Gain setting and watts M50

[Mr. Wild]

I'm going to set my M50 gain with a DMM. How much unclipped output voltage can I expect from the M50 unloaded and with the car running?

I had unsatisfactory output from my front speakers. The sound began to distort at volume ~45/63 on my old Pioneer HU.
The gain was at minimum on the M50, because that means 2,0V sensitivity and my HU has 2,2V output.

Turns out it was the HU which was distorting and increasing the gain on the M50 gave me lots more undistorted volume.

I figure 2,0 volts input on the M50 with the gain at minimum corresponds to the rated 50W@4ohm, but the amp has lots of headroom. Does that sound reasonable?

[tonym]

but the amp has lots of headroom. Does that sound reasonable?

damn straight it does....best amps I have ever used...and I drive them like they are stolen....

[The Golden One]

you can get some good sound from pioneer but im not gona candy coat thing's, there is a fine line between where they sound good and where they sound real bad. and trust me ive used them mostly as a back up radio since the old school days and most other head unit's i had always sounded a little better. but there is hope if you can find where the unit distort's you can set the item after it just below distortion like a line driver, eq,processor or amp and you can get some good sound. the main thing is finding the point of distortion because it is a very fine line, but you may need to just use your ear's to find it, and then you may use a DMM to set the amp unclipped below the units point of distortion.

[ttocs]

but wait golden one, wouldn't a pioneer deck played into a pg amp still sound golden?

[The Golden One]

but wait golden one, wouldn't a pioneer deck played into a pg amp still sound golden?

yes and no it can be a real chore trying to find that sweet spot, but once found it sound's pretty good.

[ttocs]

just giving you a hard time. I didn't think, you thought, it was possible for our PG's to sound bad. I think almost every shop I worked at sold pioneer but I honestly have never considered buying one short of their p9 or other sq decks.

[The Golden One]

just giving you a hard time. I didn't think, you thought, it was possible for our PG's to sound bad. I think almost every shop I worked at sold pioneer but I honestly have never considered buying one short of their p9 or other sq decks.

yea i had to literally set my line driver while driving down the road last time i used a pioneer, luckly my zx450 at the time was behind the seat so i could do some on the fly tuning but i did get some decent sound doing so.

[ttocs]

one word about your pioneer, or anyone that is using poineer decks is to be carefull and make sure the rca cables do not ground out after it has been powered on as in some models there is a pico-fuse that blows and will then cause noise in the system. This noise can often be cancelled by grounding the outer shield of the rca's but still just better not to do it.

[Mr. Wild]

Thanks for the input guys!

But what about the original question? How many unclipped RMS volts is the M50 capable of?

I think TGO is right about Pioneer. Mine is a 10 year old DEH 5600MP which came with my car when bought second handed. I think it sounds fine with my heavy metal. I thought my speakers sounded harsh when driven hard but as noted previously, its the HU which sounds harsh when playing loud.

This was an easy fix, just upped the gain levels on my amps. But I'm going to set my gains properly. Maybe use test tones to find the exact clipping threshold and then use a DMM to set the gains. But I need to know how much voltage to set on the M50.

[ttocs]

people have been doing it by ear for decades, there really isn't a whole lot of use for a meter as your ears are the final judge even with a meter.

[Mr. Wild]

I think I'm onto something here!

BIG thanx to The Golden One for his insight on Pioneer head units!

I've been struggling to remedy the harsh sound I've had at loud volume for ever. But it has been very educational.

First thing I did was install an amplifier to get more power. Good thing, but still harsh sound.

Then I installed a better amplifier (M50). Best thing EVER! But still harsh sound.

I was about to start the never ending process of changing speakers but then I was shown the light. This stupid Pioneer puts out harsh sound when the volume setting is over 40/62. Nothing after the HU can fix the sound..

Now I have the gain on my amps turned all the way up and I get plenty of volume before the Pioneer starts to sound like crap. Before this I assumed loud equals harsh. Now I know better.

I know, I have to be careful with the volume knob to prevent clipping. My only concern is that I just might become a power junkie, now that I know what clean and loud sounds like.

[dwnrodeo]

you can get some good sound from pioneer but im not gona candy coat thing's, there is a fine line between where they sound good and where they sound real bad. and trust me ive used them mostly as a back up radio since the old school days and most other head unit's i had always sounded a little better. but there is hope if you can find where the unit distort's you can set the item after it just below distortion like a line driver, eq,processor or amp and you can get some good sound. the main thing is finding the point of distortion because it is a very fine line, but you may need to just use your ear's to find it, and then you may use a DMM to set the amp unclipped below the units point of distortion.

Yes, that fine line is where you start to see a clipped signal. Hook up a oscilloscope to your headunits RCA jacks, play a pink noise track, and turn up the volume until you see the point where your nice looking sine wave starts to plateau. That is where the headunit begins to clip the signal. Most headunits clip the signal before reaching maximum volume, that is why PG recommends only using 3/4 of the headunits volume when setting gains properly. My Kenwood does the same thing, as it clips at 31/35 volume.

[stipud]

Yes, that fine line is where you start to see a clipped signal. Hook up a oscilloscope to your headunits RCA jacks, play a pink noise track, and turn up the volume until you see the point where your nice looking sine wave starts to plateau. That is where the headunit begins to clip the signal. Most headunits clip the signal before reaching maximum volume, that is why PG recommends only using 3/4 of the headunits volume when setting gains properly. My Kenwood does the same thing, as it clips at 31/35 volume.

Not pink noise... test tone!

I was soo lucky... my STOCK headunit never clips, even at max volume! And it has balanced line outputs.

I don't understand why they design aftermarket headunits to clip before max volume... I guess because ignorant people assume clipping distortion = louder = better?

[ttocs]

by limiting the decks clipping, it limits the output and is keeping you from getting every last little bit out of the deck(yes at risk to componants). Have you ever had your deck all the way up, and stil wanted a little more before? what if it was for an spl setup? I can see both sides of the coin?

-obviously you would not use a stock deck for spl, but a limited deck in general

[stipud]

by limiting the decks clipping, it limits the output and is keeping you from getting every last little bit out of the deck(yes at risk to componants). Have you ever had your deck all the way up, and stil wanted a little more before? what if it was for an spl setup? I can see both sides of the coin?

-obviously you would not use a stock deck for spl, but a limited deck in general

If you're planning on clipping on purpose, you can always do it by fudging the amp gains. No need for the vast majority of headunits to do it by default.

[dwnrodeo]

Yes, that fine line is where you start to see a clipped signal. Hook up a oscilloscope to your headunits RCA jacks, play a pink noise track, and turn up the volume until you see the point where your nice looking sine wave starts to plateau. That is where the headunit begins to clip the signal. Most headunits clip the signal before reaching maximum volume, that is why PG recommends only using 3/4 of the headunits volume when setting gains properly. My Kenwood does the same thing, as it clips at 31/35 volume.

Not pink noise... test tone!

I was soo lucky... my STOCK headunit never clips, even at max volume! And it has balanced line outputs.

I don't understand why they design aftermarket headunits to clip before max volume... I guess because ignorant people assume clipping distortion = louder = better?

I did it with a 60hz test tone, but when I read bcae's website for setting gains, it recommended pink noise. I think this was in part due to the spectrum analyzer portion. Test tone is probably easiest because you only have one sine wave.

http://www.bcae1.com/settinggainswithscope.htm

[stipud]

I did it with a 60hz test tone, but when I read bcae's website for setting gains, it recommended pink noise. I think this was in part due to the spectrum analyzer portion. Test tone is probably easiest because you only have one sine wave.

http://www.bcae1.com/settinggainswithscope.htm

For me, that would be more for matching the levels in the system with an RTA. With your gains set to a hair below clipping using sine waves and an o-scope, your midrange might be way louder than the tweeter. Using an RTA and pink noise would let you lower the midrange level to match the tweeter's level.

[Eric D]

A clipping head unit is more of a poor design than anything else. Even an audio idiot can tell how bad a clipping head unit sounds, yet the manufacturers still produce them.

The only idea I can come up with is on a lower end head unit the manufacture may be using "off the shelf" parts. The digital to analog gain control circuit for example driven by the volume knob or button may be built for higher voltage than the head unit's rails can produce. There are chip based DC-DC converters to get you a range of rail voltages, but "better" head units have more elaborate discrete designs. This in itself may be why cheap units clip.

[Stryker]

people have been doing it by ear for decades, there really isn't a whole lot of use for a meter as your ears are the final judge even with a meter.

exactly, I've never used a meter either use your ears and be done with it.....

[Eric D]

Setting by ear and setting with a meter can both give good results, but using the meter (assuming you know what you are doing) has the advantage of knowing it is right, and never having anything fail.

I use a meter to find the max I can get out of my equipment, then go back and turn it DOWN by ear to were I want it. Most people setting it by ear end up running their equipment at or slightly beyond its limits. Nothing beats throwing a scope on your buddies install he tuned by ear, only to find he is running at 6db or more of gain overlap...

And he is always confused why he keeps having to send his woofers back for repair or replacement...