Amp clamp car audio

[SuzukiGS750EZ]

Hey guys. I was previously looking for a dc/ac clamp trms. I'd still like one but now I have another element to add to it. It won't be used often so I don't want to spend $400 on one... I'm looking now to read what my audio system is drawing. I have a 1400 watt Amp and installing an 800 watt into the car as well now. I want to see what the system is drawing and what the alternator is producing as well as what's at the battery. I had a uni-t unit in my cart, but unsure if this will still serve my needs?

 

[BukitCase]

If those are REAL watts, at 13.5 volts it'd take just under 163 amps to make 2200 watts, NOT counting any efficiency losses - my next question would be what's your ALTERNATOR rated for??!? ... Steve

 

[SuzukiGS750EZ]

In total, about 1800w RMS between the two amps themselves. Now subwoofer Amp doesn't pull 1400w continuously, which is why I want an Amp clamp to view it all. Mids and highs will probably pull close to their RMS I'd think.

Stock alternator is rated 110 Amp. I have zero issue with my 1400w Amp currently.

 

[FigureItOut]

Your system's current is going to fluctuate widely and rapidly, you're never going catch peak current without using a scope. Using something like this this with even the cheap $100 Pico scope is probably the minimum you'd need to get any informative measurement. Even still, I'm not sure how useful that information is going to be to you. In any case, having the scope will almost certainly come in handy and that probe isn't too much at $90.

A more useful measurement would be check your voltage drop both at the battery and at the distribution block for your amps. A decently fast meter with min/max function will accomplish this for you. If voltage is dropping much below 12v when you're going full bore, you need to rethink some elements of your setup.

If those are REAL watts, at 13.5 volts it'd take just under 163 amps to make 2200 watts, NOT counting any efficiency losses - my next question would be what's your ALTERNATOR rated for??!? ... Steve

Assuming the amplifiers are made by a reputable company, they should be real watts, not WLS (when lightning strikes) units. Even if capable of doing so, the system will rarely if ever spike to that full rating, and then only in millisecond bursts. A decently sized battery should be able to handle the occasional extra draw, provided the rest of the electrical system is healthy, but with those numbers he's on the verge of needing to consider an upgraded alternator and/or auxiliary batteries.

Sent from my SM-G975U1 using Tapatalk

 

[SuzukiGS750EZ]

I have a scope, it's pc based. I'm not very proficient with it but can understand what I'm looking at if I know how to set it up.

I was looking at these two...

http://esitest.com/698.html

http://esitest.com/655.html

But was unsure if they're worth the money or if there's something better.

I know which songs I listen to that hit the hardest so I figured reading at the peak would give me an idea of that split second draw as well as averaging throughout the song. I understand your recommendation for voltage drop.

I plan to upgrade grounds & alternator wiring come spring. Before I install the Amp I'm trying to get everything in order.

 

[Brownsfan]

I have a Klein i got at Home Depot that did 600a ac/dc. Never had an issue reading DC amps.

 

[SuzukiGS750EZ]

How high of a rating do you think I'd need?

For household voltage, how many amps?

For dc, automotive stuff, how many amps?

Under 400, 600, 1000?

 

[ItsNemo]

I have a Fluke 325 that does the job quite nicely...up to 400 amps DC.

 

[shawhite]

How high of a rating do you think I'd need?

For household voltage, how many amps? 200A-300A

For dc, automotive stuff, how many amps? Most of the time 20A or less but if you want to check total output from the alternator 200A ish

Under 400, 600, 1000?

You can do all these measurements without an amp clamp.

 

[SuzukiGS750EZ]

You can do all these measurements without an amp clamp.

Do share?

 

[2ndGearRubber]

If you have a scope just get a amp clamp for it. 600amp generic clamp us about 100 bucks.

 

[shawhite]

Well you can put your dmm in series with the circuit on the amp setting and it will give you the amp draw. You can also calculate it based on the voltage drop across which ever component. P=I x V or I=P/V you know what your rated power is then divide by the voltage drop and that will give you the rough current draw.

 

[shawhite]

But honestly you can buy a cheap dc clamp meter on Amazon for under $50 that will do what you need to do.

 

[SuzukiGS750EZ]

Well you can put your dmm in series with the circuit on the amp setting and it will give you the amp draw. You can also calculate it based on the voltage drop across which ever component. P=I x V or I=P/V you know what your rated power is then divide by the voltage drop and that will give you the rough current draw.

I'd blow the meter if i passed more than 10 amps through it

 

[shawhite]

Not sure what your end goal is but you can measure the voltage drop at the amp then divide the rated power by the voltage drop. So 1000 W RMS / 14 V= 71.42A

 

[2ndGearRubber]

I'd blow the meter if i passed more than 10 amps through it

Amp clamp on main power wire to amp, channel two is a voltage lead onto the same wire, to check system voltage.

Depending on how big the system is, you want a capacitor. Nothing like the headlights dimming when the two 12s hit.

 

[SuzukiGS750EZ]

Amp clamp on main power wire to amp, channel two is a voltage lead onto the same wire, to check system voltage.



Depending on how big the system is, you want a capacitor. Nothing like the headlights dimming when the two 12s hit.

They actually don't! Which is why I want to make sure the system can support the other Amp I'm adding lol. Cap's are crutches to a bigger issue in audio systems, small ones anyways like what I have. I'm gonna do a few grounds and alternator power upgrade. If the issue arises, I'll buy a high output alternator.

Amp clamp will still be used outside of this project

 

[2ndGearRubber]

Not sure what your end goal is but you can measure the voltage drop at the amp then divide the rated power by the voltage drop. So 1000 W RMS / 14 V= 71.42A

Still need a scope for that really. Voltage drop would be instantaneous when the sub hits, so you'd need min/max on the meter to even get an idea. Refresh rate would be the deciding factor on accuracy. Although much like using a scope on a starter circuit, one may need to come up with their own specs. Minimum voltage on a volt meter using min/max is unlikely going to be as low as a scope capturing 1M/division.

The drop across the cable, assuming it was wired properly, should be minimal. System voltage drop could be measured anywhere, even off the cigarette lighter or pin 16 on the OBDII port. Ideally you'd measure system B+ voltage within the car, as the amp clamp would be around the main power supply wire to the amp.

 

[shawhite]

Just buy a cheap clamp meter on Amazon

 

[2ndGearRubber]

https://www.aeswave.com/High-Amp-Probe-with-Banana-Plugs-p9673.html

If you scope uses BNC, you'd need an adapter. It's 0-600amp range is decent for clarity in charging systems and sustained cranking doing relative compression. Probably cheaper options, but I picked this up and do still use it occasionally. I have the Pico 200/2000 clamp now that I use more often. But if I need a second one, or am running two scopes at once, it does work well. Dial adjustable for zeroing is annoying, but I usually just get it close and live with it. +/- 2amps is irrelevant for the current we're talking about, and the scaling is the same anyways.


- scope all the things -

 

[shawhite]

Still need a scope for that really. Voltage drop would be instantaneous when the sub hits, so you'd need min/max on the meter to even get an idea. Refresh rate would be the deciding factor on accuracy. Although much like using a scope on a starter circuit, one may need to come up with their own specs. Minimum voltage on a volt meter using min/max is unlikely going to be as low as a scope capturing 1M/division.

The drop across the cable, assuming it was wired properly, should be minimal. System voltage drop could be measured anywhere, even off the cigarette lighter or pin 16 on the OBDII port. Ideally you'd measure system B+ voltage within the car, as the amp clamp would be around the main power supply wire to the amp.

You can get close enough without a scope. A DMM that has a hold feature can be set to capture the spike then you can use that to calculate your draw.

 

[2ndGearRubber]

You can get close enough without a scope. A DMM that has a hold feature can be set to capture the spike then you can use that to calculate your draw.

Very true. Turn the system up to max output, hardest hitting song, and check your peak number.


Now, if you're checking if you can drive around listening to a full "mixtape" at 75% output without ****** the charging system, that would be a much better option for a clamp and scope.

 

[theoldwizard1]

In total, about 1800w RMS between the two amps themselves. Now subwoofer Amp doesn't pull 1400w continuously, ...

No audio amplifier operates near it maximum except for a split second.

Amp clamps, by their very design, do NOT do a good job of accurately capturing instantaneous current. If you want to do that, you need a shunt and an oscilloscope.

PS. Know you know why guys with big amps in their cars have huge capacitors. Actually a big inductor would help also.

 

[2ndGearRubber]

How instantaneous are we worried about? My clamps can easily zoom in on turn-on oscillations of an ignition coil. Injectors at idle are open 2.5 m/s? Very easy to zoom in too far and just distort the image.

I'm not much of a audiophile, but I have to imagine the average "hit" of the subs on any song that isn't a bass-test can't be significantly shorter than 2.5m/s? Even the time required to move the speaker should add some delay. Admittedly, this specifically is above my knowledge set.

 

[SuzukiGS750EZ]

I have a PC based scope but to be honest, it's a pain to use. I don't use it because it's not convenient.

 

[2ndGearRubber]

Define pain to use?

Just as an example, for 1 song that's say 5min long. 10seconds per division, 10 on a screen, so that's 100 seconds per screen. Not sure how long of a buffer you have, but your total buffer length will determine your divisions. Pico will give me 32 screens of buffer. 1min 40 seconds per screen, 32 screens.

I used to feel the laptop based scope was more work than my modis. But when you add the additional power of the laptop scope IMO it's worth it. 10 foot leads and long USB cables make all the difference. The setup of the zoom function on the snap on tools makes long time base measurements difficult to me.

 

[SuzukiGS750EZ]

Define pain to use?

Just as an example, for 1 song that's say 5min long. 10seconds per division, 10 on a screen, so that's 100 seconds per screen. Not sure how long of a buffer you have, but your total buffer length will determine your divisions. Pico will give me 32 screens of buffer. 1min 40 seconds per screen, 32 screens.

I used to feel the laptop based scope was more work than my modis. But when you add the additional power of the laptop scope IMO it's worth it. 10 foot leads and long USB cables make all the difference. The setup of the zoom function on the snap on tools makes long time base measurements difficult to me.

I found that working inside the vehicle with a laptop and the scope plus the leads was just way too much cable/space taken up. I think a meter sized scope would be awesome, but i don't know as much about them as you guys so i'm sure there's a caveat..

 

[2ndGearRubber]

Well, a meter sized scope usually doesnt have a huge buffer. My uscope only shows the screen, cant save and review without transferring to a laptop. A modis or similar snap on scope would work, but you use it opposite of a normal scope. It runs 100% zoomed in, you can only zoom out. Annoying and counter intuitive.

Can you you use a tablet or something to display the scope? I figured you would set the scope, play a song, then check your buffer in a parking lot.

 

[SuzukiGS750EZ]

Well, a meter sized scope usually doesnt have a huge buffer. My uscope only shows the screen, cant save and review without transferring to a laptop. A modis or similar snap on scope would work, but you use it opposite of a normal scope. It runs 100% zoomed in, you can only zoom out. Annoying and counter intuitive.

Can you you use a tablet or something to display the scope? I figured you would set the scope, play a song, then check your buffer in a parking lot.

I have an autel ms906ts which you can add a scope to. https://www.autel.com/c/www/special/3288.jhtml

 

[shawhite]

Usually you would use a freq test input when doing measurements and tuning your audio system this way you are not chasing the peaks. For instance if you want to measure peak draw on your sub amp you would use 20-30hz and turn your gain up to 75% or highest it will go without distortion then take your measurement. The you could do the same with your mids/highs. I would have loved to have access to an oscope when I use to do car audio but they were a little harder to get back then.

 

[CoogarXR]

Call me an idiot, but couldn't you just figure the fuse in the amplifier is the maximum it could ever draw?

 

[SuzukiGS750EZ]

Usually you would use a freq test input when doing measurements and tuning your audio system this way you are not chasing the peaks. For instance if you want to measure peak draw on your sub amp you would use 20-30hz and turn your gain up to 75% or highest it will go without distortion then take your measurement. The you could do the same with your mids/highs. I would have loved to have access to an oscope when I use to do car audio but they were a little harder to get back then.

I tuned my sub Amp with my oscope using a 50hz test tone. I plan to do the same with my mid/high Amp, of course using a different frequency. I was more concerned with Amp draw though. I've been installing subs and head units for people for years, but never did mids/high amps. Everybody just adds subs and runs off HU power for speakers. This will be my first car I've done a front to back system in.

 

[richfinn]

I think if your getting into Oscilloscopes you have answered your own question, you really need an amp clamp you can use with your scope

AESwave sell the Tecpel/Pico clamps, you can use them with a multimeter too if you choose the 4mm banana plug style or maybe your PC scope with BNC

It's a no brainer, much more versatile than a stand alone clamp meter

 

[SuzukiGS750EZ]

OK so since I'm not too crazy about my pc scope, is the Autel MP408 a good scope? I have the MS906TS.

https://www.autel.com/c/www/special/3288.jhtml

I know nothing about good scope specs...

 

[richfinn]

OK so since I'm not too crazy about my pc scope, is the Autel MP408 a good scope? I have the MS906TS.

https://www.autel.com/c/www/special/3288.jhtml

I know nothing about good scope specs...

I doesn't get great reviews on the British Diagnostics scene to be honest, Pico is the benchmark worldwide

The only other Automotive Scopes I have seen which compare favourably are the TiePie (which might be Dutch??) And the ATS e-scope (American and amazing piece of equipment in Bernies hands)

The reason Pico always wins is that the users can upload captures to be shared by everybody

You want a known good cam/crank synch pattern for a particular model, its yours for free!!!

Go to Pico's site and download it for free and play around with it, your just buying the hardware really

I only have the handheld because it's conveniant and weatherproof, I have access to a Pico if required

 

[Cgw1984]

No audio amplifier operates near it maximum except for a split second.

Amp clamps, by their very design, do NOT do a good job of accurately capturing instantaneous current. If you want to do that, you need a shunt and an oscilloscope.

PS. Know you know why guys with big amps in their cars have huge capacitors. Actually a big inductor would help also.

Most of the ones really into it have huge batteries, and alternators. I know for my setup i purchased 3 300 amp alternators, and some big batteries..

 

[theoldwizard1]

I found that working inside the vehicle with a laptop and the scope plus the leads was just way too much cable/space taken up. I think a meter sized scope would be awesome, but i don't know as much about them as you guys so i'm sure there's a caveat..

Far from a "perfect" 'scope, the SainSmart DSO212 might be adequate for your needs. Battery operated, self contained, hand held and reasonably priced.

 

[theoldwizard1]

I just stumbled across another "pocket 'scope", FNIRSI 1013D Tablet Oscilloscope Review The biggest complaint the reviewer had was that the maximum usable frequency is probably about 30MHz.

Sold on Amazon as the Aiteme AD1013D II for $150.

 

[SuzukiGS750EZ]

Now that I have an oscilloscope on the way, what should I buy to use both on meter and scope?

 

[mc4life27]

They actually don't! Which is why I want to make sure the system can support the other Amp I'm adding lol. Cap's are crutches to a bigger issue in audio systems, small ones anyways like what I have. I'm gonna do a few grounds and alternator power upgrade. If the issue arises, I'll buy a high output alternator.

Amp clamp will still be used outside of this project

Switch all of your grounds out to either 4 gauge or 1/0 gauge. Just make sure it’s the same if not bigger then your power wire. Also watts don’t mean **** when it comes to car audio. Unless you only listen when lightning is sticking your car. What you need to know is the on board fusing of your amps. Plus are they regulated power supplies or variable power supply’s. Also your mids and highs amp is not going to be pulling rms voltages while your listening it to normal volume. Plus for the best possible sound don’t run your amps and wide open gains. Run them at like 30-50% that way the floor noise is lower and the amp is not working as hard also the amp is not inducing so much noise. It’s like taking your car and flooring it every where you go. Sure it will work but it’s not going to last plus noises will be coming from it after a period of time. Same for your amps. Plus make sure you start with a hood clean signal. Like from a cd or pure lossless audio. If you using you phone or other media play make sure your music that’s loaded is of high quality and make sure your settings are set for it. Sometimes the player automatically down grade the music format. Plus make sure you have multiple pre ours from your head unit and do just split one or two signals. Your system is only as good as the weakest link and you have to start with a good clean signal to end up with a clean sounding system. Also look into Steve Meade. He offers a few different TVs sound readers and Toys to help dial in your sound system. Also any real top quality stereo shops can help you do this and some may charge you for their time. But it’s kinda have to pay to play and once you find a shop that’s you can be friends with they will hook you up all the time but you first have to show them your not wasting their time and you truly want to know quality info on car audio. Don’t be that kids who just wants the best deal and expects everything done or installed for free or want the shops to pay online pricing. You will never get any where doing. Most upper end shops will be happy to teach you info and maybe even hire you later down the road just don’t waste their time and don’t act like you know everything or have read it on the internet. Every installer has spent their time and money teaching themselves and friends about their hobby and protecting their car audio skills and knowledge. Plus they have real world experience and have played with many different cars and different equipment. So if you want them to treat you right and if you want to be in the so called group. You have to show them your serious and not theirs to waste their time and expect things for free. Also bring the guys lunch, help clean up after cars are done, also if you see something wrong or out of place like maybe they missed something point it out to them but away from that cars customer and show them you are interested. Also never play the card of o the shop down the street is selling it cheaper or online it’s this price. Most shops you will loose your credibility as soon as you do. I grew up in car audio from when I was 10 till about 25 I installed custom car stereos, managed a few stereo shops, worked for some car stereo manufacturers and built many show cars (for sema and ces plus many many more and competitor cars). Most shops that truly have good guys and smart installers have been doing it for a long time and they will have true facts and be able to explain things to you on why or why not to do something or what products to get. Remember they install them all year long. So they get to play with all the equipment along with many different cars. They truly know what sounds good and what doesn’t sound good. But no stereo shops that have knowledge and have been around awhile are going to even think about kissing your *** for you business. Theirs a reason why a shop is still in business today and for a shop to have been in business for a period of time in the same or similar locations have some experience and have an idea on what works and what doesn’t work. But get real world experience and what your read on the internet 50% of it is trash and the rest is mainly hear say or just recycled from what someone else typed in. Also I have heard some of the best products so so ****** and the worse products sound so good because of their installs and the person building knew what they were doing. Also remember most of the time you get what you pay for.

Now back to your issues, just by the terms you are using and just by how your are trying to explain things it tells me you need to go back to the drawing board and learn more information and learn correct info. Also maybe try finding another shop to learn from. Where are you located at. (I know a lot of shops across the county). But stop worry about watts and what your system can handle. You need to know amperage draw and not just what the system currently needs but what the max current draw possible. Your ground wire is more important then your power, also you will have a higher chance of blowing your speakers with too little power then by over powering it if your using good quality amps and a good signal to start with. It’s all about turning. Also the car audio industry is very small and everyone know everyone that’s worth knowing. So ask around talk to people and if they n ow your serious and not wasting their time they will help you out. Also just do your homework and ask questions and ask why they do something. Also unless you have your own first hand experience and pay your bills doing so don’t ever think you know more about a product or how to do something more then someone who does with out watching them first. I have learned a few things but watching people who know they stuff in their sleep and doing things outside the box. Also if the shop has employees who are big into audio and excited about new products then get to know them. If the owner is old burnt out and it’s just a daily job to them take your business else where. Thjng change to much now in car audio to where if your not on top of the current new trends then your getting old information sometimes. Plus you can get more into if the people around you are excited about it. Also look at what components are in the installer cars. Sure they get discounts but your will soon see the good installers have what works the best for their application. I have been around many installers and even my self have had basically unlimited budgets on the audio systems and I use what sounds the best and works the best for my current car or truck. Plus I tent to hang onto my older gear rather then upgrade all the time. My old stuff sounds better and holds up way better. Plus don’t have think your have a great sound system of your always using just your phone or iPod for a music source.


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