The Questions
I've spent six months of careful adjustment and set-up by ear, and I'm 98% happy with the result. Now I'd like to get some technical understanding of the adjustments I've made. So this is a specific set of questions about:
There four knobs on the EQ section of channel 1 of the AS100D. Bass/Mid/Mid_Frequency/Treble
Questions 1: So what is the highest cut-off frequency of the bass, and the lowest cut of frequency of the treble? I ask because when I apply cut and gain, I want to understand exactly which frequencies I'm applying it to, because this is what colours the reproduction of the acoustic guitar.
Question 2: The mid control reports that it sweeps from 250Hz to 2.5Kz... So you can see why I ask the first question.... are there frequencies (for example) between the bass and the mid, that remain flat and are not subject to adjustment?
Question 3: And the mid control knob itself, is that always sweeping from a start frequency of 250Hz and so increasing the width of the frequency band that will be adjusted by the Mid knob? Or is it a fixed width of frequencies that simply moves up the frequency band?
They are the questions... and here's some background as to why I'm asking... if you're interested...
The Background
I've had my AS100D for about 6 months (I love it). I also have a Fender parlour, the Ron Emory model, an early version. Mine has a solid spruce top - I also upgraded the machine heads,and added Tusq pins to the Tusq nut and saddle set - then, using a jig, and the recommended gel I fitted a K&K Sound Pure Mini soundboard transducer.
It's a very competent guitar. The intonation is a mild wild, but I compensate the tuning. It seems to take its time settling in to a pitch, its C is over active and C# is in desperate need of steroids (problem of the dominant Helmholz frequency from the soundhole). But these are all things you can work around when playing. It's not at all "boxy", has amazing sustain, and a beautiful round and balanced bass. With its 60cms scale, it's a legitimate flat-top x-braced offspring of a French classical guitar. For me, emulating the sound of 20's & 30's acoustic blues it's perfect. Of course it's not anything like as loud or carrying the projection of my old Guild D40, hence the pickup/amp.
First use: Initially I used the guitar on channel 2 of the amp, (EQ set to null) but with the K&K Pure preamp, that I'd calibrated in a small studio. I'd say I was 93% happy with the sound... some niggles around the bass - either too little or too boomy, and I wanted the amp to add more brightness than is present in the unplugged guitar. Still the preamp is a great match for the pickup and I've used it happily in a number of standard PA systems and with simple power amplifiers/speaker sets.... and I was certainly happier with the Marshall, than handful of other acoustic guitar amplifiers I'd tried, including some considerably more expensive... they just were just too coloured or unable to offer a faithful re-creation of the bass. (I think those twin 8 inch Celestions help the Marshall).
The adjustments:
So since buying the amp, I've been trying the Fender in channel 1, without the K&K preamp, and using the paramertric EQ control....
I play the guitar amplified and unplugged daily, about the same amount, so I'm getting to know the detail of the sound. And every few days, with the amp and guitar in the same location, I've run an A-B comparison between un-plugged and amplified guitar, just using a Boss TU3 to switch the
signal in and out - so I can get an immediate comparison, note by note, chord by chord.
...And playing... as I've noticed that when I start playing the attack of my thumb and fingers varies as a result of habit when changing expression on differing acoustics... this is something I'm having to learn to adjust in a different way, now I'm playing amplified.
Procedure: With the FX and feedback circuits off, and my eyes closed I've adjusted the bass/treble and parametric controls until I think I've got the closest amplified reproduction of the original sound. I'm 98% happy - which I think is brilliant.... and the plates effects are perfect for emulating 1930's acoustic guitar recordings.
Feedback: - I'm trying not to use the feedback controls, but whatever the location, that C note gets me from time to time and I have to kick in the anti-feedback controls, which kind of neuters the superb bass, so then I have to crank up the EQ and my satisfaction drops to about 96%... but I can't blame Marshall for that... although some kind of "depth" control would be nice... and bass issues aside I think the Marshall circuit is as good as the K&K preamp.
... that's the story so far.
I've spent six months of careful adjustment and set-up by ear, and I'm 98% happy with the result. Now I'd like to get some technical understanding of the adjustments I've made. So this is a specific set of questions about:
- the frequency ranges addressed by the channel 1 EQ controls
- about the way the parametric control works
There four knobs on the EQ section of channel 1 of the AS100D. Bass/Mid/Mid_Frequency/Treble
Questions 1: So what is the highest cut-off frequency of the bass, and the lowest cut of frequency of the treble? I ask because when I apply cut and gain, I want to understand exactly which frequencies I'm applying it to, because this is what colours the reproduction of the acoustic guitar.
Question 2: The mid control reports that it sweeps from 250Hz to 2.5Kz... So you can see why I ask the first question.... are there frequencies (for example) between the bass and the mid, that remain flat and are not subject to adjustment?
Question 3: And the mid control knob itself, is that always sweeping from a start frequency of 250Hz and so increasing the width of the frequency band that will be adjusted by the Mid knob? Or is it a fixed width of frequencies that simply moves up the frequency band?
They are the questions... and here's some background as to why I'm asking... if you're interested...
The Background
I've had my AS100D for about 6 months (I love it). I also have a Fender parlour, the Ron Emory model, an early version. Mine has a solid spruce top - I also upgraded the machine heads,and added Tusq pins to the Tusq nut and saddle set - then, using a jig, and the recommended gel I fitted a K&K Sound Pure Mini soundboard transducer.
It's a very competent guitar. The intonation is a mild wild, but I compensate the tuning. It seems to take its time settling in to a pitch, its C is over active and C# is in desperate need of steroids (problem of the dominant Helmholz frequency from the soundhole). But these are all things you can work around when playing. It's not at all "boxy", has amazing sustain, and a beautiful round and balanced bass. With its 60cms scale, it's a legitimate flat-top x-braced offspring of a French classical guitar. For me, emulating the sound of 20's & 30's acoustic blues it's perfect. Of course it's not anything like as loud or carrying the projection of my old Guild D40, hence the pickup/amp.
First use: Initially I used the guitar on channel 2 of the amp, (EQ set to null) but with the K&K Pure preamp, that I'd calibrated in a small studio. I'd say I was 93% happy with the sound... some niggles around the bass - either too little or too boomy, and I wanted the amp to add more brightness than is present in the unplugged guitar. Still the preamp is a great match for the pickup and I've used it happily in a number of standard PA systems and with simple power amplifiers/speaker sets.... and I was certainly happier with the Marshall, than handful of other acoustic guitar amplifiers I'd tried, including some considerably more expensive... they just were just too coloured or unable to offer a faithful re-creation of the bass. (I think those twin 8 inch Celestions help the Marshall).
The adjustments:
So since buying the amp, I've been trying the Fender in channel 1, without the K&K preamp, and using the paramertric EQ control....
I play the guitar amplified and unplugged daily, about the same amount, so I'm getting to know the detail of the sound. And every few days, with the amp and guitar in the same location, I've run an A-B comparison between un-plugged and amplified guitar, just using a Boss TU3 to switch the
signal in and out - so I can get an immediate comparison, note by note, chord by chord.
...And playing... as I've noticed that when I start playing the attack of my thumb and fingers varies as a result of habit when changing expression on differing acoustics... this is something I'm having to learn to adjust in a different way, now I'm playing amplified.
Procedure: With the FX and feedback circuits off, and my eyes closed I've adjusted the bass/treble and parametric controls until I think I've got the closest amplified reproduction of the original sound. I'm 98% happy - which I think is brilliant.... and the plates effects are perfect for emulating 1930's acoustic guitar recordings.
Feedback: - I'm trying not to use the feedback controls, but whatever the location, that C note gets me from time to time and I have to kick in the anti-feedback controls, which kind of neuters the superb bass, so then I have to crank up the EQ and my satisfaction drops to about 96%... but I can't blame Marshall for that... although some kind of "depth" control would be nice... and bass issues aside I think the Marshall circuit is as good as the K&K preamp.
... that's the story so far.
