09.03.09

Element 3 - Bass, direct

Having selected the microphones, it was time to move onto preamps. Again the microphones were placed at a near distance (about 3 inches) from the grill of the cabinets, with the mic element centered at the center of the cone. This should give the brightest sound for placement. We'll want to keep this in mind as we pick preamps - we can always give a darker sound by moving the mic away, so it's better to err on the side of more high frequency than less.

I'm not sure I phrased that right. In other words, since the default placement on the two microphones we've already picked is right in front of the speaker cone centers, it's going to sound more treble-y than if we were placing them more off center. Since we can always take some of the edge off later on when we're dealing with placement, we shouldn't get too scared off by a preamp that sounds too bright.

As Q-Tip says, "On with the program".

Preamps

CHOICES - (same for HI and LO)

1. Sytek MXP-4A channels 1/2

2. Sytek MXP-4A channels 3/4 (Burr Brown Op Amp)

3. FMR RNP

4. Hamptone HFJP2

RESULTS

I tested the Hi and the Lo separately, cheating a little bit. That is, to compare the different preamps on the high frequency cabinet, I cycled through each of the choices above in order, as noted by the audio note. Since the blend of the two mics is important, I wanted to make sure I was listening to the comparison with the sound coming from the low frequency cabinet, and so kept feed from the Sytek Channel 3 miking the low cabinet on the whole time. Thus, the only thing switching in the high comparison is the high frequency mic's preamp. I then did the same thing with the low frequency cabinet, holding the Sytek Channel 1 on mic from the high frequency cabinet.

Bass - 4 way comparison of preamps for HF cabinet mic.

Bass - 4 way comparison of preamps for LF cabinet mic.

As with the microphone, the HF cabinet choices show a more clear distinction than the LF. On the HF cabinet, the 1/2 channels of the Sytek obviously sound the brightest, which works well considering the placement point noted above. Although this choice misses some of the midrange content that the other three preamps seem to fill in, this doesn't worry me - we should be able to find some of that sound when it comes to placing the amp.

For the LF cabinet, the biggest differnce seems is betweent the 2 Sytek choices and the other two. Most surprising is how similar the RNP and Hamptone sound and that neither are particularly desirable - they both give a more nasal sound while the two Syteks offer a good pair of clearer choices. There's obviously a LF bump on the 3/4 channels that I think serves the cabinet nicely.

DECISION AND NEXT STEPS

The Sytek does a good job of capturing the bass. We'll use either channel 1 or channel 2 with the RE20 on the 4x10 and channel 3 (or 4) with the e22s on the 2x15.

Final step on the bass, chums: mic placement.

Oh, and did you notice that we didn't post any pictures of the different preamps "in action"? I mean, what could possibly be more boring than that photo. "Here's a picture of a box, and you'll notice that the green LED is on!"

No, those aren't the mics we actually ended up using. Thanks for noticing, smartass.

Comparing the preamps on the LF cabinet. The brown track is the HF mic premp, not changing. The purple, green, yellow, pink tracks are the different LF preamp selections, one at a time.