about what? | | | worum gehts? | |
Hearing - the underestimated sense - it provides you vision in the darkness. | |
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| | | HiFi horn loudspeaker My optimum - Listening area room size 20-80 qm - point source - distance 2,5-8 meter - no crossover network - SPL max. 100 dB - horn housing
less is more !
the DIY benefitUp to 80% of the manufacturing costs for a bass horn lies in building the cabinet. What about additional costs for trade profit margins and transport !? Both can be removed from the Project Budget if you do it yourself. | |
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Context: | | | | | | | | | | | | | | |
- the loudspeaker is by far the weakest member in the sound reproduction chain, a LS on average has less than 1% efficiency, i.e. 99% of the energy sent to the LS will be lost as heat, the remaining energy will produce the actual sound - an inexpensive LS lead of 1,5 square mm is quite sufficient up to 10 m - connection terminals are never better than the wire - approx 70% of the cost of a sound system should be spent on the loudspeakers
- the standard pitch tone (a) has the frequency 440 Hz - this note lies very close to the center of the violin clef - nearly 90 % of all played notes are 2 octaves over and below this note - your amplifier delivers only ca 1 Watt peak effect to the speakers base drum to reproduce a beat on a base drum with the volume control standing at "10 o'clock"!! - normal speech has a sound pressure level of about 60 dB - a bad recording cannot be compensated by even the best of sound reproduction equipment unfortunately only approx. 2 out of 10 CD's contain high quality recordings
- due to today's furnishing (leather, parquet, shutters, glass), I consider a strong direct sound something to be prefered - if you are positioned closely (40-70cm) to a wall, you should use "wall rug", 4 cm in front on the wall behind your head - bad room charateristics can be checked by way of hand claps by a person in front of the LS diaphragm, while the other person sits in the normal listening position, hence disclose any flutter echo - by damping the room corners, with for instance partly (3/4 ) filled bookshelves opposite to the LS, it is possible to improve the room acoustics - the room acoustics and the listening position are very important factors, mainly because you can influence them - placing a heavy concrete slab (the normal garden Walk-path type) on a piece of thick rug in your room and using adjustable spikes between LS and the slab is a cheap, worthwhile solution - over 90% of the resulting reproduced sound from a good recording, depends on: the room, the drivers, the building elements used for the cabinet and the cabinet design. The remaining percentages may be obtained through careful choices of electronics for signal processing, cabels and equipment dampers etc.
- When you are satisfied with the sound, when you have an emotional or relaxing listening experience, then is also the sound correct- persons with limited, or no experience from speaker comparizons, should always ask for a possibility to listen to an established and well known "Reference speaker in a listening room for comparison. | |
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| An important building material for my horn constructions is the soft fiber, usually 11-13 mm thick, and with a paper layer pasted on one side, always glue with this page. You can work on the material with a carpet knife easily. Also called sound reducing board and very low-price, it is used with bass horns to silence1/4 Lamda over 100 Hz. | |
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Why? A horn is the most natural and efficient way to produce sound. With horns, the moving mass can be reduced about 90% and theperformance can be increased up to 15 dB SPL. Due to the very small membrane movements needed, the bass plays faster and more lively.This is the main reason for choosing this hobby since 1972 with various speakers variants, however since 1980 exclusively horns.The art of speaker development consists of omitting, minimizing and simplifying,the resulting sound reproduction will have less distortion, and can also follow the weakest of pulses, since each unnecessary component changes the signaland distorts the music reproduction.Any given speaker creates a signal-depending load on an amplifier, dependingon the the music signal, the more complex, the greater are the feedback to theamplifiers, with negative implications on the signal processing. Therefore, I scarcely use anything but fullrange drivers without any crossover in my horns. Why do I mostly use small bass speaker?The inertia of the a heavy membrane slows the music signal down and this is especially noticeable on lower sound levels, typical for a normal living room, where the larger the mass of the membrane, the more it will dampen the signal, which is the main reasonfor the serious lack of bass resolution in heavy bass membranes.How can this be improved?Through the courage of the developer, to question supposedly irrefutable principlesand to follow your own paths. The series of double horns are prime examples ofimprovement in horn innovation and minimized enclosure sizes.What difference can membrane movement interlacing and bass horn mouth distance make?An extension of the low-transmission area by at least one octave, reducingthe housing volume by up to 50%, in comparison to a single driver solution.Indirectly right / left radiation and bass horn mouth distance prevents soundpressure increase over 100 Hz, reduction and linearization of membrane strokegives a very fast, tight, contoured and clean bass response, with outstandingproperties. The double horns presented her are an unexpected andsensational development of the horn principle. I didn't expect that the expression"less is more" once again would prove to be so very true.Some of the fundamental principles and theories for horns now need to be reviewed and rewritten. My research shows clearly: in normal living rooms is the funnel constant andlength of a bass horn far more important than the horn mouth opening. That nobody got this in the last century is absolutely incomprehensible to me! Especially since my subsequent research in the psychoacoustic effect of residual listening noticed in organ triads. Wiki: "This phenomenon has long been used in organ building: With the simultaneous use of the 8-foot and 51/3-Fuß which is about a fifth, you can hearthe 16-foot, one octave below the 8-foot. This enables an absence of tone simulating sound in the two-tone generator to the octave and the twelfth pure while the tone isnot really existing. "
In my double horns measurements however, I used a microphone, so it can not be a matter of a psycho acoustic effect. In reality, the double horn reproduces frequencies at least one octave lower in comparison to the single horn simulations.
Why is the bass of the double horns so tight, effortless and fast? Through membrane movement interlacing there are more bass, due to the bass horn mouth distance, there's no rise above 100 Hz. So the pressure chamber can be kept extremely small, both horns are extremely small. Small is also the air mass in the horn and the wall-to-wall distance inside the horn is short, the impedanz is very flat, no bassresonanz, the relatively small cabinets also contributes to the fast, contoured bass reproduction.
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| An attempt to explain these graphs:
By way of parallel operation of the two different horns, the driver of the long horn controls the stroke of the driver in the short horn. The little horn will not be acoustic short circuited, but instead creates sound pressure, amazingly much, more pressure than the long horn below 40 Hz.
At the same time, the impedance peak of the lowest octave is eliminated by non-interlacing, below 50 Hz~4 Ohm.
See system horn mouth measurement and single simulation of the CORNET and impedanz. | |
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| Membran movement interlacing:
My haptic verifications show a rather linear membrane movement, similar to a normal distribution curve. Which means a reduction of "pressure changes", and hence less mechanical membrane stress and maximized sound and SPL. | |
| | Still a funny phrase out of quantum mechanics, exchanging of just one word yields: Two or more horns can be called interlaced if it can´t be described independently from each other. ;-))
"Without music life would be a mistake," F. Nietzsche | | | |
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copyright hm-moreart Horst Möller 2007 | |
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