Subwoofer no output at low input volume

Thread Starter

edgar peace

Joined Nov 28, 2018
21
I just bought a konzert ks12 subwoofer (300 watts). Sounds great at moderately loud to loud input from my yamaha receiver sub out or even if connected parallel to my main speaker ("from amp" input).
But if i'm listening at low volume, the subwoofer does not produce any sound. I have to crank up the volume to get an output and even so after a while of no low frequency output from the receiver, the sub out stops.
My receiver setting if using sub out is small front speakers and subwoofer use, and if using parallel to main speaker my setting is large and subwoofer none.
I think my sub needs a high enough input to drive it, but at nights i like to listen at low volume but can still hear the sub out. Any way i can get it to produce an output at low volume?
Merry Christmas and A Happy Covid-free 2022!!!
 

MisterBill2

Joined Jan 23, 2018
11,556
I am not familiar with either of those products, my subwoofer is a different brand. What is unclear to me is if you are using a speaker output to drive it, or a dedicated line-level signal output.
In addition, there may be crossover frequency settings that need to be adjusted. On my unit that makes a big difference.
 

ElectricSpidey

Joined Dec 2, 2017
2,140
My first guess would be...if it is actually 300 watts that because it takes some good power to move the cone on a high power speaker, that may be where the problem is. (it's probably not actually 300 watts)

If you enjoy listening to music at lower volume levels, you may want to consider a lower wattage sub.

If the sub is crapping out at higher volume levels as well it may be defective, or just a poor quality unit.

One workaround could be having 2 different EQ settings...one for day and one for night.
 
Last edited:

MisterBill2

Joined Jan 23, 2018
11,556
Even if the amp were actually only 30 watts, that would be plenty for low level listening, so that does not seem like it would be the problem, especially since it is satisfactory at higher volume levels. I have used a receiver that has a "night" mode and that does reduce the bass volume more than the middle range. It also reduces the dynamics, and so it might possibly be that the change is designed into the amplifier. I suggest reading the users guide for the amp if you have it. Some features are not what we like, I have discovered.
 

Audioguru again

Joined Oct 21, 2019
4,523
I heard a demo of the sub-woofer and it played ordinary bass that I can sing, not deep sub-woofer frequencies. It might not produce sounds below 60Hz and we can hear down to 20Hz.

The Konzert manufacturer has NO detailed audio specs for the subwoofer. They say 300W that could be horribly clipping and distorted peak Whats and it might produce only 100 low distortion real Watts continuously at all very low frequencies.
They do not say its frequency response or say how much the response reduces at low frequencies.

High power speakers are not made with reduced sensitivity, but our hearing has the Fetcher-Munson frequency response curve which shows that our hearing is not sensitive to low frequencies at low sound levels. That is why many amplifiers have a "loudness bass boost" switch. I rarely have very loud blasting music at home so I use the loudness bass-boost switch almost all the time so that I can hear very low bass frequencies. The loudness switch also boosts high frequencies a little as shown on the Fletcher-Munson curve.

@ElectricSpidey:
1) A high power speaker has the same or higher sensitivity as a lower wattage sub or speaker.
2) It is normal for our hearing to have less sensitivity to low frequencies at low levels.
3) Many "loudness" switches allow variable bass boost so there is a lot of boost when the volume control is turned down and less bass boost when the volume control is turned up. Then the sound is correct at any loudness.
 

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MisterBill2

Joined Jan 23, 2018
11,556
I heard a demo of the sub-woofer and it played ordinary bass that I can sing, not deep sub-woofer frequencies. It might not produce sounds below 60Hz and we can hear down to 20Hz.

The Konzert manufacturer has NO detailed audio specs for the subwoofer. They say 300W that could be horribly clipping and distorted peak Whats and it might produce only 100 low distortion real Watts continuously at all very low frequencies.
They do not say its frequency response or say how much the response reduces at low frequencies.

High power speakers are not made with reduced sensitivity, but our hearing has the Fetcher-Munson frequency response curve which shows that our hearing is not sensitive to low frequencies at low sound levels. That is why many amplifiers have a "loudness bass boost" switch. I rarely have very loud blasting music at home so I use the loudness bass-boost switch almost all the time so that I can hear very low bass frequencies. The loudness switch also boosts high frequencies a little as shown on the Fletcher-Munson curve.

@ElectricSpidey:
1) A high power speaker has the same or higher sensitivity as a lower wattage sub or speaker.
2) It is normal for our hearing to have less sensitivity to low frequencies at low levels.
3) Many "loudness" switches allow variable bass boost so there is a lot of boost when the volume control is turned down and less bass boost when the volume control is turned up. Then the sound is correct at any loudness.
TRUE, all the above! On some amplifiers the power rating is stated as being at 10% distortion, which is, to put it bluntly, "BAD".
 

Audioguru again

Joined Oct 21, 2019
4,523
TRUE, all the above! On some amplifiers the power rating is stated as being at 10% distortion, which is, to put it bluntly, "BAD".
In addition to saying the power with lots of distortion making the power number falsely higher:
Peak or Maximum power is frequently said for cheap amplifiers. It is simply double the real power.
Some amplifiers are rated for "music power" that is only momentary power before the power supply voltage sags.
They say the power at only one frequency instead of the entire audio band of frequencies.
Then peak music power is really no power when it has low distortion.
 

Thread Starter

edgar peace

Joined Nov 28, 2018
21
How about inserting a preamp between the receiver subw out and subwoofer low level input? I have one unused preamp but i don't know its frequency response at subwoofer frrquencies. Will just have to control the subwoofer main volume level.
Using 100 watts power out of max 300w at good enough fidelity for the ordinary human ear is achievable with this subwoofer as i tested. But at nights, i still want to hear some of the LF that the sub can output.
 

Audioguru again

Joined Oct 21, 2019
4,523
I also have an old Yamaha receiver that has a "loudness" variable control that can be set to enough bass boost for the speakers sensitivity and their distance from you. It also has a "bass extension" switch for more bass boost.

I do not understand whey the very expensive ($1255 US) powered subwoofer has absolutely NO detailed audio specs and why the demo I heard produced ordinary bass and not sub-bass

I listened to two more demo videos that played "Hindi" sounds that have a one-note-bass drum and are very different to the music over here.
 

crutschow

Joined Mar 14, 2008
29,466
Are you sure it is outputting absolute no sound a at low level?

The sub may have a circuit that turns it off when there is no signal, but it may not be sensitive enough to keep the sub on at low power levels.
 

k1ng 1337

Joined Sep 11, 2020
413
I heard a demo of the sub-woofer and it played ordinary bass that I can sing, not deep sub-woofer frequencies. It might not produce sounds below 60Hz and we can hear down to 20Hz.

The Konzert manufacturer has NO detailed audio specs for the subwoofer. They say 300W that could be horribly clipping and distorted peak Whats and it might produce only 100 low distortion real Watts continuously at all very low frequencies.
They do not say its frequency response or say how much the response reduces at low frequencies.

High power speakers are not made with reduced sensitivity, but our hearing has the Fetcher-Munson frequency response curve which shows that our hearing is not sensitive to low frequencies at low sound levels. That is why many amplifiers have a "loudness bass boost" switch. I rarely have very loud blasting music at home so I use the loudness bass-boost switch almost all the time so that I can hear very low bass frequencies. The loudness switch also boosts high frequencies a little as shown on the Fletcher-Munson curve.

@ElectricSpidey:
1) A high power speaker has the same or higher sensitivity as a lower wattage sub or speaker.
2) It is normal for our hearing to have less sensitivity to low frequencies at low levels.
3) Many "loudness" switches allow variable bass boost so there is a lot of boost when the volume control is turned down and less bass boost when the volume control is turned up. Then the sound is correct at any loudness.
I have experienced this Fletcher-Munson effect many times with analog guitar pedals (phaser, flange, chorus) and Low Frequency Oscillators in FL Studio with digital music. It really it quite the phenomenon as the sound seems to disappear. For TS I would suggest a basic equalizer stage and it's placement in the chain can yield interesting effects.
 

MisterBill2

Joined Jan 23, 2018
11,556
One very simple "cheating trick" to see if there is any bass being produced when yo don't hear it would be to gently put your fingers on the speaker cone and see if you feel the vibration. Very simple and usually easy, unless the speaker part is one of the glued together packages that is intentionally made so that it can not be repaired. It is quite possible that below some sound level the bass is not audible.
 

Thread Starter

edgar peace

Joined Nov 28, 2018
21
Thanks for all the suggestions. I' m happy now that I have the solution to this: an old cheap preamp did the trick. The subwoofer out from yamaha receiver was preamped above the level needed to drive the subw. I then controlled the subw main volume level to my ear's satisfaction. I tried it for several hours and the subwoofer is working great.
Thanks and happy new year!
 
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