aharps Publish time 28-11-2019 02:43:35

Kef r300 / rotel a10 - sensible?

Hey I currently own a rotel a10 40watts per channel Amp and I’m looking for some speakers, I’ve been scouring the used market and I’m considering the KEF R300s but I’m a little unsure about whether my amp will be sufficient.



The kef speakers state they go down to 3.2 ohm but my amp states 4ohm min. This coupled with only 40wpc has me worried.



I wouldn’t be listening at high volume, and the room is only 3m x5m so not enormous.



Other options would be the kef r100 or q350, but I’m concerned about the depth of bass on those. Unfortunately I can’t get anywhere to try these all out.



Any thoughts?

gibbsy Publish time 28-11-2019 02:43:36

All KEFs like a bit of power to get the very best out of them. Indeed the R100s are somewhat harder to drive than the R300s and certainly the Q350s. In this case you would be better off with the R300s as they will take more easily to being driven at moderate levels and I doubt that you will miss that extra ohm dip. If you can find a more powerful amp with a stronger power supply then the R300s will thank you and reward you for it. Given the right power supply and amp the 300s have a terrific bass control.

FWIW I'm giving my R300s 105 watts per channel. Perhaps others can point you towards others amps on the used market. I would look for Rega Elex as they are more capable of driving the KEFs.

Costello Publish time 28-11-2019 02:43:37

Considering the size of the room, the KEF R100s will fill that without any problem. I use mine in a 4.5 x 4.5 room without any issues. Although the R300 would give you a bigger scale and greater bass response.
I would agree that a 40W Rotel could be improved. Rotels are good amps and their power claims are usually lower than what they actually deliver but, as Gibbsy says, the KEFs thrive on power. I use a 50W Rega Brio with mine. However, your room isn't too big so you might be alright.

Rockets Publish time 28-11-2019 02:43:39

The power consumption is 220w which suggests good current capacity on the A10, most 40w amps do not have this sort of capacity. What this means to the user it should drive lower ohm speakers relatively well.

To put that in context the Rega Brio mentioned above with 50w has less power consumption @ 195w.

If you like in simple to understand terms.
Watts would be a bit like BHP for a cars engine.
Current capacity is like torque for a cars engine.

Low ohm speakers are like a car pulling a caravan so torque of the engine is important.

Ugg10 Publish time 28-11-2019 02:43:40

Just to add to @Rockets says -

Typically, at normal listening levels you will not be using more than 5W of power (105w into an r300 would be something like 115dB which would be above the pain barrier!), equating this to a car - you only need about 25hp to keep a steady 70mph on a flat road. However, if you want to accelerate quickly you need the power and torque to do so. Similarly the amp need to have the reserves to cater for sudden increases in transient volume which is supplied by the capacitors in the power supply and they are then "refilled" by the transformer. Therefore having a healthy bank of capacitors and a decent size transformer in the power supply is the key to an amp that can drive a less efficient or low impedance speaker. (note this is for class A and AB amps, things get a little different for class D and G).

As said, Rotel tend to have pretty good power supplies and can drive demanding speakers quite well.

FWIW, I would get the R300, try them with the Rotel as you already have it and see how it goes.
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