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<blockquote data-quote="Peter Morris" data-source="post: 205632" data-attributes="member: 652">I think there are a couple of reasons why we don’t like the flat response we measure using Smaart or Systune - the environment and the measurement compromises we often make do not give us a “real” anechoic response especially with respect to the lower frequencies; some additional LF energy still tends get into the measurement. When we EQ it out, it sounds thin. In addition the distortion products of the compression driver tend to make it sound a little louder than it is … quantifying these is difficult.You can use a half space measurement to see what the LF end is doing and then measure the box as far away as possible from any boundaries, and about 4m in the air for the mid and HF response. Then try and splice to two measurement together remembering the half space measurement is +6db at the same distance.The only problem is loading this horn into half space tends to flatten its response a little (1 or 2 dB) compared to full space.If you want to do a power measurement you should have look at Acoustic Power Labs stuff – that’s their approach, measure the power response of the speaker then use EQ so the power response matches a correction cure. A suitable correction curve will be something like + 8 dB at the low frequency end relative to about 2K – 3K and flat- ish there after depending of the directivity of the speaker.At the end of the day I aim for a smooth response and “voice” the speaker with a little LF boost so that it sound natural to me.</blockquote>

[QUOTE="Peter Morris, post: 205632, member: 652"] I think there are a couple of reasons why we don’t like the flat response we measure using Smaart or Systune - the environment and the measurement compromises we often make do not give us a “real” anechoic response especially with respect to the lower frequencies; some additional LF energy still tends get into the measurement. When we EQ it out, it sounds thin. In addition the distortion products of the compression driver tend to make it sound a little louder than it is … quantifying these is difficult. You can use a half space measurement to see what the LF end is doing and then measure the box as far away as possible from any boundaries, and about 4m in the air for the mid and HF response. Then try and splice to two measurement together remembering the half space measurement is +6db at the same distance. The only problem is loading this horn into half space tends to flatten its response a little (1 or 2 dB) compared to full space. If you want to do a power measurement you should have look at Acoustic Power Labs stuff – that’s their approach, measure the power response of the speaker then use EQ so the power response matches a correction cure. A suitable correction curve will be something like + 8 dB at the low frequency end relative to about 2K – 3K and flat- ish there after depending of the directivity of the speaker. At the end of the day I aim for a smooth response and “voice” the speaker with a little LF boost so that it sound natural to me. [/QUOTE]

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