[Jila]

Further to my blog from 22. Sep. 2021 on the same topic:

The usable ProAc Tablette 10 Signature bass response ends at circa 50 Hz, and I felt the need to extend the available bass below that range by adding a single SVS Pro subwoofer. The overall frequency response for ProAc Bass/Middle, the ProAc Tweeter and the SVS Pro Subwoofer is shown below. You might like to compare this graph with the one shown in my blog from 22.Sep. 2021. All measurements are taken at very close range with REW and miniDSP UMIK-1 calibrated USB measurement mic:



The SVS Pro subwoofer has a wide adjustable range (by smartphone App and at the rear panel) of volume, phase, polarity, parametric equaliser and crossover adjustments, of which I only used volume and Crossover point adjustments with the above result. By including this subwoofer, the improvement is impressive, positively affecting the overall tone and the lower frequency response. Boosting bass is a feature enjoyed by many, but walks a thin line to becoming unpleasant due to the potential for room resonances and 2nd / 5th order harmonics peaking, i.e. coloration. I set the SVS Pro sub woofer crossover frequency to 80 Hz, and will probably go even 10 Hz lower to 70 Hz to reduce room resonances.

ProAc Tablette 10 Signature overall impulse response for Bass/Middle, Tweeter and SVS Pro Subwoofer :


ProAc Tablette 10 Signature Bass/Middle, Tweeter and SVS Pro Subwoofer combined decay:


ProAc Tablette 10 Signature Bass/Middle, Tweeter and SVS Subwoofer Pro combined Waterfall:


SVS Pro Sub Woofer Waterfall alone (without Bass/Middle and Tweeter):


I would very much appreciate your feedback concerning your experience with ProAc Speakers in general, and the crossover component quality in particular.

[DannyBadorine]

There looks two be a significant drop between 2kHz and 10Khz.  Is there a phase issue here or am I misreading something?  Where was the measurement microphone placed?

[Jila]

Thank's for your question Danny,

Mid/Bass, Tweeter and Sub were measured individually with the microphone as close as possible without touching the driver. As the unmeasured drivers were off, there can be no phase issue. Then I overlaid each resulting curve. So this is different from measuring the entire speaker response (all drivers together) at the standard 1m distance, 2.8 V (1W). In theory, the Sound Pressure (SP) energy below the green and yellow curve should act constructively, i.e. additive assuming correct phasing, if the drivers are working simultaneously and not individually. And you're right, I would still expect somewhat a drop between 2 and 10 kHz, but far less deep.

The purpose of my measurements was to analyze the crossover characteristics. As a next step, I should measure the entire speaker characteristic at the standard distance, perhaps on axis and off axis. But that is for another day. I'll keep you posted.

[DannyBadorine]

Thank's for your question Danny,

Mid/Bass, Tweeter and Sub were measured individually with the microphone as close as possible without touching the driver. As the unmeasured drivers were off, there can be no phase issue. Then I overlaid each resulting curve. So this is different from measuring the entire speaker response (all drivers together) at the standard 1m distance, 2.8 V (1W). In theory, the Sound Pressure (SP) energy below the green and yellow curve should act constructively, i.e. additive assuming correct phasing, if the drivers are working simultaneously and not individually. And you're right, I would still expect somewhat a drop between 2 and 10 kHz, but far less deep.

The purpose of my measurements was to analyze the crossover characteristics. As a next step, I should measure the entire speaker characteristic at the standard distance, perhaps on axis and off axis. But that is for another day. I'll keep you posted.

Excellent explanation.  I look forward to seeing more measurements.