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Check Actual Ouput Of An Amplifier?


Aukland

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This belongs to the thread that the post above goes too.

I don't have much time to answer abunch of questions tonight but I left out a real important detail about setting your gains with a bass knob.

Someone correct me about amplifier companies if I'm wrong about RF being the only company useing a dash mounted bass boost instead of a gain control knob.

Of coarse RF uses a bass boost circuit in their dash mounted knobs and that is why I told you to set your gains with it turned all the way down and use the 0db test tone recording and that gives you the ability to use the dash mounted bass boost and have a clean amount of bass boost before clipping.

95% of all the other companies use what are called dash mounted bass knobs or dash mounted line level controls in their amps. The difference is a dash mounted line level controller does not boost bass instead they turn your whole spetrum of bass down that the amp is playing.

In this case when you set up your gains with an amplifier that has a line level control, you want to plug in the dash mounted controller and turn it all the way up then set your gains.

Why? because the line level control on those amps are actually at 0db turned all the way up(this is equall to not even haveing the controller hooked up to the amp at all) and as you turn it down it goes into the negatives which gives you less overall bass.

The instruction manuals should tell you what you have (like I said I think only RF uses a bass boost).

Examples:

Here are the specs on acouple of amplifier companies.

1st - Rockford Fosgate T20001bd (since you have one) says in their manual:

Remote Bass – The Para-Punch Remote Bass connection is made with a RJ-45 cable and can be installed

in a variety of ways for easy control access. One control is used to boost low frequency information to

overcome road noise and put the bass in your face.This Bass control is a narrow band adjustment

variable from 0dB to +18dB with a Gyrator based Punch EQ that eliminates frequency shift with boost.

The other control is used for adjusting center frequency variable from 35Hz to 70Hz.

This is under the specifications section of the manual:

Equalization (Variable Punch Bass) Variable from 0dB to +18dB @ variable 35 to 70Hz

Look at the bold print and it says 0db to +18db - that means that control turns bass up.

Same goes for my older RF bd amps that only boost one frequency.

The 2003 BD amps specifications page says: Equalization (45Hz Punch Bass) Variable from 0dB to +18dB @ 45Hz

Now lets look at the Kicker amps and I have to use their old explanation as they don't really explain what it does as well in the new manuals.

The Kicker RGX Module explanation and what most amplifier companies use in their bass knob designs.

The manual for the RGX module (Remote Gain Crossover Module) says:

RGX (Active Remote Gain Crossover Module)

Control amplifier gain from your dash for balancing amplifier output

Controller range - Fully clockwise: +0dB; fully counter-clockwise: -26dB

This is the same for all Kicker amplifiers and as you can see instead of boosting bass, it lessons the amount of bass the amp puts out.

That is why when you use a line level control you set your gains with it turned all the way up.

I'll give you a tip: When setting a line level control bass knob and useing a 0db record to set your gains with an O-scope I suggest turnning it 2/3rds to 3/4 the way up instead of all the way up so you can still boost the bass some for those songs that just don't have much bass but when you go to listen to rap make sure the control is turned back to wherever it was when you set your gains as rap usually has the bass emphisized already and will clip your amp hard and may harm or blow your subs.

The explanation I used from Kicker applies to most amps out there except Rockford Fosgate and maybe some company that I have never heard of.I hope this helps clarify some things about dash mounted devices and setting your gains.

What if you have an amp that needs a load to set gains,??

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What if you have an amp that needs a load to set gains,??

Not exactly sure what your question has to do with all the line level and bass boost items in bold.

Obvisouly you are experienced. I'll give it a try!

Are you talking about a situation were you have found your best possible frequency (I can't spell tonight sorry) to burp at and want to try and get a little extra edge by maybe adding a Phoenix Gold Bass Cube or Paramic EQ?

In Short:

Make sure your O-scope can take the input voltage these newer and bigger amps can put out.

Add something like a barrier stip to someplace easily excesible to you and your meters but try to keep the bairer strips as close to the amps as possible.

Now when you hook up your subs add a piece of 14g or 12g wire to the 8g your probably already useing at the speaker terminals on the amp (Tight fit) and run that to the barrier strip that you have placed in a conveint place for you and your equipment and don't forget to label all info for all you spots on the barrier strip.

Attach your scope and meters up there and you know the rest of it. Its all trial and error. Start burping.

Are you talking about an amp that has to have something hooked up before you can even power it up without takeing a chance on blowing it.

Heck do the above but just start out at a much lower volume point and start running sweaps on the Term Lab and see what you have to work with and the O-scope should tell you everything else.

Boone touched on this a little above and this is all SPL burping information for the most part. If I was wanting to use a Paramic EQ with music I would do it the same way I do my fosgates. 0 db Recording and the rest is up to my ears since music is dynamic.

Barrier sritps also come in handy when setting gains on 4 amps going to a Quad coil sub.

LOL Edit: Thats all my bold print. Sorry man.

Isobaric - Refers to the practice of coupling two drivers together to make them act as one.

"Giving up doesn't always mean you are weak; sometimes it means that you are strong enough to let go."

Insanity: doing the same thing over and over again and expecting different results.

The Destruction of a person builds character.

 

Terryswork001.png

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  • 1 month later...
its crazy how much it really takes to know the true output

Beleive it or not its actually very easy, it just looks hard.

Heres the last system I built and I did all my testing in 45 mininents(can't spell NEED REDBULL STAT)

IMG_1896.jpg

IMG_2231.jpg

Isobaric - Refers to the practice of coupling two drivers together to make them act as one.

"Giving up doesn't always mean you are weak; sometimes it means that you are strong enough to let go."

Insanity: doing the same thing over and over again and expecting different results.

The Destruction of a person builds character.

 

Terryswork001.png

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its crazy how much it really takes to know the true output

LOL and so you know your stealling the name of the shop I wanted to have. JPS Custom Designz.

Just playing.

Isobaric - Refers to the practice of coupling two drivers together to make them act as one.

"Giving up doesn't always mean you are weak; sometimes it means that you are strong enough to let go."

Insanity: doing the same thing over and over again and expecting different results.

The Destruction of a person builds character.

 

Terryswork001.png

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  • 3 weeks later...

so does the tuning of the box have an effect on the readings? like my box is tuned @30hz so should i be using a test tone lower than 50?

1 Crossfire XS v2 15"

2 Deka group31a's

1 XS Power D3400 (under hood)

1 Addictive Audio 500.1 :D

1 Rockford 3sixty.2

4 Crescendo pwx 6.5s

2 Pyle Pro Super tweets

1 Crescendo 1000c4

Kenwood excelon x494 Head unit

Big Three upgrade

All 0 gauge of course

1 4.56c^ft box @28hz

(New Best official db score= 151.2 @ 36hz)

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so does the tuning of the box have an effect on the readings? like my box is tuned @30hz so should i be using a test tone lower than 50?

Yes to the part in bold. No to the second part of your question.

This tutorial for the most part is dedicated to people that have daily drivers and daily drivers are vehicles that play all sorts of different frequencies. (music playing vehicles.) The reason I recommend a 50 hertz at 0db recording is because there are more and more amplifiers out these days that do not have a flat frequency response and this bump in the frequency response on average is where ever the amplifiers bass boost is.

An example again is Rockford fosgate and there black T series amps and testing I have done on the Sundown SAX-100.2 before they put a variable bass boost on the new model (sax-125.2)(I have not done any testing on the 125.2 since I have pretty much left the car audio game awhile back.)

The amplifiers from both companies above still show more output at what ever frequency their bass boost is dedicated at even when it is totally turned down and what ever the frequency is your amp is going to push out the voltage to reproduce it. So an amp may put out 44 volts from 70 hertz to 10,000 hertz but from 70 or 60 hertz you will start to see the voltage rising as you get close to the targeted number of the bass boost on the amp and we will use 45 hertz as the set frequency of the bass boost and by the time you get down to 45 hertz your voltage may be as high as 55 volts and as you start going back down torwards 20 hertz you will see the voltage fall back down to the 44 volts the rest of the frequency response sees. (When the voltage starts to go up and then back down all depends on the type of bass boost the company uses, narrow band or wide band.)

All this testing is done with NO load on the amp and I recommend 50 hertz just because it feels like a good area to split the difference(common ground is the wording I wanted to use) at if you don't own an O-scope.

If I had left everything in my truck the same but changed the box that paper up there would look totally different, heck that paper might even look different if I did the same testing with the seat in but that info is beyond this tutorial I'm offering.

This tutorial is more for the average person setting up a system in a daily driver where there are alot of variables and you want to find a common ground for all the variables involved.

The only time I recommend changing the gain to put out power at one known frequency is when you are designing a pure SPL burp vehicle that does not play music.

Isobaric - Refers to the practice of coupling two drivers together to make them act as one.

"Giving up doesn't always mean you are weak; sometimes it means that you are strong enough to let go."

Insanity: doing the same thing over and over again and expecting different results.

The Destruction of a person builds character.

 

Terryswork001.png

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  • 1 month later...

i dusted off the old audiobahn can someone tell me rms and peak watts on it just curious. im trying to sell it.

want to do? = 2 18's on 7,500 watts 3 rf 2500bd ... blowthrough 2000 gmc sierra

done? = chipped programmer intake headers exhaust

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i dusted off the old audiobahn can someone tell me rms and peak watts on it just curious. im trying to sell it.

LOL wrong place to post, you might want to try the General Audio section or posting in the Subwoofer section.

Isobaric - Refers to the practice of coupling two drivers together to make them act as one.

"Giving up doesn't always mean you are weak; sometimes it means that you are strong enough to let go."

Insanity: doing the same thing over and over again and expecting different results.

The Destruction of a person builds character.

 

Terryswork001.png

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Lately I have been over at the Crown website, checking out some amplifiers for the house and I came across a fun little section on their website with a few different calculators.

One of the calculators that I came across just happen to calculate impedance rise and output wattage of an amplifier.

I thought this calculator might be helpful to some of the people that are new to this type of testing and checking plus I had fun with it, so I got permission from Harman International to add a link to their Ohm's Law/Watt's Law Calculator.

To have fun with and to help, Ohm's Law/Watt's Law Calculator:

http://www.crownaudio.com/apps_htm/designtools/ohms-law.htm

Very neat!

Along with the Ohm's Law/Watt's Law Calculator the person I Emailed with asked if I would share their whole Application Guide with everyone here and that was pretty nice as there is alot of different information and different calculators to check out.

Crown's Application Guide:

http://www.crownaudio.com/gen_htm/appguides.htm

Crown's Application Guide is definetly worth takeing a few minutes to check out.

Thank you to the people of Harman International for the use of their calculator's.

Whoops My mistake,heres the other calculator's:

http://www.crownaudio.com/amp_htm/designstools.htm

Isobaric - Refers to the practice of coupling two drivers together to make them act as one.

"Giving up doesn't always mean you are weak; sometimes it means that you are strong enough to let go."

Insanity: doing the same thing over and over again and expecting different results.

The Destruction of a person builds character.

 

Terryswork001.png

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