Better to be up front with both and to discuss the situation with the first, how your expectations apparently are not being matched by your agent's work.
You indicated that you signed an agreement with one. Does that agreement specify an area? If it does not, you may need to clarify, amend, and address this with that agent.
You mentioned that you are not pleased w/ this agent. You deserve to have good representation in both areas you are searching in order to help you make the best decisions. Sometimes communication can be valuable provide better results for you. I suggest you have a candid discussion with your Realtor about your expectations that are not being met. If your agent believes he/she cannot live up to the expectations, you might find a mutual agreement to part company and a release may be signed. If your agent believes he/she can better meet your objectives, the candid discussion may be your turning point for better results.
My first suggestion is a candid discussion with a clear definition of your needs and expectations. Next, if the relationship falls short, request a release from the agreement. If the inability to service you is a factor, a release request is reasonable.
If the geographies warrant different agents, work with two, but let each know that you are doing do. If one agent can service you properly, formulate a winning relationship w/ one and move forward.
Donâ€™t be reluctant to say, â€˜This is not working well for me. This is what I needâ€¦â€¦â€