Amp gain

[AzrielID]

hi, i need some help with the gain setting
car: bmw f34 base audio (no amp)
i have a 3 way on the front channel with Audison specific bmw component 4 inch (50w RMS) and axton sub specific bmw 8 inch (150w RMS) and on the rear a coaxial audison bmw specific 4inch (40w RMS)
Everything power up by and impact model 4 (110w RMS x 4)
i set the gain following the 1000hz 0db at 24V on the front and 1000hz 0db at 12.5V on the rear
now, i have the 8 inch sub on the front, i'm i supposed to use the 50hz 0db to set the gain for the 150w RMS woofers or would be better to use (again) the 1000hz 0db for the 50w RMS component for better balance with the rear?
every speaker is 4ohm on the system

Just for info: does anybody know better info about the impact amp brand?

 

[staticV3]

Don't use a single tone for matching levels between drivers.

These can easily align with a trough or peak in the driver response, throwing the balance out of whack.

A better approach is to use Pink noise and the Moving Microphone Method to take actual in-car response measurements.

The resulting visual representation of the system's response will make aligning the drivers much more straightforward and precise.

 

[AzrielID]

i don't have a dsp for calibrate the single driver per channel, sadly even the amp is a bit poor of calibration (HPF on the front + gain without full range only HPF mode, LPF on the back + gain + bass boost with setting for LPF and Full range)

I can only reproduce the Pink noise and play with the gain, but idk how i will tollerate the noise ahah
i should keep 3/4 of the volume or go with the max?
Other ways to set only the gain?

 

[staticV3]

i don't have a dsp for calibrate the single driver per channel, sadly even the amp is a bit poor of calibration (HPF on the front + gain without full range only HPF mode, LPF on the back + gain + bass boost with setting for LPF and Full range)

I can only reproduce the Pink noise and play with the gain, but idk how i will tollerate the noise ahah
i should keep 3/4 of the volume or go with the max?
Other ways to set only the gain?

A long as you have individual gain control for each driver type (sub/coax), you can do level matching.

There's no need to play the test tone at super high volumes. As long as you get some 20-30dB of SNR, the resulting measurements will be useful, regardless of the absolue SPL.

 

[Blumlein 88]

The pink noise doesn't need to be loud. Do you have some microphone or something to measure this or are you just setting gain measuring voltage levels with a multimeter at amp inputs or how are you attempting to do this?

 

[audio_tony]

You could use a sound level meter app on your phone, as you don't need a calibrated measurement, you just need to ensure that the output is equal from all speakers.
With regard to the sub, you should just adjust the levels on that by ear, as trying to uses tones or pink noise would be very difficult.

 

[AzrielID]

The pink noise doesn't need to be loud. Do you have some microphone or something to measure this or are you just setting gain measuring voltage levels with a multimeter at amp inputs or how are you attempting to do this?

i used a volti meter and the equation square root (speaker rms power x ohm) and the value was:
150w rms (highest one in the 3 way) on the front with 24.3V
40w rms (coax) on the back with 12.49V

i misured the voltage (nice challenge because i have molex style connector) from the channel (both with 1kz 0db) and increased the gain until the value was reached
the volume was at 75% and the max db read (from app on the phone) was near 110db (maybe to high)

You could use a sound level meter app on your phone, as you don't need a calibrated measurement, you just need to ensure that the output is equal from all speakers.
With regard to the sub, you should just adjust the levels on that by ear, as trying to uses tones or pink noise would be very difficult.

actually i think they are more some woofer than subwoofer, they are literally connected in parallel with the front channel



i'm a noob on this things, i'm trying to learn as much as i could, maybe the amp isn't the best thing on the marked (paid 99 euros in discount, normal price 250/300)
i see most of people use audison amp with integrated dsp, but most of the time they have the stock amp (hi-fi/harman kardon) and is much easier than no amp (i had to rewire some stuff), at least i have coded from high level to low level output

 

[Blumlein 88]

i used a volti meter and the equation square root (speaker rms power x ohm) and the value was:
150w rms (highest one in the 3 way) on the front with 24.3V
40w rms (coax) on the back with 12.49V

So sounds like you are trying to set each speaker so it will get to max rated output at the same time. That won't guarantee a balance of loudness between them. Neither would feeding the same power to each one.

Setting level off of a phone using a dB app can work. An iPhone if you have one has pretty good response even at lower frequencies. If you have an Android some roll off below 200 hz and some don't.

 

[AzrielID]

So sounds like you are trying to set each speaker so it will get to max rated output at the same time. That won't guarantee a balance of loudness between them. Neither would feeding the same power to each one.

Setting level off of a phone using a dB app can work. An iPhone if you have one has pretty good response even at lower frequencies. If you have an Android some roll off below 200 hz and some don't.

I dont know what are the right words to express, but i think yes
When i set the gain for the first time i give more power to the front channel because of the underseat woofers, but now i decided to consider the door speaker rather then subwoofer (onestly, i want to change them to a lower RMS power and 2ohm)
Even notice clipping in some song where the bass is more present, but i tried to lower the output voltage near the same as the back channel and i doesnt sound bad at all and the clipping seems to be harder to reach (still issue with bassy songs), just give time to the time, i still need to find a good place for the amp itself and rewire the cables to make them twisted and change the woofer ahah

About the amp, i still dont know anything, like the real power output (measured) and and efficency, i see the discount price, looked fine to me and told myself "just do it", i only know is a 1280W MAX output, 640W RMS at 2ohm (110w RMS x4 4ohm, 160w RMS x4 2ohm), is an italiand brand and is more exprensive than a pioneer GM-D8704, i will leave a photo of the PCB, maybe a looks could be usefull

 

[DVDdoug]

I would probably just "balance" them by ear. The subwoofer would need to be measured with a measurement mic and REW (or similar)

But you still might want to tweak it by ear, or adjust the bass depending on the song.

And if you have a front-rear fader you'll probably be adjusting that occasionally by-ear too.

 

[AzrielID]

just for info
what is better, low gain and high volume or high gain low volume?
and notice that the woofer need to be near the max volume to give a good bass feel, that's why i thinking to increase the gain