Here is the analysis of
@bennybbbx's measurements from
post#194 using
Arta.
Since
@bennybbbx didn't link the speaker models, I'm going to guess they are
Presonus Eris E3.5
Kali Audio LP-6
Preliminary remarks:
- For most plots (CSD and Burst Decay BC), downsampling of the impulse response from 44.1k to 16k was performed. This increases the frequency resolution in the CSD at low frequencies - see Arta Handbook section 7.3 for more information.
- To make the Eris sound more similar to the Kali in the bass frequency range, @bennybbbx has boosted the bass range of the Eris via miniDSP - quote: "I have boost the bass in the Eris(in t.racks mini dsp) so it is stronger as on Kali".
- Near-field measurements (best <1cm from woofer dome) of the woofers almost completely mask the BR port. Accordingly, possible problems caused by the BR port, such as port resonances, are not displayed (strong cabinet or port resonances may be transmitted in attenuated form).
The order is the same for all diagrams, Eris is shown first, then Kali.
1. frequency response of the near field measurement
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The Kali shows an early frequency response drop, which doesn't make the comparison easy.
In the range 100-200Hz both LS show their sound pressure level maximum, so this frequency range is particularly well suited for a comparison.
Since the crossover frequency of the Kali is 1.5 kHz, the frequency response drops very early. With the Eris, the crossover frequency is 2.8 kHz.
Already above 400-500Hz, the frequency response drop of the Kali is so large that the comparison to the Eris is no longer fair.
With the Eris it seems as if no baffle-step correction is made (flat frequency response in the near field measurement), with the Kali the baffle-step is taken into account (slight frequency response drop from 150Hz).
This circumstance alone could explain the different sound impressions.
2. Culmulative spectral decay (CSD) waterfall (30dB attenuation)
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Above 200Hz, the Eris shows better decay than the Kali, based on 30dB attenuation. Below 150Hz, the opposite is true.
We will take a closer look at how big the difference is in the decay behavior later.
3. CSD spectrogram
A much easier to read presentation of the decay behavior. The frequency range of occurring resonances can thus be determined precisely.
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These are exactly the same measurements as in 2, only in an easier-to-interpret representation.
Here one can see that the resonances of the Kali, which are noticeable in the waterfall diagram and swing out for a long time, are already attenuated by 20dB or more - so they do not play a major role.
If you look at the boundary of the orange area (12dB attenuation), slight advantages for the Eris are also apparent here from 150Hz.
Below 150Hz, it becomes dramatic for the Eris in this representation as well.
4. Burst decay waterfall
It's a kind of CSD with a oscillation period based plot, instead of a time based plot. Impulse response is convoluted with a sine burst - more details see
Arta user manual section 6.5
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This type of visualisation makes the resonances at different frequencies directly comparable, since the number of oscillation periods serves as a measure.
But even with this visualization, the direct comparison is difficult due to the 3D plot. The visualization as a spectrogram is better suited for this purpose.
5. Burst decay spectrogram
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If we look at the yellow area with 18dB damping, there are only minimal differences on average.
With the Kali, the range 600-1200Hz shows delayed decay (to be able to compare it better with the Eris, the sound pressure would have to be increased in this range).
The Eris shows a delayed decay in the 800-900 range. In addition, there is a resonance between 100-140Hz. The delayed oscillation around 50 Hz is certainly the most problematic.
The frequency response boost by the miniDSP in the low frequency range of the Eris is not such a good idea - but it may be that
@bennybbbx has done this only for the measurement.
6. Burst decay spectrogram (only 15dB attenuation)
Since
@bennybbbx said that for his "theory" (a better stereo imaging of the Eris because it is "faster") it is the first 12dB of attenuation that matters, we look at the oscillation period based decay up to an attenuation of 15dB.
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From 200-500Hz there is hardly any difference in the decay behavior. Above 500Hz, the frequency response of the Kali drops too steeply to be comparable. But one can see that the Kali LS should have slight decay problems in the 700-1100Hz range.
The Eris shows delayed decay around 100-120Hz and heavily delayed decay around 50Hz.
7. Step response Eris vs. Kali
Here is the step response comparison of Eris and Kali. I think it should be clear from the above diagrams that in most cases the interpretation of the step response is more guesswork than scientific evaluation.
What you can see very nicely, however, is the delayed decay of the Eris woofer in the low frequency range - Eris (yellow curve), Kali (green curve)
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