Understanding Sub Level(RCA OUTPUT VOLTAGE) On Modern Aftermarket HeadUnits!

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[@cwbintn8949]

My head unit keeps cutting off when my system is hittin' hard, but I think it might be due to still running a stock alternator on my 07 Ford Mustang, and a 10+ year old Kenwood head unit, lol. Still, a very informative video, I usually do the opposite and start low on sub levels on the head unit side, then work my way up. Might try this next time, and start by turning my gain down directly at the big Skar Audio amp, and adjust the bass levels with the bass remote instead of the head unit itself, when I get in the mood to tinker and tune again.

[@fatboy1917]

Never has this been explained to where it's easily understandable, till now. Thank you MB

[@MykeHawke-r9r]

Tag team back again... Do you guys remind me high School

[@dougloyd5988]

Can you add info about changing the EQ setting for better sound and how it effects subwoofer RCA voltage.

[@felixaguirre3954]

What's up mbe love the show ... I learn Soo much because if you and want to thank you

[@M.B.Enclosures]

I appreciate that

[@Justice4allJustice4all]

Yes more information I needed..I knew about S.M.D. but didn't fully understand the sub control on the head unit..I was just thinking volume up and volume down about the sub control settings.. aka voltage ⚡ nice MB 👍

[@M.B.Enclosures]

Glad I could help

[@MiguelLgarcia-pz3hn]

​@@M.B.Enclosures what head unit is this I need this for my 2 solo x subs

[@therealjohnymexican]

Such a user friendly little tool from Steve. You have to be REALLY dense to not understand how to use it. A must have in any car audio enthusiast’s tool box.

[@JasonWW2000]

I think that would be true if it came with good instructions and different tones to play.

[@JasonWW2000]

Of course, an inexpensive oscilloscope can do the same for less money. So there are different options for people.

[@MatthewGuynn-ki8rn]

I can't knock the distortion detection on his devices.. but one thing I do know is I don't trust the Dyno reads off his devices.. ​@@JasonWW2000

[@greenbassboosts8872]

I had a problem with a friends subs, just weren't hitting. I did a lot of messing around before checking the voltage of the rca out... 0.6V maxed out lol. The amp said it could take up to 9V so that was not working

[@M.B.Enclosures]

So you would have had needed to turn gain up to match max input voltage of amp. Or purchase a line driver to step up voltage

[@greenbassboosts8872]

@@M.B.Enclosures They ended up just switching the head unit out. It would start clipping at 3/4 gain up. Amp was only pushing 30-35V at that point so it was a problem for sure

[@jerryruff6456]

Thanks for the heads up and I wouldn’t work for free unless someone is helping you while you promote their products

[@gonenutz5150]

Great explanation, could you do one on how to use the DD1? Also do you sell enclosure designs for a single 18”?

[@jjay2650]

My kenwood is 4 volts i didnt even have to turn my gain up on my rockford amp when i had it….ended up having to back down the sub level to match the voltage to get the correct watts for my amp…this wat u talkin is key👍🏾

[@dereckp2485]

hey man, i saw a video of yours showing ur batteries and what not and you showed a battery charger/maintainer that you use weekly, which one was it? thanks man love the content

[@georgebailey6307]

Thank you MB, going out now to set properly, happy Saturday all..

[@imahellraiser5288]

What type of sub amp are you running and what the total wattage your truck puts out

[@mrjayarnold5608]

I know most people think it’s a second gain for the amp

[@Skipzz97]

Thank you Mbe you the GOAT 💯

[@gilliam355]

Thanks I needed this video

[@MrSlabking81]

I did not know that 🤯

[@swaggreen2674]

How about the doorspeaker levels? I have a pioneer headunit and there i also can adjust the door speakers from -20 till +10

[@JasonWW2000]

What is the setting called? Normally a head unit will not give you an option to turn the four main channels up or down. The default setting should deliver the rated RCA voltage. You can verify this yourself. Let's say the RCA voltage is rated at 4 volts RMS. Attach a digital multimeter to the RCA ends and set it to AC voltage. The reading it gives should be RMS voltage. Run your 1K hz 0 dB test tone at full volume and see what your voltage is. (Make sure none of your equalizer settings are affecting that frequency) You should hit 4.0 volts at either full volume or a notch or two below that. Typically the subwoofer level control in a head unit will not give it's full rated voltage unless it is turned all the way up. So they basically give you the option to turn it down. It depends on the headunit, though. Some brands have a sub level positive and negative. Those usually give full signal at zero setting.

[@swaggreen2674]

The setting is called: Speaker Level ' Thanks for the explaining!

[@JasonWW2000]

​@@swaggreen2674 I don't really know. You might check the owners manual. Some headunits let you adjust signal levels in relation to each other so you don't get a big jump in volume switching between sources. I don't think it's that. If they are giving you control over each speaker it might be to fine tune the levels. Kind of like balance and fader, but more precise. I know some Pioneer headunits have Network mode that lets you run in 3 way mode. A speaker level adjustment there makes sense to let you fine tune the sound. I'm guessing your unit has full rca voltage at the zero position.

[@swaggreen2674]

Yes i wil measure the rms voltage, also to check on which volume its start to distort. But i think most pioneer are distortion free

[@JasonWW2000]

@@swaggreen2674 To know for sure when the signal starts to clip you would need an inexpensive oscilloscope to view the sine wave. You can get them from $40 to $70. If you could get an oscope that also shows RMS voltage at the same time, that's even better. You wouldn't need to also connect a digital multimeter.

[@Mr.Hoskin]

Question: my set up is the following; head unit connected to DSP, from my DSP connected to my sub amp. I was told to keep my head unit sub level at 0, and max out my sub level on my DSP and remote gain knob on my sub amp when setting my sub gain to not clip. Is this the correct way to do it? Or should I have turned my head unit sub level to the max like you're suggesting? I appreciate any help.

[@M.B.Enclosures]

Yes that is the correct way.. because you have the DSP

[@Mr.Hoskin]

Thank you sir.

[@k-sell4065]

Good afternoon MB i have a question. I have power acoustic class D series A3000DB amplifier. On the setting it has level, sub sonic and low pass. What does the sub sonic do and can you do a video explaining how that work?

[@JasonWW2000]

The subsonic filter is basically a high pass filter for the subwoofer. It's job is to roll off extremely low frequencies that might damage your subwoofer. Let's say you have a ported enclosure tuned to 33hz. Once you start playing really low frequencies like 25 or 20 hz you'll notice the subwoofer unloads and starts flopping around with really high excursion levels. This can potentially damage the sub. So you turn on the subsonic filter and set it to maybe 25 or 30 hz. It will reduce the signal at those lower frequencies and protect the subwoofer.

[@k-sell4065]

@@JasonWW2000 thank i understand now 💯👊🏾👊🏾👊🏾👊🏾👊🏾

[@scamchan]

I never set my sub level at max since it was installed. I wonder what would happen if I did?

[@M.B.Enclosures]

If you don’t reset the amp at the new level you will be clipping

[@scamchan]

@@M.B.Enclosures That sounds scary because I don't even know what my max sub level is I am going to have to check.

[@Mad21X]

Absolute gems this man is dropping. MB could you expand on this video by explaining the Toslink digital output on this head unit?

[@JasonWW2000]

There isn't too much to talk about. You would run a fiber optic cable from the head unit to a DSP with an optical input. What kind of questions did you have?

[@Mad21X]

@@JasonWW2000 the output voltages using RCA’s (2v to 6v) vs digital output, what does the higher voltage mean, how does it translate to the audio setup and why would one choose digital output over the 2v rca ?

[@JasonWW2000]

​@@Mad21X To answer all that will be long. As far as lower volt rca vs higher volt: Let's say you have an amplifier that can put out 40v (about 400 watts). If you feed the amp a 2v signal it has to amplify it with a 20:1 ratio. If you feed it with a 4v signal it has to amplify it with a 10:1 ratio. The big difference here is if you get any type of low-level noise-induced into the RCA signal. Let's say alternator whine or a humming noise from a vehicle module. Amplifying that noise 20 times is going to be louder than amplifying it 10 times. So the higher voltage will usually have less background noise or whine/hum. As far as digital vs analog: A digital signal, either through fiber optic or a copper wire, is not susceptible to picking up any kind of stray noise. Plus it usually has a better signal to noise ratio compared to rca's. This makes it ideal for the long run from the front of the vehicle to the rear. High voltage RCA is going to be better than low voltage rca, but digital is going to be the best. Once the signal is in the back plugged into the dsp it's no big deal to run short rca cables from it to each amp. Most good dsp's will output 4 or more volts.

[@Mad21X]

@@JasonWW2000 ahhhhh! I understand now! Thank you for taking your time to explain this, much appreciated sir. I have definitely learnt some things here today that I would carry with me & pass on.

[@matthewdavis2448]

DD-1 is a great tool for finding the clipping point of the head unit. In my opinion however it is not a good tool for setting subwoofer amplifier gains as it only recognizes one frequency (40hz). If an enclosure is tuned to 33hz, for example, then that is most likely the lowest impedance value(i.e. 1 ohm). If you set the gain at 40hz then the resistance value can be (and usually is) much higher(I.e. 4ohms). This can result in sending too much power near the tuning frequency if the amplifier is capable of producing more than what the woofer/s can safely handle.

[@M.B.Enclosures]

Not possible.. as frequency lowers power applied diminishes …severely

[@matthewdavis2448]

@@M.B.Enclosures how so? Is voltage at the amplifier terminal not relatively constant within the usable frequency range? Or are you saying that there is a predefined “roll-off” so to speak of the voltage that matches exactly with the roll-off in impedance?

[@JasonWW2000]

​​ You might be overthinking things. A clipped amp output has to do with the voltage rails inside the amplifier. The output will start to clip when the output voltage tries to exceed the internal rail voltage. It's not really affected by the load on the amplifier. The power that the amplifier puts out is going to vary based on impedance, yes, but it's not going to affect the internal rail voltage. So you don't really have to worry about what frequency your setting the gain with. There are other things, though that can change the clip point. Namely battery input voltage. In an unregulated power supply amplifier as the input voltage sags that could also cause the internal rail voltage to sag causing the output to the sub the clip earlier than normal. People with really big systems that have a lot of voltage sag typically stay under their max clean voltage. Like if the signal from the head unit causes the amplifiers output to clip at volume 40, they can estimate that when the system is playing and the voltage is sagging it will probably start clipping at volume 38. So they don't go higher than volume 38. Really, the best option is to have a clip light so that no matter the circumstances you'll know if the output is clipping or not.

[@matthewdavis2448]

@@JasonWW2000 yeah I’m not referring to clipping because clipping doesn’t damage woofers heat does. If a 1000 watt rms rated woofer is getting 1000 watts it should be okay but if it is getting 4000 watts it most likely won’t survive long. I don’t know how many enclosures you’ve modeled in software but you’ll notice that most often when an enclosure is tuned in the low 30’s and wired to 1 ohm nominally it is around 1.5-2.0 ohms at tuning but around 4.0-5.0 ohms around the 40-50hz range. Meaning that the woofer is going to receive approximately 4x the power at tuning when compared to the 40-50hz impedance peak. If you’ve maximized the gain at 40hz then when the woofer receives signal at full volume near tuning it very well may receive 4X the power. With today’s music, bass lines have become synthesized sine waves. 4x power sine waves will destroy woofers.

[@JasonWW2000]

​@@matthewdavis2448If you don't trust my answer and you're wanting a second opinion you might try asking Steve Meade, Tony D'Amour or maybe Loud Fiat (he's an electrical engineer specializingin car audio. Dean at Five Star. Kicker will sometimes answer technical questions.