GB2482204A

GB2482204A - Horn-loaded loudspeaker with additional hf drivers on phase plug

Info

Publication number: GB2482204A
Application number: GB201013648A
Authority: GB
Inventors: Davies Richard Roberts
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-07-13
Filing date: 2010-08-16
Publication date: 2012-01-25
Anticipated expiration: 2030-08-16
Also published as: GB201011714D0; GB2482204B; GB201013648D0

Abstract

A loudspeaker enclosure design includes a phase plug which provides additional high frequency driver housing and horn loading of the main transducer in one device. The design includes a wave guide assembly that when coupled with the phase plug divides the acoustic wave created by the transducer into two equal horizontal channels to form a double horn loading of the main transducer. The horn loading and phase correction this achieves greatly improves the efficiency of the transducer and gives a flat frequency response. Two additional high frequency drivers are installed in the front of the phase plug assembly which is directly in front of the main transducer. The high frequency transducers are divided on a vertical plane opposite to the main transducer to reduce destructive interference. The mounting of the high frequency drivers directly in front of the main transducer ensures correct time alignment can be achieved and reduces the enclosure size. A number of enclosures can be arranged together to form a PA array.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

This invention relates to equipment for sound reinforcement and reproduction, more specifically, to a loudspeaker.

Description of the Prior Art

There is and has been for some time a need to reproduce or reinforce speech & music for a variety of situations in entertainment and public address situations. These needs can range greatly depending on the size of audience and layout of venue and can also have factors placed on them such as sound limits outside the venue.

A number of different loudspeaker designs have been developed over the years to supply this need and a number of ways to control the dispersion has been attempted. Most loudspeakers consist of 2 main parts; the speaker driver (transducer) and the enclosure (the box surrounding the transducer).

There are a number of loudspeaker designs which are used today at events but the 2 most common systems at larger events are the Point Source' and Line Array' systems. A point source loudspeaker system is a group of speakers stacked or flown so that each speaker points to a single part of the audience, this solution means that in general no person is listening to more than a pair of speakers (left and right) at any one time which achieves a high level of audio quality. The drawback with the point source system is that it is generally quite large and heavy as every speaker is separate meaning that most point source boxes are large and cumbersome and a lot of enclosures are required to achieve the desired coverage. A Line Array system works by hanging or stacking a group of smaller speakers into a line making one large hanging formation, this has the effect of coupling the speakers together making them more efficient. The draw back with the line array system is the lack of sound quality due to multiple sources of information from the speakers arriving at the listener at the same time caused by the line of speakers having different distances from the listener.

Home or Hi-Fi' loudspeakers are direct radiator' systems which means that the transducer is placed at the front of the enclosure; this has the effect of radiating the sound in a wide direction without adding much distortion from the enclosure. This effect has its use in small environments but in larger venues and outdoor events this solution spreads the sound in an uncontrolled manor meaning that noise outside the event is increased and the sound falls short of getting to the rear parts. A common way around this is to use a horn on the front of the transducer to increase the transducers output by transforming the energy into a focused wave which also controls the sound waves direction. The drawback with horn loading is that it adds distortion and sound nodes; this is due to the lack of a phase plug as the sound reflects inside the horn which affects the overall sound quality and has an undesirable effect on the listener.

Most current transducers are made of a cone construction so that they can withstand the stresses of movement they need to make in order to create a desired sound. The issue with the cone design is that all sides of the transducer face inward; this has the effect of forcing the sound waves collide with each other which means some frequencies are lost or degraded event before they leave the enclosure. To get around this a issue a device known as a phase plug' is used in some enclosures to block the sound waves moving inwards and prevent them colliding, this helps flatten the frequency response. The negative effect of a phase plug is a loss of efficiency which has a detrimental effect of the loudspeakers ability to throw sound over long distances increasing the need for further loudspeaker enclosures.

Another problem with current loudspeaker designs is the positioning of separate drivers to cover different frequencies within each enclosure. Because each driver is placed apart from one another it causes time alignment issues between the different drivers reducing sound quality. There are drivers known as dual and tn centric where they place two or three drivers in front of each other within the same driver casting however this type of driver is impossible to correctly horn load due to the way different frequencies react in horns which would result in poor quality of certain frequencies.

Currently there is no solution available that deals with the issues of phase correction, horn loading, dispersion control and in line driver mounting in one solution.

This patent application is for an invention of a loudspeaker enclosure that has multiple benefits over current loudspeaker enclosure designs. This invention describes a new way of handling phase correction, horn loading, dispersion control and in-line driver housing from one compact enclosure.

This invention allows the construction of a new loudspeaker enclosure to be made similar in size to a Line Array' system whilst maintaining all the properties of point source. It will result in the loudspeaker being of a higher quality, more compact size, more sound efficient and throw sound over much greater distances whilst maintaining controlled dispersion of the sound.

SUMMARY OF THE INVENTION

A new design of a loudspeaker enclosure is detailed in which at least one mid frequency transducer is mounted within an enclosure that incorporates a phase plug, horn loading, in line driver mounting and dispersion control. This assembly divides the high mid sound wave into 2 equal channels from the transducer on a horizontal plane correcting the phase and then converting the circular transducer shape into 2 oblong horn channels. These channels amplify the sound wave whilst controlling the dispersion. The design of the phase plug & horn loading assembly creates space for 2 additional high frequency transducers to be installed inside the front of the phase plug/horn device.

Each high frequency driver having their own separate horn which allows them to divide their dispersion on a vertical plane in line with the mid transducers dispersion divided on the opposite plane with each high frequency transducer covering 50% of the area of the mid frequencies driver.

This results in a more compact enclosure whilst maintaining perfect phase characteristics between the transducers and reduces destructive interference between the drivers when coupling. The sound exits the loudspeaker fully controlled having been phased corrected, horn loaded and in perfect time alignment between the drivers.

The design of the horn loading which is created by the enclosure results in a very efficient enclosure that increases the loudspeakers ability to throw sound over longer distances whilst achieving a flat frequency response, perfect time alignment and a high degree of dispersion control. This concept is unique to this invention and overcomes the main issues created by phase plugs, horn loading and time alignment issues in other loudspeakers.

This invention can be used to construct a new style of loudspeaker with multiple enclosures set side by side in one main enclosure to create a wider horizontal dispersion angle whilst maintaining the same vertical dispersion. This will allow the new loudspeaker to be used as point source system but hung in a similar way to line array style systems. This enclosure will have all the benefits of both point source and line array systems in one compact enclosure. Due to the design and layout of these new enclosures set side by side audio coupling occurs between them on a horizontal plane allowing these new loudspeakers to throw sound much further and have a much higher audio quality than in existing loudspeaker designs.

BRIEF DESCRIPTION OF THE DRAWINGS

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings.

Sheet 1, FIG. 1 is a front view of complete assembly.

Sheet 2, FIG. 2 is a side perspective through view of the entire assembly.

Sheet 3, FIG. 3 is a rear cut out view of the complete assembly.

Sheet 4, FIG. 4 is a side section through the complete assembly.

Sheet 5, FIG. 5 is a front view of the wave guide enclosure.

Sheet 6, FIG. 6 is a side perspective view of the phase plug enclosure.

Sheet 7, FIG.7 is a rear perspective view of the phase plug enclosure.

Sheet 8, FIG. 8 is a rear view of the phase plug enclosure.

Sheet 9, FIG. 9 is a side view of the phase plug enclosure.

Sheet 10, FIG. 10 is a front view of an completed example loudspeaker.

Sheet 11, FIG. 11 is a side view of an example standard line array system.

Sheet 12, FIG. 12 is a top view of an example standard point source system.

Sheet 13, FIG. 13 is a front view of the invention arranged in a line array configuration.

DESCRIPTION OF A PREFERRED EMBODIMENT

FIG. 1 shows a front view of the invention; the phase plug/horn device is shown in the middle with the two mounting positions inside for the high frequency drivers and is surrounded by the wave guide. Item 1 shows the wave guide working in conjunction with item 2 to create the horn loading.

Item 3 shows space inside the phase plug for additional high frequency drivers to be installed directly in line with the mid transducer. Item 4 shows the driver mounting which is mounted from the front when the phase plug is removed. Item 5 is the phase plug braces that support the phase plug, these phase plug braces secure top and bottom, the phase plug assembly can be removed to allow mid transducer access. The entire assembly is acoustically closed on all sides.

FIG. 2 front side perspective cut through; Item 1 (2) shows the controlled and constant horn loading created between the wave guide and phase plug.

FIG. 3 side rear perspective; Item 1 shows the transducer mounting which is mounted from the front when the phase plug is removed. Item 2 shows the rear of the phase plug that divides the sound wave into 50% upwards and 50% downwards direction. This is achieved by the V shape of the rear of the phase plug dividing the wave by matching the angle of the cone shape of the transducer. As the sound enters each horn the distance is controlled by item 3 to ensure it matches the angle of the transducer so that no nodes are created from oversized gaps. Item 4 then horn loads the sound controlling the dispersion increasing the enclosures ability to throw the acoustic wave over greater distances.

FIG. 4 side view; shows item 1 dividing the sound then item 2 horn loading the result.

FIG. 5 front view; of the wave guide only; Items 1 and 2 control the dispersion created by the shape of the wave guide. Item 3 shows the slide in mounting for the phase plug to be secured both top and bottom. Item 4 is the rear support to the phase plug that ensures it does not move and locates correctly in position with the wave guide. Item 4 also acts as a node controller reducing the amount of space inside the wave guide at the corners and edges. Item 5 shows the transducer baffle, the transducer mounts from the front and secures by 4 screws.

FIG. 6 shows the phase plug; Item 1 shows the slight angle on the top and bottom of the phase plug which when coupled with the wave guide completes the horn loading. Item 2 shows the two high frequency transducer mounting holes inside the phase plug.

FIG. 7 shows the rear perspective of the phase plug; Item 1 is the sound divider which divides the sound up and down into the wave guide for horn loading, it is the V shape that causes this division.

Item 2 shows the mounting of the phase plug brace onto the phase plug. A groove is carved in the top of the phase plug body so that the brace can be attached in the correct place.

FIG. 8 shows the rear of the phase plug; Item 1 shows the angle of the sides of the phase plug that match the exact same angles as the wave guide so that the two parts fit perfectly together sealing the sides that is crucial for the horn loading to work correctly.

FIG. 9 shows a side view of the phase plug; Item 1 is the mounting of the phase plug brace onto the main part of the phase plug which is inset in a groove. Item 2 shows two securing holes within the phase plug brace, once the phase plug assembly is connected with the wave guide assembly, these holes allow the phase plug to be secured by 2 bolts on the top and bottom of the wave guide that screw into 2 round nuts that slide into the holes on the phase plug brace ensuring a perfect strong fit that will be in the exact position required.

FIG. 10 is a front view of a completed loudspeaker featuring multiple invention enclosures showing how the invention can be scaled into a larger loudspeaker of compact size.

FIG. 11 is a side view of an example standard line array system showing how the line array segments form a line, coupling their energy together to join and couple into one combined source.

FIG. 12 is a top view of an example standard point source system showing how each loudspeaker covers a specific area and is a separate loudspeaker covering a specific area.

FIG. 13 is a front view of the invention showing how multiple loudspeakers could be stacked or hung in a line array formation whilst maintaining true point source capabilities and coupling on a horizontal plane individually.

It will be understood that variations are possible in the design and construction of embodiments within the scope of the invention. In only one example, the ratio of relative length to width can be altered.

Claims

Claims 1. A loudspeaker enclosure which comprises of a wave guide, phase plug, horn loading device and additional high frequency transducers mounted in line of the main transducer being constructed in one phase plug device, the combination of phase correction and horn loading and additional transducer mounting in one device, the phase plug assembly that divides the acoustic wave equally on a horizontal plane, the phase correction features phase plug design which removes destructive acoustic interference created by the main transducers cone and divides the resulting wave, the horn loading created by the phase plug of the main transducers wave by dividing the wave on a horizontal plane and controlling the dispersion to the desired angle, two additional high frequency drivers located in the phase plug allowing alignment between high frequency transducers and the main transducer, the dividing of the high frequency drivers on an opposing vertical plane to the main transducers horizontal dividing, consistent horn loading top and bottom of the main transducer, the phase plug being removable for driver access, the phase plug being secured by 2 vertical braces and located by a rear support, the divided horn loading of the main transducer being sealed at both sides, the phase plug taper to assist the horn loading top and bottom, the acoustic coupling created by multiple enclosures being constructed side by side into one main enclosure, the point source characteristics being maintained when used in a line array formation, the horizontal coupling of both frequencies when multiple enclosures are formed into one larger loudspeaker, the alignment of the high frequency transducers to the main transducer, the multiple features of phase correction and horn loading and alignment of high frequency transducers in one enclosure.
2. The loudspeaker assembly of claim 1 wherein the phase plug divides acoustic energy on an even horizontal plane.
3. The loudspeaker assembly of claim 1 wherein second high frequency transducers are mounted inside the phase plug and horn loading device of the main transducer.
4. The loudspeaker assembly of claim 1 wherein the phase plug divides the acoustic wave on an opposing plane to the high frequency drivers.
5. The loudspeaker assembly of claim 1 wherein the phase plug is removable and secured by locking bolts top and bottom to allow for main driver access.
6. The loudspeaker assembly of claim 1 wherein the phase plug tapers inwards to control the dispersion and horn load the acoustic energy.
7. The loudspeaker assembly of claim 1 wherein the wave guide tapers outwards to control the dispersion and horn load the acoustic energy in combination with the phase plug.
8. The loudspeaker assembly of claim 1 wherein the enclosures are mounted together into one larger enclosure to form a new larger enclosure.
9. The loudspeaker assembly of claim 1 wherein the enclosures can be hung in a line whilst maintaining point source characteristics.
10. The loudspeaker assembly of claim 1 wherein the mid and high frequency drivers couple on a horizontal plane when formed together in one larger enclosure.
11. The loudspeaker assembly of claim 1 wherein the main transducer is in line with the high frequency transducers.
12. The loudspeaker assembly of claim 1 wherein the phase plug is also a horn loading device and additional driver housing.
13. The loudspeaker assembly of claim 1 wherein the phase plug is also a horn loading device.
14. The loudspeaker assembly of claim 1 wherein the rear of the phase plug is the same angle as the main transducers cone.
15. The loudspeaker assembly of claim 1 wherein the phase plug correction is then directly horn loaded.