Has anyone verified the output voltage of the stock Bose HU (before it reaches the stock Bose amp)? I have seen anywhere from 1V-2V, but what I do not know is that supposed to be peak to peak voltage, RMS, etc. Also, how were those measurements taken? With a scope or just a DMM?

I am going to be adding two zapco amps to my car, and I don't want to add a line driver unless I really need to...

 

if you're going to be running them off the factory wiring don't worry about the output voltage, usually you only use a line driver if you've got a deck that only outputs 2 volts or less. Do the Zapcos have a high level input? if they do just use that as your LOC, if they don't go with the JL Cleansweep, rockford 360.2. Regardless you're more likely to get the best sound out of the Cleansweep/360 setup.

 

I think I do need to worry about output voltage The bose headunit has no internal amplifier, so it puts out only a preamp level signal. According to some other posts here, it is <2V. That is what I'm trying to verify. I want to know more specifics about the preamp level signal coming out of the HU. I am going to cut the bose amp out of the picture completely.

The frequency output of the bose HU is relatively flat (all EQ is done in the Bose amp), so I do not see the need for a cleansweep or 360. The Zapcos do not have high level inputs. They have separate balanced and unbalanced inputs. I will be making a custom cable so I can use the balanced inputs on the Zapco amp.

A standard LOC would completely defeat the purpose because that would take the balanced output of the Bose system and make it unbalanced.

 

Personally I think you'd be better off running a cleansweep with the system you're thinking of. you're guaranteed a strong input signal into the amps. Sure the Cleansweep will flatten out your EQ even more, but it will also take the signal wires and put them to RCA for you.

but if you want to test the voltage, go to each pair of speaker wires put your DMM to analog voltage, and if your dmm has an avg, or even a Max option you can use that. once you figure out each avg or max you should be able to see a trend. I think it's going to be higher than you expect.

 

Well, either way, a cleansweep or 360 isn't in the plans I appreciate the recommendation, but it just isn't going to happen. Plus, I do NOT want to convert anything to RCA. The Zapco's use a mini-din6 (basically PS/2) connector for its balanced inputs. RCA's are only used for unbalanced on Zapco's. So I basically need to convert all the wires to the mini-din6 plug, not convert them to RCA.

As for testing the voltage with a DMM, I just generally do not like testing low voltage AC measurements with handheld multimeters. They are not very accurate for that. Sure, they work great for sticking the probes in an outlet to see if you have voltage, but beyond that most are not very useful (IMO). Setting the DMM to max hold and using DC could work, but is still an imprecise art. AC functions on the DMM generally only work at ~60Hz anyway. I would want to find out the voltage across the audible range

I guess what I really want is someone who has verified the output voltage using an oscilloscope so I know RMS vs peak to peak output.

Finally, I HOPE they are higher than I expect. If they are, I will not need any sort of voltage gain between the HU and amplifier

 

Well good luck man. I always wondered what than din connector was used for. At the places I worked I didn't see a lot of Zapco amps so I don't know a lot about them and their technology. I'm interested to hear how your system sounds after you're done. Keep me in the loop