And since I'm on the topic of this latest audio installation, I should probably tell you guys that I went a little crazy with the tuning procedure as well. In past installs I've always relied on the BT355 LOC presets to get me close enough to fine tune the BT355 gain and HPF settings. Using the Cerwin Vega B2, B52 and B54 I always set the AMP to Full Pass instead of High Pass. I've tried HP on the CV AMPs before, but when using in conjunction with the filtering on the BT355 the sound was just too bright, especially at highway speed volume. I worked around this by using Full Pass on the AMP and then tuning the HPF on the BT355s to "open" up the frequency range just a little bit.
On this latest install I went against all known current convention, set the AMP to HP and then turned the BT355 HP filter down to it's minimum setting (completely counter-clockwise). Then used the HP filtering on the AMP to tone down those low frequencies that can cause distortion at the volume we need on the highway. My initial tuning was all by ear, but afterwards disconnected the speakers and put my TPI 440 o-scope to work. Using a 1kHz 0dB test tone I measured 240W coming out of the AMP (the Micro4v2 is rated at 300W bridged 4 Ohms). I may have to be careful with the volume control on the radio
Maximum un-distorted volume was achieved (6.5GT at 13 out of 17 clicks on the volume) and the Micro4v2 HP dial set almost exactly at the 12 o'clock position. The Micro4v2 installation sheet said to start the HP frequency setting at the 8-9 position and go from there. So I thought I must have really killed the 100Hz frequency by setting the HP control to the 12 o'clock position. I put my 100Hz test tone on my thumb drive and checked. To my surprise 100Hz was still audible and it was just a little lower in volume than the 1kHz test tone. The main drawback with this approach is that the bass control on the radio doesn't really add or subtract a lot to the bass frequencies.
The system sounds good with the bike running and standing still in the garage. I finished most of the work Friday night, but at around midnight the Mrs. started complaining about the noise. I hit it again Saturday morning and by the time I had everything buttoned back up the rain set it. I may have to fine tune a bit more after a few road tests, but my gut feel is that I'm close.
This system is loud. Really loud. Hope the volume and SQ pan out at road speeds.