Clipping light on bass knob accuracy?

[Nugg32 10+ year member]

I have a Sundown audio SAZ 1500d amp and I'm using the bass knob that came with the amp.

I was tuning my amp with a oscilloscope and thought I had my gain set perfectly but when I look at my bass knob the clipping light is still on. How accurate is this light? I also did not bring the gain to a fraction below it's clipping point. I brought the gain down a little more just to make sure

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[1aespinoza 10+ year member]

How accurate is this light?

The complicated circuitry of an oscilloscope might be a smidget more accurate than a bass knob. Go by the O-scope readings.

 

[metalheadjoe 10+ year member]

You own an oscope and the bass knob light... why are you asking us how accurate it is?

 

[Bobbytwonames 5,000+ posts]

When I'm doing demo's I'm constantly adjusting my bass knob to a soft clip from song to song. Isn't that how everybody does it?

 

[ThxOne Premium Member]

I just wait for the smell from the port to get really strong.

Is the O-Scope of good quality on the display. Are you familiar with what a clipped sign wave looks like on an O-Scope? The clip light should be set for a specific amount of distortion i.e. 1 percent or 5 percent and so on. If the display on the O-Scope is a good resolution then it will show clipped sooner than the knob I am sure. Like maybe .1 or .25 or .50 percent. Ya follow?

What signal are you using to set the gain?

 

[Nugg32 10+ year member]

You own an oscope and the bass knob light... why are you asking us how accurate it is?

What? My question is are bass knobs truly accurate. Did the manufacturer purposely set the bass knob to clip at a certain point for a reason? Or is the bass knob just not that accurate.

 

[Bobbytwonames 5,000+ posts]

What? My question is are bass knobs truly accurate. Did the manufacturer purposely set the bass knob to clip at a certain point for a reason? Or is the bass knob just not that accurate.

I've actually been told to only use the bass knob for your particular type of amp. I switched from an SFB amp to an SIA amp and was told to change the bass knob out as well. Btw, you never want a solid clip light. A flickering clip light is fine.

 

[Nugg32 10+ year member]

I've actually been told to only use the bass knob for your particular type of amp. I switched from an SFB amp to an SIA amp and was told to change the bass knob out as well. Btw, you never want a solid clip light. A flickering clip light is fine.

Yeah, I would never use a different bass knob that didn't come with the factory amp unless I purchased a RCA style knob. Like I said in my OG post, I am using the bass knob the came with the amp. I just don't know why the O'scope says I'm good but my bass knob says I'm not.

not sure if this will make sense but if I set my gain dial at the 9 o clock position, the O'scope says I'm good and that is the absolute max I can go before I start slightly clipping. I set my gain dial at about the 8:30 position to be safe but my bass knob has a solid light. For the light to go away I need to set the dial to the 8 o clock position. So basically the O'scope says I'm good at the 9 o clock but my bass knob says I'm good at 8 o clock

 

[Bobbytwonames 5,000+ posts]

Yeah, I would never use a different bass knob that didn't come with the factory amp unless I purchased a RCA style knob. Like I said in my OG post, I am using the bass knob the came with the amp. I just don't know why the O'scope says I'm good but my bass knob says I'm not.

not sure if this will make sense but if I set my gain dial at the 9 o clock position, the O'scope says I'm good and that is the absolute max I can go before I start slightly clipping. I set my gain dial at about the 8:30 position to be safe but my bass knob has a solid light. For the light to go away I need to set the dial to the 8 o clock position. So basically the O'scope says I'm good at the 9 o clock but my bass knob says I'm good at 8 o clock

I'm different and like to set my bass knob at 50%. Subwoofer level at max on headunit at about 80% max volume. Set your mids/highs first with the sub off at just below noticeable distortion. Then set the bass knob at 50% and turn gain up to a "soft" clip. Then you can back it off a tad if you want to.

 

[hispls 5,000+ posts]

What? My question is are bass knobs truly accurate. Did the manufacturer purposely set the bass knob to clip at a certain point for a reason? Or is the bass knob just not that accurate.

Those built in "clip indicator" circuits do not actually sniff out a clipped sine wave they're just set to light up at some specific voltage or current that the manufacturer decides is the maximum output of the amp. Generally they'll have a little bit more on tap when you start seeing that light start to come up, but the difference in output between that light and the absolute most the amp will deliver will be inaudible. If you're not chasing numbers you really shouldn't be trying to push too hard beyond that, and if you are chasing numbers you should be watching the SPL meter and not some clipping light or scope.

 

[metalheadjoe 10+ year member]

What? My question is are bass knobs truly accurate. Did the manufacturer purposely set the bass knob to clip at a certain point for a reason? Or is the bass knob just not that accurate.

I understood your question but you didn't understand my answer. You're asking people to speculate. You own both the knob in question and an oscilloscope. Any answer you get here is an educated guess.

I can tell you when I tested the clipping light on my bass knob, it was spot on, but that doesn't tell you about yours.

@hispls what makes you think these things don't actually detect clipping?

 

[Popwarhomie 5,000+ posts]

Music vs tones?

 

[mat3833 10+ year member]

In my experience (14ish years, 4 amps - 1 big 'ol A/B 2ch, 1 full bridge Brazilian, and 2 Koreans) the clip light always comes on before actual clipping at the terminals.

Clip indicators can be awesome, but they are more of an indicator that you are comming up on full tilt.

You can check how accurate your clip light is fairly easily as well.

Matt

 

[mat3833 10+ year member]

I understood your question but you didn't understand my answer. You're asking people to speculate. You own both the knob in question and an oscilloscope. Any answer you get here is an educated guess.

I can tell you when I tested the clipping light on my bass knob, it was spot on, but that doesn't tell you about yours.

@hispls what makes you think these things don't actually detect clipping?

Clipping in itself isn't really any different than a regular sine wave if you are just measuring peak voltages. In order to "sense" a clipped signal there would need to be some kind of sampling of the output signal to detect any peak voltages measured longer than a specific cycle period. That cycle period would vary by the tone being played or the waveform being reproduced.

An accurate clip indicator would need some actual circuitry inside of it, or the amp would need it to be built into the board and the "remote bass knob with indicator" would just be a display and level adjustment.

Matt

 

[metalheadjoe 10+ year member]

Clipping in itself isn't really any different than a regular sine wave if you are just measuring peak voltages. In order to "sense" a clipped signal there would need to be some kind of sampling of the output signal to detect any peak voltages measured longer than a specific cycle period. That cycle period would vary by the tone being played or the waveform being reproduced.

An accurate clip indicator would need some actual circuitry inside of it, or the amp would need it to be built into the board and the "remote bass knob with indicator" would just be a display and level adjustment.

Matt

What does that have to do with my post?