Does Yamaha RX-V871 use Transistors OR an STK IC in its Amplifier Section? How safe it is to connect 4 Ohm Towers to it Front Channels & 6 Ohms to remaining channels leaving the Receiver Ohms settings at Default 8 Ohms?

If you want blown output transistors then connect your 4 ohm speakers. Swap them for some 6 to 8 ohms. You can go higher with ohms, say 16 ohms, but NEVER lower than rated.

The watts of the speakers are not too important when connecting to an amp. With large wattage speakers such as yours the amp will drive them. What you only need to worry about is someone turning the volume up to much, but only if the Sony amp can deliver a greater wattage than the speakers. If it can it will destroy the speakers at the highest levels.
However when connecting speakers to any amp, you must look at the Ohms of the two items. You must NEVER connect a speaker of lower Ohms to an amp of higher Ohms than it. Must amps and speakers will fall between 4 to 16 Ohms. If your amp says 4 ohms you can connect just about speaker to it. But if says 8 Ohms, you must not connect any speaker rated lower than 8 Ohms. Connecting a 4 Ohm speaker to an 8 Ohm amp will destroy the output transistors of the amp.

No, you don't want to do that. The Ohm output on the amplifier must match the speakers. Run 8 Ohm speakers on 8 Ohm and run all your speakers on the same impedance (Ohms). Your gonna burn your amplifier up if you run different impedances.

This is a problem I have had as well. Know that Yamaha and other manufacturers that give an 8 ohm minimum spec DO NOT reccomend hooking 4 ohm speakers up to their amplifiers. That being said, I have had no problems with the Behringer 1C on Onkyo, Sony and JVC amps. You *must* be careful to regulate your listening volume, and be aware that the distortion the amp produces into a 4 ohm load is much higher than with 8 ohms. You also take the risk of cooking your output transistors.
It is up to you to decide if the risk, the neccessary self imposed volume limiting and the added distortion are worth it.

You can try bridging the amp but you need to know how low of an ohm load your amp can safely handle. Most amps are either 2 ohm or 4 ohm stable.

It should not be a problem. Most speakers nowdays are 4 ohms and since your mains are 4 ohms there should not be a problem. Your manual should stipulate the impedance and it should also be on the amplifier somewhere. Let me know if you need more help.

hardrocko

Thanks for using FixYa

Officially this receiver supports only 6 and 8 ohm speakers. But for surround speakers it should not do any harm, because they are not played at full volume. But be sure to set yamaha for 6 ohm speakers.
Using only 4 ohm speakers makes the amplifier work more hard and produce more heat, that's why you can't use it at high volume.

I would not suggest mixing. Use either 6 or 8 only but i highly suggest not mixing unless it gives the option to set a certain input for a certain Ohm. If you mix your either going to mess up a speaker or the receiver itself.

You can use any wattage speakers as long as they are not less than the watts from your amp. However you can still use lower wattage speakers as long as you don't turn up the volume full or two loud! Otherwise your damage the speaker.
HOWEVER you must get the ohms matched up right. You must never connect any speaker with a low Ohm to a high rated amp. Or you will blow the output stage transistors or IC.
Most Amps are 8 ohms, so you could connect an 8 or 16 etc, but not a 4 ohm.

You are probably aware on how to use these output figures, but I'll write a quick explanation on the specifications for future readers anyways :)

The concpet CC-452 amplifier has the following power output specifications:

Calculated at 14.5 volts DC;

At 4 ohms per channel - 45 watts x 2 (RMS)
At 2 ohms per channel - 70 watts x 2 (RMS)
At 4 ohms bridged - 150 watts x 1 (RMS)


This means that your amplifier would provide 45 watts of power each for your front speakers, which are normally a 4 ohm load per side (45 watts for left, 45 watts for right), that's unless they are one of those exotic higher end brands (eg: Boston Z6s which are 3 ohms). Rarely, you will find speakers that are rated at 2 ohms per side, but in this instance the amplifier will provide 70 watts of power into each speaker. On your speaker specifications, you will find a value termed "nominal impedance" which will give you the ohm rating of the speakers being used..

On the other hand, if you "bridge" both channels into a single channel (using a diagram often marked on the speaker terminals of the amp), you could then provide 150 watts into a subwoofer (providing it was a 4 ohm woofer).

It's not recommended to use this amp bridged under 4 ohms..

Some subwoofers may be lower than 4 ohms, and you will not be able to use this amplifier for these types of speakers without risking amplifier failure. Also, some subwoofers may have 2 seperate voice coils, and you will have to use both channels of the amplifier seperately (not bridged) in order to correctly connect this type of speaker for use.