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Test if audio output is high or low?

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=85068
Printed Date: May 01, 2024 at 11:56 AM


Topic: Test if audio output is high or low?

Posted By: *theone*
Subject: Test if audio output is high or low?
Date Posted: November 03, 2006 at 3:31 PM

hey everyone, I'm trying to add sub and amp to existing bose system w/o sub. Wondering how to test if audio signal from deck is high or low level? I've looked at bose amp but there is no markings and it doesn't look like it has a sub out. Customer came in with system already hooked up at left kick panel area with a fixed level line out converter, doesn't seem to have any low freq. Maybe I should use an adjustable LOC? Any help would be greatly appreciated.

Ryan



Replies:

Posted By: aznboi3644
Date Posted: November 03, 2006 at 5:44 PM
Low level is RCA's...High level is speaker leads

Pretty much every factory system is high level...well I don't know of any factory systems that use RCA's




Posted By: 1lowgalant
Date Posted: November 03, 2006 at 7:19 PM
there are alot of factory systems that use low level. just because a system is low level doesn't mean it's going to have RCA cables. on some mach and bose systems, you simply cut the end off an rca cable and attach them to the factory wires to use an aftermarket head unit. without knowing what kind of vehicle it is, it's hard to tell which one it is.

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Whatever you do, DO NOT let the white smoke leak out of the wires.....




Posted By: 1lowgalant
Date Posted: November 03, 2006 at 7:20 PM
high and low level has to do with the signal, not the wiring.

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Whatever you do, DO NOT let the white smoke leak out of the wires.....




Posted By: i am an idiot
Date Posted: November 03, 2006 at 8:53 PM

Sounds like they got input for the LOC from the rear speaker  it is a high pass output.  You need to find the factory sub and try hooking the LOC there





Posted By: chucksnee
Date Posted: November 03, 2006 at 11:39 PM
1lowgalant wrote:

you simply cut the end off an rca cable and attach them to the factory wires to use an aftermarket head unit.


Can this even be done?




Posted By: *theone*
Date Posted: November 04, 2006 at 12:34 AM
OK, I found that using an adjustable LOC as opposed to a fixed level LOC tapped into any of the speaker wires after the bose amp worked the best in my case. I ended up using the front left speaker(tan+/gray-) for the LOC and worked out OK. 2004 GMC Sierra extended cab w/ Bose system. I was told the wires off the back of the deck were low level and they were not RCA's.

Thanks for the input

Ryan




Posted By: 1lowgalant
Date Posted: November 04, 2006 at 2:22 PM

chucksnee wrote:

1lowgalant wrote:

you simply cut the end off an rca cable and attach them to the factory wires to use an aftermarket head unit.


Can this even be done?

it's done every day at install shops across the country. what's not to understand?



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Whatever you do, DO NOT let the white smoke leak out of the wires.....




Posted By: chucksnee
Date Posted: November 04, 2006 at 9:32 PM
1lowgalant wrote:

chucksnee wrote:

1lowgalant wrote:

you simply cut the end off an rca cable and attach them to the factory wires to use an aftermarket head unit.


Can this even be done?

it's done every day at install shops across the country. what's not to understand?




I just find it hard to believe, 2 different types of output. Thats why you need a LINE OUT convertor to convert your speaker wire to RCA.

I could be wrong.....what do some of the power's to be say on cutting RCA's?




Posted By: sin0cide
Date Posted: November 04, 2006 at 11:01 PM
Yah if that is possible then why does everyone use a line level output to do that? that has to be way too much power to go into an amp rca input... in the event its a stock unit which outputs a low amount of power that could work... that sounds dangerous




Posted By: ferretvw
Date Posted: November 04, 2006 at 11:10 PM
Just because no RCA's are present does not mean it cannot be low level as was stated before. On some factory amplified systems the output from the head unit to the factory amp is low level so if you cut an RCA end off you can attach it to this low level output only. hopefully this clears up the confusion. You should not however cut off a high level output and attach an RCA to it as most if not all amps will not take this properlt

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2008 Scion xB
Pioneer AVIC-D3
RF 3Sixty.2 sound processor
Stock speakers (for now ;))




Posted By: aznboi3644
Date Posted: November 04, 2006 at 11:17 PM
Ah icic...didn't know that

Thanks




Posted By: master5
Date Posted: November 05, 2006 at 12:05 AM

Yep...can't be general with this topic..depends on the particular system. Bose are low level, even though it uses wires and not RCA cables. The new interface modules for chime retention have RCA's for the bose system.

Sometimes the factory system is low level..but higher voltage then others so splicing on an rca will work, but may not have enough volume..once again, it depends.

And anyone cutting the RCA's off the radios...heres a better idea.  Cut the ends off another set of RCA's and splice those to the factory inputs. Then you can plug the headunit in like a human and not butcher it

My 2 cents.



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Posted By: aznboi3644
Date Posted: November 05, 2006 at 9:41 AM
Question, Master

Can you cut the end off of RCA's and splice them to say the speaker outputs of a head unit and have some pretty high level RCA's?? Like instead of buying a bass booster module thing that kicks up the voltage of the signal???




Posted By: DYohn
Date Posted: November 05, 2006 at 10:46 AM

aznboi3644 wrote:

Question, Master

Can you cut the end off of RCA's and splice them to say the speaker outputs of a head unit and have some pretty high level RCA's?? Like instead of buying a bass booster module thing that kicks up the voltage of the signal???

If you are asking if RCA connectors could be used to send speaker-level signals to speakers, sure.  That used to be a fairly common design.  But if you are asking if you can splice RCA connectors onto a speaker-level output then run that into an amplifier's low-level input to gain some sort of "bass boost," no.  Sure, you could physically DO it, but it would be a really dumb thing to do and would most likely lead to a blown input stage on the amplifier.



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Posted By: master5
Date Posted: November 05, 2006 at 9:55 PM

Agreed w/ DYohn as well.

In that case an adjustable LOC is the proper way to do it. Sending too much voltage into an amps line level input can't be a good thing.



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Posted By: aznboi3644
Date Posted: November 06, 2006 at 12:30 AM
Lol...I was just asking. Cuz some people use those boosters to "get more bass" from their amps




Posted By: master5
Date Posted: November 06, 2006 at 12:38 AM

I would imagine this "bass booster module thing" is preamp level and only boosts specific frequencies and if a professional item should have some kind of curve.

However it is hard for me to tell what this really is as "bass booster module thing" is a bit general..lol

If it is a simple "bass control" that does not boost the bass to the amp. It allows you to adjust the low freqs via a remote knob but does not give any more input. If you unplugged the bass knob while it was adjusted all the way  up the bass level woudn't change.

Is either of these what you are talking about azn?

Good to see you again BTW.



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Posted By: aznboi3644
Date Posted: November 06, 2006 at 12:44 AM
I'm talking about those preamp things that can boost the rca voltage up to like 12 volts and crap...like an epicenter kinda




Posted By: master5
Date Posted: November 06, 2006 at 1:16 AM

An epicenter is actually a great piece. It boosts specific low freqs to all the speakers (if installed properly) not just the subs. However, that is a quite sophisicated unit.

With an Epi if the music you are playing already has a ton of bass information it doesn't do a thing. But on music in which the original recordings didn't use alot of bass..well at the time systems did not reproduce them like today, it would enhance certain freqs that are barely audible and kind of artifically reproduce them (things like harmonics come into play here).

Now of course if you overdrive the input it can cause problems, like anything else it requires proper installation, setup and user responsibilty. But regardless I would not look at an epicenter as a bass booster thing although in a sense thats what it does. But it is not designed to increase the voltage to the amps input simply to boost the bass if you can understand my description. A basic preamp can do that but once again,improper setup and abuse are the culprit if things blow.

But you can't compare that to running a high level signal into an amp by putting RCA's onto the speaker wires. If your system needed more bass, doing it that way will only cause damage in the longrun. It would be like putting nitro methane in the gas tank of a stock vehicle for more power. Might work for a second...but then expect an explosion.



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Posted By: aznboi3644
Date Posted: November 06, 2006 at 4:23 PM
It'd be cool though lol





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