speaker level to preamp level assistance

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=100614
Printed Date: May 17, 2024 at 12:40 PM

Topic: speaker level to preamp level assistance

Posted By: sum1snzeros
Subject: speaker level to preamp level assistance
Date Posted: December 31, 2007 at 12:45 PM

I have an Alpine amp with speaker level inputs.
If I connect parallel to the OEM head and speakers does this effect the OEMs speakers output any? Or is the draw so little there is no audible effect?

Thanks.

Replies:

Posted By: stevdart
Date Posted: December 31, 2007 at 2:18 PM

I don't think you mean to say "parallel". The speaker level input in the Alpine amp is a converter and will provide a line level signal input if you grab a pair of OEM left/right speaker wires for signal. The speakers (or sub) that you wish to power with the Alpine is connected at the amplifier output terminals.

Now, does doing this diminish signal to the original speakers? No. They will still be supplied power via the OEM head unit and will still work the same whether the signal is tapped or not. Use them if you wish or disconnect them and tape off the wires...either way you want.

Parallel is a situation where sets of speakers are both connected to the same output. This is not the case when using a signal converter.

If you run into problems, look into getting a separate line output converter. Often the unit built into an amplifier is unsuitable. There could be input voltage issues that it can't overcome. If that becomes the case, the results will be erratic and it will be hard to pinpoint the cause of the problems. Get a "high quality" LOC if these problems occur, and there will be a voltage matching pot on it so you can adjust to the head unit's output.

Personally, I would just do the aftermarket LOC to begin with and not even fool with the one built into the amp. But it doesn't hurt to give it a try.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

Posted By: i am an idiot
Date Posted: December 31, 2007 at 7:40 PM

The input of the amp will not affect the output of the radio at all. The input impedance is so high that it will put no extra load on the internal amplifier of your radio. The only possible drawback of doing it this way versus the Line Out Converter Steve mentioned, is that you have 10 feet of speaker wire ran through your vehicle. This is only a problem if it gets a screw driven through it or a seat bolted down on top of it. Either of these situations = possible grounded speaker wire. Thus damaging your radio. A converter behind the radio really is the best way to go. But speaker wire is much cheaper than a converter and a Patch Cord.

Posted By: speakermakers
Date Posted: January 01, 2008 at 10:57 PM

Someone needs to check the definition of parallel (stevdart).
Think beyond speaker arrangements.
The power available from the head unit will be unaffected. As i am an idiot pointed out the impedance of the amps converter is so high that all available power will still be directed to the speakers.
As far as the converter on the amplifier goes, the on board converter is quite likely superior to any out board LOC that you can buy. This is partially due to the fact that most line level converters built into amps are of the balanced differential variety. An engineer from JBL\HARMON CONSUMER GROUP gave me the low down on this at an industry convention a few years ago. This simply is the best possible way to sample speaker level signal. And that’s why manufactures include them so often. Think about it the manufacturer is attempting to make your experience a positive one while a third party out board line level manufacturer is trying to turn a profit. In the event that you are not satisfied with the results of the built in converter purchase an Audiocontrol LC6 or some variant. Its actually of the balanced differential variety and is far superior to any high quality LOC that you will ever find.

Posted By: sum1snzeros
Date Posted: January 02, 2008 at 9:25 AM

Thanks for all your input folks.
I wanted to make sure I wasn't missing something as the diagrams in the Alpine manual didn't show that type of installation. They only showed direct connection to the head without any speakers. I am connecting up the amp for the addition of a sub so I will be keeping the OEM speakers in tact. That's why I was inquiring.

Thanks again. :-)