So I bought a Massive NX4 from another user on this forum and I'm having issues with figuring out the correct gain setting.
It's marketed as 400W RMS x 4 so if I use the normal equation that would be sqrt-1600w, but since it has two gains and I use 100wx2chx4ohms=sqrt800.
Now I could not get any of those voltages. The only way I could achieve it was if I bridged the front channel. I lowered the gain back quite a bit and it's still distorting badly when I turn up the volume and some bass hits. The EQ,etc is flat.
HU: Pioneer deh 80prs in standard mode. Should I just take it to someone with an o-scope or what? I called crutchfield and they just mentioned some stuff about impedence of the amp (which is unknown to me and them) and since it was Massive they had no support. I am however skeptical about their level of expertise at times.
I have both sets of rca's plugged in, but I'm only using the front two speakers right now. Will that mess with my voltage?
What is the impedance rating of the speakers connected to the amplifier? The NX4 is rated at 100W x 4 at 4 Ohms at 14.4V. If you're using 4 ohm speakers the voltage to watch for is 20V. The formula is voltage = square root (watts x impedance).
They're 4 ohm CDT eu 6cx speakers. I can get 20v, but at higher volume I had distortion. Any idea on that? Should I back down or turn up the hpf? I turned the hpf on the amp up a little but the speakers come with passives so idk how much that matters?
They're 4 ohm CDT eu 6cx speakers. I can get 20v, but at higher volume I had distortion. Any idea on that? Should I back down or turn up the hpf? I turned the hpf on the amp up a little but the speakers come with passives so idk how much that matters?
thanks!
Try turning up the HPF. The passives don't provide a high pass filter for the mids, just the tweeters.
The CDT site labels them the power rating of the speakers at 130rms with a 120hz HPF. I'm not pushing 130w rms so what is a good setting for the HPF on the amp? It goes from 0-200 on the amp, do you just kinda guess the position relative the numbers?
I also have some settings for HPF etc, in the headunit, there is an option for 60 or 80hz, I wasn't sure which to use once I get there. These speakers are rated for 60Hz-20.000Hz, I'm newish to this stuff.
The actual low frequency handling of the speakers is going to depend on your installation and tuning. Without using your speakers, and based on my experience with CDT Audio speakers, they should probably handle a 60 Hz HPF at the very lowest. This might not allow the output you want. If you try the 80 Hz filter on the head unit and turn the amp's filter up to 200 Hz that might work. If you need a higher HPF then turn off the head unit's filter and try setting the amp in the middle of the range and work up or down from there. Yes, you do just basically guess the amplifier's crossover frequency.
So if you set the HU to 80 then wouldn't that give a 80+ at the amp, then then amp cutting 80-200 if you set it at 200 HPF right? Isn't that cutting too much out? I guess I was just thinking 200hz would cut out all the bass (and I'm using two speakers right now for everything). The deh-80prs also has a 100hz setting I believe as well. Hopefully tomorrow I'll be able to try this out.
Second thought: Would this explain the early clipping of 1,000hz test tone? That's not a low freq.
I was thinking about something else, sorry for the confusing advice. Don't set the amp's filter to 200. Set the switch to Full if you use the head unit's filter.
Still lost on why a test tone at 1000 would distort at 70% volume, I'm guessing output isn't really 100 and the voltage needs to be less.
That's just the reality of mobile amplification at work, I wouldn't let it bother you. Music is dynamic, and transient peaks typically only last for milliseconds at a time, so you are not likely to notice the distortion nearly as easily when playing tunes at high volume.
If you do, then you probably just need a more powerful amp altogether.
With Hu on 80 hpf I'm fine until past 3/4 volume, then I get burbles on the bass hits. The volume should be higher than 3/4 with distortion. Should I back off the gain?
Is this on the same music the entire time you've been testing this, or have you been trying different stuff? You either need to back the gain down or don't turn the volume up so high. Either way will get about the same result, but I prefer to turn the head unit up higher to get a higher pre-out voltage. I don't know when your head unit starts to distort on the volume setting, if ever, but if you can max the volume without distortion that's helpful.
Remember that not all music is recorded at the same level, so you need to have some room to turn up the volume for quieter recordings.
Setting Front Ch. Gain
Re: Setting Front Ch. Gain
Linear Mode
