Amp Testing Article!
08-23-2005, 08:41 AM
#1
2000 Watt CAFz'r
Thread Starter
Join Date: May 2003
Posts: 2,819
This is a copy/paste of an small srticle I put together for the car audio section of www.jspeed.ca forum,where they have dubbed me the resident car audio guy....figure that one...
Anyway,Thought you may like to take a gander thru it as well to see some findings we we came up with...
If there's something you might advise me on that we could have done different, feel free....just please dont hijack this thread with stupid remarks...thanks...
We tested 3 different combonation of amps...
My Hardcore RipRock 500D wired to .5 ohm.The RipRock is in reality a modded Memphis Mojo.
When I use the term "Modded" it means the circuit protection has been removed to allow it to handle either/both a high voltage and/or low impedence.IE:The RipRock is modded to handle 18V and and .5ohm load(on a burp)
My friends two Kicker XS100 amps.These things are a really neat amp.They fall under whats called a Cheater Amp, meaning its rated output is waaaaaaay lower than its true potential.This particular cheater amp is rated 50x2 making it a 100 watt amp,but bridging the amp down to one ohm brings the output up to 1200-1500 watts.Great amp to have when competing in a power class competition.
We also tested on another friends EarthQuake D2 amplifers.Very sweet amps indeed.Honkin' power from an amp about the size of your typical 300 watt front stage amp.Great for people who are limited in space,but want/need some serious power.
All 3 setups were run on a pair of brand new Kicker L712's with dual 2 ohm voice coils in my SuperStreet NoWall setup.And line voltage was held as close to a constant 13-13.8 volts as possible.
We first tested on the XS100's.We wired 1 sub per amp at 1 ohm each to bring out as much power as we could.After a few test burps, we acheived a max output of 145.? db.We hooked up a bass level controler to see if we could work with it a little.We found that with this hooked up,at full output,the level dropped aprox. .4 db.Not exactly the results we had hoped for.
Next we hooked up the EarthQuakes.I was little sceptical to be honest, but the results were impressive indeed.Right out of the box we pulled a mid 147 db reading.Not bad...not great..but not bad...After doing some line matching(when you set the adjustments to get equal out put on both amps)we pulled a 148.9!!Sweet indeed!This again was with one sub per amp at 1 ohm.
Another thing we looked into was deck output,during this test.We found that at a higher volume level the line output spiked up from .8 to 1-1.1volt.In SPL,this could be a win or loose difference.
Next, for pure curiosty sake we hooked up both subs to the single RipRock,bringing down the impedence to .5 .This was really cool for me as I had never tested an amp at this low.I just prayed for no magic smoke..hehe.We were able to burp it at lower volumes, but after volume 18 on the deck,the amp cutout.We beleive this was due to a lack of voltage.I beleive if the voltage had been between 15 and 18 V, we could have done some serious things with it, but we were only able to pullout a 145ish with it,which is still a really decent number all things considered.
So the end result we went with the EarthQuake D2's for the 3x dBDrag event this last Sunday.
As a small side note,a friend of mine did some power testing(testing the output voltage of an amplifer).He was having problems with a lack of power.So he and another friend line tested his Crossfire 4000D(Thats right..a 4000 watt amp!).In his own car,it had an output of 60 volts aprox.They then swapped the amp over to the other car and ran it and got an output of 180 volts!!!Its beleived the difference was caused by either a worn battery or possibly a bad ground.The problem is still being investigated.They also found that this amp was cutting out at higher volumes while still in "the good car".They hooked up a 2nd 4000D, and had no problems.So there is some internal problems with the amp as well.
I hope by this article you have learned a little about amps, and not jsut taking its size and/or power rating for granted.There's a number of amps on the market that while rated at a low output, will put out a larger wattage than you might beleive.
If you have any questions about this testing, feel free to ask.I'll be more than happy to answer them to the best of my ability.
Here's some really cool pics of the inside of some of the more popular amplifiers...
http://forum.sounddomain.com/forum/u...=2;t=041017;p=
And here's a great article I found about the Memphis Mojo,the base of my HardCore RipRock...
New Super High Output Power Supply Helps Memphis Car Audio Improve Its Testing Capability
Thursday, March 28, 2002 by Rob Granger
Car audio amplifiers and subwoofers seem to get more powerful every year. As an example, Memphis Car Audio recently introduced the new Memphis Mojo amp (model 16-2000D) which is rated at a whopping 2,000 watts RMS at 13.8 volts. Soon to be released are the SPL-only MOJO subs.
The development of these extreme high-power amps and subs creates a unique set of problems for manufacturers who must test the equipment. Generating the necessary current to power even a single 2000-watt amplifier, much less two or more of these amps, presents quite a challenge. Most readily available DC power supplies simply cannot provide the current required to power such amps.
That's why Memphis Car Audio recently purchased a super high output Regulated DC Power Supply. The ordinary-looking appliance - affectionately known as "The Fridge" or "Big Bertha" around the Memphis Technical Services department - makes it possible to test these monster amplifiers, as well as powering these amps during subwoofer testing. Further, these tests can be conducted over long periods of time allowing for some real torture and durability testing of components.
"If you are a company that is serious about developing high-power amplifiers and subwoofers then you must have a supply with this kind of output capability," states Jeff Triplett, director of technical services for Memphis Car Audio.
As an example of why such a device is needed, Triplett pointed to testing currently underway on the new Memphis Mojo subwoofer. To test the woofer's peak power, durability and SPL capability, Triplett needed a power source capable of generating in excess of 300 amperes of current for sustained periods of time.
"You would need three or four SUVs connected in parallel to get that kind of power," adds Triplett. Conventional "bench" power supplies are just not up to this kind of demand.
The Fridge easily met the power needs for the Memphis Mojo amplifier and subsequent subwoofer testing. The device can deliver 400 amperes of current, with voltage that is variable from 0-20 volts. This allows testing of amplifiers at various voltage levels, to better replicate what actually goes on within the bounds of an actual vehicle charging system. Furthermore, since many SPL vehicles use higher voltag systems, Memphis can perform power tests at these higher levels as well.
"The Regulated DC Power Supply enables us to verify the power ratings on our components," explains Triplett. "We know that the power numbers we print on the box are accurate and attainable. We also know the limits of our equipment, which is valuable information for installers and car audio competitors."
Triplett said investing in testing equipment such as The Fridge is necessary because amps and subwoofers will continue to get more powerful.
"Who knows what kinds of amps and subs will be testing in five years. I'm sure these components will seem small by then," he noted.
http://www.memphiscaraudio.com
Thanks for taking time to read this, I hope you enjoyed reading it as much as I had fun doing the testing!!
Thanks to Gary Zuffa from Anytime Installations,Clay Schaffer from A-Team Audio,and Rob V.O. for the use of their equipment and shop space for this testing session.
Anyway,Thought you may like to take a gander thru it as well to see some findings we we came up with...
If there's something you might advise me on that we could have done different, feel free....just please dont hijack this thread with stupid remarks...thanks...
We tested 3 different combonation of amps...
My Hardcore RipRock 500D wired to .5 ohm.The RipRock is in reality a modded Memphis Mojo.
When I use the term "Modded" it means the circuit protection has been removed to allow it to handle either/both a high voltage and/or low impedence.IE:The RipRock is modded to handle 18V and and .5ohm load(on a burp)
My friends two Kicker XS100 amps.These things are a really neat amp.They fall under whats called a Cheater Amp, meaning its rated output is waaaaaaay lower than its true potential.This particular cheater amp is rated 50x2 making it a 100 watt amp,but bridging the amp down to one ohm brings the output up to 1200-1500 watts.Great amp to have when competing in a power class competition.
We also tested on another friends EarthQuake D2 amplifers.Very sweet amps indeed.Honkin' power from an amp about the size of your typical 300 watt front stage amp.Great for people who are limited in space,but want/need some serious power.
All 3 setups were run on a pair of brand new Kicker L712's with dual 2 ohm voice coils in my SuperStreet NoWall setup.And line voltage was held as close to a constant 13-13.8 volts as possible.
We first tested on the XS100's.We wired 1 sub per amp at 1 ohm each to bring out as much power as we could.After a few test burps, we acheived a max output of 145.? db.We hooked up a bass level controler to see if we could work with it a little.We found that with this hooked up,at full output,the level dropped aprox. .4 db.Not exactly the results we had hoped for.
Next we hooked up the EarthQuakes.I was little sceptical to be honest, but the results were impressive indeed.Right out of the box we pulled a mid 147 db reading.Not bad...not great..but not bad...After doing some line matching(when you set the adjustments to get equal out put on both amps)we pulled a 148.9!!Sweet indeed!This again was with one sub per amp at 1 ohm.
Another thing we looked into was deck output,during this test.We found that at a higher volume level the line output spiked up from .8 to 1-1.1volt.In SPL,this could be a win or loose difference.
Next, for pure curiosty sake we hooked up both subs to the single RipRock,bringing down the impedence to .5 .This was really cool for me as I had never tested an amp at this low.I just prayed for no magic smoke..hehe.We were able to burp it at lower volumes, but after volume 18 on the deck,the amp cutout.We beleive this was due to a lack of voltage.I beleive if the voltage had been between 15 and 18 V, we could have done some serious things with it, but we were only able to pullout a 145ish with it,which is still a really decent number all things considered.
So the end result we went with the EarthQuake D2's for the 3x dBDrag event this last Sunday.
As a small side note,a friend of mine did some power testing(testing the output voltage of an amplifer).He was having problems with a lack of power.So he and another friend line tested his Crossfire 4000D(Thats right..a 4000 watt amp!).In his own car,it had an output of 60 volts aprox.They then swapped the amp over to the other car and ran it and got an output of 180 volts!!!Its beleived the difference was caused by either a worn battery or possibly a bad ground.The problem is still being investigated.They also found that this amp was cutting out at higher volumes while still in "the good car".They hooked up a 2nd 4000D, and had no problems.So there is some internal problems with the amp as well.
I hope by this article you have learned a little about amps, and not jsut taking its size and/or power rating for granted.There's a number of amps on the market that while rated at a low output, will put out a larger wattage than you might beleive.
If you have any questions about this testing, feel free to ask.I'll be more than happy to answer them to the best of my ability.
Here's some really cool pics of the inside of some of the more popular amplifiers...
http://forum.sounddomain.com/forum/u...=2;t=041017;p=
And here's a great article I found about the Memphis Mojo,the base of my HardCore RipRock...
New Super High Output Power Supply Helps Memphis Car Audio Improve Its Testing Capability
Thursday, March 28, 2002 by Rob Granger
Car audio amplifiers and subwoofers seem to get more powerful every year. As an example, Memphis Car Audio recently introduced the new Memphis Mojo amp (model 16-2000D) which is rated at a whopping 2,000 watts RMS at 13.8 volts. Soon to be released are the SPL-only MOJO subs.
The development of these extreme high-power amps and subs creates a unique set of problems for manufacturers who must test the equipment. Generating the necessary current to power even a single 2000-watt amplifier, much less two or more of these amps, presents quite a challenge. Most readily available DC power supplies simply cannot provide the current required to power such amps.
That's why Memphis Car Audio recently purchased a super high output Regulated DC Power Supply. The ordinary-looking appliance - affectionately known as "The Fridge" or "Big Bertha" around the Memphis Technical Services department - makes it possible to test these monster amplifiers, as well as powering these amps during subwoofer testing. Further, these tests can be conducted over long periods of time allowing for some real torture and durability testing of components.
"If you are a company that is serious about developing high-power amplifiers and subwoofers then you must have a supply with this kind of output capability," states Jeff Triplett, director of technical services for Memphis Car Audio.
As an example of why such a device is needed, Triplett pointed to testing currently underway on the new Memphis Mojo subwoofer. To test the woofer's peak power, durability and SPL capability, Triplett needed a power source capable of generating in excess of 300 amperes of current for sustained periods of time.
"You would need three or four SUVs connected in parallel to get that kind of power," adds Triplett. Conventional "bench" power supplies are just not up to this kind of demand.
The Fridge easily met the power needs for the Memphis Mojo amplifier and subsequent subwoofer testing. The device can deliver 400 amperes of current, with voltage that is variable from 0-20 volts. This allows testing of amplifiers at various voltage levels, to better replicate what actually goes on within the bounds of an actual vehicle charging system. Furthermore, since many SPL vehicles use higher voltag systems, Memphis can perform power tests at these higher levels as well.
"The Regulated DC Power Supply enables us to verify the power ratings on our components," explains Triplett. "We know that the power numbers we print on the box are accurate and attainable. We also know the limits of our equipment, which is valuable information for installers and car audio competitors."
Triplett said investing in testing equipment such as The Fridge is necessary because amps and subwoofers will continue to get more powerful.
"Who knows what kinds of amps and subs will be testing in five years. I'm sure these components will seem small by then," he noted.
http://www.memphiscaraudio.com
Thanks for taking time to read this, I hope you enjoyed reading it as much as I had fun doing the testing!!
Thanks to Gary Zuffa from Anytime Installations,Clay Schaffer from A-Team Audio,and Rob V.O. for the use of their equipment and shop space for this testing session.
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