I have a subwoofer hooked up to my hifi system and I’m sure that there is a delay between the bass and the rest of the music. The bass always comes in a little bit late. The signal to the sub amp panel comes from the speaker outputs of my stereo amp and into the bass amps high level input.
Could this be causing the delay?
I don’t have a phono o/p on my amplifier, this is why I’m using the high level signal. Could I use the headphone o/p of my amp to feed the signal to the sub amp panel?
Any help will be appreciated
Thanks in advance
Could this be causing the delay?
I don’t have a phono o/p on my amplifier, this is why I’m using the high level signal. Could I use the headphone o/p of my amp to feed the signal to the sub amp panel?
Any help will be appreciated
Thanks in advance
Based on the fact that the signal to your sub is travelling at about .7 X speed of light there is no audible electronically derived delay. In fact, for frequencies below 80 Hz the notion of any delay problem is questionable. The human ear can detect quite easily time align differences of as little as 2 msec. in the midrange, but that ability does not exist in the lowermost frequencies. The same biological function that allows us to hear time align anomalies also allows us to localize the direction of sound sources. Frequencies too low to be directionally localized are also too low for time align differentials to be perceived.
As an example, I work at a 6,000 seat amphitheatre that has auxiliary speakers some 300 feet from the stage; they are time aligned with the main clusters at the stage, and operate from 80 Hz; below that all information comes from the sub clusters at the stage. Despite the 300 foot / .26 second differential there is no audible lag in the sub-bass.
As an example, I work at a 6,000 seat amphitheatre that has auxiliary speakers some 300 feet from the stage; they are time aligned with the main clusters at the stage, and operate from 80 Hz; below that all information comes from the sub clusters at the stage. Despite the 300 foot / .26 second differential there is no audible lag in the sub-bass.
(sorry for my english)
Best sub-amp module must have phase control infinitely adjustment between 0-180°. If your have not, reverse polarity of sub ( or sat).
Sometimes works!
Also, change the low pass frequency (maybe too high?) and readjust the sub level.
Maybe the order of your low pass filter is not ok for your sat.
Perfect integration sub-sat is not symply
Hi!
Best sub-amp module must have phase control infinitely adjustment between 0-180°. If your have not, reverse polarity of sub ( or sat).
Sometimes works!
Also, change the low pass frequency (maybe too high?) and readjust the sub level.
Maybe the order of your low pass filter is not ok for your sat.
Perfect integration sub-sat is not symply
Hi!
I have a continuously variable phase control (0-180deg), I will play about with this when I get home tonight. My crossover is set at 60/70Hz so, from what blitz has said I couldn't possibly here a delay due to the time it takes for the wave to travel to my ears (especially since I am 2 meters away from my sub). The fact that I'm using the high level i/p instead of the low level i/p should give no delay either because blitz stated that the signal travels at 0.7 x speed of light.
Are there any other ways this delay could have been caused?
Thanks for all of the valuable feedback.
Are there any other ways this delay could have been caused?
Thanks for all of the valuable feedback.
Member
Joined 2003
(sorry for my english)mart34 said:
I don't understand very well , anyway :
time delay = phase shift ( approximately, for simplicity
) Your sat is filtered or not? You sum natural high-pass of the sat with
electrical high-pass of the module-amp and obtain the real high- pass function of your sat. This is the target for the total low-pass of the sub.
Same frequency, same order. Then you start your job. If these condition are not obtained is normal you can here "strange bass" .
Are you surprise?
Hi!
How about the inertia of the driver vs. amp strength?
In theory, if we send a 3kHz sine wave to a mid driver and 300Hz to a woofer simultaneously, then the mid will cycle 10 times the woofer in one sec.
But, it is the (lack of) acceleration of the woofer that concerns me. Since most signals are not sinus and peaks are often very short, any particular sound may only last of 2 or 3 cycles. So the massive woofer will be slower to respond to the signal than a smaller driver.
I cannot give the math, but I tried this with mains (6.5") on top of the sub (10") to make the distance to ear and the room reflections almost the same for each driver. The sub blurs the low note attacks and low notes are more crisp without the sub.
ensen.
PS: It could be the sub, but I also tried by listening at low volume to minimze room and distance <1m to minimize delay and still the same effect.
In theory, if we send a 3kHz sine wave to a mid driver and 300Hz to a woofer simultaneously, then the mid will cycle 10 times the woofer in one sec.
But, it is the (lack of) acceleration of the woofer that concerns me. Since most signals are not sinus and peaks are often very short, any particular sound may only last of 2 or 3 cycles. So the massive woofer will be slower to respond to the signal than a smaller driver.
I cannot give the math, but I tried this with mains (6.5") on top of the sub (10") to make the distance to ear and the room reflections almost the same for each driver. The sub blurs the low note attacks and low notes are more crisp without the sub.
ensen.PS: It could be the sub, but I also tried by listening at low volume to minimze room and distance <1m to minimize delay and still the same effect.
ensen, here's a fun experiment for you to try which will make the issue of woofer "speed" and the relationships of the Fourier transform. Generate the tone burst you're talking about. Use, say, a 300 hertz sine wave set for 3 or 4 cycles width. Run that through a low pass and high pass filter (use first-order filters if you like so that their sum is "transient perfect") and look at the resulting waveforms.
Hi SY,
It is important to admit that I didn't do my experiment with a waveform generator, just some bass heavy music and swapped the sub with the stand and listened close. Not only are there no measurements and the opinions wholly subjective, but I'm sure there are also psycho-acoustic factors affecting the "results."
The test you proposed seems much like harmonics math. As I've said before, I no longer have the math for it, but my grasp of the theory is that a 300Hz sine will produce harmonics at 600Hz, 1200Hz, 2.4kHz etc... and these are limited by the X-over filters for each driver (not to say that another driver will not deliver the rest, but that any given driver is limited).
Are you saying that adding a sub is both good and bad? Good in that you get lower frequencies and bad since it also reproduces the harmonics that normally get delivered by the midwoofer.
ensen.
It is important to admit that I didn't do my experiment with a waveform generator, just some bass heavy music and swapped the sub with the stand and listened close. Not only are there no measurements and the opinions wholly subjective, but I'm sure there are also psycho-acoustic factors affecting the "results."
The test you proposed seems much like harmonics math. As I've said before, I no longer have the math for it, but my grasp of the theory is that a 300Hz sine will produce harmonics at 600Hz, 1200Hz, 2.4kHz etc... and these are limited by the X-over filters for each driver (not to say that another driver will not deliver the rest, but that any given driver is limited).
Are you saying that adding a sub is both good and bad? Good in that you get lower frequencies and bad since it also reproduces the harmonics that normally get delivered by the midwoofer.
ensen.
Perhaps groupdelay (GD) is the problem as others have noted. Apart from the subwoofer, the crossover also introduces GD. A steep transferfunction and low crossoverfreq. means high GD; of which order is your crossover?
If GD is the problem I guess you have a ported box. The sharp knee in the frequency response of a ported box give a higer GD than a closed box. But if you're not willing to reconstruct the sub there isn't much to do about it.
Groupdelay is usually not a big problem even i ported boxes, but one should consider it when constructing the box. As noted the audiability of GD depends on the frequency, a guideline might be that the GD shouldn't exceed 1/f in seconds (including GD introduced by crossover, and distance between front speakers and sub).
If GD is the problem I guess you have a ported box. The sharp knee in the frequency response of a ported box give a higer GD than a closed box. But if you're not willing to reconstruct the sub there isn't much to do about it.
Groupdelay is usually not a big problem even i ported boxes, but one should consider it when constructing the box. As noted the audiability of GD depends on the frequency, a guideline might be that the GD shouldn't exceed 1/f in seconds (including GD introduced by crossover, and distance between front speakers and sub).
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