engin_ear

iTrader: (1)

SIGNAL QUALITY:
I have been seeing many issues with sound quality of satellite radio in vehicles, and people's associated complaints. Some come from the fact that sat radio was installed by a dealer or electronics shop, while others come from the fact that most satellite radios these days are equipped with internal FM modulators so that initial installation is quick and easy, requires no car disassembly, and needs the fewest wires. Unfortunately, just like most other things, this is in the 'can't get something for nothing' category, and will put you squarely in sound quality hell.

For those of you that are unable, for whatever reason, or otherwise unwilling, to do a direct-wired satellite radio install (using RCAs and some combination of aux input/adapter or harness), I offer the following advice:

There has been some debate over whether the sound quality of FM modulator is better than cassette aux input adapter. After living with both for a while, the answer is unequivocally NO. The cassette adapter sounds much better than both the wired FM modulator and wireless modulation into unused FM frequency, no question.
The wireless version of FM modulation, where your receiver is basically doing a local broadcast into your car radio, is pretty pathetic. I've heard the stories, but after trying it recently in both an RX300 and a 4Runner with factory radios and windshield antennas, it's obvious that it is horrendous. Vocal quality is poor, music sounds horrible and undefined, loads of interference, etc. It actually sounds quite a bit worse than other regularly broadcast FM stations on the rest of the dial, and I didn't think this was possible until I did these experiments.
I recommend the cassette solution to anyone that is currently using this method and actually has a cassette player in the headunit. It isn't the best either, but it is a LOT closer to the direct wired solution than the FM is. It is not subject to the same kinds of interference, so it is relatively quiet and less distorted. These days, the frequency response of a cassette deck tape head & electronics is not too bad. Try to use a good quality cassette adapter though, like Sony or Maxell. (Yeah, I know, I hate the wire coming out of the cassette deck, but.....)

Preference should be as follows, in sound quality order:
Best!!!: Direct-Wired audio input (RCA) - no modulation
Better!: Cassette-wired aux input adapter
OK: Wired FM modulator, direct into antenna line
Sucks: Wireless FM modulator, transmission thru air

Having said that, if you happen to already be using the wireless FM modulator, are having few or no problems, enjoy what you are listening to, and aren't willing to do any additional wiring, then by all means stick with it. Can also be OK if you listen to mostly talk radio.

The other thing that happens when only using the wireless FM modulator is that as you drive away from or into metro areas, a stronger station that appears on the previously-unused radio frequency that you were using will take over the airwaves, Sat radio will go away, and you'll then hear the new, usually unwanted (i.e. country ) station.


RECEPTION QUALITY:
I have been hearing many (too many!) complaints about the Lexus dealer-installed Sirius systems. Most, if not all, are regarding the reception quality and muting. Here's the primary story:

When you go to a Lexus dealer to have Sirius installed, they will install a custom kit for Lexus vehicles in your car. This kit includes a triangular antenna that was made specifically for Lexus/Toyota, and it fits up next to your rear-view mirror, at the top of the windshield glass, on the INSIDE of your car. This antenna is not mounted in an optimum location to receive both satellites at all times, as a roof-mounted antenna can do. Due to the inherent geometry involved, the roof tends to block one or both signals at many angles and at many times of the day. This usually causes poor performance and more-than-average muting.
The solution to this problem is to have the installer use a roof-mounted antenna instead of the inside, windshield mount one. If it has already been installed, you can disconnect the existing triangular antenna from the receiver unit, then install a roof-mount one and plug it right in.
The roof-mount antenna is available at any Sirius dealer, including Best Buy & Circuit City, or on the Sirius website, www.sirius.com, or on ebay. Price is about $30 to 40. The "dot" antenna works especially well.
That addresses the antenna problems with standard dealer installs. If your dealer, not being an electronics aficionado, also screws up the wire runs, grounding, or other parts of the install, that can also cause noise or other problems. Best thing to do is take it back, have them go over it again, or better yet, have an experienced installer check their work.

Jerry

mikal

I once had a wireless FM Modulator for my ipod. There are many times where i had to switch to a different FM station to broadcast.

Also, I've picked up the police frequency before. I was crusing on the freeway while a local police office was about 2 lanes over. My Ipod signal was then over powered by the police frequency and I heard nothing but police stuff for about 3 seconds.

Dman

I had my Sirius install done at the dealership. the sound quality sucks. i assume they used the FM modulator. How do I do a direct-wired satellite radio install? Can i redo their install? Also, I am using the Vaistech SLI for an ipod link. will this affect my install options?

engin_ear

iTrader: (1)

Which Sirius unit did they install? Does it display thru your factory Lexus radio? If so, they installed a receiver-only unit that has no FM modulator, unless thay added one. If you got the Lexus-Sirius kit, it apparently come with a triangular antenna for your windshield, and I'm not exactly sure what the interface to the radio is. Yes, you can re-do their connections, provided you know enough about what you are doing.
For the Vaistech SLI, the first aux input is dedicated to iPod, the second is universal. You can wire the Sirius receiver's outputs to that second aux input, if that hasn't been done already. That will give you a direct-wire input for best sound quality.

audax

iTrader: (10)

Yesterday I changed my XM radio from using the FM modulator to a direct connection via RCAs without a third party adapter (i.e. Viastech). This was done in an 02 GS430 with the Mark Levinson audio.

At the amplifier, I spliced into the battery, ACC and ground wires for the XM tuner's power and ground sources. I wanted to the satellite radio to be switched with the AM/FM/tape source since I rarely use those. I cut the signal wires from the radio to the amp and connected them to the normally closed pins on a 4PDT relay. The XM tuner feeds the normally open pins through a pair of RCA cables with the connectors hacked off on one end. The common pins on the relay are then connected to the amplifier's input. I used a simple switch connected to the relay coil that allows me to switch back and forth between the normal radio/tape and the sat radio. The display unit is mounted inside the ash tray.

Pros: Better sound quality, cheap misc parts cost ($8 for the relay and switch)
Cons: Satellite radio sound still heard when in CD changer mode until manually turned off

I'll post some pictures if anyone is interested.

In regards to the sound quality of the satellite radio... it is now much much better than the FM modulator was. I'm still not hearing crystal clear CD quality audio though. I'm not sure if this is due to the input on the amplifier (maybe the tape/radio input on the ML amp has a filter on it?) or if that's just as good as satellite radio gets. The sound just doesn't seem as "full" as it would on a CD. I was listening to 'Ethel' this morning on the way to work and a Coldplay song came on.... it seemed shallow to me and I luckily had the same song on a CD in the changer... I switched over and listened to the CD version and it just sounded a hell of a lot better. Bass was deeper and the imaging was better. Anyone have some thoughts on this?

engin_ear

iTrader: (1)

OK, don't forget - Satellite Radio, BOTH XM and Sirius, is DIGITAL, but it IS compressed. it is digital in the same sense that an iPod is. It will rarely have the prisitne quality and impact of a well-recorded CD. However, it is better than FM - dynamic range, frequency response, noise levels are all better. (This is a good reason why you just don't want to use FM circuitry to process satellite radio signals.) But satellite radio compression will tend to slightly smear the sound stage and cloud the detail of instruments. The source material for satellite radio is near-lossless MP3 files. These files are played out through a server and then undergo another stage of compression (this one lossy - affectiing the audio quality much more) to allow the audio signal to be efficiently transmitted via satellite.

So CD is always going to be better - it is not compressed, it is the original recording. MP3 compression on an iPod needs to be done at 192 kb/s and up to approach CD quality.

As a related aside, many people seem to think that iPod audio is just as good as CD. it is generally NOT. If I were to show you the iPod waveform vs. the original CD waveform on an oscilloscope, you'd be surprised.

Jerry

audax

iTrader: (10)

I figured just as much. The quality of the XM radio definitely sounds like the quality of a ~192kbps MP3. I just wanted to make sure that it wasn't the inputs on the amplifier having some type of filter since it was the radio/tape input.

Thanks for the confirmation.

JCHO

Hello all,

I too use FM modulator for my XM radio but my Nak won't allow me to use cassett adaptor. When I stick it in, it sits there for few seconds and spits it back out. Any suggestion for workaround or how to make it work?

Thanks.

engin_ear

iTrader: (1)

Your tape deck is apparently complaining that there is no actual tape that is rolling. Some decks have a sensor that relies on the tension of the stressed tape, and if this is not spoofed properly, it will think there is a problem with the tape and eject it.
I recommend gettting an aux input adapter for Toyota/Lexus radios, then inject the signal directly.

JCHO

Thanks for the advice. I will check it out at local shops.

blange400

Is this a dealer item, or do you know a vendor, and model number? Price?

thanks

engin_ear

iTrader: (1)

AUX INPUT ADAPTERS for Lexus/Toyota.


These things are changing/improving constantly. An Aux Input Adapter will work for Sirius or XM, and will provide a dramatic improvement in sound quality vs. FM modulators. Here are the options:

Manufacturers:

www.vaistech.com
www.soundgate.com
www.peripheralelectronics.com
www.blitzsafe.com

Distributors:

www.autotoys.com
www.crutchfield.com
www.sounddomain.com

Also check the manufacturer's website for direct purchase, or their distributors. Contact the manufacturer for application advice & technical help.
There are also iPod adapters available as well.

Jerry

Jesse95911

Does anyone know if Longo Lexus uses the FM modulators? If so... will the dealer do a Direct-Wired audio input (RCA) - no modulation install? I love the programing but the sound quality is just terrible.

HSN

hello, I am new here. I am getting ready to purchase an '00 LS400 with the Nakamichi system and cd changer. I want to look into the possibility of adding an auxilliary input for satellite radio and/or iPod, but it seems there is no plug and play solution. Have I missed something?

If there is indeed no plug and play solution, is splicing an RCA connection into the CD changer wiring a possibility?

Thank you

Lexmex

Both XM and Sirius work well down here in Mexico City.

However, recently I was in an expatriate forum about satelittes and such and we were discussing XM and reception and whether the newer models that use the FM Modulator got better signal quality than the old tape deck models (like the one in my RX300) and keep in mind the antenna needs to be up at all times to get reception here. I told them I had one friend who had the FM Modulator in his 2004 Camry down here and he could still pick up scratches in hisses even when we were parked compared to the same location with my RX300 (Nakamichi). No question cassette is superior.