Harp Info - Harp Amplification with an "Amp"
written by Stephen Vardy
Introduction
So where does one start? Amplifying the Celtic harp is a large topic with many facets; the technology, the skills, the uses and the philosophy as to why have amplification at all? What works best where?
Do not give up easily on your quest as using amplification will double or triple the opportunities for a harpist to play because they are able to perform in almost any environment and be heard well.
The Celtic harp music has roughly the same audio range as the human voice and tends to disappear amongst conversation. In effect, the harp becomes moving wallpaper, hence, the need for amplification almost anywhere where there is not a small quiet audience. Amplification with the larger audiences allows for full use of the harp’s dynamics rather than having forced play with an “edgy” and limited repertoire to achieve audible volume.
The purpose of what follows in this page is to introduce harpists to the topic. The intent is to raise awareness levels of the opportunities created by amplification, and have some inkling of where to start.
It is definitely not the purpose of this page to provide a set formula for buying specific brand name pieces of gear for those who wish to just plug in and play. What works for one harpist may not work for the next. Gear mentioned here will be recommended in part from personal experience, in part from referrals from trusted harpists with a good ear and, in part, from a manufacturer’s reputation.
Some Simple Terminology:
Transducer - device that turns sound into electric signal or visa versa
Signal source – mic (transducer), pick-up (transducer), CD player
Preamp - to control and shape the signal from the source
Equaliser – boost or diminish specific frequency ranges of the signal
Power Amplifier - to boost the final overall preamp signal
Speaker - to transduce the amplified signal back into sound
For the purposes of this chapter, the word “amp” will be defined as the whole guitar amp in a box and the word “amplifier” will be defined as the internal circuitry part of the amp that amplifies.
What is an Amp?
A guitar, keyboard or combo amp is a multi part sound system in a single box. All the components of a larger system can be designed into a single unit albeit without all the functionality and versatility of a large sound system. What remains in the amp are usually a couple of input channels, a rudimentary equaliser (EQ) or tone controls, a single speaker and possibly some effects (FX) such as reverb and chorus. The amp configuration is beneficial for the solo performer for its lower cost, ease of use and relatively small size and weight as compared to the larger fully functioned sound systems.
Preamp & Power Amplifier
In general, the job of an audio preamp [pre-amplifier] is to amplify a very low level signal source (possibly at high impedance such as a pickup) to a level compatible with the power amplifier stage input. This is known as gain and is adjustable by the musician. Other common low level signal sources would include transducers like microphones and turntables. Tone controls and equalisation may also be used for shaping the signal and feedback control.
Most guitar amps have a simple pre-amp stage built into the box with adjustable gain and simple tone controls but most harpists need extra equalisation across at least five frequency ranges to control feedback. An external add-on preamp plugged into the amp input can accomplish this.
In an amp, the second amplifier after a pre-amplifier stage is typically a one step power amplifier. The pre-amplifier provides variable voltage gain (about: 10millivolts to 1volt) but no significant current gain. The power amplifier stage provides the higher current in one predetermined amplification step to provide the current necessary to drive loudspeakers. The speaker volume is controlled by the gain stage in the preamp.
Microphones versus Pick-ups
The best sound reproduction will usually come from the more expensive microphones (usually condenser instrument mics) but they can be more fragile, harder to find, and most importantly, they require either phantom power on the amp or an internal mic battery to operate. (Phantom power requires the option of an internal 48 volts to come from the amp to power the microphone.) Condenser mics can pick up a gnat's fart at fifty paces so be prepared to know the sound craft well before doing public performances with them or the feedback screech will rule.
The next best sound comes from a dynamic instrument microphone. These mics plug and play on any amp that accepts a vocal microphone. This can be the cheapest option overall. Avoid microphones from local consumer stereo stores, however. Use a proper instrument microphone.
The next best sound comes from an internal microphone system clipped on the inside of the harp’s sound box. These mic systems can give reasonably good sound but can be prone to feedback and difficult to place for a well-balanced sound. The internal mic will be less obvious as compared to a mic and stand.
Remember, if buying a microphone, the best choice is the one that sounds the best when listened to while someone else is playing the harp. Audition, audition, audition.
The most convenient and practical sound comes from a pick-up affixed to the harp soundboard used with an external pickup preamp combination. This works very well in noisy environments but does not necessarily have the sound detail of a microphone.
For the remainder of this page we will be recommending and discussing the uses of the pick-up and an external preamp.
Pickup Placement
Placing a pickup is simple. Making sure that it sounds well takes a little patience and some help from a harpist while the installer listens to the pickup.
The trick is to mount the pickup on the Celtic harp soundboard about 1/3 from the bottom. For trial purposes use some poster sticking putty available at a stationary supply (buy the expensive brands as they are tackier and leave no residue). Mount the pickup head externally and play it through an amplifier that should be set with neutral knob positions. Move the pickup up and down until you get a nice balance of base and high end frequencies. Move it laterally in and out to find the loudest point without string buzz.
Note that ideal location and mount the pickup internally at the same spot. Make sure you choose a pickup with a long cable to the output jack as you need to then route the cable back to a sound hole for external access. Mount both the pickup and the cable jack end using the same poster putty. Also use the putty to anchor the loose cabling against buzz. I further anchor the cable output end with duct tape. The whole set-up is removable/ replaceable with no damage to the harp.
Understanding the “Wires”
Cabling is probably the easiest and best place to start the nitty gritty of Celtic harp amplification. Different cables have different jobs and are constructed differently as a result. An understanding of the cabling is more than half way to setting up an amp.
This is a simple scenario of an amp’s audio signal path. A pickup transduces an audible sound into an electrical signal, which follows a cable to and through the circuitry of an external pickup preamp. The signal then is inputted into the amp’s preamp where it travels internally through the various circuitries to the speaker. Along this path the voltage levels of the signal vary to suit various electrical requirements. This is reflected in the type of cable used. The cable connection styles usually reflect and adhere to industry accepted voltage standards.
There are usually are 3 possible cables used with an amp
XLR cable for a microphone and some external preamps
Phone jack plug for a pick-up or external pre-amp
Power cable for 120V mains to run the amp
An XLR (mic) cable consists of two fine insulated wires twisted around each other with a braided third wire surrounding the first two as an audio signal electrical shield or “ground”. The two fine wires are considered “balanced” as they carry identical currents (“hot” send leg and “cold” return leg) in opposite directions. Mic levels typically run around 2 millivolts. Compare this with the normal input levels of 1.23 volts, and it becomes apparent just how much input amplification is going on in a microphone preamp, and why it is essential that preamps be of as high quality as possible! XLR cables are well shielded against externally induced electrical noise.
So where does one start? Amplifying the Celtic harp is a large topic with many facets; the technology, the skills, the uses and the philosophy as to why have amplification at all? What works best where?
Do not give up easily on your quest as using amplification will double or triple the opportunities for a harpist to play because they are able to perform in almost any environment and be heard well.
The Celtic harp music has roughly the same audio range as the human voice and tends to disappear amongst conversation. In effect, the harp becomes moving wallpaper, hence, the need for amplification almost anywhere where there is not a small quiet audience. Amplification with the larger audiences allows for full use of the harp’s dynamics rather than having forced play with an “edgy” and limited repertoire to achieve audible volume.
The purpose of what follows in this page is to introduce harpists to the topic. The intent is to raise awareness levels of the opportunities created by amplification, and have some inkling of where to start.
It is definitely not the purpose of this page to provide a set formula for buying specific brand name pieces of gear for those who wish to just plug in and play. What works for one harpist may not work for the next. Gear mentioned here will be recommended in part from personal experience, in part from referrals from trusted harpists with a good ear and, in part, from a manufacturer’s reputation.
Some Simple Terminology:
Transducer - device that turns sound into electric signal or visa versa
Signal source – mic (transducer), pick-up (transducer), CD player
Preamp - to control and shape the signal from the source
Equaliser – boost or diminish specific frequency ranges of the signal
Power Amplifier - to boost the final overall preamp signal
Speaker - to transduce the amplified signal back into sound
For the purposes of this chapter, the word “amp” will be defined as the whole guitar amp in a box and the word “amplifier” will be defined as the internal circuitry part of the amp that amplifies.
What is an Amp?
A guitar, keyboard or combo amp is a multi part sound system in a single box. All the components of a larger system can be designed into a single unit albeit without all the functionality and versatility of a large sound system. What remains in the amp are usually a couple of input channels, a rudimentary equaliser (EQ) or tone controls, a single speaker and possibly some effects (FX) such as reverb and chorus. The amp configuration is beneficial for the solo performer for its lower cost, ease of use and relatively small size and weight as compared to the larger fully functioned sound systems.
Preamp & Power Amplifier
In general, the job of an audio preamp [pre-amplifier] is to amplify a very low level signal source (possibly at high impedance such as a pickup) to a level compatible with the power amplifier stage input. This is known as gain and is adjustable by the musician. Other common low level signal sources would include transducers like microphones and turntables. Tone controls and equalisation may also be used for shaping the signal and feedback control.
Most guitar amps have a simple pre-amp stage built into the box with adjustable gain and simple tone controls but most harpists need extra equalisation across at least five frequency ranges to control feedback. An external add-on preamp plugged into the amp input can accomplish this.
In an amp, the second amplifier after a pre-amplifier stage is typically a one step power amplifier. The pre-amplifier provides variable voltage gain (about: 10millivolts to 1volt) but no significant current gain. The power amplifier stage provides the higher current in one predetermined amplification step to provide the current necessary to drive loudspeakers. The speaker volume is controlled by the gain stage in the preamp.
Microphones versus Pick-ups
The best sound reproduction will usually come from the more expensive microphones (usually condenser instrument mics) but they can be more fragile, harder to find, and most importantly, they require either phantom power on the amp or an internal mic battery to operate. (Phantom power requires the option of an internal 48 volts to come from the amp to power the microphone.) Condenser mics can pick up a gnat's fart at fifty paces so be prepared to know the sound craft well before doing public performances with them or the feedback screech will rule.
The next best sound comes from a dynamic instrument microphone. These mics plug and play on any amp that accepts a vocal microphone. This can be the cheapest option overall. Avoid microphones from local consumer stereo stores, however. Use a proper instrument microphone.
The next best sound comes from an internal microphone system clipped on the inside of the harp’s sound box. These mic systems can give reasonably good sound but can be prone to feedback and difficult to place for a well-balanced sound. The internal mic will be less obvious as compared to a mic and stand.
Remember, if buying a microphone, the best choice is the one that sounds the best when listened to while someone else is playing the harp. Audition, audition, audition.
The most convenient and practical sound comes from a pick-up affixed to the harp soundboard used with an external pickup preamp combination. This works very well in noisy environments but does not necessarily have the sound detail of a microphone.
For the remainder of this page we will be recommending and discussing the uses of the pick-up and an external preamp.
Pickup Placement
Placing a pickup is simple. Making sure that it sounds well takes a little patience and some help from a harpist while the installer listens to the pickup.
The trick is to mount the pickup on the Celtic harp soundboard about 1/3 from the bottom. For trial purposes use some poster sticking putty available at a stationary supply (buy the expensive brands as they are tackier and leave no residue). Mount the pickup head externally and play it through an amplifier that should be set with neutral knob positions. Move the pickup up and down until you get a nice balance of base and high end frequencies. Move it laterally in and out to find the loudest point without string buzz.
Note that ideal location and mount the pickup internally at the same spot. Make sure you choose a pickup with a long cable to the output jack as you need to then route the cable back to a sound hole for external access. Mount both the pickup and the cable jack end using the same poster putty. Also use the putty to anchor the loose cabling against buzz. I further anchor the cable output end with duct tape. The whole set-up is removable/ replaceable with no damage to the harp.
Understanding the “Wires”
Cabling is probably the easiest and best place to start the nitty gritty of Celtic harp amplification. Different cables have different jobs and are constructed differently as a result. An understanding of the cabling is more than half way to setting up an amp.
This is a simple scenario of an amp’s audio signal path. A pickup transduces an audible sound into an electrical signal, which follows a cable to and through the circuitry of an external pickup preamp. The signal then is inputted into the amp’s preamp where it travels internally through the various circuitries to the speaker. Along this path the voltage levels of the signal vary to suit various electrical requirements. This is reflected in the type of cable used. The cable connection styles usually reflect and adhere to industry accepted voltage standards.
There are usually are 3 possible cables used with an amp
XLR cable for a microphone and some external preamps
Phone jack plug for a pick-up or external pre-amp
Power cable for 120V mains to run the amp
An XLR (mic) cable consists of two fine insulated wires twisted around each other with a braided third wire surrounding the first two as an audio signal electrical shield or “ground”. The two fine wires are considered “balanced” as they carry identical currents (“hot” send leg and “cold” return leg) in opposite directions. Mic levels typically run around 2 millivolts. Compare this with the normal input levels of 1.23 volts, and it becomes apparent just how much input amplification is going on in a microphone preamp, and why it is essential that preamps be of as high quality as possible! XLR cables are well shielded against externally induced electrical noise.
XLR - Male
|
Phone Jack - Male
|
A Phone (1/4”, TS, jack) cable is considered “unbalanced” as it has a single fine internal wire (“hot” send leg) which is insulated from a surrounding wire braid shield which acts both as “ground” and a “cold” return leg. Input voltage levels vary depending on use - normally about 1.23 volts. Phone cables are poorly shielded against external electrical noise and hum. Shorter cable runs to a maximum of 25 or 50 feet are advised.
A 120V mains power cable is simply 3 parallel wires referred to as positive (hot leg), negative (cold return leg) and the electrical earth (ground). It is important that the 3 wires are in "phase" or electrocution may occur. All venue outlets should be tested before use as a significant number are defective or “out of phase”. Use a three prong circuit tester available at the hardware store and test every circuit before performing.
Feedback and Room Resonance
A harp will have a dominant resonant frequency where the whole instrument will resonate in the presence of the same frequency. Celtic harps are natural microphones. Rooms also have natural resonant frequencies and will amplify those same frequencies when presented. If the resonance of the room and the amplified harp matches then problems may occur.
When amplified, a harp may put a frequency (say 400 Hz) thru the amp out in to the room, which is then resonated at an even louder volume by the room. This in turn makes the harp resonate more strongly, which puts an even stronger 400hz from the harp back into the sound system - around and around the signal loops until the system becomes unstable and propogates a feedback screech.
The resonant frequency of a room changes slightly with temperature and humidity but the easiest way to dampen resonances is to fill the room with people as clothes and bodies absorb reflected resonating sound quite nicely.
Placing carpet under the harp reduces sound reflections and is great for reducing resonance. Ditto curtains and soft materials around the harpist. Distance the harp and /or the amp from glass.
Pickups are the most stable in these situations. Get a piezo matching preamp with a small 5 band graphic EQ built in for personal resonating frequency control.
"Inside the harp" microphones are the least stable. They suffer greatly in noisy reflective environments thru the harp over-resonating. The space inside the sound box is a very acoustically complex area with lots of internal resonance nodes. Plugged sound holes do not look professional nor give the best harp sound. Specialty internal microphones like the Dusty Strings model will suffer somewhat less feedback as they are designed for the task.
NB: Microphones placed farther away from the harp (and hence running a little hotter to get a large enough signal) also become more feedback prone. Microphones with a broad pickup pattern with poor side rejection of frequencies coming from off axis are more prone to feedback as well. Cheaper mics fit into this category.
Work out the dominant resonant frequencies in a room once the harp is set up and the amp is on at a reasonably loud setting. To do this make sure every thing in the room is quiet . Then one by one pluck the strings thru the octaves from the bottom to the top of the harp. Certain strings will jump out as being louder than the rest. The amp’s corresponding specific frequency output will need to be reduced until the offending string sounds only as loud as its neighbouring strings. When the lowest fundamental note/string is reduced the corresponding upper related harmonic notes/strings disappear too. When the string volumes all sound in sync - Hey presto! No feedback for that volume level! Life can be very sweet!
So when the screeches and rumbles continue to occur swath the area in carpet and curtains. Keep the volumes down. Equalise if possible.
Amp Placement
This is a most difficult topic attempting to describe the subjective qualities of sound. This will be avoided as much as possible by describing the tangible results achievable, thereby setting a suitable direction for starting out with an amp. Three different types of sound reinforcement are described: Stereo, background and foreground performance.
1) Stereo Celtic Harp Performance - This mean creating a sound zone or field directly in front of the harpist that surrounds and bathes the listener in harp music. This is irrespective of the background din at events such as Christmas fairs, craft shows and trade gatherings. What is happening is that a stereo sound field is created in front small product/CD sales table with the harpist on one side and the amp on the other. Create an imaginary triangle with the listener positioned in front of the table, the harpist by the table on the listener's left and an amp pointing upwards at the right of the table (the listener's right). This triangular set-up creates a stereo listening field that fills both of the listener's ears respectively where the amplified volume matches the harp volume. This is very effective in noisy environments.
This stereo effect is very useful outdoors where that second point source of amplified sound can be used to create a stereo effect which fools the listener's ear into receiving the music as a more enveloping surround sound and overall warming experience. At outdoor wedding ceremonies, have the amp spread 10' to 40' from the harp and on the ground. Increase the volume on the amp as the distance increases. Create a stereo field which need not be very loud.
2) Background Celtic Harp Performance - The most common difficulty with amplified background music is the speakers are aimed too low in height. Most background gigs are usually large noisy crowds, standing, eating and drinking - the classic corporate gig. It is a mistake to aim the music closer to their socks than their ears. The secret is to get the music over their heads and let it drift down. Small amps on a 6-7 foot stand work very well.
Alternately, if using a floor amp, tilt it so that the music bounces off the ceiling over people's heads. This is very subtle and very effective. Extraordinary sound dispersion can be achieved by making the room “resonate”.
3) Foreground Celtic Harp Performance - "A room, an amp on stage, an audience and a harpist. Can't be all that difficult. Right?" Maybe not! Amplifying a harp in concert is an exercise in subtlety, extreme subtlety. It takes experience and a self-trained ear to make a concert truly "sing" for a harpist. It can be learned with a little care. A few thoughts:
Equalise the amp so that resonant frequencies do not spoil the day - called "ringing out the room"
Match reverb and natural room reverberation well – then reduce reverb until it can/cannot be heard
Do not over amplify - every room has a natural sounding volume point
Tilt the amp upwards and reflect the sound off the ceiling down onto the audience
Keep the amp in front of the harp to prevent feedback
Spread the amp and harp apart as much as possible
Do not trap the amplified sound inside a structural alcove - IE: church roof beams
Avoid hard surfaces directly behind the harp - audio/harp slapping back into mics yielding resonance issues
Aim amp over top of the first two audience rows to prevent saturating natural harp sound with loud volumes to listeners in front
Say it again - Do not over amplify!
A helper using long cables and an external preamp can “mix” the performance from the front row
Continuously sonically experiment for a better sound but do it cautiously and in small degrees during performance – requires helper
We hope this helps and is a good point to start off from. Go yea forth and amplify! It's fun and satisfying for those that dare and persevere.
Reverberation
The remainder of sound that exists in a room after the source of the sound has stopped is called reverberation. It is the audible bounce off the walls after the instrument's note has silenced. All enclosed performance spaces have some reverberation, even though it may not always noticed as such. These characteristics of the reverberation are a big part of the subjective quality of the sound heard in any room.
Listen to an amp that is "dry" without reverb added - the music sounds like it comes out of a tunnel as if from a single point source. Nothing apparently comes from the room. The speaker overwhelms the natural room acoustics. Our ears, which are amazingly acute to the nuances of reflected sound within a confined space, register something is wrong. The result? - a sonically irritating audio performance.
When using too much added reverb, the ear registers a confusion of perceptive cues as to the original point source of the music. This creates a spacey, murky and muddy sonic result. If the amount of added reverb is reduced to the "can it be heard? Or can it not be heard?" listening point, the natural room acoustics start to blend with the artificial speaker reverb.
You can always appreciate a well-matched reverb because the room seems to have an additional audible lift, sparkle and clarity. Often the amp can seem warmer and more enveloping too. In a good set-up a well-matched reverb can make the amp disappear from the listener's consciousness.
Choosing an Amp
Best way to choose an amp is to take another harpist with you, plus your widest octave range harp and listen to a number of amps yourself comparatively while your friend plays harp music through each proffered amp. If nothing else you will make the salesman work for his commission. If you cannot discern the sound differences between the amps, do more listening research until you can. Choose a pleasant clean sound to your ear. Your ear loses discernment ability very quickly (10-20 minutes). Be patient, take a long break away from any noisy environment and reconfirm choices with fresh ears before buying. Ask about resale value and resale opportunity. Alternately, there are always used amp dealers around, find one you trust personally and wait for a deal to pop up for a given choice.
Good sound gear costs more. It is pointless to spend big money if you cannot hear the difference however (the Emperor’s new clothes). Listen to lots of gear at live events. Find an amp/ small system that sounds good to you. Ask the performer/engineer why. And start a new journey into amplified Celtic harp music.
Some things to consider - What purpose do you intend to use the amp for? - For example...
Amp used as a point source beside harp versus creating big volume to fill a room?
Does the physical size/ volumes/ looks fit your “presentation” as a harpist?
Can you lift it? Now and in 10 years?
Will it fit in car?
120V versus battery? (safety, busking, outdoors, setup time)
Does it need a preamp for your pickup?
Do you want to use a vocal microphone?
Resale value?
Crate and Fender amps are respected names. AER are new to North Americans but they make a superb amp. There are lots of other good brands out there. Watch out for the boy guitarist rigs that sell excessive features, sexy geejaws, and lousy sound. Look for “combo” amps designed for acoustic and base instruments as opposed to just acoustic amps for guitars. Keyboard amps are a possibility but may not have the range of inputs necessary.
Amp Features to Look For:
Longer battery life with recharging capability if battery powered
Speaker dispersion – wide angle versus narrow beam (both have advantages)
30/60/90 degree box shape for projecting sound at ceiling with a narrower speaker dispersion
Alternately an incorporated speaker stand socket to raise amp up high for good projection which suits a wider speaker dispersion (max. weight of 30 lbs)
Microphone input
48V Phantom power for condenser microphones
Pickup input
External preamp input
Tone controls on inputs
CD player input
Colour and looks – highly visible colours on floor are better for stopping tripping
Good strong bass sound
Background noise/ hum from the amp circuitry should be minimal
Some amps successfully used by harpists are the:
Crate Taxi (battery)
Crate Limo (battery)
Fender Acoustasonic 30 DSP
AER Compact 60
AER Mobile (battery)
The AER amp line has wonderful tone and has many more features than the Taxi, notably the option for a phantom powered condenser microphone. As in all sound gear good sound is definitely more pricey. The Acoustasonic has many useable features at a relatively low price.
Amplified harpists have lots of other favourite amps for their Celtic harp music. We prefer the Taxi simply because it is battery powered (very long life), inexpensive and it has a unique body shape which adapts well to many amplification positions. The sound is not all that bad either for the very low price. The older wooden version with black corners allows for mounting an external speaker socket.
A 120V mains power cable is simply 3 parallel wires referred to as positive (hot leg), negative (cold return leg) and the electrical earth (ground). It is important that the 3 wires are in "phase" or electrocution may occur. All venue outlets should be tested before use as a significant number are defective or “out of phase”. Use a three prong circuit tester available at the hardware store and test every circuit before performing.
Feedback and Room Resonance
A harp will have a dominant resonant frequency where the whole instrument will resonate in the presence of the same frequency. Celtic harps are natural microphones. Rooms also have natural resonant frequencies and will amplify those same frequencies when presented. If the resonance of the room and the amplified harp matches then problems may occur.
When amplified, a harp may put a frequency (say 400 Hz) thru the amp out in to the room, which is then resonated at an even louder volume by the room. This in turn makes the harp resonate more strongly, which puts an even stronger 400hz from the harp back into the sound system - around and around the signal loops until the system becomes unstable and propogates a feedback screech.
The resonant frequency of a room changes slightly with temperature and humidity but the easiest way to dampen resonances is to fill the room with people as clothes and bodies absorb reflected resonating sound quite nicely.
Placing carpet under the harp reduces sound reflections and is great for reducing resonance. Ditto curtains and soft materials around the harpist. Distance the harp and /or the amp from glass.
Pickups are the most stable in these situations. Get a piezo matching preamp with a small 5 band graphic EQ built in for personal resonating frequency control.
"Inside the harp" microphones are the least stable. They suffer greatly in noisy reflective environments thru the harp over-resonating. The space inside the sound box is a very acoustically complex area with lots of internal resonance nodes. Plugged sound holes do not look professional nor give the best harp sound. Specialty internal microphones like the Dusty Strings model will suffer somewhat less feedback as they are designed for the task.
NB: Microphones placed farther away from the harp (and hence running a little hotter to get a large enough signal) also become more feedback prone. Microphones with a broad pickup pattern with poor side rejection of frequencies coming from off axis are more prone to feedback as well. Cheaper mics fit into this category.
Work out the dominant resonant frequencies in a room once the harp is set up and the amp is on at a reasonably loud setting. To do this make sure every thing in the room is quiet . Then one by one pluck the strings thru the octaves from the bottom to the top of the harp. Certain strings will jump out as being louder than the rest. The amp’s corresponding specific frequency output will need to be reduced until the offending string sounds only as loud as its neighbouring strings. When the lowest fundamental note/string is reduced the corresponding upper related harmonic notes/strings disappear too. When the string volumes all sound in sync - Hey presto! No feedback for that volume level! Life can be very sweet!
So when the screeches and rumbles continue to occur swath the area in carpet and curtains. Keep the volumes down. Equalise if possible.
Amp Placement
This is a most difficult topic attempting to describe the subjective qualities of sound. This will be avoided as much as possible by describing the tangible results achievable, thereby setting a suitable direction for starting out with an amp. Three different types of sound reinforcement are described: Stereo, background and foreground performance.
1) Stereo Celtic Harp Performance - This mean creating a sound zone or field directly in front of the harpist that surrounds and bathes the listener in harp music. This is irrespective of the background din at events such as Christmas fairs, craft shows and trade gatherings. What is happening is that a stereo sound field is created in front small product/CD sales table with the harpist on one side and the amp on the other. Create an imaginary triangle with the listener positioned in front of the table, the harpist by the table on the listener's left and an amp pointing upwards at the right of the table (the listener's right). This triangular set-up creates a stereo listening field that fills both of the listener's ears respectively where the amplified volume matches the harp volume. This is very effective in noisy environments.
This stereo effect is very useful outdoors where that second point source of amplified sound can be used to create a stereo effect which fools the listener's ear into receiving the music as a more enveloping surround sound and overall warming experience. At outdoor wedding ceremonies, have the amp spread 10' to 40' from the harp and on the ground. Increase the volume on the amp as the distance increases. Create a stereo field which need not be very loud.
2) Background Celtic Harp Performance - The most common difficulty with amplified background music is the speakers are aimed too low in height. Most background gigs are usually large noisy crowds, standing, eating and drinking - the classic corporate gig. It is a mistake to aim the music closer to their socks than their ears. The secret is to get the music over their heads and let it drift down. Small amps on a 6-7 foot stand work very well.
Alternately, if using a floor amp, tilt it so that the music bounces off the ceiling over people's heads. This is very subtle and very effective. Extraordinary sound dispersion can be achieved by making the room “resonate”.
3) Foreground Celtic Harp Performance - "A room, an amp on stage, an audience and a harpist. Can't be all that difficult. Right?" Maybe not! Amplifying a harp in concert is an exercise in subtlety, extreme subtlety. It takes experience and a self-trained ear to make a concert truly "sing" for a harpist. It can be learned with a little care. A few thoughts:
Equalise the amp so that resonant frequencies do not spoil the day - called "ringing out the room"
Match reverb and natural room reverberation well – then reduce reverb until it can/cannot be heard
Do not over amplify - every room has a natural sounding volume point
Tilt the amp upwards and reflect the sound off the ceiling down onto the audience
Keep the amp in front of the harp to prevent feedback
Spread the amp and harp apart as much as possible
Do not trap the amplified sound inside a structural alcove - IE: church roof beams
Avoid hard surfaces directly behind the harp - audio/harp slapping back into mics yielding resonance issues
Aim amp over top of the first two audience rows to prevent saturating natural harp sound with loud volumes to listeners in front
Say it again - Do not over amplify!
A helper using long cables and an external preamp can “mix” the performance from the front row
Continuously sonically experiment for a better sound but do it cautiously and in small degrees during performance – requires helper
We hope this helps and is a good point to start off from. Go yea forth and amplify! It's fun and satisfying for those that dare and persevere.
Reverberation
The remainder of sound that exists in a room after the source of the sound has stopped is called reverberation. It is the audible bounce off the walls after the instrument's note has silenced. All enclosed performance spaces have some reverberation, even though it may not always noticed as such. These characteristics of the reverberation are a big part of the subjective quality of the sound heard in any room.
Listen to an amp that is "dry" without reverb added - the music sounds like it comes out of a tunnel as if from a single point source. Nothing apparently comes from the room. The speaker overwhelms the natural room acoustics. Our ears, which are amazingly acute to the nuances of reflected sound within a confined space, register something is wrong. The result? - a sonically irritating audio performance.
When using too much added reverb, the ear registers a confusion of perceptive cues as to the original point source of the music. This creates a spacey, murky and muddy sonic result. If the amount of added reverb is reduced to the "can it be heard? Or can it not be heard?" listening point, the natural room acoustics start to blend with the artificial speaker reverb.
You can always appreciate a well-matched reverb because the room seems to have an additional audible lift, sparkle and clarity. Often the amp can seem warmer and more enveloping too. In a good set-up a well-matched reverb can make the amp disappear from the listener's consciousness.
Choosing an Amp
Best way to choose an amp is to take another harpist with you, plus your widest octave range harp and listen to a number of amps yourself comparatively while your friend plays harp music through each proffered amp. If nothing else you will make the salesman work for his commission. If you cannot discern the sound differences between the amps, do more listening research until you can. Choose a pleasant clean sound to your ear. Your ear loses discernment ability very quickly (10-20 minutes). Be patient, take a long break away from any noisy environment and reconfirm choices with fresh ears before buying. Ask about resale value and resale opportunity. Alternately, there are always used amp dealers around, find one you trust personally and wait for a deal to pop up for a given choice.
Good sound gear costs more. It is pointless to spend big money if you cannot hear the difference however (the Emperor’s new clothes). Listen to lots of gear at live events. Find an amp/ small system that sounds good to you. Ask the performer/engineer why. And start a new journey into amplified Celtic harp music.
Some things to consider - What purpose do you intend to use the amp for? - For example...
Amp used as a point source beside harp versus creating big volume to fill a room?
Does the physical size/ volumes/ looks fit your “presentation” as a harpist?
Can you lift it? Now and in 10 years?
Will it fit in car?
120V versus battery? (safety, busking, outdoors, setup time)
Does it need a preamp for your pickup?
Do you want to use a vocal microphone?
Resale value?
Crate and Fender amps are respected names. AER are new to North Americans but they make a superb amp. There are lots of other good brands out there. Watch out for the boy guitarist rigs that sell excessive features, sexy geejaws, and lousy sound. Look for “combo” amps designed for acoustic and base instruments as opposed to just acoustic amps for guitars. Keyboard amps are a possibility but may not have the range of inputs necessary.
Amp Features to Look For:
Longer battery life with recharging capability if battery powered
Speaker dispersion – wide angle versus narrow beam (both have advantages)
30/60/90 degree box shape for projecting sound at ceiling with a narrower speaker dispersion
Alternately an incorporated speaker stand socket to raise amp up high for good projection which suits a wider speaker dispersion (max. weight of 30 lbs)
Microphone input
48V Phantom power for condenser microphones
Pickup input
External preamp input
Tone controls on inputs
CD player input
Colour and looks – highly visible colours on floor are better for stopping tripping
Good strong bass sound
Background noise/ hum from the amp circuitry should be minimal
Some amps successfully used by harpists are the:
Crate Taxi (battery)
Crate Limo (battery)
Fender Acoustasonic 30 DSP
AER Compact 60
AER Mobile (battery)
The AER amp line has wonderful tone and has many more features than the Taxi, notably the option for a phantom powered condenser microphone. As in all sound gear good sound is definitely more pricey. The Acoustasonic has many useable features at a relatively low price.
Amplified harpists have lots of other favourite amps for their Celtic harp music. We prefer the Taxi simply because it is battery powered (very long life), inexpensive and it has a unique body shape which adapts well to many amplification positions. The sound is not all that bad either for the very low price. The older wooden version with black corners allows for mounting an external speaker socket.
What we use with a Taxi:
Para-acoustic DI - the phone plug output goes into Taxi channel 1
Alfredo Ortiz/ Barcus Berry pickup
1 x 6' unbalanced phone plug cable
2 x 25' unbalanced phone plug cables
1 x phone plug to phone plug connector (Neutrik) - makes a 50' cable out of above
This assortment allows for the Taxi played in close to the harpist or at a distance to create a stereo field. The Taxi can also be mixed from the front row in concert venues.
Note: A comment is necessary about Musical Instrument (MI) stores which abound in shopping malls. They survive by selling to 18 year old boy guitarists with $200 in their pockets. MI sound gear is designed for that market with a $200 price point. What goes inside the box does not matter as long as it looks sexy. Harps are comparatively hard to amplify as they are natural microphones and co-resonate with rooms plus the attendant amps to cause feedback more easily. Buy components from specialist audio stores, the web, eBay(?) and use the web extensively for reviews from neutral parties.
Para-acoustic DI - the phone plug output goes into Taxi channel 1
Alfredo Ortiz/ Barcus Berry pickup
1 x 6' unbalanced phone plug cable
2 x 25' unbalanced phone plug cables
1 x phone plug to phone plug connector (Neutrik) - makes a 50' cable out of above
This assortment allows for the Taxi played in close to the harpist or at a distance to create a stereo field. The Taxi can also be mixed from the front row in concert venues.
Note: A comment is necessary about Musical Instrument (MI) stores which abound in shopping malls. They survive by selling to 18 year old boy guitarists with $200 in their pockets. MI sound gear is designed for that market with a $200 price point. What goes inside the box does not matter as long as it looks sexy. Harps are comparatively hard to amplify as they are natural microphones and co-resonate with rooms plus the attendant amps to cause feedback more easily. Buy components from specialist audio stores, the web, eBay(?) and use the web extensively for reviews from neutral parties.