Alpine PDX amps... setting gains with DMM?

[FoxPro5 5,000+ posts]

If his 9887 is like my 9885s, I highly doubt the subwoofer output EVER hits 4 volts //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif I am going to verify clipping and voltage output with my oscilloscope when I replace one of the 9885s with a 9887 in the near future!

Meh, they're Alpine's....they always clip. //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

 

[gunz4me 10+ year member]

Meh, they're Alpine's....they always clip. //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

Here, I am going to give you back that knife you just drove into my back. You might need it again:laugh:

If someone else would come up with a GD Ipod interface that is as good as the Alpine's, I would consider switching... Unfortunately the Apple Lossless codec along with the IPOD has replaced CDs for me

 

[FoxPro5 5,000+ posts]

Here, I am going to give you back that knife you just drove into my back. You might need it again:laugh:
If someone else would come up with a GD Ipod interface that is as good as the Alpine's, I would consider switching... Unfortunately the Apple Lossless codec along with the IPOD has replaced CDs for me

I have a tendency to think my Pioneer is ******* :boobies:

 

[pjhabit 10+ year member]

My comps amp puts out 300x2 in bridged and I know several people that gave 300 per side to Focal 165 K2Ps in passive even though they are rated 100RMSx2. Also, my sub is rated 500RMS (DLS Iridium 10") and my 1.600 is 600RMS so I know that even if I turn the gains ALL the way up that neither my comps or the sub will be sent to the grave. I think I currently have comps at around 75% and sub around 90%.
I am real new when it comes to tuning the system and I have no idea how to even set up my Parametric EQ. However, I do plan on getting the system RTA tuned in near future by a pro.

You have no idea of the gains purpose. Max gain does NOT equal max clean power from the amp. You can (& likely will) burn up your **** w/ that setup.

OP, I've set the gain on a PDX several times w/ a DMM, w/o any problems (1khz 0db test tone for the mids/highs & 50 hz for the subs). Follow the tutorial @ suicidaleggroll.com to a T & you should be right as rain.

 

[linksyz 10+ year member]

Your DMM's not reading watts. But that's kind of besides the point, here.
Just take the loudest, most dynamic music track and put it on repeat. Turn your amp gains to minimum and crank you HU to 30-32 out of 35 (assuming the output is not linear and 35 is clipping). Add gain in small increments or have a friend slowly add a little until you're satisfied with the volume.

Your HU preouts are rated at 4v MAX power. You won't get 4v until you're at 35/35 with a 0 dB tone playing. The RMS of a 0 dB tone is about -3 dB. Most modern music is about -10-12 RMS. Just threw that in there so you understand what's going on with playing tones and using your DMM.

I know that DMM does not read watts but voltage which is calculated by using watts and ohms so essentially you can say that DMM reads certain wattage depending on the corresponding voltage you get after plugging in said wattage in the formula. Thank you for explaining the other part to me, I didn't know that.

You have no idea of the gains purpose. Max gain does NOT equal max clean power from the amp. You can (& likely will) burn up your **** w/ that setup.
OP, I've set the gain on a PDX several times w/ a DMM, w/o any problems (1khz 0db test tone for the mids/highs & 50 hz for the subs). Follow the tutorial @ suicidaleggroll.com to a T & you should be right as rain.

I realize that max gain does not equal max clean power from the amp... thats why people always say get amp that can provide more power than your speakers can handle so you the gains are not set all the way up thus providing a cleaner signal.

Don't worry... I'm not that big of a newb or a jacka$$ to burn up my stuff just like that...

Thanks for the eggroll website I'll check it out at home as I can't open it at work...

When you set your gains on PDX amps... did you plug in your DMM in the speaker plug or directly into the amp? I just plugged in the DMM leads into the speaker plug without tightening it and I didn't get any reading from the DMM //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[gunz4me 10+ year member]

I still say your meter probably can't read voltage above the average AC household frequency which is between 50 and 70 Hz... Actually 60 Hz if you want to be exact!

Place the red lead in the speaker + and the black lead in the speaker -, tighten down, play the tone, then read the AC voltage. As I said before, try it with a 50 or 60 Hz tone, and if it works you are in business. Try it again with a 1,000 Hz tone, and if it doesn't work, your meter can't read outside the normal frequency of AC current!

Just remember, all processing should be disabled and all speakers should be disconnected when doing the DMM method. When I say processing, I mean no crossovers enabled, loudness off, bass and treble set at flat, etc.

 

[linksyz 10+ year member]

Thanks gunz4me... I know of all of those things, I read a tutorial jmac or someone else posted here and it's in the sticky here. However, I do need to try out 50 or 60 Hz tone to see if that works and if it does... then I know that you are right that DMM can't read outside of the normal frequency of AC current. I will work on it this weekend as well as grounding the RCA's and making sure grounds are good as I am getting a slight alternator whine //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[pjhabit 10+ year member]

I realize that max gain does not equal max clean power from the amp... thats why people always say get amp that can provide more power than your speakers can handle so you the gains are not set all the way up thus providing a cleaner signal.

Well...it still sounds like you don't understand. The gain is used to match the preout voltage of your HU. When pulling the max clean power from your amp, the gain setting will be the same no matter what the power handling of your speakers are. Just as a reference, my gains were set ~25% & anything above ~40% was severely clipping (my hu had 4v preouts).You might have a better understanding than I give you credit for. But the way you worded things made me suspect.

When you set your gains on PDX amps... did you plug in your DMM in the speaker plug or directly into the amp? I just plugged in the DMM leads into the speaker plug without tightening it and I didn't get any reading from the DMM //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

I tightened the leads to the speaker plug (red +, black -), then plugged them into the amp.