Help please - slow broadband after adding Airport Extreme

Hi all,

This is my first post here and I'm after some help or advice please.

Until recently my set-up was quite simple, in the room that I spent most time I had my Virgin router that had my Airport Time Capsule plugged into it. The Time Capsule was acting as my Wi-Fi network and I was enjoying the super fast speeds that the Virgin fibre provides, my little test app was running at over 100mbps at times.

We have now completed work on the house and our main room is now an extension which is about 30 feet and one wall away from the Time Capsule. The speed as measured by my app dropped significantly to around 20 or 30 mbps. I realise this is probably still relatively fast but I'm after the speeds that I'm paying a premium for.

I dabbled with a Devolo 1200 dlan wireless extender that didn't really improve the situation so have invested in an Airport Extreme to extend the network.

I currently have the Devolos running in lan mode only (the wi-fi is turned off). The Time Capsule is plugged into one end using Cat 6 cable and the Airport Extreme is plugged into the other Devolo again using Cat 6 cable.

The Airport set-up worked like a charm and I was looking forward to getting my speed back but when I tested it I was still getting the slower speeds (20-30 mbps).

The Devolos are communicating at over 200 mbps which seems like it should be enough and I've checked where my iPhone/iPad is connecting and it's to the Airport Extreme where I get the slower speeds.

So, to the questions, is this what I should expect ? What if I ran a cable directly to the Airport Extreme from the Time Capsule ? Are there any settings that I may need to change ?

Any help or advice would be much appreciated.