Need Sony Expert (Bus Control)

I have a Sony CDX-CA650X  that has a set of RCA ins labeled  "BUS AUDIO IN".  I am want to put audio into the unit for a auxilary sound input.

My problem is that without a source selector or MD changer control conneted to the "BUS CONTROL IN" the unit will not switch to AUX AUDIO. 

According to Sony and others my only choice would be to buy a XA-300 which is $ 100. 

QUESTION, is there a backdoor to select aux audio or do I have to buy the XA-300?  I am hoping there is some way to conect something that cost less.

XA-300 http://www.crutchfield.com/cgi-bin/S-gRtfvBsIGwS/ProdView.asp?s=0&cc=01&g=50900&id=morephotos&pi=2&i=158XA300&display=XL

IF interested this system is in a wakeboard boat and has 4 tower speakers, crossover, 400 watt / 260 watt amps, 12 " sub and 4 speakers in boat.  It sounds greeat, however when hitting wakes the CD skips.  I am using the AUDIO IN to connect a laptop where I have copied all my fav music and can set up multiple playlist.

Thanks,

JP

Sorry but the XA-300 is your only option.  The problem lies in the unilink protocols--the head unit needs something to tell it what type of input it is getting and how to control that input.  This is basically what the XA-300 does, and there is no way around this even if you could somehow make stuff plug in to each other.  The head unit wouldn't recognize that there's another source to switch to and so you'd never be able to switch to your aux input. 

If you had a sony cd changer or xm tuner I suppose it might be possible to use the bus audio in on the back of your head unit, but you'd end up switching to a source labeled "XM" or "cd changer" on the deck's display.  All the deck needs is a signal from a compatible unilink device that basically tells the deck that there's another source hooked up and to receive the audio via the bus audio inputs.  The head unit responds by letting you switch over to that new source via the "source" button, and switches over to using the bus audio input.  Once it activates those audio inputs, any functions of the unilink component that might be controlled via the head unit are irrelevant--it'll still use the bus audio input.

Needless to say, the xm tuners and cd changers are all well over $100 bucks each, and you'd essentially just be buying them for their unilink connnectivity--you wouldn't get the xm or the cd changer capability unless you wanted to be constantly switching cables back and forth whenever you want to go from your laptop to xm/cd changer or vice versa.

That is what I thought, will I lose sound quality by using a FM modulator?  My truck has one for DVD and it  has very low volume.

JP

This one is a tough question to answer as it really varies from vehicle to vehicle, and listener to listener.  Usually there's enough road noise in a vehicle to make it pretty hard to tell a difference between a direct connection and a fm modulated connection.  One of the side effects of fm modulators is, as you had noticed, decreased signal to noise ratio.  sO basically you have to turn it up to get it to be as loud as if you had hooked it up with RCAs.  In this aspect there are sometimes differences between brands of modulators and also brands of head units, but most sound the same.

The other side effect of using modulators is that you have to turn them off whenever you want to listen to the normal radio.  This is because the modulator basically takes over the antenna reception when it's turned on.  This is a good thing in that it prevents interference from radio stations that might use the same frequencies, but it is definitely annoying to have to turn the modulator on and off.  Obviously some people might be more annoyed by this than others.

However, you seem to be the type that liked fairly high end sound and I really think you'd be much more happy with a system using the XA-300 than with an fm modulated system.  It's nice having those two sets of RCA inputs, and it also gives you room for future audio output expansion (dvd player, tv tuner, etc.)

That XA-300 has a USB audio input feature too which might prove useful for you with using your laptop as the input source.  And the nice thing about the XA-300 is that it uses the power that's part of the unilink cable.  It does not require you to hardwire separate power, accessory, and ground connections.  With fm modulators you DO have to make these connections.

Yeah your right, it crazy not to spend another $ 100.  This boat is laid out pretty nice.  I also am using a sony hardwired commander in the middle of the boat so the driver can focus on driving and the crew canhandle the volume.  I thought about changinf to a deck with aux input on the front but prefer to stay with Sony.

Thanks for your help,

JP