Are you sure it is the room? Perhaps some nearfield measurements will reveal that your speakers have a peak in their response.
Ten dB is quite a bit and can be heavily influenced by your measuring technique. Is the meter clear of anything reflective including you that could be skewing the readings. If you hold it in your hand or lay it your chair then that can affect the accuracy. It's not that accurate in the first place. Assuming this data on the Radio Shack SPL meter is correct then take this in to account. A 10dB spike above the reading at 1Khz may be a problem but a 10dB spike in relation to lower frequencies may just be showing how inaccurate the meter is?
Ten dB is quite a bit and can be heavily influenced by your measuring technique. Is the meter clear of anything reflective including you that could be skewing the readings. If you hold it in your hand or lay it your chair then that can affect the accuracy. It's not that accurate in the first place. Assuming this data on the Radio Shack SPL meter is correct then take this in to account. A 10dB spike above the reading at 1Khz may be a problem but a 10dB spike in relation to lower frequencies may just be showing how inaccurate the meter is?