Hello friends,
I always enjoy reading this thread and I have been getting various useful information on subwoofers (as well as on low Fq sound of woofers) on this thread.
As for the speed and/or tightness of the subwoofer sound, I believe we should have more focus and attention on time alignment between subwoofer and woofer, since our subwoofer is always used together with woofers having considerable overlap of the sound Fq between them based on passive or active, digital or analog, XO configuration depending on the slope(s) of the low-pass (high-cut) filter for subwoofer and high-pass (low-cut) filter for woofer.
I recently found (I assume it would be already common for some of you here) that Adobe Audition's sound color spectrum analysis (time/Fq/amplitude 3D representation) is much useful and helpful in objectively observing the "tightness" of the low Fq sound given by subwoofer and woofer, independently as well as together.
Let me share here just two typical diagrams as examples of such objective measurements of subwoofer and woofer transient behaviors by 8-wave and single-wave 31.5 Hz and 63 Hz sine wave stimulation.
Excitation with 8-wave 31.5 Hz, 63 Hz tone bursts;
Excitation with 63 Hz single-wave pulse;
Here you may easily understand the importance of time alignment between subwoofer and woofer; of course, the transient characteristics of low Fq sound is also greatly depending on the room acoustics, though.
If you would be interested in my recent objective measurements of SP time alignments as well as SP transient characteristics, please visit my posts on my project thread;
- Precision measurement and adjustment of time alignment for speaker (SP) units:
Part-1_ Precision pulse wave matching method:
#493
- Precision measurement and adjustment of time alignment for speaker (SP) units:
Part-2_ Energy peak matching method:
#494
- Precision measurement and adjustment of time alignment for speaker (SP) units:
Part-3_ Precision single sine wave matching method in 0.1 msec accuracy:
#504,
#507
- Measurement of transient characteristics of Yamaha 30 cm woofer JA-3058 in sealed cabinet and Yamaha active sub-woofer YST-SW1000:
#495, #497, #503,
#507
- Perfect (0.1 msec precision) time alignment of all the SP drivers greatly contributes to amazing disappearance of SPs, tightness and cleanliness of the sound, and superior 3D sound stage:
#520