I agree it does no harm to have a try. Jeroen seemed to find a benefit in his Cessaro system.
Zero Distortion: Tango Time
- Thread starter bonzo75
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I agree it does no harm to have a try. Jeroen seemed to find a benefit in his Cessaro system.
I believe he said that even though they were "closer" ie perimeter of basshorn cabinet closer to listener, the basshorn drivers were still 5m from the listener, the same as the main horn drivers.
Theoretically (and no theory is perfect, aside from belief in God), how is time alignment of bass horns supposed to work? Let’s say they play from 30 Hz to 85 Hz in Tang’s case, then roll-off at 3rd order (acoustically).
Mid-bass horn plays down to 125 Hz or so and then rolls-off pretty fast (have not seen specific measurements as how fast, though).
What does movement of the bass horns back or front +/- 1 meter aims to achieve?
What one does have to measure to know he is doing the right thing (and measurement at these frequencies is pretty hard)?
Remember, we are not searching to reduce the room nodes’ impact (which are not 30-85 Hz wide but rather narrow) by this method...
Mid-bass horn plays down to 125 Hz or so and then rolls-off pretty fast (have not seen specific measurements as how fast, though).
What does movement of the bass horns back or front +/- 1 meter aims to achieve?
What one does have to measure to know he is doing the right thing (and measurement at these frequencies is pretty hard)?
Remember, we are not searching to reduce the room nodes’ impact (which are not 30-85 Hz wide but rather narrow) by this method...
There is a concept of “locking-in” the room in subwoofer placement - but this concept means that you try to find a place where the subwoofer stops to excite any of the specific room modes - thus the bass response becomes generally even and thus “tight” and “punchy”
But this has nothing to do with time alignment (i.e. launching the bass wave at instantaneously the same moment in time/space the other speakers fire)
But this has nothing to do with time alignment (i.e. launching the bass wave at instantaneously the same moment in time/space the other speakers fire)
Not in my case. I am running separate L/R preamp outputs to L/R sub bass amplifiers.
Ralph mentioned it is important to keep the “mouths” together for the bass waves to continue their way out of the horn smoothly and not break up - this might be - I am just speculating now! - the reason for Jeroen’s dissatisfaction with his initial bass horns placement - as he left a space in-between the left and right horn for the equipment rack
Ralph mentioned it is important to keep the “mouths” together for the bass waves to continue their way out of the horn smoothly and not break up - this might be - I am just speculating now! - the reason for Jeroen’s dissatisfaction with his initial bass horns placement - as he left a space in-between the left and right horn for the equipment rack
VladB, first "time alignment" is mostly nonsense in itself. What matters is wave propagation, how it affects phase, power response, and lobing. What is more accurate would be wavelength alignment. You need drivers that cross at a frequency to be within a wavelengths distance for where they cross. If they are not then they will sound like different sources even if phase and comb filtering aren't a problem.
Here's a calculator I like to use for figuring out wavelengths (you have to get the settings right).
Punch in those low frequencies and you'll see you actually have a lot of distance that you can use. The distance is from cone to cone so you lose a little just by having the drivers not being right next to each other.
Here's a calculator I like to use for figuring out wavelengths (you have to get the settings right).
Punch in those low frequencies and you'll see you actually have a lot of distance that you can use. The distance is from cone to cone so you lose a little just by having the drivers not being right next to each other.
Group delay of bass frequencies has been examined over the years , KEF presented some studies they did back in 1985 as to the audibility of group delay at AES in the frequency 50 to 100hz
several others have examined this with similar results
like everything with hearing there is a threshold where it becomes evident , and is probably more obvious with transients than steady state sounds
the analog to orchestra is not accurate and in fact invalid, as it fails to take into account the adaption of the players to compensate for the significant delays
as a former orchestra trumpet player , whom always sit in the back rows, I was acutely aware I had to come in ahead of the baton beat to be in time , after a while this becomes instinctual but varies in different venues
to quote from a PhD thesis on this very issue, https://www.researchgate.net/public...cs_for_symphony_orchestras_-_just_black_magic
which points out the problem, of delay which can be excessive
there is some tolerance as a listener to these delays from the Haas effect and then cocktail party effect
there is also a good discussion on ASR about this very issue of audibility of bass group delay
https://www.audiosciencereview.com/...ility-of-group-delay-at-low-frequencies.8571/
The subjective relevance of the within-orchestra sound levels and delays
The musicians need to take into account the synchronicity of sound as heard by the audience. Players at the back of
the stage normally need to compensate for their sound being physically delayed relative to the players at the front
part of the stage. Players sitting across the stage must start their note at the same time; otherwise the sound will not
arrive synchronised for the audience. The distance between players across the stage leads to significant delay of
the direct sound mutually between these players – approximately 3 ms delay is added per 1 m propagated. If the
players wait for each other based on what they hear, the orchestra risks slowing down the tempo. Visual
communication between each other and with the conductor will therefore be essential to keep synchronicity across
the stage. The maximum delay of direct that could be experienced within a symphony orchestra will be
approximately 60 ms. This corresponds with a maximum distance between players equal to approximately 21 m
(diagonally across a 16 m wide and 12 m deep orchestra.
If the delay of direct sound from different players is consistent the players appear to be able to adapt to the delay of
sound from instruments across the stage. It appears likely that orchestral players are able to adapt to (more or less
subconsciously) and not get rhythmically disturbed by delays of the direct sound within approximately 60 ms, which
is the approximate maximum delay they will experience. This would imply that any sound events within 60 ms may
be perceived as the ‘direct’ or the ‘immediate’ orchestra sound among the players. But the different delays from
different instrument groups can contribute to perceptual temporal masking, where the sound from the instruments
that arrives first contribute to make later arriving sound inaudible. Such an effect appears difficult to adapt to and
overcome, since the masking effects origins much from the biological construction of our auditory system.
several others have examined this with similar results
like everything with hearing there is a threshold where it becomes evident , and is probably more obvious with transients than steady state sounds
the analog to orchestra is not accurate and in fact invalid, as it fails to take into account the adaption of the players to compensate for the significant delays
as a former orchestra trumpet player , whom always sit in the back rows, I was acutely aware I had to come in ahead of the baton beat to be in time , after a while this becomes instinctual but varies in different venues
to quote from a PhD thesis on this very issue, https://www.researchgate.net/public...cs_for_symphony_orchestras_-_just_black_magic
which points out the problem, of delay which can be excessive
there is some tolerance as a listener to these delays from the Haas effect and then cocktail party effect
there is also a good discussion on ASR about this very issue of audibility of bass group delay
https://www.audiosciencereview.com/...ility-of-group-delay-at-low-frequencies.8571/
The subjective relevance of the within-orchestra sound levels and delays
The musicians need to take into account the synchronicity of sound as heard by the audience. Players at the back of
the stage normally need to compensate for their sound being physically delayed relative to the players at the front
part of the stage. Players sitting across the stage must start their note at the same time; otherwise the sound will not
arrive synchronised for the audience. The distance between players across the stage leads to significant delay of
the direct sound mutually between these players – approximately 3 ms delay is added per 1 m propagated. If the
players wait for each other based on what they hear, the orchestra risks slowing down the tempo. Visual
communication between each other and with the conductor will therefore be essential to keep synchronicity across
the stage. The maximum delay of direct that could be experienced within a symphony orchestra will be
approximately 60 ms. This corresponds with a maximum distance between players equal to approximately 21 m
(diagonally across a 16 m wide and 12 m deep orchestra.
If the delay of direct sound from different players is consistent the players appear to be able to adapt to the delay of
sound from instruments across the stage. It appears likely that orchestral players are able to adapt to (more or less
subconsciously) and not get rhythmically disturbed by delays of the direct sound within approximately 60 ms, which
is the approximate maximum delay they will experience. This would imply that any sound events within 60 ms may
be perceived as the ‘direct’ or the ‘immediate’ orchestra sound among the players. But the different delays from
different instrument groups can contribute to perceptual temporal masking, where the sound from the instruments
that arrives first contribute to make later arriving sound inaudible. Such an effect appears difficult to adapt to and
overcome, since the masking effects origins much from the biological construction of our auditory system.
The first thing I learned here is you don’t know what group delay is if you think distances at an orchestra is part of group delay. (Or even about subwoofer distance)
The second is that within 60ft everything sounds in sync, but that is a fairly poor indicator for a stereo since you’re judging tempo and rhythm of separate instruments as oppose to drivers playing the same instrument.
I think what you are saying is nonsense.
For sure in relation to what is discussed in this topic, the distance listening position to mainspeaker and to basshorn.
I only agree with the above theory when it's on the vertical ax or to the side with still the same Listeningposition to speaker distance, e.g. in a MTM speaker where there are e.g. two mids above eachother with a tweeter inbetween.
Really ? So a woofer can be 1 or 2 feet behind (or before) a midrange when crossed at 500hz, with no audible effect to you ? Or a mid 2 inch (~5cm) behind the tweeter when crossed at 5000hz ?
Just 2mm difference tweeter to mid is very audible to me (and to many).
To time align all drivers mechanically in many Cessaro speakers (and Wilsons e.g.) makes a huge difference (to me). It is very audible when you adjust it. Just my 2 cents.
mechanical time alignment is extremely critical in my DIY horn system as well
Jeroen, hi!
You have a really unique experience with setting up your Zeta system, in particular in light of an even lower cross-over point for your bass horns than either Tang or me have in our Gammas.
Could you please share your story with regard to original sub horns placement and the way you found the final placement on the sides of your room? I read your system thread where you said that It was a very audible effect as if two different systems were playing ..
Did you aim to achieve just the same physical distance between your listening point and the mains and the speakers inside the bass horns when you moved them to the side walls?
Did you adjust the phase on the bass amps at the initial horn location and still no setting of the phase helped?
Did Ralph support the idea of such a radical change in placement? With my system he was quite insistent on keeping the Left and Right bass horns joint in the middle to keep their horn character and not turn them into direct radiators...
You have a really unique experience with setting up your Zeta system, in particular in light of an even lower cross-over point for your bass horns than either Tang or me have in our Gammas.
Could you please share your story with regard to original sub horns placement and the way you found the final placement on the sides of your room? I read your system thread where you said that It was a very audible effect as if two different systems were playing ..
Did you aim to achieve just the same physical distance between your listening point and the mains and the speakers inside the bass horns when you moved them to the side walls?
Did you adjust the phase on the bass amps at the initial horn location and still no setting of the phase helped?
Did Ralph support the idea of such a radical change in placement? With my system he was quite insistent on keeping the Left and Right bass horns joint in the middle to keep their horn character and not turn them into direct radiators...
Yes, not the main towers. The main towers position perfect as is. I did try moving the bass horns in/out +/- 0.5 meter given limited space I have, it did not yield tangible delta. May be +/- 1 meter or more would be different. In my room the cut point and slope are most crucial to get the music that plays as if it was not generate from the physically intimidating bass horns and main towers. You cut yours at 115 Hz and from the video sounded great. I cut mine at 85Hz. Don't know where Audioquattr cut his. Funny three almost similar speakers but each work at different setting. In the end, it could be just because we have different pair of ears.
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What do you mean by active? There is a 1000 watt amp in each main speaker tower that power each side of bass horn.
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