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View Full Version : Measured crossover slopes of Alpine CDA-9887 - see what the HU's doing!



keep_hope_alive
08-05-2012, 12:32 AM
Data was taken by using the SoundDevices USBPre line level rca input from the Alpine CDA-9887 output directly. Levels are relative. Autosound 2000 Track 18 (un-correlated pink noise) was used as the source.


I am using the Alpine DRE-A200 as a crossover between my tweets and mids off the Front outputs on the 9887. you can see the 12dB/oct slope of that crossover.

There is the same consistent drop at the crossover frequency (6 and 12 are the same, 18 and 24 are the same at the xover point). Certainly, when choosing crossover slopes and points, the drop at the crossover point should be taken into consideration - resulting in some overlap with the crossover points.

4kHz crossover point, slope varies 6 to 24dB/oct. Front output of 9887
http://i38.photobucket.com/albums/e128/phat_funky_beats/accord/RTA%202012/9887_4kHz_HPF.jpg

1kHz crossover point, slope varies 6 to 24dB/oct. Front output of 9887
http://i38.photobucket.com/albums/e128/phat_funky_beats/accord/RTA%202012/9887_1kHz_HPF.jpg

200Hz crossover point, slope varies 6 to 24dB/oct. Rear output of 9887
http://i38.photobucket.com/albums/e128/phat_funky_beats/accord/RTA%202012/9887_200Hz_HPF.jpg

50Hz HPF, 250Hz LPF, slope varies from Full to 6, 12, 18 & 24dB/oct. Rear output of 9887
http://i38.photobucket.com/albums/e128/phat_funky_beats/accord/RTA%202012/9887_50Hz_250Hz_BPF-1.jpg