Double Bass AMT SB25 output

[bassbuddie]

I just buyed an AMT Sb25. The output on my amp is not very hot. I have a clarus II, I pluged it in the MIC input, phantom power on. I put the gain at 12 o clock and master at 12 oclock. I have a feedback, cut the mid to kill it but the output is weak not, a lot of volume. My amp is 3 feet from the floor 45 degree angle at my right. I have a full carved bass, good projection, I put the mic between the bridge and the neck 2 inches high. Any advice?

 

[Peck_Time]

Open up the preamp and turn up the internal gain pot.

 

[bassbuddie]

There is no gain pot, I have the s25b, not the sP25b.

 

[Peck_Time]

There is no gain pot, I have the s25b, not the sP25b.

OK, sorry. Have you tried different mic positions? You shouldn't need to cut mids as the AMT has a built in eq curve in the preamp.

Also as it's a condenser microphone it can't get very loud without feedback.

Also, does the Clarus supply enough phantom power? Can you put a battery in the preamp?

 

[bassbuddie]

I tried the battery, as they suggest at AMT. I tried different position too. I will continue experimenting position. Where do you position the mic on your bass?

 

[bonaventura]

I just buyed an AMT Sb25. The output on my amp is not very hot. I have a clarus II, I pluged it in the MIC input, phantom power on. I put the gain at 12 o clock and master at 12 oclock. I have a feedback, cut the mid to kill it but the output is weak not, a lot of volume. My amp is 3 feet from the floor 45 degree angle at my right. I have a full carved bass, good projection, I put the mic between the bridge and the neck 2 inches high. Any advice?

I tried the battery, as they suggest at AMT. I tried different position too. I will continue experimenting position. Where do you position the mic on your bass?

I play with an AMT SB25 on a Clarus 2 III for over two years. If you are using a battery in the AMT, you do not need phantom power (in fact AMT customer service told me it can damage the unit, but I've played with both by accident and no harm done).

The AMT SB25 is actually good at avoiding some of the feedback produced by other mics, e.g., I have a Neumann I really like that is designed to avoid feedback, but it is a bit more susceptible to feeding back than the AMT.

I think (from what you've said) the position you have the AMT in is not the best for getting good volume. I position the mic at 2" distance from the top, with the mic pointing directly at a spot just one half inch inside the F hole and 1" northeast of the G bridge foot. Sometimes I move it a bit further in or out.

The AMT performs best positioned near, but not directly over, the F holes. When I tried centering it like you did between the C bouts and at the mid-point between neck and bridge, the volume was not satisfactory. The other extreme is putting it close, like 1" and directly over the F holes, which produces a lloud, thick, muddy, deep tone and can feedback easily.

 

[bassbuddie]

Thanks, look a the blue dot on the JPEG, is it the place where you put the mic ?

 

[bassbuddie]

I am disapointed, I tried everything, every position and still have more noise and feedback than sound. My Full Circle sounds more Natural.

 

[Bob Branstetter]

Thanks, look a the blue dot on the JPEG, is it the place where you put the mic ?

I've found that placing the AMT mic over the ff holes is the worst possible position. Try moving the mic near the center seam just under the fingerboard. Several of us have found this be be the best for our basses. If you do a search, you'll find this has been discussed previously.

 

[charmicarmicat]

bassbuddie, have you tried putting the mic between the legs of the bridge. i've used that set up together with my rsII pick up and got excellent results. even the amt on its own sounded good in that position.

 

[bassbuddie]

I'll try beetween the legs of the bridge. I have a Clarus and a wizzy cab. The wizzy is nasal sounding and I think it contribute to the feedback. If I cut the mids, I can crank a little. But then I have an underwater sound.

 

[bonaventura]

Bassbuddie, don't give up on it...

One other thing about the AMT SB25, the mic clamp must be tightened firmly to prevent the mic from rattling.

This happened to me once, and I it took me a while to figure out what was causing the horrible sound.

By the way, your blue dot might be too close to the f-hole...

 

[Adrian Cho]

One important question - how loud is your acoustic sound? If it's not very loud you will have a lot of trouble getting a sufficient signal/noise ratio from any mic.

 

[Bob Branstetter]

Another point to consider is the height of the mic head above the top. I keep mine as close as possible without touching the top, positioned right on the center seam slightly below the end of the fingerboard. I've been using this way for several years now and get a great sound with no feedback problem. However, as Adrian pointed out, you need to have a strong acoustic signal from your bass to get the best sound from the mic.

 

[bassbuddie]

My acoustic sound is good, quite loud. I have to admit, I tried the mic yesterday on a gig in a small club. No feedback, I had to blend it with the Full Circle, because the room was big. The sound was very very good. I guess the room i tried it at first was the problem. Thank you for all your feedback, I am now a happy AMT user.