Help home theater set up with separated amplifier

[paul99]

Hi
I am really new to the audiophile. I want to set up my home theater. Recently, I got Kef R900 as a front speaker, R600C as a center and R800ds as a surround. I purchased the Yamaha RX-V773 receiver to use as a pre-amp. (Actually, I was trying to use only the receiver with out amp. However, today after I talked with the kef. It seams like I made a mistake. He told me that the minimum power to operate the Kef R900 is 200w; otherwise, I just ruin the speaker.) Therefore, I was in the market to find the amp for my HT. I came across with the ADCOM GFA-7705 5 channel, 200 watts/channel. The center and the front speaker need 200-250w ;however, the surround can only use maximum power of 100w. If I hook up my system with the ADCOM GFA-7705, it will work good for the front and center but Is it going to destroy my surround? If it is not going working, which kind of set up of preamp and amp that can be work for my home theater system?

Thank you
Paul

 

[jagdish_p]

Hi
I am really new to the audiophile. I want to set up my home theater. Recently, I got Kef R900 as a front speaker, R600C as a center and R800ds as a surround. I purchased the Yamaha RX-V773 receiver to use as a pre-amp. (Actually, I was trying to use only the receiver with out amp. However, today after I talked with the kef. It seams like I made a mistake. He told me that the minimum power to operate the Kef R900 is 200w; otherwise, I just ruin the speaker.) Therefore, I was in the market to find the amp for my HT. I came across with the ADCOM GFA-7705 5 channel, 200 watts/channel. The center and the front speaker need 200-250w ;however, the surround can only use maximum power of 100w. If I hook up my system with the ADCOM GFA-7705, it will work good for the front and center but Is it going to destroy my surround? If it is not going working, which kind of set up of preamp and amp that can be work for my home theater system?

Thank you
Paul

Since the surround channels only have a dynamic signal for short duration's the chances of damaging them are not high , unless you play at very high volume levels.You should be able to make out if the surrounds are getting strained by listening to them individually at your desired volume setting.

below are the ratings of your equipment at 8 Ohms

Rated Power and Sensitivity dB of speakers
Front KEF R900 / 25-250 W / 90dB
Centre KEF R600c / 25-200 W / 89dB
Satelite KEF R800ds / 25-100 W / 85dB
AVR RX-V773WA / 140 W Dynamic
Amp GFA-7705 / 200W per channel

You will not have a good surround experience given the fact that they are low powered and low sensitivity also. Best solution is to change them.
If you are still keen on using them you can try any of the following.

a) Run the YPAO room equalization and reduce the levels for surrounds by about -6db for the surrounds in the manual mode of speaker settings. This is to reduce the load on the surrounds though it will also reduce their sound level.

b) Connect the surrounds directly to the AVR and the front and center speakers to the Amp. This will limit the power to surrounds.

Request to other FMs. Please correct me if I made any wrong statements above. The above are conjectures and are not based on actual experience.

 

[rbalagopalan]

Hi, From your op I presume that you are yet to buy the power amp, if so don't worry just go ahead and setup your system and do the calibration. Normally in HT setup all the speakers are assigned as small only. So your receiver alone should be ok. Still if you are not satisfied you can add the power amp. Your surrounds being smaller but of greatly lower in sensitivity nothing will happen to the drivers even if you pump up the volume.

The history of the driver failures are more due to clipping during shutdowns and while pumping up the volume when hooked up to a very low powered amps. So your package seems to be fine just hook up and get started.

R. Balagopalan.