oscilloscope vs multimeter

[YeahToast 10+ year member]

fi recommends using an oscilloscope instead of a multimeter but i don't have an oscilloscope... so my question is can i use the multimeter for my tuning instead of the oscilloscope or would it not really make a difference?

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[KyleBechtold 5,000+ posts]

you can but its not even in the same realm as an oscope

 

[YeahToast 10+ year member]

how much do they go for? i don't really feel like spending lots of money on one... would using the mutli even be worth it?

 

[nauc 10+ year member]

the MM will tell you how much V youre getting, but not how clean those V's are

but if you have lots of headroom, you wont need the scope

 

[Burton6431 10+ year member]

An oscilloscope is not the same as a multimeter. From my understanding/ or what ive read, an O-scope shows the max performance or power before clipping. A multimeter can read your volts, and ohms if you need. What i do is wire the sub up for different impendances or ohms such as 4, 2, or 1(some wont be exact when measured) then use the multi meter to read the exact impendance. Plug in the amp with speaker hooked up, put in a test cd and with different tracks of Hz. I read the voltage going in to the amp, then read the volts coming out. Lets say your amp puts out 70 volts on 50Hz at maximum gain, so you turn down the gain to do about max but without pushing the amp, so at 3/4s gain you do 66 volts, so you tune to whatever Hz for your box then test for volts your amp puts out, then figure out the wattage from that to your speaker at your specified ohm load. Its very complicated and im no expert just trying to give you some help...

 

[KyleBechtold 5,000+ posts]

$20 and a shop will usually set em for you with one.. or check local forums for members with em they will usually help out for free or cheap

 

[nauc 10+ year member]

x2..............

 

[YeahToast 10+ year member]

alright thanks for the help ill check out the local shop and see what they say.

 

[smgreen20 10+ year member]

There's a pocket sized O-scope for ~$100, just can't seem to find the link.

 

[nauc 10+ year member]

i have this, it works great...

VELLEMAN HPS10 PERSONAL PORTABLE DIGITAL OSCILLOSCOPE - eBay (item 180023929587 end time Jul-11-10 10:00:10 PDT)

 

[gunz4me2 10+ year member]

I have the HPS40 which will even calculate RMS power for you. I still prefer the display on my old school CRT oscilloscope though.

 

[ptannjr 10+ year member]

We use the TPI440. Its a real nice piece. it is a O-Scope and multi meter all in one. to get as close to perfect as possible, we scope the output of the radio to find the maximum unclipped signal on the RCAs. We then set the radio at this level and move to the amps (or signal processors if used). we set the highs amp with an all high bit test tone with a -5db signal. The bass amps we do at a -10db signal since the subs can handle a little more clipping. Since we have started doing this our warranty returns have almost completely ended. Well on units that we install and can scope. The o-scope really is a great tool for your system.

 

[YeahToast 10+ year member]

i think im going to pick one up.. now to just figure out how to use it lol.

 

[audioholic 5,000+ posts]

If you find a local shop using an o-scope, that's probably a good shop. Most "professionals" ive talked to from local shops probably have no idea what you would even use an o-scope for in car audio.

 

[gunz4me2 10+ year member]

I never understood how the custom shops in my area make it without oscilloscopes and RTAs. Many of those professional installs tuned by ear sound like ass!

Then again, I don't just use the oscilloscope for setting gains because I actually had to work on my old school amplifiers.