Gain Setting Tutorial

[Stem 10+ year member]

PS1-5500D amp, (2500w @ 2ohm)

2 DVC2ohm Subs

SQRT(2500 x 2) = 70.7v

that sound right?

 

[twisztdauthorit 10+ year member]

Guys is this really that hard?

grab your handy dandy calculator

and get the square root of:

your expected RMS wattage x your ohm load...

 

[VirgilGoneMad]

If my amp makes 60 RMS x 4 @ 4 ohms, that would give 15.5 volts at the speaker outputs right? Now it also makes 80 RMS x 4 @ 2 ohms. How many watts x 4 @ 3 ohms would it make and how many volts at the speaker outputs would I be looking for? Thanks in advance.

 

[cocoleveo7686 10+ year member]

i have a few questions, i think i did this right but im not 100 percent sure...i have the hifonics bxi2006d its 2000rms at 1 ohm the voltage i got was 44.7 does that sound right?

on my headunit, its an old one its a pioneer premiere, it has 80hz and you can go to +6 someone told me to keep that on while i am setting the gains. it also has slam that goes to +6 i keep that at 0, and it has low mid and high level gains on it too, the low gives more bass the highs give more treble...i keep the high level on +5 but everything else on 0, is that how it should be?

also on the amp it has - - ++ on the amp...so i just did 1 neg to 1 positive cause i bridged the subs at the box....i dont know if that makes a difference either

on my amp it has Phase which is 0-180, i have that on 0

level goes from 0.2-9V- i have that set to 3.4 of the way to 0.2 because thats where the voltage read 44.1 can i turn it up to like 48 volts since when you drive on the street you dotn listen to test tones?

the bass eq is 0-10DB i have it half way up

subsonic is 15-35HZ its a quater of the way up

Low pass is 35-250hz its about a quarter of the way up

should any of these be higher?

 

[Casey K]

How do you do this if the crossover is permanently set?

 

[jblayz1 10+ year member]

I'm sorry I"m so stupid i forgot to mention the watts.well the hifonics is rated at 1500 watts x 1 @ 1ohm but I heard it's over rated so I don't really know the real wattage it will be putting out.the JBL is rated 104 watts x 4 @ 4ohm

thanks in advance

hifonics = 38.7

jbl = 20.4

 

[jblayz1 10+ year member]

Hi, I have two Rockford p210d4 4 ohm subs hooked up bridged to a rockford p5002 amp. I tried this method, and my subs were crackling and making bad noises like zapping/ electrical sorta after I increased the gains until 44.7 v. The subs and amp are new, and before I had the gain on 0. This was also at a much lower volume than what I tested them at. I have an Eclipse cd4000 hu, and the volume was on 55 when I did the voltmeter gain setting, after when I hooked back up the subs, they were crackling on 45. I turned the gain back down until they sounded OK, which was from about 2/3 when I tested it back to about 1/3. I have the lp on 80, and everything on 0 except sub volume is the highest it can go. Bass boost is 1/4 or less. The subs are so quiet, you can barely hear them. Is that normal for these subs? Can someone help me out? This is the first time I installed an amplifier before, but I think I did everything OK. Sorry this is so long. //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif Thanks for any help you can offer

that's a pretty small amp for 2 subs. turn your bass boost off.

 

[jblayz1 10+ year member]

I have a Lanzar 286 and I have it wired 4 ohms ...... whats the number im looking for? I dont understand the **** JL audio thing thing..
yah im kind of ignorant cut some slack....

and help plz ftw.

what sub?

 

[Castro]

sorry for the newbie question

running 2 subs single 4 ohms coil rated at 300w rms each. and connected in parrallel --> therefore a 2ohm load , do i add the rms wattge in the formula?

eg sqrt((300+300)*2)=34.64v

correct?

 

[Jekku 10+ year member]

sorry for the newbie question
running 2 subs single 4 ohms coil rated at 300w rms each. and connected in parrallel --> therefore a 2ohm load , do i add the rms wattge in the formula?

eg sqrt((300+300)*2)=34.64v

correct?

300W is what? Sub or amp rms?

You use your amps rms wattage in 2ohms.

 

[Castro]

sorry dude, i should elabourate

Im running an orion hcca d2400 monoblock which is rated at 800w RMS at 2ohm

I have 2 clarion subs rated at 300w RMS each, they are single 4ohm coil subs, I want to connect them in parallel on the amp which means its a 2ohm load

since the total rms wattage of the subs is less than that of the amp

that is, 300w + 300w = 600w

i used that. is this correct

therefore v = sqrt ((300+300)*2)

v= 34.64

arnt i supposed to use the lesser on of the two

 

[Jekku 10+ year member]

sorry dude, i should elabourate
Im running an orion hcca d2400 monoblock which is rated at 800w RMS at 2ohm

I have 2 clarion subs rated at 300w RMS each, they are single 4ohm coil subs, I want to connect them in parallel on the amp which means its a 2ohm load

since the total rms wattage of the subs is less than that of the amp

that is, 300w + 300w = 600w

i used that. is this correct

therefore v = sqrt ((300+300)*2)

v= 34.64

arnt i supposed to use the lesser on of the two

Ok. Your subs can handle 300wRMS continuously, so you'll use 300W only. It doesn't matter how you connect them parallel or series, they'll still handle only 300w. But I'd use the amps 800w as the goal, therefore you'll get better sound quality with less volume.

Anyways, set as you want, but use 300w instead of 600w. Your target voltage is 24.5V.

 

[vipervin 10+ year member]

after reading about how to setup your amp gain through multiple resources, i do not understand why the OP suggests to keep the load disconnected. is this specific only to JL amps?

i followed all the steps of the tutorial with my JBL BP1200.1 amp, and output was severely lacking. target voltage is 49V. i hooked up my load and the DMM measured approx. 33V.. a huge difference.

i eventually figured out that my amp was actually seeing a resistance of 3ohm, not the nominal 2 ohm. so now my target voltage became 60V. set the gains to this voltage WITH the load connected and it sounds much better. i double checked with my oscope from work and it was producing a clean wave

so why is it recommended to keep the wires disconnected? i was reaching no where near the amp's max capabilities using the tutorial.

 

[vipervin 10+ year member]

actually, i think i understand now. JL amps are regulated and my amp is unregulated. however.. arent most amps unregulated?

 

[Castro]

Ok. Your subs can handle 300wRMS continuously, so you'll use 300W only. It doesn't matter how you connect them parallel or series, they'll still handle only 300w. But I'd use the amps 800w as the goal, therefore you'll get better sound quality with less volume.
Anyways, set as you want, but use 300w instead of 600w. Your target voltage is 24.5V.

hmmm

so i dont add the wattage of the 2 subs?????

but then if i was to run 1 sub only the the formula would look like

v=sqrt(300*4) ---> 4ohm 1 sub only

then i would get v = 34.64

it would only make sense that you add the RMS wattage of the 2 subs and since they are both connected to the amp and because they are in parallel then the fromula would look like

v = sqrt ((300+300)*2) ---> 2ohm resistance(parallel)

v= 34.64

if they were in sereis the formula would look like

sqrt((300+300)*8) ---> 8ohm resistance (series)

v=69.28

which makes sense 69.28=2*34.64 to accomidate the voltage drop across the 2 4ohm coils (2subs) connected in series

sorry to sound arogant, i just really want to understand whats goin on