Van Zyl BB10 Horn Subwoofer
- Thread starter Kingrex
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Great session with the designer Johan. Deep knowledge on horn design. He talked a whole lot about philosophy and design. Why horn subs are superior to a cone in a box.
On a simple level, as I understand, a horn woofer excells as it has high impulse power and speed. The BB10 is 106 db efficient. The driver excursion is very small to get the same volume of sound compared to a low efficiency driver in a box. He explained it like this. You have a 10lb weight in one hand. Your arms are wide apart. How much effort and how quickly can you move that weight from on extended arm over to the other arm and back again. Now do that again but hold your hands 5 inches apart. Its much easier and much quicker. Same with a horn assisited driver. The cone hardly has to move and the ability to stop it and reverse its direction is small. That is why so many subs fail. Why you hear people say they can't get them to work. They are slow, and bloated. To try and make them work, they build large line arrays of stacked subs and use thousands of watts of power. They are trying to use surface area and power to reduce the amount of excursion needed to move air. But you still have bass that is heavy with overhang. It may go to 20 hertz. But is it a good 20 hertz bass.
With a horn, Its fast, tight, natural and keeps up with the main speakers. As such, its been easy for me to sit with the amp in my lap and dial it in by ear. Its easy to have all the bass I need with a single 10 inch driver.
On a simple level, as I understand, a horn woofer excells as it has high impulse power and speed. The BB10 is 106 db efficient. The driver excursion is very small to get the same volume of sound compared to a low efficiency driver in a box. He explained it like this. You have a 10lb weight in one hand. Your arms are wide apart. How much effort and how quickly can you move that weight from on extended arm over to the other arm and back again. Now do that again but hold your hands 5 inches apart. Its much easier and much quicker. Same with a horn assisited driver. The cone hardly has to move and the ability to stop it and reverse its direction is small. That is why so many subs fail. Why you hear people say they can't get them to work. They are slow, and bloated. To try and make them work, they build large line arrays of stacked subs and use thousands of watts of power. They are trying to use surface area and power to reduce the amount of excursion needed to move air. But you still have bass that is heavy with overhang. It may go to 20 hertz. But is it a good 20 hertz bass.
With a horn, Its fast, tight, natural and keeps up with the main speakers. As such, its been easy for me to sit with the amp in my lap and dial it in by ear. Its easy to have all the bass I need with a single 10 inch driver.
OK but you do realize that the period for 30 hz in mil seconds doesn't ever change. So you can not play it faster without increasing the frequency. All speakers all sizes are locked into this same periodic time domain.
There is no fast bass. You will get excursion differences they are still moving at the same rate per cycle. Just covering a larger distance.
Rob
There is no fast bass. You will get excursion differences they are still moving at the same rate per cycle. Just covering a larger distance.
Rob
What we did today was run Audio Tools sofware. We recorded pink noise and dialed in on 30 to 120 hertz. With the data we went into the eq and pulled a little hump at about 61 hertz down.
At this time, I can't tell the sub is behind me doing work. Not until I pull the interconnect. As soon as I do the bottom end falls away leaving a less than satisfying level of enjoyment. As soon as you plug the interconnect back in, it jumps back to a fully fleshed out, well weighted performance.
And I don't fully get why, but its like the entire system feels like its running on thousands of watts of power now. Nothing changed on the main speakers. Still a pair of KT88 in PP. 40 watts. But OMG. It feels like anothet 400 has been added. FWIW, Scott Sheaffer with Found Music should be a world renowned amp builder. My Blade amps slaughtered my Dartzeel. With the addition of the BB10 sub, my stereo has amazing resolution, body, drive. Its got it all. Look at this amp. This is a single 40 watt, transformer coupled, differential design PP KT88 amp. 78 lbs. Serious amounts of steel and stainless as well as mammoth Monolith Iron. You can't get a better amplifier if your running a 92db efficient speaker.
The BB10 is an amazing suwoofer. Best sub I can imagine. I'm close to done. What I do need to mess with is a peak at about 8kh to 10kh. It may be my horn tweeter. I need to run the pink noise again and pull the wire to the horn tweeter and see what that does. If that eliminateis the hump, I should only need to adjust a resistor to the tweeter.
And of course I need to rebuild the electrical to the house and the room. Also make some changes to the space such as removing the wall to carpet and putting cork floors in.
At this time, I can't tell the sub is behind me doing work. Not until I pull the interconnect. As soon as I do the bottom end falls away leaving a less than satisfying level of enjoyment. As soon as you plug the interconnect back in, it jumps back to a fully fleshed out, well weighted performance.
And I don't fully get why, but its like the entire system feels like its running on thousands of watts of power now. Nothing changed on the main speakers. Still a pair of KT88 in PP. 40 watts. But OMG. It feels like anothet 400 has been added. FWIW, Scott Sheaffer with Found Music should be a world renowned amp builder. My Blade amps slaughtered my Dartzeel. With the addition of the BB10 sub, my stereo has amazing resolution, body, drive. Its got it all. Look at this amp. This is a single 40 watt, transformer coupled, differential design PP KT88 amp. 78 lbs. Serious amounts of steel and stainless as well as mammoth Monolith Iron. You can't get a better amplifier if your running a 92db efficient speaker.
The BB10 is an amazing suwoofer. Best sub I can imagine. I'm close to done. What I do need to mess with is a peak at about 8kh to 10kh. It may be my horn tweeter. I need to run the pink noise again and pull the wire to the horn tweeter and see what that does. If that eliminateis the hump, I should only need to adjust a resistor to the tweeter.
And of course I need to rebuild the electrical to the house and the room. Also make some changes to the space such as removing the wall to carpet and putting cork floors in.
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Exactly. Have you ever watched a sub cone pulsing in and out. Thats a whole lot of overhang. A whole lot pulling back on the reigns, turning it around and trying.to accelerate to the other end, overshooting and starting over again.Just covering a larger distance.
Rob
I can't see my 10" driver move. When I put my head by the driver I don't hear much. I can touch it and feel its vibrating. Put your head by the throat and its quite loud. My driver and amp are hardly working. The horn is amplifying the sound. Air is easy to manipulate and move. Its light. And I would say that does make it sound fast. There is little overshoot.
FWIW, Johan was telling me he makes some 12" and 15" versions of horn subs. He has to use aluminum drivers. For some reason the force on the cone shreds the drivers made of paper. They fall apart after 3 days. Thats 3 days. There is a lot of power in that horn.
With the BB10, he impregnates the paper front and back with something. I think its on his website. Its dramatically stiffens the driver cone and keeps if from falling apart. This sub is not joke. It puts out serious power.
With the BB10, he impregnates the paper front and back with something. I think its on his website. Its dramatically stiffens the driver cone and keeps if from falling apart. This sub is not joke. It puts out serious power.
It’s about the acceleration and deceleration , not the velocity…acceleration affects the SPL generated for a given input signal and deceleration determines the perception of speed…when the system stops vibrating is not the same for all bass loading principles.OK but you do realize that the period for 30 hz in mil seconds doesn't ever change. So you can not play it faster without increasing the frequency. All speakers all sizes are locked into this same periodic time domain.
There is no fast bass. You will get excursion differences they are still moving at the same rate per cycle. Just covering a larger distance.
Rob
That right, but he interesting question is how quickly a loudspeaker decays and settles after a 30 Hz pulse. The faster this happens, it is perceived by the ear as" fastbass". Open baffles and horns are superior in this case, as there are virtually no energy storage effects in the cabinet that could slow the decay time. Consider the step response of various designs.OK but you do realize that the period for 30 hz in mil seconds doesn't ever change. So you can not play it faster without increasing the frequency. All speakers all sizes are locked into this same periodic time domain.
There is no fast bass. You will get excursion differences they are still moving at the same rate per cycle. Just covering a larger distance.
Rob
If you want a horn bass below 20 Hz, it looks like this. Or with a tapped horn.
But it's rather unrealistic in normal living spaces, so stick with 30hz, it's easier to achieve. no need 20hz, that will cause more problems than benefits.
No, but there is slow bass.There is no fast bass.
Rob
When you have 2 15 inch woofers moving just a little with minimal grip, the amount of air moved is a lot and timely, and in comparision smaller woofers requiring to move greater distance move slower, in a cone create a bloated overhang sound that is highly unnatural (unless decibel value is all that one is concerned about), and require worse electronics to move them.
What? Did you think this through?
You have a 15" woofer moving 2 mm peak to peak. You have a 10" woofer moving 10 mm peak to peak. Same SPL same frequency.
How is the smaller woofer moving slower when it is covering 5x the distance in exactly the same amount of time?
The frequency sets the time per cycle and is not a variable. D displacement is a variable. With a larger value D the velocity increases.
V = d/t
Worse electronics to drive them? Seriously?
Rob
OK so basically how well damped the system is. None of these systems OB, Horn or Reflex should be ringing.
Rob
Only if you assume the smaller woofer is moving 5x in the same amount of time. That means you are assuming it moves faster (covering greater distance in that time as compared to the other woofer).What? Did you think this through?
You have a 15" woofer moving 2 mm peak to peak. You have a 10" woofer moving 10 mm peak to peak. Same SPL same frequency.
How is the smaller woofer moving slower when it is covering 5x the distance in exactly the same amount of time?
The frequency sets the time per cycle and is not a variable. D displacement is a variable. With a larger value D the velocity increases.
V = d/t
Worse electronics to drive them? Seriously?
Rob
worse electronics, yes, high current SS amps with lots of damping factor.
Well if they are reproducing the same frequency at the same SPL it's a given. To match SPL with a smaller Sd higher excursion required.
As opposed to VT with low dampening factor so no control over the woofers? That's an opinion and not factual.
Rob
It shouldn't, but everyone does for the following reason, which is called "electromotive force" (EMK). The current flowing through the voice coil induces a voltage that moves the speaker. This voltage acts as a counterweight to the voltage coming from the audio signal. Amplifiers with a high damping factor can compensate for this, while others only compensate for it to a limited extent. The ear perceives it as dry bass. An amplifier that compensates for this little can be described as lively, full bass, but you only hear more distortion and perceive it as better. Your brain is fooling you.OK so basically how well damped the system is. None of these systems OB, Horn or Reflex should be ringing.
Rob
P.S
I once had outsider equibe class A mono amps where you could adjust the damping factor from 20-5000 with a potentiometer on the back. Most people who visited here said that they liked the sound of the damping between 150-300 the best. That why i love now yamaha studio amp.(200)
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The larger, likely higher sensitivity woofers are moving much less to compress the air with the same amplitude. This means they have much higher acceleration to produce the same amplitude wave as the smaller long stroke woofers.What? Did you think this through?
You have a 15" woofer moving 2 mm peak to peak. You have a 10" woofer moving 10 mm peak to peak. Same SPL same frequency.
How is the smaller woofer moving slower when it is covering 5x the distance in exactly the same amount of time?
The frequency sets the time per cycle and is not a variable. D displacement is a variable. With a larger value D the velocity increases.
V = d/t
Worse electronics to drive them? Seriously?
Rob
Probably the smaller ones require 10x or more power to achieve the same SPL as well, meaning higher mass and/or weaker magnets.
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Horns are nearly always critically damped and so the speaker doesn’t require or even want an amp with high electrical damping. Most vented systems sound bloated with a low damping factor amp unless designed with a relatively low Qb (almost never seen commercially because it doesn’t maximize bass extension or power) or used with a high damping factor amp…so, quite different in practice. As a result, horns tend to like drivers with low Qts and vented boxes want a higher Qts than a horn. OB prefers high Qts to help with cancellation effects…and low damping factor amps.OK so basically how well damped the system is. None of these systems OB, Horn or Reflex should be ringing.
Rob
What would be the excursion to 112 dB without the horn? Sensitivity with the horn? What are the native driver sensitivities? Just trying to understand the amplification factor of the horn…
What it also shows is how the horn does the heavy lifting for the driver and critically damps it.
101dB each
compression ratio is 2:1 and 87cm conical "straight" horn
"vented" rear chamber to balance pressure on both sides of drivers
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