Need VERY SPECIFIC help with amp gain

 

Silver Member
Username: Rosrock

Michigan

Post Number: 526
Registered: Mar-09
ok first off I do not have a test tone cd. My f5710 xplode HU has 2 volt preouts. My amp does 1400 at 1 ohm(cadence a7hc), and i have a pretty decent digital multimeter. My sub reads 1.5 when parralled(not sure how, its supposed to be d2, is this normal?). So what is my EXACT voltage to look for? I usually get a steady reading of around ~14.0 at amp (i already know about equalizing everything and turning up 3/4 on hu with no bass boost. Now i also have another question, if im to put the sub output down below where i normally put it and set the gain, when i turn on my car and start bumping down the road does this basically mean if i put my subout up am i clipping? this gain stuff seems a little confusing, like to talk to someone on the phone tomorrow about it when im doing it, i think that would be best. But anyways, the more detailed help the better. if you have any other info u need to know let me know.
 

Silver Member
Username: Rosrock

Michigan

Post Number: 527
Registered: Mar-09
and yea and also what dmm setting do i use and do i place the leads at 1 of the terimnals - and + on the amp for voltage part
 

Gold Member
Username: Gcs8

Atlanta, Ga

Post Number: 1048
Registered: Sep-09
http://www.glasswolf.net/papers/dmmgain.html
 

Silver Member
Username: Rosrock

Michigan

Post Number: 528
Registered: Mar-09
"Play a test tone 50-60hz (if you do not have a cd, tape, etc with a test track, then play your favorite song with similar features)." well now my question is which song has a solid 50 hz test tone? BTW would someone here be willing to ship me a
 

Platinum Member
Username: Nd4spd18

Philadelphia, PA

Post Number: 11198
Registered: Jul-06
http://www.realmofexcursion.com/downloads.htm
 

Gold Member
Username: Gcs8

Atlanta, Ga

Post Number: 1049
Registered: Sep-09
http://gcs8.serveftp.net/projects/50hzmono.wav
 

Silver Member
Username: Rosrock

Michigan

Post Number: 529
Registered: Mar-09
ok thx i hope i can do this
 

Silver Member
Username: Rosrock

Michigan

Post Number: 530
Registered: Mar-09
i kinda like test tones, i cant wait to download a bunch of those and have the sub do the 20hz to 80 hz.
 

Silver Member
Username: Skdooley

Roanoke, VA Usa

Post Number: 942
Registered: Oct-09
Be careful playing constant tones for extended periods of times, especially if they're well below your port tuning and/or at loud volume levels.
 

Silver Member
Username: Jbpitt

Pittsburgh, Pa. Usa

Post Number: 617
Registered: Jul-09
You should think about an upgrade on that hu too. Makes a world of difference.
 

Silver Member
Username: Rosrock

Michigan

Post Number: 546
Registered: Mar-09
really? hmmm. how? is 2 volt preouts bad?
 

Silver Member
Username: Jbpitt

Pittsburgh, Pa. Usa

Post Number: 619
Registered: Jul-09
No,i just meant that sony isnt to good. Reason i say that is, years ago i went from a sony to an alpine hu an it was a night an day difference. Both had 2v preouts too, it just made everything sound so much better.
 

Silver Member
Username: Tedsprogz

Nunya, Florida US

Post Number: 108
Registered: Aug-05
source is everything
 

Silver Member
Username: Jbpitt

Pittsburgh, Pa. Usa

Post Number: 621
Registered: Jul-09
^ exactly
 

Gold Member
Username: Extrmndor3

Http://illuzonemu.serv..., ^^^Sick Game

Post Number: 8071
Registered: Feb-06
fu-ck all of that sh!t... if you just want a daily driver do this:

turn your head unit to 75% of volume

on your amp turn all the gain down and bassbost

slowy start increasing the gain till you hear distortion or dimming lights if you do lower it alil bit

check the bass boost and raise it alil bit ( when raising the bass boost dont raise it too much since it will cause clipping of your amplifier) raise the bass like 1/4 max if you still have the chance

when everything done enjoy your set up


fu-ck multimeters and fu-ck all that sh!t..
no multimeters of decibel meters will beat your own eyes and hears..
 

Gold Member
Username: Extrmndor3

Http://illuzonemu.serv..., ^^^Sick Game

Post Number: 8072
Registered: Feb-06
test tones my nuts
 

Gold Member
Username: Southernrebel

Monroe, Louisiana Team Audible...

Post Number: 8168
Registered: Mar-04
Sorry, but IMO....setting the gain w/ a multimeter is just a VERY BASIC place to start when tuning a system.

My reasoning:

1) Different songs will have different bass. Some will have ALOT of bass, some will have very little.

2) A 0dB reference tone will be the MAX signal your amp will ever see, and it is constant. Songs will have peaks and troughs.

3) Different recordings (even of the same sounds) will give you different input signals to the amp.

4) Many times your HU will not actually give you flat output at different frequencies. Even w/ your EQ at 'flat', some HU's will have roll off for low freq...EX: stock HU's. So, setting the gain w/ a 0dB 60hz tone might mean you will actually get as much as a -6dB output at 30hz.

5) Different people will have different listening habits. Some will like more bass, some more highs/mid, some flat response.



The best thing you can do is set your gain's and have an adjustable sub-output control on the HU, or possibly on the RCA line. For instance using a Pac Audio LC1 RCA level attenuator, or possibly the amps bass control (given that it is a GAIN CONTROLLER, not a bass boost.)

Set your gains w/ the RCA line attenuator or gain control at around 50-60% (or HU sub control at a mid-way setting) and the HU volume at 75%. Use a song w/ ALOT of bass, preferably a song w/ alot of freq range. Listen for distortion/clipping. Then you get to that point, stop turning the gain up.

Now, from this point on, you just need to LISTEN FOR CLIPPING when you play music. You can use the HU's bass control to boost the signal when you need a little more bass, just keep it within the unclipped range.

ABOVE ALL THINGS....
You have to learn not to abuse your ability to attenuate the signal.
Listen, learn, don't blow speakers.
 

Platinum Member
Username: Nd4spd18

Philadelphia, PA

Post Number: 11202
Registered: Jul-06
I use one of those PAC LC1 level controls. Great little accessory.
 

Gold Member
Username: Southernrebel

Monroe, Louisiana Team Audible...

Post Number: 8169
Registered: Mar-04
I love that little Pac LC1.

I can't tell you how many people come in every week looking for 'bass knobs'. I sell them as 'better than a stock bass boost knob'...and its 100% true.

I have even used them to attenuate amps for horn tweeters
 

Bronze Member
Username: Shopvac

Post Number: 25
Registered: Jun-10
Was looking for this type of hardware (PAC LC1 level controls), thanks for sharing this guys..
 

Gold Member
Username: Southernrebel

Monroe, Louisiana Team Audible...

Post Number: 8172
Registered: Mar-04

quote:

Was looking for this type of hardware (PAC LC1 level controls), thanks for sharing this guys..




Amazing what you will learn in one of my random rant posts
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