A record head, on the other hand, has a gap typically six times larger than that of the replay head, this gives a larger flux to magnetise the tape. The ideal gap size in a cassette deck are; wide record head gap and narrow playback head. The larger gap does not affect frequency response because the 'image' is largely made by the trailing edge of the gap. A combined record/replay head has a compromise size gap typically three times that of a replay only head.