x600.1 Gain Setting

[xluben 10+ year member]

I just got my Phoenix Gold Xenon x600.1 today. I was unable to correctly set the gains with my Profile amp, because, for some reason, my DMM wouldn't give me a reading. With the x600.1 I get numbers that make sense, but they're in mV instead of V. What could be going on? If I just ignore the units and pretend the numbers are volts the readings make total sense (40 with gain just over halfway).

I'd also like to know the correct way to set the gains since the x600.1 uses the Xe.load technology to get the same wattage from any load (1-4ohms). The amp has two sets of outputs, which I assume are wired in parallel internally. If I wire one 4 ohm sub to each output, should I use 2 ohms when calculating voltage?

It has been discussed around the internet that you can get double the power from the Xenon mono amps by tricking the Xe.load and making it give full output to 2 ohms. This can be done by powering up the amp, and then hooking up the subs. I can verify that this DOES change the output voltage! I set my gains to 40 (after letting the Xe.load sense the subs) and then turned my car off, and then back on (with subs still unhooked). This bypasses the Xe.load and now my reading was 60! Very interesting, but concerns me that the gains cannot be adjusted in the normal fashion.

Last but not least, when I set the gains to what I believe is not clipping (but I do have quite a few issues mentioned above, so I don't know if they're correct), I get a lot less output than from my Profile amp (which I set the gains totally by ear)! What's wrong here? With the gains turned up I can get a lot of output, but I don't want to damage the amp. With the Xe.load trick and the gains up it gets REAL loud (like I want //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif).

Sorry for the rambling, hopefully someone can help me get this thing setup right.

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[jasperpso 10+ year member]

i understand gain can be set with a multimeter to get precise results.. however since i am not a tweeker and i dont own a dmm, i have ALWAYS (10 yrs)set the gain audibly.. the gain knob is a potentiometer on power output.. depending on how much input signal you are giving it, the amp may or may not perform well at very high gain settings, but as long as you cannot hear any audible distortion, and your subs can handle it, run the gain as high as you want. if there is no distortion and the amp doesnt audibly clip, then dont worry about it.. i may be way off base, but has worked for me for years, and i have never blown a sub..

 

[zfactor 10+ year member]

yes if you use 2 4ohm subs it will be a 2ohm load on the amp.. with the xeload bypassed you are getting the "Real" 2ohm output power of the amp thats why you see the difference. with se-load on you should see the 40 at any ohm load or close to 40 anyway if thats what you have it set to

 

[xluben 10+ year member]

yeah, set at 40V (for 800W @ 2 ohms) it's not loud at all. I'm pretty disapointed, I was hoping it'd be louder.

If I do the xe.load trick it's quite a bit louder, but it's even better if I do the trick and have the gain set a littler higher. It's still keeps giving me more output all the way up to 35/35 on my head unit (40V was set with HU at 25/35). Does this mean I can safely turn the gain even higher?

Unfortunately making my subs get really loud (and thus turning the HU volume way up) I believe I have blown one of my coaxials. When I noticed it I wasn't even listening loud, though. It was raining, so I thought maybe water got on it, but by now it should be dry and still sound crackly. I guess I might have to get new 6.5's //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[zfactor 10+ year member]

the xenons want lots of input

 

[jasperpso 10+ year member]

good point.. what HU are u using? casue when i switched to a 6.5v input, my spl went up dramatically..

 

[xluben 10+ year member]

HU is in my sig. I think it's got a 2V pre-out.

I turned the gain all the way up today //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif It was REALLY loud. I liked it a lot. Sounded fine in the car, but I could hear major slapping when I opened the trunk. I guess I'll just have to turn the gain down to where it should be and wait for my ported box.

Also, I rigged up an SPST switch to disconnect the subs while I turn on the car, and then flip them back on and get my 2 ohm power.

 

[hondarider 10+ year member]

I bet if you wanted to set the gains correctly you would have to use a 4 ohm load in the equation because the amp makes the most power it can at 4 ohms with xe load but it limits the power at 2 ohms and 1 ohm to whatever it makes at 4 ohms. So i think no matter what ohm you show the amp if you want to do it correctly it would be 800x4=3200 sqrt3200=56.6 V.

 

[jasperpso 10+ year member]

i believe hondarider to be correct on that. the point of the xeload is to equalize all speaker connections to full power which it creates at 4 ohm.. try 56.6 and see if those are the results you are looking for.. but i have heard the assassins will take 450 daily so if it takes a bit more to pound like u want it, dont be afraid to push the amp a little harder.. and it is air cooled, and i understand it will take it.. i woudlnt run the mod.. this amp should do it without the mod.. you are giving those subs WAY too much power with th\at mod, and with that you risk blowing them..

you might look at getting a phoenix gold 'line driver' it essentiallly boosts the output level of the HU before it gets to the amp.. i have not personnaly used one, but it sounds like it would be right up your ally..

i was just using a jvc HU with a 2v preout, and i had to run the gain nearly all the way up to get the output i wanted.. more input signal(my new premiere hu) and it is down below halfway..

 

[squeak9798 5,000+ posts]

I bet if you wanted to set the gains correctly you would have to use a 4 ohm load in the equation because the amp makes the most power it can at 4 ohms with xe load but it limits the power at 2 ohms and 1 ohm to whatever it makes at 4 ohms. So i think no matter what ohm you show the amp if you want to do it correctly it would be 800x4=3200 sqrt3200=56.6 V.

The amplifier doesn't defy ohms law.

To output X amount of watts into a 2ohm load, it will require X voltage and X current of output. For the equation, you would want to use the impedance you will be presenting the amplifier, and the power output at that impedance.

 

[hondarider 10+ year member]

The amplifier doesn't defy ohms law.
To output X amount of watts into a 2ohm load, it will require X voltage and X current of output. For the equation, you would want to use the impedance you will be presenting the amplifier, and the power output at that impedance.

But if the power output is the same at 1-4 ohms and you wanted to put its full power, lets say 800 watts into 1 SVC 4 ohm sub then you'd use 56.6 volts but to put the same 800 watts into 2 DVC 4 ohm subs presenting a 1 ohm load you wouldnt use 28.3 volts because then the gain would be 50% lower and would not put out 800 watts. So once you set the gain once correctly even if you change subs that have a different resistance you shouldn't have to change the gane.