We've all been there before, and the guys here schooled me: Hoffman's Law. For mea that translates to, big bass equals big gear. Nowadays I call a Keystone portable and OTHORN mid sized. LOL.
Thanks GM, miss the days when Dennis would do that.
Thanks GM, miss the days when Dennis would do that.
Surprised no one has posted these charts:
To calculate: Efficiency and sensitivity conversion - loudspeaker percent and dB per watt and meter loudspeaker efficiency versus sensitivity vs speaker sensitivity 1 watt = 2,83 volt box chart - sengpielaudio Sengpiel Berlin
GM
To calculate: Efficiency and sensitivity conversion - loudspeaker percent and dB per watt and meter loudspeaker efficiency versus sensitivity vs speaker sensitivity 1 watt = 2,83 volt box chart - sengpielaudio Sengpiel Berlin
GM
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as the late DJK often stated, a 6th order bass reflex (ideal qts=0.312) offers some of the best tradeoff of boxsize vs LF capability. Without the boost, its a SBB4 having the best transient response of the vented box family.
The drawback is having sufficient power at that narrow band of tuning. Done properly with highpassing (20Hz 2nd order in example below - it would be better yet with highpass corner around 25Hz) its win win as junk below tuning doesn't waste power.
I had a MaxxBass box - besides adding distortion, it had some boost of the fundamental when fed with sine -
Here's what it did on a crude horn. It only worked for a few
weeks before failure and no support.
FWIW here's an example with the inexpensive Dayton PA310-8 12" woofer in a 37 liters box tuned to 39Hz and boosted 6dB at tuning in 4pi
The drawback is having sufficient power at that narrow band of tuning. Done properly with highpassing (20Hz 2nd order in example below - it would be better yet with highpass corner around 25Hz) its win win as junk below tuning doesn't waste power.
I had a MaxxBass box - besides adding distortion, it had some boost of the fundamental when fed with sine -
Here's what it did on a crude horn. It only worked for a few
weeks before failure and no support.
FWIW here's an example with the inexpensive Dayton PA310-8 12" woofer in a 37 liters box tuned to 39Hz and boosted 6dB at tuning in 4pi
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hi GM, somehow I missed those charts - here's an enlargement of the vented box chart
Regarding the 6th order PA310 reflex above, here's the effect of moving the highpass function
from 20Hz to 35Hz while retaining the 6dB/Q=2 peaking boost @39Hz:
Regarding the 6th order PA310 reflex above, here's the effect of moving the highpass function
from 20Hz to 35Hz while retaining the 6dB/Q=2 peaking boost @39Hz:
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Uff, those efficiency tables give me goosebumps. While there is some merit to that, It doesn't seem to always hold true? At least Hornresp sims very different outcomes regarding efficiency, and my calculation by hand from WinISD data (doesn't have efficiency sims) shows similar outcome.
What does your common sense tell you?
Double your cone area nets you 3 db more with same power applied.
Double your power nets you 3 db more with the same cone area.
Double your cone area AND double your power nets you 6 db more.
+ 6db will sound more or less twice as loud.
No magic. EVER.
OK..I guess I must just really be quite dense because now I am confused. According to the above statements, in order to increase SPL we need more power and/or more cone area. No magic. So if this basic doubling rule and no magic applies, then how can any particular enclosure be "more efficient"? Perhaps the statements are relative to each enclosure. For instance, to get 3db more in a sealed enclosure we have to double the cone area. But sealed vs. ported is a different story?
Doubling cone area and enclosure size (basically adding another identical sub) adds 3 db.
Doubling power adds 3 db.
A 6 db increase will sound more or less twice as loud.
This holds true regardless of enclosure type, sealed ported or anything else.
Two different types of enclosure can have different efficiency and different frequency response due to their different physical characteristics even when using the same driver and same power. For example a ported box and sealed box can have the same efficiency in mid bass and midrange frequencies but the ported box will be more efficient at frequencies surrounding the tuning frequency. Even if the sealed and ported boxes are the same size the port produces a resonance which increases efficiency over a.narrow frequency band.
Now take that idea to.an extreme. Use the same driver with the same power in a horn large enough and you can see increases of 6 db or more. It's not magic, it's a much larger box size with several resonances inside a 2 or 3 octave frequency band. The large size and multiple resonances increase the efficiency.
Grab a free simulator and you can quickly and easily see all this in action. I recommend hornresp. And to make things easier maybe try to visualize frequency response vs spl instead of efficiency. Efficiency can be hard to grasp at first while a frequency response graph is pretty intuitive.
Doubling power adds 3 db.
A 6 db increase will sound more or less twice as loud.
This holds true regardless of enclosure type, sealed ported or anything else.
Two different types of enclosure can have different efficiency and different frequency response due to their different physical characteristics even when using the same driver and same power. For example a ported box and sealed box can have the same efficiency in mid bass and midrange frequencies but the ported box will be more efficient at frequencies surrounding the tuning frequency. Even if the sealed and ported boxes are the same size the port produces a resonance which increases efficiency over a.narrow frequency band.
Now take that idea to.an extreme. Use the same driver with the same power in a horn large enough and you can see increases of 6 db or more. It's not magic, it's a much larger box size with several resonances inside a 2 or 3 octave frequency band. The large size and multiple resonances increase the efficiency.
Grab a free simulator and you can quickly and easily see all this in action. I recommend hornresp. And to make things easier maybe try to visualize frequency response vs spl instead of efficiency. Efficiency can be hard to grasp at first while a frequency response graph is pretty intuitive.
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OK, that makes sense. Different boxes have different responses.
I have used WINISD and found it very easy to understand. Tried Hornresp and not as much luck. Is there a good tutorial on how to use hornresp for a complete beginner? Video would be useful. Thanks
I have used WINISD and found it very easy to understand. Tried Hornresp and not as much luck. Is there a good tutorial on how to use hornresp for a complete beginner? Video would be useful. Thanks
Hornresp is it's own guide. It comes with a help file and hovering the pointer over any input box will tell you what the box is for or what you need to enter. Double clicking many input boxes brings up a wizard to help you fill in the box. It does get a lot more complicated but a simple sim starts as simple as that. I figured it out on my own, just used a sim online, copied the inputs, made sure I got the same results and learned as I went.
Regardless winisd will allow you to do stuff like compare 1 sub to 2 (identical) subs - the 3 db increase - and double power for another 3 db increase - and compare sealed to ported to see how the port increases efficiency over a narrow frequency band. If it lets you sim 6th order bandpass you can compare a big 6th to a small ported or sealed and see how the extra size and resonances increase efficiency over a wider frequency band than a single port.
Regardless winisd will allow you to do stuff like compare 1 sub to 2 (identical) subs - the 3 db increase - and double power for another 3 db increase - and compare sealed to ported to see how the port increases efficiency over a narrow frequency band. If it lets you sim 6th order bandpass you can compare a big 6th to a small ported or sealed and see how the extra size and resonances increase efficiency over a wider frequency band than a single port.
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It's a bit dated but still holds value in grasping HR a bit quicker: Guide to WinISD Pro and Hornresp - Speakerplans.com Forums - Page 1
...and also an Input Wizard, which makes it relatively easy to get started using Hornresp.
Simply choose the required loudspeaker system type from the options provided in the wizard, and then alter the given parameter values to suit the specific design.
