How to Tune an Amplifier in Just Five Minutes
“Tune an amplifier? Isn’t an amplifier ‘tuneless’”? You might wonder. Technically speaking, yes. An amplifier doesn’t have a tune.
Nevertheless, you have to tune or adjust it so your sound source, speakers (and subs), and amp can perform to its fullest potential.
Knowing how to tune an amplifier also ensures that your amplifier produces the correct power for the speakers.
It also makes sure the gain control matches the source unit. Through tuning, you are prolonging your gadgets’ life because none gets overworked.
You wouldn’t want a mediocre sound system, would you?
This tutorial will teach you to adjust your gains, frequency, and bass in just five minutes.
What you need (aside from the amp, of course)
Whether it is a phone, online, or traditional calculator, it can work. Just make sure that it has the square root function.
You may also try to the computation manually with your mind, but that might take a long time. Unless you are the Rain Man or some other math savant.
But even then, using a calculator should still be the faster and the more believable source of answer. It might be hard to explain to your friend where you got the answer if you merely computed it in you brain.
2./ Digital multimeter
I prefer the digital multimeter because it’s more accurate. I mean, later on, when the result of the computation has decimal points, the digital multimeter can show them.
The analog, on the other hand, may not be able to show you the decimal points exactly. Rather, you might have a hard time knowing if the decimal points have already been achieved.
By the way, it doesn’t have to be a multimeter for professional use. Just the basic one will do. Just make sure it reads AC voltage.
If a multi-meter is not at all available, don’t worry. I have included a method that doesn’t use a multimeter at all.
3./ Flathead screwdriver
This screwdriver will be used to adjust the gain control, which only accommodates a flathead type. Hence, other types may not be used.
The only consideration you have to think of is the screwdriver’s size because it will depend on your amp’s gain dial size.
If your amp’s dials have knobs, a screwdriver will be unnecessary.
4./ Test tone CD
The tone should be recorded at about 50 Hz, the normal level a CD would be recorded at. You may download test tones here.
You may also use a USB where you can save the tone.
5./ CD player
This is where the CD will be played. If you’re using a USB, make sure your player is USB enabled.
1./ Get the desired RMS voltage
Using your calculator, follow this equation:
V = √ P * R
Where V is for the desired RMS voltage, P is for RMS power of amplifier, and R is for the resistance of speaker load.
If the amplifier’s RMS power is 500 watts then the speaker’s resistance is 2 Ohms, then
V = √500 * 2
V = √1000
V = 31.62
31.62 then is the desired voltage we are looking for.
2./ Play the test tone
Pop the CD (or the USB) in the player. Select the track of the test tone and set it on repeat in case it will take you longer than usual to adjust the gains. Turn the volume all the way up and play the test tone.
When playing the tone, make sure you disconnect the speakers from the amp as the speakers might be stressed.
3./ Turn the amp dials all the way down
Turn the equalization features all the way down. The low pass frequency filter, however, must be turned all the way up.
This will give you the highest possible bandwidth for your amplifier so that the gain can be set properly.
Please note that amplifiers have different equalization dials. This tutorial is for ones with gain, bass boost, and frequency only.
4./ Set the gain
Set the multimeter to AC voltage then connect it to the speaker outputs of the amp. Using the screwdriver, turn the gain dial back and forth until you reach the desired RMS voltage. In this tutorial, it’s 31.62.
You may not be able to stop at the exact voltage because the numbers on the meters move fast. The trick here is to stop as soon as you see the desired RMS voltage. The number may move a bit when you stop, but that’s OK.
You may watch how it’s done here.
If you don’t have the multimeter, you may still manually adjust your gain.
With your sound unit hooked up to the amplifier and the speakers, play the test tone while adjusting the gain dial. Make sure that the volume is not all the way up. About 80% of the maximum will do. Once you hear distortions, turn the dial back slowly until the distortion disappears.
5./ Tune the frequencies
The frequency filter you will choose depends if you’re using subwoofer or speakers. If you’re using the full-range ones, there’s no need to tune it. Skip to step 6.
Choose HPF for speakers. Your subwoofer/speakers are rated for a certain frequency. Find that rating in the frequency filter and adjust accordingly.
You may also opt to set the high pass filter to 100Hz but make sure to set the gain first at 0. Adjust the gain accordingly until you hear the sound fit to your liking.
6./ Adjust the bass
When adjusting the bass, turn the gain dial down. Keep on adjusting until your desired bass boost combination has been reached. The main point is to have the highest bass output without the distortion.
80Hz is also a good starting point for the low pass filter. Then adjust the gain to your liking. If you want the bigger boom, lessen the LPF setting. Note, however, that enhancing the bass may be risky as it may shorten the life of your woofer. Hence, boosting the bass should be done with utmost care.
If your amp has subsonic filter, put it to the lowest setting possible. But if you are concerned with more power handling, choose a higher setting.
In case your mid and high frequencies are overpowered by the bass or vice versa, adjust the filters. The point here is that all frequencies are blended and balanced.
7./ Set the gain again
After the frequencies and bass have been adjusted, tune the gain control again. While playing music at about 70-90% of the maximum volume, adjust the gain dial until you hear distortion. Turn it back down slowly until the distortion disappears.
Your amplifier should be all set. Get your favorite music and hear the difference.
Tuning for multiple speakers
If you have more than one speaker connected to your amp, you will be doing a number of tuning sessions for each of them. Here’s how:
Note: In this tutorial, you will be using the same tools except the multimeter. Also, the sets of speakers are called front and rear although this may be left and right or whatever you want to call them.
Ensure that all your speakers are working and are installed properly. Also, be in a place where no one would care how loud you’d play your music.
2./ Set player to zero
If your deck (player) has enhancements such as bass and treble, set them all to 0. Even the volume must be completely off.
3./ Set the volume
Using your screwdriver, turn the amp’s gains all the way down. If your amp has EQ or bass boost, set them to 0 as well. If you have subs and crossovers, turn them off too.
Play your test tone. You should be hearing nothing, if not a faint sound, coming from your player as the gains are still set at 0.
Turn the deck volume to 100%. Despite playing at the maximum volume, the sound you hear should still be clear as the gain setting is low.
Slowly turn up the gain for the front speakers. Turn the gain dial until you hear distortion. Slowly turn it down until distortion disappears.
Repeat the last two steps for the rear speakers. While adjusting for the rear speakers, however, make sure that the gain for front speakers are turned all the way down. Do not forget the setting, though.
Re-set the front gain. Once you have set the gain setting for the rear speakers, re-set the one for the front speakers (the setting I told you not to forget).
4./ Do Steps 5 and 6 above
To adjust the frequency filters and the bass boost, do the same steps indicated above.
Remember you have to repeat the steps for each speaker set.
Learning how to tune an amplifier may be confusing for first timers. Note, however, that songs may require different settings. But the important thing is you already know how to tune an amplifier, which makes adjusting a piece of cake.
After learning this process, you will not only enjoy your music with enhancements but also ensure you are not overworking your entire sound system. And all of these just take five minutes of your time.
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