watts on the rotel 985

jabrax

I cant find any information on the Rotel RB985's ability to run 4ohm and at what wattage...it has 5ch at 100 for 8ohm.

Any one have this thing?

cfrizz

http://rotel.com/support/pdfs/manuals/rb985.pdf

SCompRacer

I've got a RB 985MKII powering some Polk LC-265i/LC65i in-walls (think Lsi9/Lsi7's) and it does a great job. They just list wattage specs for 8 Ohms with a minimum speaker impedance of 4 ohms. I would estimate around 160 WPC for 4 Ohms.

jabrax

See below.....What the heck is DIN? Does this mean 220 4ohm?


Continuous Power Output 100 watts/ch (20-20kHz 8 ohms, < 0.03% THD)

DIN Output 220 watts/ch (1 kHz 4 ohms, 1% THD)

Total Harmonic Distortion (20Hz - 20,000Hz) < 0.03%
Intermodulation Distortion (60Hz : 7kHz, 4:1) < 0.03%

Frequency Response 10 - 80,000 Hz, +/- 0.5 dB
Peak Current Output (.1 Ohm load, 10 ms, 1 pulse) 40 Amps
Damping Factor (20 - 20,000 Hz, 8 Ohms) 180
Speaker Impedance 4 Ohm minumum
Signal to Noise Ratio (IHF A network) 115 dB
Power Amplifer Input Iimpedance 27 K Ohms
Power Requirements
115 Volts, 60 Hz or
230 Volts, 50 Hz
Power Consumption Max 800 Watts

F1nut

DIN (Deutsche Industrie Normen) is a German spec standard. In this case it's for measuring peak power.

jabrax

Thx for the info, this just doesnt get easy.......330 watt 2ch or 100+something 5 channel for lsi9s hmmmmmm.....damit, i am buying one or the other before tomorrow is over...

Guess I will decide by when i open my eyes in the morning

cheddar

jabrax wrote:

Thx for the info, this just doesnt get easy.......330 watt 2ch or 100+something 5 channel for lsi9s hmmmmmm.....damit, i am buying one or the other before tomorrow is over...

Guess I will decide by when i open my eyes in the morning

I would always go with the most amplification on the LSI speakers that are hardest to drive. That's the mains first and then the center. Unless you plan on not upgrading in the future, there is a difference in being able to drive the LSIs and getting the best quality sound out of them. And the sound quality really improves with a lot of power. And it gives you good upgrade paths in the future to add good amplification to your surrounds. But right now, both music and movies use the surrounds a lot less than the front stage, especially the mains.

cheddar

jabrax wrote:

DIN Output 220 watts/ch (1 kHz 4 ohms, 1% THD)

1%THD? I wonder what the THD maxes out at across the whole spectrum?

unc2701

probably 2-4% at 20K, and a little lower different at 500, 100.

jabrax

Upgrade in the future is definately gonna happen...Moving soon, so keeping the cash flow in check until its settled...Then look for mass sale and upgrades within the year....But need something now, quality of sound at low volume is killing me lol

cheddar

unc2701 wrote:

probably 2-4% at 20K, and a little lower different at 500, 100.

This doesn't inspire confidence in the amp, especially driving it hard with a speaker impedance that will drop below 4 ohms. You really might want to go for better 2 channel amplification.

unc2701

Those numbers a a direct function of the fact that they're specing it at DIN. At around 160 watts, it'd be <0.05 %THD. Think of the 220 watts as a "sony spec".

THD only really tells you how hard they're driving the amp to get the wattage rating they're quoting- while there are better amps out there, that spec isn't a reason not to buy the rotel.

cheddar

unc2701 wrote:

Those numbers a a direct function of the fact that they're specing it at DIN. At around 160 watts, it'd be <0.05 %THD. Think of the 220 watts as a "sony spec".

DIN, so they're just trying to make like it's a 220W amp. But not really. That makes sense, thanks. For the limited price range he's looking at, I'd still put the money into a quality two channel amp, though. Seems like he might have better choices than to try and spread it over his surrounds too.

F1nut

Actually, the DIN specs are suppose to be a more accurate measurement than anything else.

unc2701

F1nut wrote:

Actually, the DIN specs are suppose to be a more accurate measurement than anything else.

I agree completely- they're very specific and kinda reveal how stupid the specs are for things marketed in the US.... if everyone used DIN, then we wouldn't have the "sony spec" phenomenon.

My only problem with DIN is that they're written more with device failure (as in meltdown) in mind rather than quality sound.