Bass Knob

[SamIam71]

SO, I know before I ask the question that many will say don't use them, but, why do we have them? With so many amps made across the decades, why do we have remote access to the gain control if there is a "proper" setting for it?

I know as a rule, we should set gains to match head unit outputs using a DMM and even an oscilloscope if available. So, what would be the purpose for millions and millions of dollars worth of amplifiers to be sold, and even more perplexing, engineered with remote control to gains if they were not to be adjusted on the fly?

In a thread earlier this week a guy with a Ground Zero amp said he needed to get the bass knob for it because he would be "Bass Racing" I believe is how he put it. I have seen some ads say the amp came with remote "Bass Boost" knobs, which makes a little more sense than a remote gain.

So, there must be a time and place for the proper use of these controls for them to be an industry standard. What sort of situation would require such an adjustment?

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[Chromatic]

My understanding of bass knobs -- (And it's quite limited).. is that some control a (dB attenuation and increase of x slope).. and some control the actual gain to the "sub/bass channel).

I'll just give you my own take on them.. for MY use.

Many people said don't use the Bass knob that came with my amp.. but, I used it anyway, and I absolutely love the at your fingertips analog control of the bass.

The way I set mine up was I set the Bass knob to "max" and then set my gains on the amp with a DMM to the proper voltage for RMS wattage to the Sub. So Max on my bass knob = the RMS rating of the sub.. (this is a "safe" setting for me.. as I can't go beyond the rated power.. even though many subs can handle much more than the rated RMS especially with clean power.. and even moreso if you hook a DD-1 up and ensure at the levels you are pushing it aren't causing clipped waves, distortion...

For me it's all about simple, quick easy adjustments to the bass due what type of music, DVD, (movie? what kind of movie?) -- Rock song? Rap? Grungy? Clean? etc..

So let's say I have oh, I don't know.. Dave Mathews Band playing.. I generally have that bass knob cranked up fairly high.. it's a clean generally upper range of the sub with the kick pedal, even though the bass guitar hits lower notes.. Then say the next song switches to a more grunge/alternative music with lots of distortion pedals, etc.. I will likely drop the bass back a touch on that knob... Then let's say Gangsta's paradise comes on next.. I'll again adjust (if necessary)... then let's say the passenger pops in a DVD of let's say Braveheart.. I'll again likely adjust the knob a bit to get the best sound for the movie (Movies really sound great in cars.. a concept I'm just now beginning to enjoy )..

So for me.. it's just a very, very practical and handy tool that I don't have to go to my amp and adjust.. or even press a few buttons and LOOK at my headunit to adjust anything.. It's a no look twist of the fingers while driving.

It also comes in handy if it's late.. and I"m in a residential area,.. and am listening to my tunes but don't necessarily want to mute or attenuate the volume too much.. I can drop that bass knob adjustment to half or less and it's not going to bug anyone and still sounds good inside the vehicle. Or let's say I have a business client in the car.. I will turn the bass down easily and quickly with the knob for more professional reasons.. unless they are interested in the car stereo system.. then it's a split second and it's back to "wow mode" to impress/show off the system.

For competitions and such.. I'm sure they have great usage.

I understand the concept of people not recommending using them for various reasons, but I think if you set them up properly and safely then they can have much more "pro's than con's".

Probably not what you were after in explanation,.. but that's my take and personal usage of my base knob on my PPI 900 watt amp. It's one of my favorite features of the amp to be honest.

 

[bbeljefe]

To my knowledge, there are no remote bass knobs that include any sort of boost.... with the obvious exception of bass processors.

Bass knobs are indeed remote gain pots and they are enormously convenient and can save your subs, if they're properly used. How do you properly use one? You set the system with all bass contours flat, all bass boost & loudness circuits off (bass boost on the amp can be used sparingly and should be set before gain setting) and the bass knob at its maximum setting. You then set the amplifier's gain properly and after all that, you have control of your bass, a known safe maximum amount of bass and the ability to turn the bass down or off, if needed. "If needed" can include any number of situations. You might want to be courteous while driving through town. You might see a cop. You might smell coils being roasted. All of those situations call for an easy to reach knob that allows you to turn the bass down.

Also, since a lot of people listen to a variety of music genres, there is often a lot of difference in bass levels between songs. With a properly set bass knob, you'll have it set at, say, half way most of the time. When you play 70s rock, you can turn it up all the way and hear what little bass there is in that music. And then, when you pop in your favorite rap song, you can quickly turn the bass down so you don't smell coils roasting.

As for their use in competition, they allow control of the bass level in case of problems or when the source material is recorded too hot.

 

[SamIam71]

To my knowledge, there are no remote bass knobs that include any sort of boost.... with the obvious exception of bass processors.
Bass knobs are indeed remote gain pots and they are enormously convenient and can save your subs, if they're properly used. How do you properly use one? You set the system with all bass contours flat, all bass boost & loudness circuits off (bass boost on the amp can be used sparingly and should be set before gain setting) and the bass knob at its maximum setting. You then set the amplifier's gain properly and after all that, you have control of your bass, a known safe maximum amount of bass and the ability to turn the bass down or off, if needed. "If needed" can include any number of situations. You might want to be courteous while driving through town. You might see a cop. You might smell coils being roasted. All of those situations call for an easy to reach knob that allows you to turn the bass down.

Also, since a lot of people listen to a variety of music genres, there is often a lot of difference in bass levels between songs. With a properly set bass knob, you'll have it set at, say, half way most of the time. When you play 70s rock, you can turn it up all the way and hear what little bass there is in that music. And then, when you pop in your favorite rap song, you can quickly turn the bass down so you don't smell coils roasting.

As for their use in competition, they allow control of the bass level in case of problems or when the source material is recorded too hot.

Thanks, and those uses all make sense. I know there are uses for bass boost and remote gains, but so often it is said to never use them under no circumstance. Being that they have been engineered into our components for as long as I can remember, I know they must have some good use.

A question though, if they are gain controls, how will it work to to turn them all the way up, and then set the gain on the amp itself? I have seen in the literature for an amp once that when the bass knob was plugged in that the gain knob on the amp was defeated. Maybe this isn't the case for all, but either way, if they are one in the same, I don't understand how they can be up and down at once. Unless this works like the gain and volume knob on a guitar amp. That would actually make more sense as all the examples we are using here are akin to using it as a volume knob, which most everyone vehemently opposes.

I will use the one that is coming with the amp I have ordered. And, for the most part, I will use it as a volume control for the sub channel. I don't intend on abusing my subs or asking them for more than they can give in the first place.

 

[Chromatic]

You have the right attitude with it. Don't let other people tell you not to use a bass knob. I had the same thing said to me many times,.. You have to take some advice, and leave other. As long as you set it up properly,.. a bass knob is incredibly useful as I described in my former post. As I mentioned.. I maxed my bass knob (with the headunit set with flat EQ, loudness off.. and so on... just as you would/should set gains for any speaker) Then I went to the amp.. speaker wires not in.. put leads into the sub channel + and - .. on the Digital Multimeter,.. And set my gains according to the voltage for the wattage the amp was rated at for that channel (which is right at what my sub is rated at as well). In my case, iirc, it was 34.64v for 300watts RMS @ 4ohms, but I'm just powering a single JL 10" sub, nothing major.

Then, Max I know is "max" voltage. Now not to get confusing here.. but the voltage I experienced did differ depending on the frequency I used to set my gains. I used test tones. On my sub I initially used a 40hz sine wave.. I didn't like the result.. so I went back to zero on the sub channel gain.. and put on a 79hz sine wave and set the gains to that tone.. Was a much better result. Why? This isn't some universal thing that everyone should do, it just applied to my type of music. I listen to rock/alternative and so on.. Which generally has a bit higher frequency bass note going (ie: Kick drum).. as opposed to say Rap. So when I was setting my gains with the 40hz tone,.. when the 70-80hz notes played with my type of music the voltage (as I measured in real time) was HALF of what it should have been with my bass knob set to Max. I remember seeing it dropping down to 12-14v.. and not going past 15volts with the knob maxxed as I went through tons of different bands I listen to. I popped in a rap song and bam, the voltage jumped up to 30v+ ..

So for MY music,.. I needed to set my sub gains with a higher tone.. But, I also know that with lower hz tones if a rap song, or other music that may have the low notes.. that I need to adjust my bass knob down a bit because at those hz the voltages are likely going to be higher than the 34.64v I am aiming for as a "max".

If that makes zero sense.. ignore it.

Bottom line.. use your bass knob. And when dialing in gains for your sub,.. dial them in with a tone in the range of the music you MOST listen to.. or dial it in with your music. I just prefer to eliminate variables with single tone tracks, then I tweak it ever so slightly by ear after that.

@bbeljefe had a great point with dropping it down with cops, etc.. Of course you can just mute or turn your volume down,.. but with a bass knob you can just adjust it to a less "attention grabbing" level and still have a good sound coming out without having to mute or attenuate your headunit completely in such circumstances.

The bass knob just gives you more control over your sound system in my opinion. It's that simple to me.

And.. yes.. you are absolutely right, the equipment is designed to work with the bass knob,.. using one does not make your sub sound worse or any other nonsense, but it isn't a "volume" control,.. though if you understand how gains work then you can think of it as "volume" if you wish //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

have fun with your amp and setup! Hope you aren't doing what I just did .. lol.. and ripping your entire car apart and spending 40 hours building your system,.. if so buy some Advil now,.. and get ready for some beat up hands. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

My best recommendation is read, read, and read some more. Watch videos (of competent people) on any subject you are curious about, gain settings, bass knobs, amps etc.. and you will learn an incredible amount.

 

[SamIam71]

You have the right attitude with it. Don't let other people tell you not to use a bass knob. I had the same thing said to me many times,.. You have to take some advice, and leave other. As long as you set it up properly,.. a bass knob is incredibly useful as I described in my former post. As I mentioned.. I maxed my bass knob (with the headunit set with flat EQ, loudness off.. and so on... just as you would/should set gains for any speaker) Then I went to the amp.. speaker wires not in.. put leads into the sub channel + and - .. on the Digital Multimeter,.. And set my gains according to the voltage for the wattage the amp was rated at for that channel (which is right at what my sub is rated at as well). In my case, iirc, it was 34.64v for 300watts RMS @ 4ohms, but I'm just powering a single JL 10" sub, nothing major.
Then, Max I know is "max" voltage. Now not to get confusing here.. but the voltage I experienced did differ depending on the frequency I used to set my gains. I used test tones. On my sub I initially used a 40hz sine wave.. I didn't like the result.. so I went back to zero on the sub channel gain.. and put on a 79hz sine wave and set the gains to that tone.. Was a much better result. Why? This isn't some universal thing that everyone should do, it just applied to my type of music. I listen to rock/alternative and so on.. Which generally has a bit higher frequency bass note going (ie: Kick drum).. as opposed to say Rap. So when I was setting my gains with the 40hz tone,.. when the 70-80hz notes played with my type of music the voltage (as I measured in real time) was HALF of what it should have been with my bass knob set to Max. I remember seeing it dropping down to 12-14v.. and not going past 15volts with the knob maxxed as I went through tons of different bands I listen to. I popped in a rap song and bam, the voltage jumped up to 30v+ ..

So for MY music,.. I needed to set my sub gains with a higher tone.. But, I also know that with lower hz tones if a rap song, or other music that may have the low notes.. that I need to adjust my bass knob down a bit because at those hz the voltages are likely going to be higher than the 34.64v I am aiming for as a "max".

If that makes zero sense.. ignore it.

Bottom line.. use your bass knob. And when dialing in gains for your sub,.. dial them in with a tone in the range of the music you MOST listen to.. or dial it in with your music. I just prefer to eliminate variables with single tone tracks, then I tweak it ever so slightly by ear after that.

@bbeljefe had a great point with dropping it down with cops, etc.. Of course you can just mute or turn your volume down,.. but with a bass knob you can just adjust it to a less "attention grabbing" level and still have a good sound coming out without having to mute or attenuate your headunit completely in such circumstances.

The bass knob just gives you more control over your sound system in my opinion. It's that simple to me.

And.. yes.. you are absolutely right, the equipment is designed to work with the bass knob,.. using one does not make your sub sound worse or any other nonsense, but it isn't a "volume" control,.. though if you understand how gains work then you can think of it as "volume" if you wish //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

have fun with your amp and setup! Hope you aren't doing what I just did .. lol.. and ripping your entire car apart and spending 40 hours building your system,.. if so buy some Advil now,.. and get ready for some beat up hands. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

My best recommendation is read, read, and read some more. Watch videos (of competent people) on any subject you are curious about, gain settings, bass knobs, amps etc.. and you will learn an incredible amount.

Well said friend. I already knew how I would use the knob, which is how I have always used them. The topic needs some discussion here, or so I think, because it has seemed to to become purely an almost archaic and generic response for people to just say never use them. Many of us will use them, so I think it is better to talk about how to do so properly.

Remember, if we don't talk to our kids about bass knobs, someone else will.

 

[SamIam71]

Chromatic, what area of the 'Ham are you from? I am in Upstate New York right now with 10th Mountain Warfare, but Birmingham is home. Actually, I am from Moody, but when referencing a hometown in Alabama, we tend to claim to be from Huntsville, Birmingham, or Mobile, as all other locations are too obscure for most to have heard of.

 

[RoYALbLUE08 10+ year member]

i have 2 bass knobs one for my sub and one for my speakers best thing ever because some songs sound like crap so you turn down the knob...

 

[SamIam71]

i have 2 bass knobs one for my sub and one for my speakers best thing ever because some songs sound like crap so you turn down the knob...

That would make for a nice set up man. I bet it makes it easy to match up volume levels of music and bass from track to track.

 

[bbeljefe]

You have the right attitude with it. Don't let other people tell you not to use a bass knob. I had the same thing said to me many times,.. You have to take some advice, and leave other. As long as you set it up properly,.. a bass knob is incredibly useful as I described in my former post. As I mentioned.. I maxed my bass knob (with the headunit set with flat EQ, loudness off.. and so on... just as you would/should set gains for any speaker) Then I went to the amp.. speaker wires not in.. put leads into the sub channel + and - .. on the Digital Multimeter,.. And set my gains according to the voltage for the wattage the amp was rated at for that channel (which is right at what my sub is rated at as well). In my case, iirc, it was 34.64v for 300watts RMS @ 4ohms, but I'm just powering a single JL 10" sub, nothing major.
Then, Max I know is "max" voltage. Now not to get confusing here.. but the voltage I experienced did differ depending on the frequency I used to set my gains. I used test tones. On my sub I initially used a 40hz sine wave.. I didn't like the result.. so I went back to zero on the sub channel gain.. and put on a 79hz sine wave and set the gains to that tone.. Was a much better result. Why? This isn't some universal thing that everyone should do, it just applied to my type of music. I listen to rock/alternative and so on.. Which generally has a bit higher frequency bass note going (ie: Kick drum).. as opposed to say Rap. So when I was setting my gains with the 40hz tone,.. when the 70-80hz notes played with my type of music the voltage (as I measured in real time) was HALF of what it should have been with my bass knob set to Max. I remember seeing it dropping down to 12-14v.. and not going past 15volts with the knob maxxed as I went through tons of different bands I listen to. I popped in a rap song and bam, the voltage jumped up to 30v+.

Ahhh. Now I know why your amp got so hot.

Movies have a shite ton of low frequency information in them and even though you probably turned the bass knob down, you very likely clipping the sub for two hours. This is the reason why it's important to set the gain on a subwoofer amp with a 40 Hz tone and a scope or distortion detector.

Imma beat a dead horse here but.... the gain on your amp is not a "set to my music" device. It's a sensitivity matching device and it's there to make sure your amp and head unit are set so there is (virtually) never a clipped signal being created by the amplifier. By setting it the way you did, there is only one way to ensure that you never clip your signal and that way would be using a scope or distortion detector to find out exactly how far down you must turn the bass knob in order to match the amplifier's sensitivity with the source.

Now with all that said, I'm not saying you're going to be roasting coils on a regular basis but, it's important to note that your gain is not correctly set and if you leave it that way you will be clipping your sub more often than you may think.

In the end, if the system is properly set up and there's just not enough bass... you can't simply fool mother nature and set it by a different method. ;-)

 

[SamIam71]

Ahhh. Now I know why your amp got so hot.
Movies have a shite ton of low frequency information in them and even though you probably turned the bass knob down, you very likely clipping the sub for two hours. This is the reason why it's important to set the gain on a subwoofer amp with a 40 Hz tone and a scope or distortion detector.

Imma beat a dead horse here but.... the gain on your amp is not a "set to my music" device. It's a sensitivity matching device and it's there to make sure your amp and head unit are set so there is (virtually) never a clipped signal being created by the amplifier. By setting it the way you did, there is only one way to ensure that you never clip your signal and that way would be using a scope or distortion detector to find out exactly how far down you must turn the bass knob in order to match the amplifier's sensitivity with the source.

Now with all that said, I'm not saying you're going to be roasting coils on a regular basis but, it's important to note that your gain is not correctly set and if you leave it that way you will be clipping your sub more often than you may think.

In the end, if the system is properly set up and there's just not enough bass... you can't simply fool mother nature and set it by a different method. ;-)

But, you just said it is a "Set to my music device" . "

Also, since a lot of people listen to a variety of music genres, there is often a lot of difference in bass levels between songs. With a properly set bass knob, you'll have it set at, say, half way most of the time. When you play 70s rock, you can turn it up all the way and hear what little bass there is in that music. And then, when you pop in your favorite rap song, you can quickly turn the bass down so you don't smell coils roasting"

 

[RoYALbLUE08 10+ year member]

That would make for a nice set up man. I bet it makes it easy to match up volume levels of music and bass from track to track.

its awesome... i use it ALL the time depending on the song. heres how my setup looks, the 2 blue dots on the bottom are my crescendo bass knobs

 

[bbeljefe]

But, you just said it is a "Set to my music device" . "Also, since a lot of people listen to a variety of music genres, there is often a lot of difference in bass levels between songs. With a properly set bass knob, you'll have it set at, say, half way most of the time. When you play 70s rock, you can turn it up all the way and hear what little bass there is in that music. And then, when you pop in your favorite rap song, you can quickly turn the bass down so you don't smell coils roasting"

No I didn't. I was talking about the bass knob in the quote you provided and I was talking about the gain on the amp when I was addressing Chromatic. I understand that physically they are the same device and they do the same thing but they serve distinctly different purposes in this case.

The gain is used to set the maximum gain the amplifier will attempt and the bass knob serves to attenuate the signal... not limit it.

 

[d77543020 10+ year member]

there are gain knobs(harmless) and bass boost knobs(i would not use) depends on your amp and the reason i use them and will continue to use them is for them COPS

 

[Chromatic]

Remember, if we don't talk to our kids about bass knobs, someone else will.

lol! //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif