Hi,
I just ordered a RioCar 60GB player for my truck. Although I have no idea whether or not I will get one (strange things keep happening with their online in/out stock status?), here's hoping.

The question I have concerns the exact requirements for an external car amplifier. I have a decent bit of experience over the years with installation, and am wondering:

1) Do I really need a 4 channel amplifier?

I have a 1987 GMC Caballero, with 4 speakers. Two are truck boxes, two are 3.5" dash speakers. Currently, power is coming from a Kenwood headunit. All speakers are good quality aftermarket products (MTX and Pioneer speakers), but this isn't a killer hi-fi setup.

I really don't want to have to purchase a huge, loud 4 channel amp if I don't have to. I would rather buy a good quality 2 channel amp like Rockford, Lightning Audio, etc amp from Best Buy/Circuit city type stores. I simply don't need the power.

Is it not possible to simply wire left/right channels from the amp in coordination with the outputs of the RioCar? I don't want to lose channel separation. I don't care one bit about fader controls from front/rear or even left to right for that matter.

Am I missing something? You can't really download a copy of the Riocar manual, so for those of you who have one and experience with car stereo installations, could you please answer this question?

Thanks in advance,

corey

You can so , but in the empeg you have the fader and 'place' the sound with the fader from front to rear.
I have now a 2 ch amp but I bought a 4 ch and I am sure I'll see the difference.

Okay i am confused here you say you have 4 speakers but you wish to buy a 2 channel amp. you can do this no problem but you will only be able to run one speaker per channel so you will only have two speakers running.

Your other option is see if you can mount emepg and kenwood in dash and have an input into the kenwood from the empeg.

I really don't want to have to purchase a huge, loud 4 channel amp if I don't have to.

You don't have to. Just get a decent-sized, medium-volume 4-channel amp of decent quality like this Jensen XA4100. Only $159.00 at the moment. (Ignore the fact that it comes with a promo pair of cheap subwoofer drivers and just use the amp.)

Remember that a powerful amp does not have to mean "loud". The idea with amps is to have enough headroom so that you can send it a very clean signal at moderate listening levels.

Is it not possible to simply wire left/right channels from the amp in coordination with the outputs of the RioCar?

You are talking about driving two speakers per amp channel, so that you can run four speakers off of two channels. This is called wiring the speakers in either "Parallel" or "Series" mode.

This can be done, but your amplifier has to be able to handle it (meaning you need a more expensive amp to begin with).

See, when you do that, you are either doubling (series) or halving (parallel) the reistance on that amp channel. This is called the "Load" that the connected speaker(s) present to the amplifier. In most car systems, the speakers and the amplifiers are matched to a given load (usually 8 ohms if I recall correctly), expecting that only one speaker will be hooked up to a given amp channel.

So the speakers will either play twice as loud or half as loud, depending on how you wire them. If they're playing twice as loud as the amp was meant to handle, then that puts a strain on the amp and makes it run hot. If they're playing half as loud, then you have to turn the volume way way up to hear them and you get distortion.

Some amplifiers (as I said, the more expensive ones) will say things like "stable down to a 2-ohm load". This means they're meant to tolerate that kind of abuse.

But it's much easier and better to simply buy a four-channel amp. It need not be huge or loud, just good. And remember that they have gain adjustments so that you can set them to never overdrive your speakers (in fact this adjustment is a critical part of installation as described in the FAQ, here).

Let us know what you end up doing.

Tony,

Thanks for the info. I am familiar with all of the concepts you discussed. Just didn't want my original post to be too lengthy and wordy...:)

The reason I was interested in the 2 channel amp vs 4 channel was largely due to amp size, cost, and overkill in a truck with a less than perfect speaker arrangement. I figured if I purchased a 2 ohm capable amp, like a rockford, then I could run the speakers in parallel, effectively having 2 speakers running off each channel.

Since the truck boxes are 2-way, with a horn tweeter and 6.5 speaker, I wouldn't even be employing the use of the crossover type features most 4 channel amps contain.
Also, since this is a truck, the 4 channel amps today seem ungodly huge, compared to some of the good 2 channel amps.

Based on the way the outputs work on the riocar, will I lose with regards to how the unit does channel separation?
How does this work? What exactly is the deal with the outputs on the riocar units?
Is it front L/R, rear L/R? And then the headunit control features depend on this?

I would welcome folks suggestions with regards to a well-made SMALL 4 channel amp. If I went this method, 25x4 is the most I would require. Compared to the lousy headunit power, this would be a vast improvement anyway.

Worst case, I shell out some more $ for the 4 channel amp. I already have a 2 channel amp from my last car, that's in fine working order and a good brand. Either way, I doubt I could complain if i get a 60GB unit for $499.

Finally, has anyone ordered a unit recently and tried selecting the out of stock tuner option? Any chance in hell that I might actually receive the one that I ordered? I saw earlier posts that seemed pretty negative, and folks are posting in other groups that they would like to buy them. But hey, who figured they would mysteriously announce more stock of the head units? Maybe there is a case of tuners laying around in a warehouse somewhere and I will get lucky...

thanks again,
corey

You can use a two channel amp and get excellent separation DEPENDING on your speaker placement. The advantage of a 4 channel amp is to utilize the fader control and wonderful 4 channel eq built into the empeg. Four channels will give you the ability to "shift" your soundstage frontwards or backwards. I would recommend a 4 channel amp for these reasons.

Based on the way the outputs work on the riocar, will I lose with regards to how the unit does channel separation? How does this work? What exactly is the deal with the outputs on the riocar units? Is it front L/R, rear L/R? And then the headunit control features depend on this?

The outputs on the Rio Car are exactly like any other head unit. Two stereo L/R pairs, controlled by an ordinary Front/Rear fader.

If you were to use only a two channel amplifier, you would connect only one of the stereo pairs, either the front pair or the rear pair, and leave the other one disconnected. Then you would leave the Fader set to "center" at all times.

Very minor nit; car audio stuff is mainly meant/made for a 4 Ohm load, while 8 Ohm is what's common in home audio stuff.

/Michael

Thanks. I remembered that one wrong. You're correct, cars are a 4-ohm load, that's why many amps talk about being "2 ohm stable", so they can run a pair of subwoofers off of the same channel.