Amplifier Setting Tutorial

[2kchevy06civic 5,000+ posts]

holy cow nice write up.........lol

good to see you jmac.

Click to read more...

 

[ssj2xxgotenxx 10+ year member]

High your post count is.

 

[thch 10+ year member]

I would propose an appendum to this guide to detail alternative methods for tonal balence. the guide above sets the highpass to a value which is safe, then sets the lowpass based upon this setting. realistically the process will be more iteritive, as the settings are not independent.

for example, once you decide to lower the level of the speakers (last part, level matching), you would probably want to reconcider the highpass filter because at lower outputs the filter could be lowered. likewise, lowering the output of the sub may reduce some of the distortion which made the bass sound funny, allowing it to have a lower SSF and a high LPF.

this would be especially useful to know if the HPF was set to 120hz and the LPF only set at 60hz. in such a case to get good sound, it may be required to lower the volume of both the woofer and the speakers to allow better blending. eg, the woofer will sound localized above 100hz, and the speakers will distort below 120hz, so the speakers volume must be lowered to allow at least a 100hz cutoff, but now the woofers are overpowering so the volume gets lowered and the LPF set to 100hz.

i'm not entirely sure setting SSF by calculation is the ideal thing. it may be easier just to use low frequencies and lower the SSF from its maximum setting until the excursion is too high. this gives optimal results that are based upon the system, and not based upon some estimate like Fb*0.75. for example, someone using a high excursion woofer on a lower power amplifier may not have issues with overexcursion ever, in which case the SSF just removes some of the bass needlessly.

this is not to say that I am displeased by this guide. it is IMO more practical then some other guides that say that the DMM is a good method to set gains, and an OScope is never wrong...

It is my opinion that the setting of a system is highly based upon the goals of the user. it is also my opinion that the process will be iterative. with so many options, it will be impossible to try everything, but with resolve, it should be possible to set the system to a near optimal setting with only a few changes from the base settings.

 

[backtofront001 10+ year member]

Wow, This is an amazingly helpful guide...Thank You JMac

 

[PollyCranopolis 10+ year member]

So for example, setting gains on a 4 chan amp for a component set.

Amp=110X4 (2 comp sets, 110w each side, front+back)

Speaker RMS= 90

Avg. voltage for my car while running=13.8

front set CDT's = 4ohm

Voltage = SQRT(Power*Resistance)

eg. 110*4=440=sqrt=20.97

 

[thch 10+ year member]

I will post a table in this part later today. just reserving space on page 1 atm.

Table:50 Watts -- 1.0 Ohms, V=7.07 -- 2.0 Ohms, V=10.0 -- 4.0 Ohms, V=14.14 -- 8.0 Ohms, V=20.0

100 Watts -- 1.0 Ohms, V=10.0 -- 2.0 Ohms, V=14.14 -- 4.0 Ohms, V=20.0 -- 8.0 Ohms, V=28.28

150 Watts -- 1.0 Ohms, V=12.24 -- 2.0 Ohms, V=17.32 -- 4.0 Ohms, V=24.49 -- 8.0 Ohms, V=34.64

200 Watts -- 1.0 Ohms, V=14.14 -- 2.0 Ohms, V=20.0 -- 4.0 Ohms, V=28.28 -- 8.0 Ohms, V=40.0

250 Watts -- 1.0 Ohms, V=15.81 -- 2.0 Ohms, V=22.36 -- 4.0 Ohms, V=31.62 -- 8.0 Ohms, V=44.72

300 Watts -- 1.0 Ohms, V=17.32 -- 2.0 Ohms, V=24.49 -- 4.0 Ohms, V=34.64 -- 8.0 Ohms, V=48.98

350 Watts -- 1.0 Ohms, V=18.70 -- 2.0 Ohms, V=26.45 -- 4.0 Ohms, V=37.41 -- 8.0 Ohms, V=52.91

400 Watts -- 1.0 Ohms, V=20.0 -- 2.0 Ohms, V=28.28 -- 4.0 Ohms, V=40.0 -- 8.0 Ohms, V=56.56

450 Watts -- 1.0 Ohms, V=21.21 -- 2.0 Ohms, V=30.0 -- 4.0 Ohms, V=42.42 -- 8.0 Ohms, V=60.0

500 Watts -- 1.0 Ohms, V=22.36 -- 2.0 Ohms, V=31.62 -- 4.0 Ohms, V=44.72 -- 8.0 Ohms, V=63.24

600 Watts -- 1.0 Ohms, V=24.49 -- 2.0 Ohms, V=34.64 -- 4.0 Ohms, V=48.98 -- 8.0 Ohms, V=69.28

700 Watts -- 1.0 Ohms, V=26.45 -- 2.0 Ohms, V=37.41 -- 4.0 Ohms, V=52.91 -- 8.0 Ohms, V=74.83

800 Watts -- 1.0 Ohms, V=28.28 -- 2.0 Ohms, V=40.0 -- 4.0 Ohms, V=56.56 -- 8.0 Ohms, V=80.0

900 Watts -- 1.0 Ohms, V=30.0 -- 2.0 Ohms, V=42.42 -- 4.0 Ohms, V=60.0 -- 8.0 Ohms, V=84.85

1000 Watts -- 1.0 Ohms, V=31.62 -- 2.0 Ohms, V=44.72 -- 4.0 Ohms, V=63.24 -- 8.0 Ohms, V=89.44

1100 Watts -- 1.0 Ohms, V=33.16 -- 2.0 Ohms, V=46.90 -- 4.0 Ohms, V=66.33 -- 8.0 Ohms, V=93.80

1200 Watts -- 1.0 Ohms, V=34.64 -- 2.0 Ohms, V=48.98 -- 4.0 Ohms, V=69.28 -- 8.0 Ohms, V=97.97

1300 Watts -- 1.0 Ohms, V=36.05 -- 2.0 Ohms, V=50.99 -- 4.0 Ohms, V=72.11 -- 8.0 Ohms, V=101.98

1400 Watts -- 1.0 Ohms, V=37.41 -- 2.0 Ohms, V=52.91 -- 4.0 Ohms, V=74.83 -- 8.0 Ohms, V=105.83

1500 Watts -- 1.0 Ohms, V=38.72 -- 2.0 Ohms, V=54.77 -- 4.0 Ohms, V=77.45 -- 8.0 Ohms, V=109.54

1600 Watts -- 1.0 Ohms, V=40.0 -- 2.0 Ohms, V=56.56 -- 4.0 Ohms, V=80.0 -- 8.0 Ohms, V=113.13

1700 Watts -- 1.0 Ohms, V=41.23 -- 2.0 Ohms, V=58.30 -- 4.0 Ohms, V=82.46 -- 8.0 Ohms, V=116.61

1800 Watts -- 1.0 Ohms, V=42.42 -- 2.0 Ohms, V=60.0 -- 4.0 Ohms, V=84.85 -- 8.0 Ohms, V=120.0

1900 Watts -- 1.0 Ohms, V=43.58 -- 2.0 Ohms, V=61.64 -- 4.0 Ohms, V=87.17 -- 8.0 Ohms, V=123.28

2000 Watts -- 1.0 Ohms, V=44.72 -- 2.0 Ohms, V=63.24 -- 4.0 Ohms, V=89.44 -- 8.0 Ohms, V=126.49

2100 Watts -- 1.0 Ohms, V=45.82 -- 2.0 Ohms, V=64.80 -- 4.0 Ohms, V=91.65 -- 8.0 Ohms, V=129.61

2200 Watts -- 1.0 Ohms, V=46.90 -- 2.0 Ohms, V=66.33 -- 4.0 Ohms, V=93.80 -- 8.0 Ohms, V=132.66

2300 Watts -- 1.0 Ohms, V=47.95 -- 2.0 Ohms, V=67.82 -- 4.0 Ohms, V=95.91 -- 8.0 Ohms, V=135.64

2400 Watts -- 1.0 Ohms, V=48.98 -- 2.0 Ohms, V=69.28 -- 4.0 Ohms, V=97.97 -- 8.0 Ohms, V=138.56

2500 Watts -- 1.0 Ohms, V=50.0 -- 2.0 Ohms, V=70.71 -- 4.0 Ohms, V=100.0 -- 8.0 Ohms, V=141.42

2600 Watts -- 1.0 Ohms, V=50.99 -- 2.0 Ohms, V=72.11 -- 4.0 Ohms, V=101.98 -- 8.0 Ohms, V=144.22

2700 Watts -- 1.0 Ohms, V=51.96 -- 2.0 Ohms, V=73.48 -- 4.0 Ohms, V=103.92 -- 8.0 Ohms, V=146.96

2800 Watts -- 1.0 Ohms, V=52.91 -- 2.0 Ohms, V=74.83 -- 4.0 Ohms, V=105.83 -- 8.0 Ohms, V=149.66

2900 Watts -- 1.0 Ohms, V=53.85 -- 2.0 Ohms, V=76.15 -- 4.0 Ohms, V=107.70 -- 8.0 Ohms, V=152.31

3000 Watts -- 1.0 Ohms, V=54.77 -- 2.0 Ohms, V=77.45 -- 4.0 Ohms, V=109.54 -- 8.0 Ohms, V=154.91

 

[thch 10+ year member]

and some of the odd loads:

50 Watts -- 1.33 Ohms, V=8.15 -- 1.5 Ohms, V=8.66 -- 3 Ohms, V=12.24 -- 6 Ohms, V=17.32

100 Watts -- 1.33 Ohms, V=11.53 -- 1.5 Ohms, V=12.24 -- 3 Ohms, V=17.32 -- 6 Ohms, V=24.49

150 Watts -- 1.33 Ohms, V=14.12 -- 1.5 Ohms, V=15.0 -- 3 Ohms, V=21.21 -- 6 Ohms, V=30.0

200 Watts -- 1.33 Ohms, V=16.30 -- 1.5 Ohms, V=17.32 -- 3 Ohms, V=24.49 -- 6 Ohms, V=34.64

250 Watts -- 1.33 Ohms, V=18.23 -- 1.5 Ohms, V=19.36 -- 3 Ohms, V=27.38 -- 6 Ohms, V=38.72

300 Watts -- 1.33 Ohms, V=19.97 -- 1.5 Ohms, V=21.21 -- 3 Ohms, V=30.0 -- 6 Ohms, V=42.42

350 Watts -- 1.33 Ohms, V=21.57 -- 1.5 Ohms, V=22.91 -- 3 Ohms, V=32.40 -- 6 Ohms, V=45.82

400 Watts -- 1.33 Ohms, V=23.06 -- 1.5 Ohms, V=24.49 -- 3 Ohms, V=34.64 -- 6 Ohms, V=48.98

450 Watts -- 1.33 Ohms, V=24.46 -- 1.5 Ohms, V=25.98 -- 3 Ohms, V=36.74 -- 6 Ohms, V=51.96

500 Watts -- 1.33 Ohms, V=25.78 -- 1.5 Ohms, V=27.38 -- 3 Ohms, V=38.72 -- 6 Ohms, V=54.77

600 Watts -- 1.33 Ohms, V=28.24 -- 1.5 Ohms, V=30.0 -- 3 Ohms, V=42.42 -- 6 Ohms, V=60.0

700 Watts -- 1.33 Ohms, V=30.51 -- 1.5 Ohms, V=32.40 -- 3 Ohms, V=45.82 -- 6 Ohms, V=64.80

800 Watts -- 1.33 Ohms, V=32.61 -- 1.5 Ohms, V=34.64 -- 3 Ohms, V=48.98 -- 6 Ohms, V=69.28

900 Watts -- 1.33 Ohms, V=34.59 -- 1.5 Ohms, V=36.74 -- 3 Ohms, V=51.96 -- 6 Ohms, V=73.48

1000 Watts -- 1.33 Ohms, V=36.46 -- 1.5 Ohms, V=38.72 -- 3 Ohms, V=54.77 -- 6 Ohms, V=77.45

1100 Watts -- 1.33 Ohms, V=38.24 -- 1.5 Ohms, V=40.62 -- 3 Ohms, V=57.44 -- 6 Ohms, V=81.24

1200 Watts -- 1.33 Ohms, V=39.94 -- 1.5 Ohms, V=42.42 -- 3 Ohms, V=60.0 -- 6 Ohms, V=84.85

1300 Watts -- 1.33 Ohms, V=41.58 -- 1.5 Ohms, V=44.15 -- 3 Ohms, V=62.44 -- 6 Ohms, V=88.31

1400 Watts -- 1.33 Ohms, V=43.15 -- 1.5 Ohms, V=45.82 -- 3 Ohms, V=64.80 -- 6 Ohms, V=91.65

1500 Watts -- 1.33 Ohms, V=44.66 -- 1.5 Ohms, V=47.43 -- 3 Ohms, V=67.08 -- 6 Ohms, V=94.86

1600 Watts -- 1.33 Ohms, V=46.13 -- 1.5 Ohms, V=48.98 -- 3 Ohms, V=69.28 -- 6 Ohms, V=97.97

1700 Watts -- 1.33 Ohms, V=47.54 -- 1.5 Ohms, V=50.49 -- 3 Ohms, V=71.41 -- 6 Ohms, V=100.99

1800 Watts -- 1.33 Ohms, V=48.92 -- 1.5 Ohms, V=51.96 -- 3 Ohms, V=73.48 -- 6 Ohms, V=103.92

1900 Watts -- 1.33 Ohms, V=50.26 -- 1.5 Ohms, V=53.38 -- 3 Ohms, V=75.49 -- 6 Ohms, V=106.77

2000 Watts -- 1.33 Ohms, V=51.57 -- 1.5 Ohms, V=54.77 -- 3 Ohms, V=77.45 -- 6 Ohms, V=109.54

2100 Watts -- 1.33 Ohms, V=52.84 -- 1.5 Ohms, V=56.12 -- 3 Ohms, V=79.37 -- 6 Ohms, V=112.24

2200 Watts -- 1.33 Ohms, V=54.09 -- 1.5 Ohms, V=57.44 -- 3 Ohms, V=81.24 -- 6 Ohms, V=114.89

2300 Watts -- 1.33 Ohms, V=55.30 -- 1.5 Ohms, V=58.73 -- 3 Ohms, V=83.06 -- 6 Ohms, V=117.47

2400 Watts -- 1.33 Ohms, V=56.49 -- 1.5 Ohms, V=60.0 -- 3 Ohms, V=84.85 -- 6 Ohms, V=120.0

2500 Watts -- 1.33 Ohms, V=57.66 -- 1.5 Ohms, V=61.23 -- 3 Ohms, V=86.60 -- 6 Ohms, V=122.47

2600 Watts -- 1.33 Ohms, V=58.80 -- 1.5 Ohms, V=62.44 -- 3 Ohms, V=88.31 -- 6 Ohms, V=124.89

2700 Watts -- 1.33 Ohms, V=59.92 -- 1.5 Ohms, V=63.63 -- 3 Ohms, V=90.0 -- 6 Ohms, V=127.27

2800 Watts -- 1.33 Ohms, V=61.02 -- 1.5 Ohms, V=64.80 -- 3 Ohms, V=91.65 -- 6 Ohms, V=129.61

2900 Watts -- 1.33 Ohms, V=62.10 -- 1.5 Ohms, V=65.95 -- 3 Ohms, V=93.27 -- 6 Ohms, V=131.90

3000 Watts -- 1.33 Ohms, V=63.16 -- 1.5 Ohms, V=67.08 -- 3 Ohms, V=94.86 -- 6 Ohms, V=134.16

 

[thch 10+ year member]

Values for Common Speakers:

5 Watts -- 4 Ohms, V=4.47 -- 6 Ohms, V=5.47 -- 8 Ohms, V=6.32

10 Watts -- 4 Ohms, V=6.32 -- 6 Ohms, V=7.74 -- 8 Ohms, V=8.94

15 Watts -- 4 Ohms, V=7.74 -- 6 Ohms, V=9.48 -- 8 Ohms, V=10.95

20 Watts -- 4 Ohms, V=8.94 -- 6 Ohms, V=10.95 -- 8 Ohms, V=12.64

25 Watts -- 4 Ohms, V=10.0 -- 6 Ohms, V=12.24 -- 8 Ohms, V=14.14

30 Watts -- 4 Ohms, V=10.95 -- 6 Ohms, V=13.41 -- 8 Ohms, V=15.49

35 Watts -- 4 Ohms, V=11.83 -- 6 Ohms, V=14.49 -- 8 Ohms, V=16.73

40 Watts -- 4 Ohms, V=12.64 -- 6 Ohms, V=15.49 -- 8 Ohms, V=17.88

45 Watts -- 4 Ohms, V=13.41 -- 6 Ohms, V=16.43 -- 8 Ohms, V=18.97

50 Watts -- 4 Ohms, V=14.14 -- 6 Ohms, V=17.32 -- 8 Ohms, V=20.0

55 Watts -- 4 Ohms, V=14.83 -- 6 Ohms, V=18.16 -- 8 Ohms, V=20.97

60 Watts -- 4 Ohms, V=15.49 -- 6 Ohms, V=18.97 -- 8 Ohms, V=21.90

65 Watts -- 4 Ohms, V=16.12 -- 6 Ohms, V=19.74 -- 8 Ohms, V=22.80

70 Watts -- 4 Ohms, V=16.73 -- 6 Ohms, V=20.49 -- 8 Ohms, V=23.66

75 Watts -- 4 Ohms, V=17.32 -- 6 Ohms, V=21.21 -- 8 Ohms, V=24.49

80 Watts -- 4 Ohms, V=17.88 -- 6 Ohms, V=21.90 -- 8 Ohms, V=25.29

85 Watts -- 4 Ohms, V=18.43 -- 6 Ohms, V=22.58 -- 8 Ohms, V=26.07

90 Watts -- 4 Ohms, V=18.97 -- 6 Ohms, V=23.23 -- 8 Ohms, V=26.83

95 Watts -- 4 Ohms, V=19.49 -- 6 Ohms, V=23.87 -- 8 Ohms, V=27.56

100 Watts -- 4 Ohms, V=20.0 -- 6 Ohms, V=24.49 -- 8 Ohms, V=28.28

110 Watts -- 4 Ohms, V=20.97 -- 6 Ohms, V=25.69 -- 8 Ohms, V=29.66

120 Watts -- 4 Ohms, V=21.90 -- 6 Ohms, V=26.83 -- 8 Ohms, V=30.98

130 Watts -- 4 Ohms, V=22.80 -- 6 Ohms, V=27.92 -- 8 Ohms, V=32.24

140 Watts -- 4 Ohms, V=23.66 -- 6 Ohms, V=28.98 -- 8 Ohms, V=33.46

150 Watts -- 4 Ohms, V=24.49 -- 6 Ohms, V=30.0 -- 8 Ohms, V=34.64

160 Watts -- 4 Ohms, V=25.29 -- 6 Ohms, V=30.98 -- 8 Ohms, V=35.77

170 Watts -- 4 Ohms, V=26.07 -- 6 Ohms, V=31.93 -- 8 Ohms, V=36.87

180 Watts -- 4 Ohms, V=26.83 -- 6 Ohms, V=32.86 -- 8 Ohms, V=37.94

190 Watts -- 4 Ohms, V=27.56 -- 6 Ohms, V=33.76 -- 8 Ohms, V=38.98

 

[DIGIDIGIBOMBO 10+ year member]

Geezzz, y am i always having verrrrrrry poor results when setting gains using a 0dB,-3,-6,even -10dB test tones( specially with woofers, they are barely moving)...now i am only setting gains by ears, after setting the amp i tried to insert a test tone and used a DMM i had voltage double then the calculation method required me to use, rather then having 300rms pumped into the sub i was getting almost 600 which is the maximum power of the sub, same thing with speakers, and i havent damaged any speaker/woofer...? how is that? Although i set the HU volume to 75% and then set the amp gain, some music are recorded at very low levels i find myself using the 100% of the HU volume, sometimes its 40% it all depends relyng on the ear:S its also good to use the Subwoofer volume control, at some songs i set it to -6, other time at+3, it all depends on every song. I cannot be a robot and always use, same settings and maximum unclipped volume relying on a 0 dB tone. Am i wrong? thx again

 

[88irocZ 10+ year member]

wow well i am really new at this and i need some help if someone doesnt mind helping me that would be great. i bought a digital voltmeter, and i made the test tone cd can someone explain a little more indepth how to use the voltmeter?

also i dont know what to plug in for this formula: SSF = Tuning*3/4

can someone help me out? if so i would definitely appreciate it. i have a profile 2000 watt amp and b4 i just had the gains half way up and the ssf and lowpass at 0 so i need to figure out how to set it up right.

 

[PollyCranopolis 10+ year member]

I'm having the opposite results. Example: I have a set of comps with a 90watt rms rating. They are 4 ohms. 90*4=360Sqrt=18.97. To get a 18.97 volt reading at my RF851x, I have to turn my gains up about 85% with a 0db test tone.

 

[88irocZ 10+ year member]

wow well i am really new at this and i need some help if someone doesnt mind helping me that would be great. i bought a digital voltmeter, and i made the test tone cd can someone explain a little more indepth how to use the voltmeter?
also i dont know what to plug in for this formula: SSF = Tuning*3/4

can someone help me out? if so i would definitely appreciate it. i have a profile 2000 watt amp and b4 i just had the gains half way up and the ssf and lowpass at 0 so i need to figure out how to set it up right.

anyone have any advice for me?

 

[PollyCranopolis 10+ year member]

I believe you turn your deck up 80%, with amp crossovers off, deck processing off, speakers disconnected from amp, gains set to 0. Set your voltmeter to measure AC. Take one channel of the amp, and put the voltmeter ends aganst the postive and negative sides of the channel. Slowly turn up gain until volt meter registers desired voltage while playing a 0 db or -3db test tone. 1000hz for highs, 60 hz for subs. Turn HU down, reconnect speakers, and add desired processing at deck.

Use equation to get desired voltage beforehand: Voltage=Sqrt(power*resistance).

Eg: 90 watt rms speakers, 110 watt per channel amp. Use the lower of the 2 for power, multiply by resistance. Eg: 90*4(4ohm speaker)=360. Take Sqrt of 360, = 18.97 volts.

 

[88irocZ 10+ year member]

I believe you turn your deck up 80%, with amp crossovers off, deck processing off, speakers disconnected from amp, gains set to 0. Set your voltmeter to measure AC. Take one channel of the amp, and put the voltmeter ends aganst the postive and negative sides of the channel. Slowly turn up gain until volt meter registers desired voltage while playing a 0 db or -3db test tone. 1000hz for highs, 60 hz for subs. Turn HU down, reconnect speakers, and add desired processing at deck.
Use equation to get desired voltage beforehand: Voltage=Sqrt(power*resistance).

Eg: 90 watt rms speakers, 110 watt per channel amp. Use the lower of the 2 for power, multiply by resistance. Eg: 90*4(4ohm speaker)=360. Take Sqrt of 360, = 18.97 volts.

i know how to do all that i just dont know how to use the volt meter... and i dont understand how to set the subsonic filter.

 

[DIGIDIGIBOMBO 10+ year member]

dude if u have a seald box, turn off the subsonic filter, for a ported box i guess around 30Hz if u dont know ur tuning box freq bla bla bla....u dunno how to use a dmm???:S well just pick AC voltage on the DMM and start testing. It has the following symbol ~ V, where ~stands for alternating. hope i helped u.