DIY Level Matching

[clyde]

Hi guys, I just want to share my first ever DIY level matching:

shown here are some pics i took out of this excitement using a newly acquired 20MHz Fluke123 digital scopemeter.

my major measurement tool and the setup:









Test Tone CDs and the scope meter users manual(still reading)



Rear view of amps over the subs boxes:



Dash-mounted tweeters of BARC61:



First signal clipping catured at 50Hz test tone: notice the voltage rating under the wave form (rms) = +80Vpp w/c can also be defined as directly related to the rms power. Alpine MRV-F1005 rated at 100W RMS per channel at 4ohms with continous supply of 12v. so this amps are quite under-rated but at least i know this time the limits of these amps



the first casualty , a blown fuse out of the excessive clipping during the frontal seps test (worst than the one shown above during the subs level matching). i was not able to capture the scope readings as this was already the second fuse blown out of the front amps(alpine mrv-f300). i hope to make use of the screen hold feature of the meter (still learning the use of it that's why   )just to show a sample what sould happen if there is excessive clippings present next time--- a blown fuse on the amps   well, i was in hurry since we have to go out on a family business last night. i just used this limited 2-hour session out of the excitement.



another signal clipping at 50Hz test tone with the subs: medyo nanginig pa yung kamay ko  trying to extract the best un-clipped signal output thinking i might blow a fuse again



what i learned here was to level match at least the subs plus the front seps. now there's more sound clarity and i always ask my better half and she always be the judge of my work oh, well gumanda daw, sabi niya  

now, i'm still learning and trying to tweek this set-up using my new tool. there are still things left unanswered specially that after coming up with a clean unclipped signal at the front seps, there was a huge door vibration a high volume though i'm already using the local Flashband effect on the door skins. hmmm, we'll see on the next quest chapter.

any comments are most welcome. do post please. tnx.

[Raymond]

Very very informative sir. Thanks

[lancer765]

how much is the fluke? and where do you get the test cd?

[clyde]

Very very informative sir. Thanks

you're most welcome Raymond and thanks for making it a sticky. i'll try to post more updates regarding this. sana kasama kita sa process since i need more suggestions and comments. hmm, thinking already to get the sub and amps replaced for more SPL, gastos naman to

[clyde]

how much is the fluke? and where do you get the test cd?

they're price US$1119.00 online but i got it from a local Fluke dealer... more expensive though . the test tone CDs, i bought them online here for US$20.00 each including shipping.

[clyde]

ok i'm back with some more details from the lab inside the car

first of all, let's get some base materials and readings. today i'm going to show only the sub woofer tuning guide. the next sessions which will follow later will be the rear 6x9 speakers/amps settings and last but not the least will be the front seps setting guide.

as most of you are familiar with the JL subs(10W7), i also took it as guide as well which is found here[/u].

scrolling down to page 5 of this manual, step no. 2 is set. Turn "Off " all processing on the head unit and amplifier (bass /treble, loudness, EQ, etc.)

with this step, i got this display from the scope. shown here is a clean and un-clipped signal. clearly seen is an 88Volts Peek-to-peek based on the wave form shown(20V/division). the MRV-F1005 gain control knob was set to Nominal position(not shown) plus the volume on the HU was at 21/30. this clearly shows that the Alpine MRV-F1005 is under rated based on it's specs sheets rated at 100W RMS/channel. where's the remaining 12W RMS well, no matter how you increase the HU volume nor the Gain Knob at the amp, sure it will clip the signal. in this pic, i was not able to acquire the Vpp reading though the scope was capable but i was not ready to do so. nevertheless i will capture the right precise reading whenever i can, the Voltage Peak-to-Peak reading which is directly related to the rms power of the amp.



increasing the gain a bit higher, while still keeping the volume at 21/30 using the non-atenuated 50Hz test tone(digitally precise), the signal starts to clip.





next one is enabling the dual probe scanning, making sure the input signal is clean and mean. Probe A of the scope shows the output signal(20V/div.), while Probe B shows the input signal(500mv/div.) at 1.8Volts clean and un-clipped input signal, the output of Channel A shows a clipped signal, maxed at 88Vpp. also shown at the output signal is a slight frequency deviation of just 0.01Hz out of the 50Hz input freq.



increasing further the HU volume at 22/30 further clips the signal.



rolling back the HU volume to 21/30 produces a clean and un-clipped signal.




further reading at the Bridged output (50V/div.) clearly showing really an under-rated MRV-F1005 alpine amp.



keeping my scope probes at the Bridge output, this time i turned on the LOUDNESS effect on the HU inducing a Bass Boost at the input signal. Again the output Briged signal starts to clip as well.



lowering the Gain Control thus increasing the Bass Tone Control of the HU further clips the signal again.






now finally, with the LOUDNESS on and the Bass Tone control maxed and Volume set to 21/30 at the HU, the amp came up with the best clean and un-clipped signal with the Gain control at 1/4 turn clockwise (3/4 more will further clip the signal) both for the Bridged output and the per channel region.

conclusion is, the amp is under-rated, it will never produce 100W RMS per channel, you can safely turn your HU volume to 21/30 maximum, more than that will clip the signal. no more no less  







our next chapter will be the Rear fills using my alpine 6x9 2-way speakers powered by the MRV-F505 4-channel amp. guess what will be the amps ratings again

[clyde]

here you go guys as i find more time attending the quest for this setup we have.

as i promised, the Vpp un-clipped output signal rating of the Alpine MRV-F1005 with Loudness ON and Bass Tone maxed driving my 2x10" alpine subs. really an under-rated amp with 84.8AC Vpp(shown at the upper left corner of the scope's screen) at 50Hz test tone against 100W RMS of the data specs of the said amp.

shown below is the captured screen again from the scope. but let me just remind you briefly here that this is still by far an initial stage for the subs' amp level matching and it will vary upon tuning the rest of the system. this we'll find out later what happened after proceeding with the other parts involved through this series of tests and tuning.



Now on to the next level. In here i was thinking to do some match-up on which amp i should drive the front seps (BA RC61 2-way Component System) knowing that the amps that i have are under-rated based on the series of test conducted. Two of the amps w/c are left untuned are MRV-F505(4/3/2 channel rated at 130W RMS x 2 bridged at 4 ohms). this used to drive my alpine 6x9 rear fills. the second one was an alpine MRV-F300 rated at 80W x 2 RMS w/c used to drive the front seps.

upon getting these readings shown below, i opted to swap things, MRV-F505 for the Front while MRV-F300 goes to the rear fills as well all know that rear fills are rear fills--- filling the rear,   whatever. we simply don't need much of power for the rears and in fact my 6x9's where rated at 30-80W max so it will perfectly fit in there. so does the 505 can maximize the front seps rated at 120W max.

MRV-F505 with Loudness OFF, BASS/TREBLE controls flat: reading at 116AC Vpp maxed GAIN control and no clipps these time but still underated. i managed to balance the output signals precisely on both channels using the dual scanning mode this gives us an edge when tuning 2 channels at the same time and not just by turning the Gain Controls and use our ear to monitor and our sight to look at the knob's position. this will give you precise reading up to the tenth level decimal.





MRV-F300 reading at 80+ AC Vpp wow, this time an amp more that it's said rating on specs with no clippings. cool. in fact it was going more than 84+ Vpp till it starts to clipp at volume 24/30 of the HU. well, it was enough to reach its specs anyway at our test in 21/30 volume level.



turning the LOUDNESS on at the HU, starts to clip the 505:



so i started to roll back the Gain controls one by one till i get the most of the un-clipped output signal:



the next step was increasing the Bass Control at the HU. well, it's TROUBLESHOOTING time . i was reading a strange but true saw tooth signals, WTF is happening. no matter how i lower the gain control it was no help, the signals are still clipped:



and lower:



and lower up to the amp's input(this is the RCA cable's far end of the EQ's front pre-out:



replacing the lenghty RCA cable with a 3ft. one still gives a clipped Front pre-out signal at the EQ with a mere 329 millivolts , this is bad signal. amplifying a clipped DC-induced signal will surely heat up your amps and much worst blow the fuse or knock of your speaker sets . this is real bad.



finally verifying the Pre-out signals of the HU itself. a clipped signal when Bass Control maxed using 50Hz test tone:



also when Treble Control maxed using 10kHz test tone.



so reducing both the Tone Controls to be utilized only at 2 steps higher from flat range. setting both tone controls higher will clip the signal further producing undesirable results at the amps output. well, this could mean that my HU is not in a good condition any longer.   well, would anyone offer me one with a good price for replacement on a 7 year old   HU

[clyde]

so as the Bass control at the HU was rolled back, so thus it will affect the subs' maximum output as well. now inorder to maximize the subs, i have increased the Gain a bit higher still keeping an unlcipped signal with 1.4 extra volt increase compared to our first previous reading of 84.8Vpp.



and so thus the front seps' amp. getting affected as well and so we move on level matching every amp we have:



upon setting this 505(front amp) using 50Hz unclipped, cross checking using 10kHz clips so we have to further reduce it to come up clean and mean at 10kHz.

at 50 Hz



on same gain as with 50hz test but at 10kHz clipped:



at 10kHz final:



on to the Rear Fills' amp(MRV-F300):



since my rear fill speakers are rated 30-80W max, i reduced the Gain Control of the F300 to match the speaker ratings using again a 50Hz tone:



at 10kHz tone with balanced 2 channels:



well, i'm left to find out what's wrong with my HU's Tone Controls this time. God knows when

I hope everyone enjoyed the show. I wish i can do the same with much more better equipment next time.

And for those who wishes to tune his/her setup, grab a scope if you can. it's a wonder tool i can say.  

[EssB]

Sir, saan po available yan? And exactly magakano po?

I'm actually planning to buy an occiloscope eh... I just want to complare the price.

[A+Audio]

Hi guys, I just want to share my first ever DIY level matching:

shown here are some pics i took out of this excitement using a newly acquired 20MHz Fluke123 digital scopemeter.

my major measurement tool and the setup:









Test Tone CDs and the scope meter users manual(still reading)



Rear view of amps over the subs boxes:



Dash-mounted tweeters of BARC61:



First signal clipping catured at 50Hz test tone: notice the voltage rating under the wave form (rms) = +80Vpp w/c can also be defined as directly related to the rms power. Alpine MRV-F1005 rated at 100W RMS per channel at 4ohms with continous supply of 12v. so this amps are quite under-rated but at least i know this time the limits of these amps




the first casualty , a blown fuse out of the excessive clipping during the frontal seps test (worst than the one shown above during the subs level matching). i was not able to capture the scope readings as this was already the second fuse blown out of the front amps(alpine mrv-f300). i hope to make use of the screen hold feature of the meter (still learning the use of it that's why   )just to show a sample what sould happen if there is excessive clippings present next time--- a blown fuse on the amps   well, i was in hurry since we have to go out on a family business last night. i just used this limited 2-hour session out of the excitement.



another signal clipping at 50Hz test tone with the subs: medyo nanginig pa yung kamay ko out of konting kaba trying to extract the best un-clipped signal output thinking i might blow a fuse again



what i learned here was to level match at least the subs plus the front seps. now there's more sound clarity and i always ask my better half and she always be the judge of my work oh, well gumanda daw, sabi niya  

now, i'm still learning and trying to tweek this set-up using my new tool. there are still things left unanswered specially that after coming up with a clean unclipped signal at the front seps, there was a huge door vibration a high volume though i'm already using the local Flashband effect on the door skins. hmmm, we'll see on the next quest chapter.

any comments are most welcome. do post please. tnx.

Hi clyde how is israel? im i correct  1st of all  congrats sa achievements. its a great attempt. I just want to add a few hints.
1. set the volume to max and check where its clipping at usually 29 or 30 or not clipping at all to get a clean signal at max volume.
2. usually start level match on the seperates ch amp not the sub and using 10khz is too high.
3. when a properly level match system when loudness is activated there should be not much difference in sound loudness cuz it is corrected so no more loudness correction. Thats wat i noticed.
4. Sub naman use higher than 50hz since u need to know the signal when you set your xover at 70hz which is not within your parameter (50hz) use like 80hz which 70hz is below the low cut level. Hope this helps.

If that unit is used properly it thus become a powerfull tool. That separates you from the chamba chamba tuning... THIS IS WHAT ALOT OF AUDIO USER NEED TO UNDERSTAND NOT BECUZ OF PROFIT BUT MERELY FOR PURE MUSIC LOVER IN ALL OF US.  

Sorry for late reply sa mail ksi now lang avail. computer ko
goodluck tnx

[A+Audio]

CLYDE

IMAGINE IF YOU HAVE TO TUNE A MULTI AMP SAY 6 TO 10 AMPS. PROBABLY WONDER HOW TO GET YOUR POWER MAXIMIZE AND LOUD WITH OUT OVER HEATING THE AMPS OR DRAINING YOUR BATTERY REALLY QUICK..

THATS WHY WE ARE VERY SUCCESSFULL SA MGA DEMO CARS NAMIN SA SHOWS. WE HAVE BEEN VERY SUCCESSFUL WITH V12 AND TARGAS AS WELL BUT OFFCOARSE MAY KONTING SECRET WE CANNOT SHARE HEHEHE

gOODLUCK  

[clyde]

Hi clyde how is israel? im i correct  1st of all  congrats sa achievements. its a great attempt. I just want to add a few hints.
1. set the volume to max and check where its clipping at usually 29 or 30 or not clipping at all to get a clean signal at max volume.
2. usually start level match on the seperates ch amp not the sub and using 10khz is too high.
3. when a properly level match system when loudness is activated there should be not much difference in sound loudness cuz it is corrected so no more loudness correction. Thats wat i noticed.
4. Sub naman use higher than 50hz since u need to know the signal when you set your xover at 70hz which is not within your parameter (50hz) use like 80hz which 70hz is below the low cut level. Hope this helps.

If that unit is used properly it thus become a powerfull tool. That separates you from the chamba chamba tuning... THIS IS WHAT ALOT OF AUDIO USER NEED TO UNDERSTAND NOT BECUZ OF PROFIT BUT MERELY FOR PURE MUSIC LOVER IN ALL OF US.  

Sorry for late reply sa mail ksi now lang avail. computer ko
goodluck tnx

Wow  finally, i got the attention of Mr. Audio Guru himself Salamat po Sir Vic

Infact this is still the first chapter and i honestly admit talagang may kulang pa specially that i found out something's wrong with the source signal, the HU itself and the show must go on. it's still a quite long way to go trying to completely level match the system. medyo nadismaya lang ako dun sa pre-out signals nung HU, well it's a 7-year old one but that's merely an excuse for such brands probably. in contrast, talaga sigurong may sabit na itong HU na ito. well, if i have the chance to get a new one, i would probably bring my scope with me when buying one at a shop and verify the pre-out signals of any HU of my choice

though it produces really crisp sound this time according to my judge(my better half - bakit di pa raw ako kuntento , haha ), what i noticed the past few days after my final attempt was that mabilis mag-init yung front seps amp so i'm pretty sure something's not right still.

with your hints and tips, i really do appreciate them and i'm gonna do some more tweaking again sometime later.

btw, di po ako sa Israel, sa Jeddah Saudi Arabia po. i wish nandiyan na lang ako, di ko na lang binili tong scope na to. i would have rather bought myself a JL amp and a sub  but overall, it's really worth doing this attempt and learning how to. it's more rewarding i may say.

CLYDE

IMAGINE IF YOU HAVE TO TUNE A MULTI AMP SAY 6 TO 10 AMPS. PROBABLY WONDER HOW TO GET YOUR POWER MAXIMIZE AND LOUD WITH OUT OVER HEATING THE AMPS OR DRAINING YOUR BATTERY REALLY QUICK..

THATS WHY WE ARE VERY SUCCESSFULL SA MGA DEMO CARS NAMIN SA SHOWS. WE HAVE BEEN VERY SUCCESSFUL WITH V12 AND TARGAS AS WELL BUT OFFCOARSE MAY KONTING SECRET WE CANNOT SHARE HEHEHE

gOODLUCK  

yup yup, i can imagine that and how much more as you said if pa-chamba chamba technique lang. uuuuuhhhhmm simply it would result to a poor producing sound system, in short di maganda yung gawa

and you're absolutely correct regarding the choice of equipment, it's not merely the item's cost nor probably the brand itself and making profit, but it all boils down on how well the entire system is tuned. good news to those who have V12's or Targas, there's a light ahead waiting for you and that you'll see when you enter A+ Audio tuning world. hurry up and get yourself some tuning from the Audio Guru himself .

i know that you're keeping those secrets in a tight bolt   . It's the secret of winning i may say

once again, thank you for all your feedback and hints. I look forward into the coming updates with further tweaking, and of course with your guidance.

can i be your student from now? am I in as one of your tech guys at are your shop

[A+Audio]

Clyde

Tnx for your support.    Visit me when you get back from Saudi i will tell you my secret since we are not competitor here in Philippines.
Goodluck..

[Brent]

Here's a link to an article from Davao with Vic Tan of SubWFour Concepts in Davao giving Autosound 101 for car audio enthusiasts.

http://www.aw2spec.com/article/audio101/index.htm

[Gino]

Vic, ako hindi competitor