Phoenix Gold Phorum

Hi Everyone, I installed an Audiocontrol Overdrive Plus today to use with my X600.1 that is pushing an RSDC102. The deck I just installed is the INA-W910. I was talking to Bchester a bit about this since he ran a similar line driver-amp combo. I got the amp from him.

I started by putting the volume up to 27 which was about 3/4 on my new headunit, turned up the line driver gain and got the 8V LED blinking and backed off slightly but it would still blink on the 8V when enough bass came through. I did this per the instructions. Then I went to set my amp gain with a DMM like usual. The AC Voltage at the speaker outputs already read 50.2V or so, 48V would be 600 watts using: root(4ohms*600). This is cool and everything, but I didn't even turn the gain up on the amp to achieve this 50.2, the line driver just made that happen.

Since I will never listen to the deck at 27, I reset the line driver at a volume of 25 which is still super loud and I will rarely if ever settle there. I got the same result at the amp speaker outputs, didn't touch the amp gain, but the speaker outputs were already sitting at the 50.2V or so like it was at the earlier higher volume.

With normal volumes of music listening, because of all of the low gain settings of the X600, I can hardly hear the bass.

What do you guys recommend I do? Should I just set the line driver to 8V at a more typical headunit volume, and then adjust the gain on the X600.1?

The bass sounded great with the new headunit on it's own, and it sounded great with the line driver and hu volume at 3/4, but if I tried to listen to it at 3/4 all the time, I would get some serious ear damage : ).

I recomend to not tune your amp with a meter but I have beat that horse to death, raised it from the dead and then pushed it back off a cliff... scopes are for tuning, using a meter to tune your amp is like trying to do fine wood-carvings with a screw-driver and a 15 lb sledge.

carry on....

ttocs wrote:I recomend to not tune your amp with a meter but I have beat that horse to death, raised it from the dead and then pushed it back off a cliff... scopes are for tuning, using a meter to tune your amp is like trying to do fine wood-carvings with a screw-driver and a 15 lb sledge.

carry on....

I can't afford a scope right now, otherwise I would be happy to pick one up. Do you have a couple of brands I can look into? Maybe they aren't as much as I am imagining.

I have always set my amps with a DMM and a 50Hz test tone since it seems like one of the safer ways to go about it, but if it isn't the best way, then I will have to do more research. I have to think that the DMM method is safe because while I always set it at 3/4 hu volume, I never listen to music that loud.

So if I am going to ditch the DMM gain setting for now, how would you recommend I tune by ear including the line driver? Should I just set the line driver to the point the 8V LED is blinking at the loudest volume I would listen? Then just turn up the amp until I feel that the sub is distorting? I find it difficult to hear if a sub is distorting by ear, that's why I have always relied on the DMM.

Oops, I guess they really aren't that expensive if a few of you have picked the one up referenced in this thread:

http://phoenixphorum.com/viewtopic.php?f=3&t=20697

That's less than the line driver was : ).


I am going to order one this weekend I think. So when I get it and can correctly set everything, it would just make sense to tune everything to the highest volume I would ever listen to, right? Doesn't seem like there would be a reason to tune to 3/4 volume of the headunit if I could never actually listen at 3/4 volume.

One question I have about the amp. When I was tuning with the amp yesterday with the line driver, and saw that the voltage was sitting at 50.2 without even touching the gain, I turned it up slightly just to make sure everything was responding right. When I turned up the gain a little, I started hear a very high pitch electronic sound. Is that just the increased current going through the amp components? I didn't leave it there for an extended amount of time but I did want to ask you guys about it.

yes that nano scope is cool as shit and will do everything you need it too.

Seriously, try your ears for a change. Again adjust it up to 2/3-3/4 peak volume with bass/treble neutral and the amp gain down all the way. Put in a couple of disks that you are familiar with that give a good example of what you like to listen too. Now go and start to tweek the amp gain up. If you start to hear static/clipping well you have gone way too far and back it of a bit. now put in another disk and see if you like where it is at and how it sounds, start to adjust bass/treble as you would like them and again feel free to tweek the gain up/down as needed. LISTEN TO THE MUSIC, not your calculator/meter and in the end not only will you be a more informed listener but also happier down the road.

ttocs wrote:yes that nano scope is cool as shit and will do everything you need it too.

Seriously, try your ears for a change. Again adjust it up to 2/3-3/4 peak volume with bass/treble neutral and the amp gain down all the way. Put in a couple of disks that you are familiar with that give a good example of what you like to listen too. Now go and start to tweek the amp gain up. If you start to hear static/clipping well you have gone way too far and back it of a bit. now put in another disk and see if you like where it is at and how it sounds, start to adjust bass/treble as you would like them and again feel free to tweek the gain up/down as needed. LISTEN TO THE MUSIC, not your calculator/meter and in the end not only will you be a more informed listener but also happier down the road.

Im gonna go 2/3 I think, 3/4 is way too high for how I listen.

Now what abou the line driver? Same thing? 2/3 and adjust until my 8v led is blinking a bit?

The clipped signal sounds like a short signal right? Like the sub can't hold a note, kind of cuts out a little?

Hooked the line driver up, cranked a couple bassy songs and a couple of my other favorites at about 2/3 volume. The bassy songs were just making the line driver 8v led flicker a bit so I felt comfortable with that.

Then I played the songs again at 2/3 with the amp and sub hooked up, turned the gain up a bit on the amp to a point where the bass was still very clean from what I could tell on the bassiest song, and left it there. Right now, I feel happy, and the gain on the amp is very low thanks to the line driver but it still sounds great even at the lower listening volumes I typically use.

When I get the oscope, I will take a look of course but I don't think I could be pushing the equipment to clipping because I don't listen anywhere near 2/3 volume.

when i had my two they needed a line driver to reach full power almost like a zpa im thinking its the load set chip that need the stronger signal

a clipped note will start to sound like a pop/crackle and in larger amounts sound like the opener of that detroit pawn shop that is always screaming at its customers... Not only do I hate the show but the opening music when the come back from commercial just sounds like badly clipping bass music and its like that on purpose.

ttocs wrote:yes that nano scope is cool as shit and will do everything you need it too.

Seriously, try your ears for a change. Again adjust it up to 2/3-3/4 peak volume with bass/treble neutral and the amp gain down all the way. Put in a couple of disks that you are familiar with that give a good example of what you like to listen too. Now go and start to tweek the amp gain up. If you start to hear static/clipping well you have gone way too far and back it of a bit. now put in another disk and see if you like where it is at and how it sounds, start to adjust bass/treble as you would like them and again feel free to tweek the gain up/down as needed. LISTEN TO THE MUSIC, not your calculator/meter and in the end not only will you be a more informed listener but also happier down the road.

see Phoenixcolt, TTocs is old school like me.

its been done like that now for decades and been working just fine. If it ain't broke....

Thanks guys, I like what I am hearing. I had no doubts about the old school method : ), I just get caught up in the details sometimes. For the system I run, and the volumes I actually listen at, by ear was a much better approach this time around. I am interested in the oscope still, but I think I will hold off for a while, probably not a necessity at the moment.

Bchester, I too really liked setting the gain in the 0 to 1/2 portion of the range as you mentioned in the pm.

If you used a DMM to set the amp gains, why not the line driver? I found the clip lights came on quite late with my Audiocontrol Three.1; I was pushing 13v out of it, and it was definitely clipping. After using my oscilloscope I dropped it down to 9 volts, but setting it to 8 with the multimeter would have been more than enough... the 1 volt difference is inaudible.

If you were in clipping when you did it, why would you recomend that he do it then with out the scope to confirm he has gone too far?

Using an oscilloscope is really the best way to go about this, but using a DMM can work, assuming certain things.

Since PG equipment is typically under rated, you should be safe if you target the rated output.

The same should be true of a good line driver such as an AudioControl.

The problem is the head unit. If you don't know where it clips at, using a DMM to set the gain is probably going to be counter productive.

So, if you have a quality head unit, you can set it at max, and set the amp at the lowest level, and then run the output on the line driver up until you hit the target output of the amp with the DMM. Chances are you will be around 4V or 5V output on the line driver.

Using a DMM works, but unless you know the exact numbers with your particular DMM where the equipment will clip at, you run a big risk of either clipping something, or not getting nearly the headroom you paid for. So, for a lot of people, setting it by ear is more effective.

Me personally, I know where all my equipment clips at, and have verified it with any of my oscilloscopes. Using this info, I can install something in one of my vehicles, and I just use the DMM to get it right (with those numbers I found on the test bench using the scope). There will be some variation due to input voltage (12.6V vs 13.8V for example), but I pick the low end to make sure nothing clips.

eric you would be the first industry professional I have ever heard that uses the meter personally if that is what you are saying. That would suprise me...

ttocs wrote:eric you would be the first industry professional I have ever heard that uses the meter personally if that is what you are saying. That would suprise me...

I only use it after knowing where my equipment clips at. For example, my head unit does not clip, I have verified it with my oscilloscope in my vehicle.

Now, say I test an amp on my test bench with my o-scope and I find that it clips at 20V RMS output (measured with my TrueRMS DMM at the same time I am using an o-scope to see the clipping).

I know I can install this amp in my vehicle, and play a sine wave with no speakers connected, then turn the head unit all the way up, and finally set the gain on the amp using the same DMM as I did before until I get 20V RMS at the speaker output. Since my test bench is 13.8V and my vehicle is 14.4V (running) I know 20V will be below the point the amp clips (maybe it will go to 21V with the engine running, but I don't care).

It is a heck of a lot easier to use a DMM in my vehicle than it is my oscilloscope. I did just buy a new smaller oscilloscope, so this summer I will have to see how easy it is to use in the vehicle. I am sure it will still be more cumbersome than my DMM is though.

Thanks guys, this is good info. I will revisit when I get the o-scope. Probably going to wait a few weeks, but I definitely plan to go for it.

As far as the line driver, given the volume I set the line driver at versus the volume I actually listen to music, the 8v LED never blinks so I don't think I would be anywhere close to clipping...I am very intrigued though. I am looking forward to the oscope as my next step in the right direction to learn about tuning systems. I am really anxious to see if there is clipping going on with the X600 that I can't hear as distortion through the sub at the 2/3 volume I set everything at.

The curiosity is killing me.

New install in the next few weeks. I have everthing I need to put 2 x600.1's on a Ti12d elite.

Should I order an additional line driver for the second amp, can I Y off of the line driver I have to the two amps, or should I install without line drivers?

I will need to match the amp voltages to make this work so I don't know if a line driver would complicate the install. May need to pick up that oscope finally as well since I will need to make sure my Xenons aren't clipping and I will need to adjust these amps pretty close to their full potential to get the Elite enough power.