. And you guys are talking some really technical stuff, I don't really understand it. So do you guys think what I'm doing will work?

[VP Electricity]

It will work, we are discussing how well. You don't seem oriented towards sq, so you may not care.

[MXracer115]

I think it'll be fine in my case

[MXracer115]

When I check the output volts on the wires do I need to have a test cd or anything playing while I check it?

[MXracer115]

When I check the output volts on the wires coming out of the amp do I need to have a test cd or anything playing while I check it?

[MXracer115]

anyone?

[mda185]

Yes, you need to feed a signal to the amplifier to measure its output voltage. Test CDs usually have tracks labeled for the frequency of the test tone and the level of the signal. 0 dB is usually the maximum level and all the others will be listed as something like -3 dB ,-10 dB, -20dB etc. Andy indicated that you will be OK running the speaker level signal into your JL sub amplifier. The JL has an input level control to match it to your factory amp output.

What are you measuring? Your earlier posts indicate you did not want to get too technical. Measuring voltage output and setting amplifier gains contradicts that comment. If you don't understand what you are measuring and why, you will have a hard time getting a good result. Don't misunderstand my question. I think it is great when any novice tries to measure things and understand their equipment better. It's just that you don't provide a level of information that suggests you have done your homework and understand what you need to know. I am pretty sure npdang put together a tutorial on setting amplifier gains in the tutorial section of this forum. That would be a good place to start if you don't already understand the process.

[MXracer115]

Thanks for the reply, I've done my research on setting the gain on my amp. I need to know the output volts out of the factory amp wires so I can set the input voltage to high or low on the JL amp. I was just needing to know what kind of track I need to play if any, while I measured the output on those wires.

[VP Electricity]

Measuring is a waste of time, try it both ways, leave it where it sounds good.

As a rule, deck power is OK low, OE amp output needs the high setting...

[MXracer115]

thanks

[MXracer115]

Sorry to bring this forum back up but I have one more question. When coverting the sub wires out of the amp to RCA, there is only one positive and one negative. Do I need to convert that to one RCA connection and then use a splitter to plug it into my amp? Or could I somehow wire the one positive and one negative to 2 channels of RCA?