If the microphone is a "generic" one--that is, one that you cannot tell what brand it is even without the logo. If it is a distinctive or recognizable one, that you would be using someone else's identifiable property to promote your business without their permission, which is illegal; they could sue you for compensation (e.g. the value of a license to use the image) or a court order that you cease and desist doing this. But if the microphone is not identifiable, you could do this.