Speaker Assembly Research Articles

Optimization for squeak and rattle reduction using vibration analysis of passenger car door trim

The quality of vehicle plays an important role during the vehicle purchase. Sound quality is one of the highly ranked and commonly identified issues in automobiles. Automotive OEMs want the right-first-time design approach thus designs should be strong enough to fulfill all the criteria in terms of safety, fatigue, quality, etc. Buzz, Squeak and Rattle (BSR) are commonly classified as vehicle quality issues and marked under NVH. It is very hard to resolve BSR due to complex mechanisms and assemblies in vehicles. In this paper, the methodology is developed to reduce Rattle issues with help of shape optimization. BSR is quite unpredictable so it is hard to completely avoid it during development of overall vehicle, hence during the test run noise and its locations are marked and the focus is shifted to solving them. The methodology presented is helpful to solve the problem during the design and development phase instead of find and cure method which is currently in use. The work is limited to reducing the rattle issue in door trim and audio speaker assembly.

An infrasound calibration system for characterizing the environmental effect on sensor sensitivity and noise floor

An infrasound calibration system has been developed at the National Center for Physical Acoustics. The calibration tank is comprised of a 1" cylindrical shell 40" in diameter, 40" long, with 40" diameter hemispherical end caps. The interior volume of the tank is approximately 1.8 cubic meters. Each hemisphere has a 10" punch-out with sealing gasket that allows either a speaker assembly or an “end cap” to be attached to each end. Normal assess is through an end cap attached to one end, with a speaker assembly attached to the other. The end cap allows rapid switching out of sensors. The speaker assembly consists of a 10" subwoofer with a sealable back volume designed to equalize the static pressure in the interior of the tank to that of the speaker back volume. The subwoofer is able to generate pressures up to 10-Pa in the interior of the chamber, with excellent isolation from external sound. Using 2 subwoofers, by playing a different frequency tone through each speaker and measuring their associated intermodulation distortion in the transduced signal, the linearity of the sensor can be accurately assessed. The measured leak constant of the tank is longer than one week, permitting the characterization the sensor response to ambient pressure to be measured. The large interior volume of the calibration chamber allows the interior be heated or cooled returned slowly to ambient conditions, so that the effects of changing temperature on the sensor can be assessed.

ACOUSTIC REFLECTOR AND ENERGY STORAGE FOR MEDIA ASSEMBLIES

A speaker assembly is provided with a housing, a speaker mounted to the housing, and a reflector spaced apart from and facing the speaker. The reflector is symmetrical and has an arcuate central convex region for reflecting pressure back to the speaker for amplifying back pressure to the speaker. The reflector has a secondary region with an arcuate cross-section for reflecting acoustic vibrations past and outboard of the housing. The reflector is partially translucent, and a light source is provided adjacent the reflector for conveying light to the reflector, past and outboard of the housing for illuminating a region that receives acoustic vibrations reflected from the reflector. A media assembly is provided with a fan operably connected to a generator so that air that passes into a housing through an inlet and out of an outlet, causes the fan to rotate thereby providing a power source to a media device.

Speaker assembly for a structural pole and a method for mounting same

A speaker assembly for a structural pole is provided, as well as a method for attaching a speaker assembly to a structural pole. The speaker assembly is provided with an elongated housing mounted to banner brackets that are fixed to the structural pole. The housing is sized to provide an aesthetic appearance that corresponds to a banner attached to the banner brackets. A speaker, or a plurality of speakers are provided within the housing for transmitting acoustic vibrations to a corresponding environment.

Bass drum with compliant resonant head

A bass drum comprises a batter head and a resonant head at opposite ends of a cylindrical shell, wherein the resonant head is excitable to produce a lower resonant pitch than what is typically achieved with conventional bass drums. In some embodiments, the resonant head includes the cone of a conventional speaker. The speaker cone, however, is driven by fluid dynamics rather than by electromagnetic force. Moreover, the speaker cone can function without relying on any active electrical pickup coil or transducer being attached to it. In preferred embodiments, the speaker cone is part of a speaker assembly that has an outside diameter that is appreciably smaller than the inside diameter of the shell, wherein an adaptor ring bridges the radial gap between the speaker assembly and the shell. The adaptor ring is particularly useful in retrofitting standard size drum shells with standard size speaker assemblies.

Dual-diaphragm speaker assemblies with acoustic passageways and mobile terminals including the same

A mobile terminal includes a portable terminal housing and a speaker housing positioned in the portable terminal housing. The speaker housing includes a first micro-speaker having a first frequency response and a second micro-speaker having a second frequency response and positioned proximate the first micro-speaker. The terminal housing further includes a first passageway extending from a front face of the first micro-speaker to a first opening in the terminal housing, and a second passageway extending from a back face of the second micro-speaker to a second opening in the terminal housing displaced from the first opening. A grommet adjacent the speaker housing acoustically separates at least a portion of the first passageway from the second passageway. The first passageway may be completely acoustically separated from the second passageway by the grommet and/or a gasket and/or a foam structure. The grommet may define a first outlet extending from a front face of the first micro-speaker to a first location on an external surface of the grommet and a second outlet extending from a back face of the second micro-speaker to a second location on the external surface of the grommet that is displaced from the first location, so that the grommet may acoustically separate the second outlet from the first outlet, although complete acoustic isolation may not be possible.

Speaker edge and resonator panel assembly

A complex speaker edge and asymmetric resonator panel in which the acoustic vibration damping capacity of the speaker edge varies longitudinally around the speaker edge. The resonator panel has an aspect ratio of approximately 1.3:1 or more, and is composed of top and bottom panels held in spaced apart relationship by a plurality of longitudinally extending ribs extending therebetween. The ribs extend at an angle of from approximately 5 to 35 degrees to the longitudinal axis of the panel. The angle is acoustically matched to the complex speaker edge to improve the accuracy with which said acoustic vibration is reproduced. The effectiveness of the differential damping capacity of the edge in improving the quality of sound output from a speaker assembly is determined by observing the average magnitude of the excursions of the sound level pressure versus frequency curves for comparable complex and single speaker edges, particularly in the 200 to 10,000 Hertz range. The speaker edge and the angle of the ribs are acoustically matched by iteratively adjusting the edge and/or the angle in response to the quality of the sound that is perceived by a trained human ear.

Head set speaker and stereo playing device

A head set speaker and stereo radio playing device exhibits improved harmonics and acoustic fidelity. A resilient and flexible headpiece is sized to fit behind the head of the user. Right and left device enclosures are carried by the ends of the headpiece, and are aerodynamic shaped to minimize wind whistle which may result when the head set is worn while moving rapidly. Right and left behind the ear flanges extend downwardly from a position adjacent to the ends of the headpiece, and aid in the positioning of the right and left ear device enclosures. In a typical application, the device enclosures are positioned immediately forward of the user's ears, allowing ambient sound to be heard. A speaker assembly and a removable battery assembly are carried within each device enclosure. The speakers are oriented within the device enclosures with the speaker magnet directed to, and in contact with, the head of the listener. This achieves two interrelated and significant structural and electronic advantages. First, sound fidelity is improved by using sound reflecting walls and baffles to redirect the sound. And second, antenna functionality is improved by attaching an antenna input to the speaker magnet which is in contact with the listener's skin, and there by connecting the listener's body to the antenna. A charging unit is sized to receive both battery assemblies simultaneously. A circuit card carried within one of the device enclosures contains a stereo radio circuit. On/off, volume up, volume down, scan and reset buttons carried by the device enclosures are in electrical communication with the circuit card, and allow control over radio functionality.

In-wall speaker system method and apparatus

The disclosure relates to an in-wall speaker system, specifically a system that is not readily visible and mounted in a room. The in-wall speaker system is comprised of a base frame that is adapted to be mounted between support members of a wall. The in-wall speaker system further has a speaker assembly mounted to the base frame and an active member that has an outer surface which is substantially coplanar with the surrounding wall section and in one form extends slightly outward therefrom. The base frame, speaker assembly, and the active member cooperate to form an acoustic chamber that is positioned behind the inner surface of the active member. Acoustic energy is transferred from the speaker assembly to the active member where the sound is produced therefrom to the room.

Speaker assembly with aiming device

A speaker assembly aimable relative to a remote target. The speaker assembly comprising a sound generating device configured to project sound in a sound pattern about a sound axis. A speaker aiming device is coupled to the sound generating device for use in visually aiming the sound generating device relative to the remote target. The speaker aiming device having first and second aiming portions spaced apart from each other and positioned along an aiming axis in a fixed orientation relative to the sound axis. The first and second aiming portions being positioned to allow a user to visually see along the aiming axis past the first and second portions aiming device to the remote target.

Modular active noise air filter speaker and microphone assembly

An air induction system comprises an air induction body and air filter to provide filtered air to a vehicle engine. A microphone is disposed within the air filter. A control unit may receive signals from the microphone. The control unit may further control a speaker, which produces a noise canceling sound to thereby reduce engine noise associated with the air induction system.

Coaxial speaker with step-down ledge to eliminate sound wave distortions and time delay

A coaxial speaker assembly ( 10 ) with reduced sound distortion, sound time delay, and polar response distortion. The coaxial speaker assembly ( 10 ) includes a high-frequency speaker system ( 16 ) mounted coaxially with and fitting within a lower-frequency speaker system ( 14 ). A baffle ( 50 ) is secured to a diaphragm ( 48 ) of the high-frequency speaker system ( 16 ). A step-down ledge ( 52 ) is circumferentially positioned adjacent to the baffle ( 50 ) and extends outwardly therefrom. A portion of the sound waves emanating from the high-frequency diaphragm ( 48 ) are reflected off the step-down ledge ( 52 ).

Acoustical transducer for recreating a spatial sound stage and improved localization of original sounds sources

The present invention relates to a unique stereophonic speaker system of unique construction and true left and right speakers assemblies, booth physically and electrically. The speaker assemblies, located to the left and right front sides of a room effectively recreate the sound characteristics of a sound stage. Each speaker assembly includes a plurality of axially aligned speakers supported one above the other in a housing made of flexible material and which can vibrate and resonate. Each speaker assembly includes cutouts in the side wall of the housing, the speakers being positioned such that the side wall with the cutouts are in facing relation. The left channel information must be played in the left speaker assembly and the right channel information must be played in the right speaker assembly.

Electronic talking compass

The invention relates to an electronic compass adapted for providing users with an audible indication of direction. The compass includes a housing assembly having a speaker for providing a user with information concerning the orientation of the housing assembly relative to the earth's magnetic field. The compass further includes a Hall Effect detector for determining the orientation of the housing assembly relative to the Earth's magnetic field and a translator for translating the orientation data relating to the position of the housing assembly relative to the earth's magnetic field into an auditory signal which is transmitted to the speaker assembly for translation into an audible signal providing a user with audible instructions regarding the orientation of the housing assembly.

Bass-reflex speaker assembly

To provide a bass-reflex speaker assembly having superior water resistance and which can be mounted on a motorcycle, while not being subjected to the influence of negative pressure due to wind during travel and which is capable of maintaining superior sound quality. A resonant duct projects downwards at an incline at a bottom surface of a speaker enclosure. It is therefore difficult for rain water to enter because the duct opens downwards and water that may enter temporarily can be easily discharged from the same duct. Furthermore, when speakers are positioned within the cowling of the motorcycle, negative pressure occurring due to wind when the vehicle is travelling acts not only on the front surfaces of paper cones of the speakers, but also on the rear surfaces via the ducts. Therefore, superior sound quality can be maintained without the influence of negative pressure being incurred and a bass-reflex speaker assembly suited to motorcycles is therefore possible.

Effects of oscillation of a mechanical hemilarynx model on mean transglottal pressures and flows

This study introduces a mechanical model of the larynx for investigating the aerodynamics of phonation. The model mimics the hemilarynx. The tracheal inlet section was rectangular (2.5 cm by 2 cm). The vocal fold was fabricated from hard plastic with an attached oscillating plunger. A speaker assembly and audio amplifier drove the plunger, mimicking one-dimensional vocal fold motion toward a flat wall. The glottal shape was rectangular. The glottal diameter was well specified or dynamically followed with a laser system. The air was sucked through the channel using a vacuum with controlled speed. Frequency and amplitude of the glottis were varied. The mean pressure and mean flow data were recorded. For steady flow conditions, the glottal gap ranged from 0.4 to 2.5 mm. The pressure coefficient for steady flow had a range of 3.1–1.3 for Reynolds numbers between 500 and 5000. For oscillation conditions: (a) the frequency was varied from 75 to 150 Hz while the amplitude was held (almost) constant; and (b) the amplitude was varied for a fixed frequency of 100 Hz. The results indicate that oscillation amplitude has a strong effect on the flow resistance of the glottis. [Work supported by NIDCD Grant No. R01 DC03566.]

Effects of oscillation of a mechanical hemilarynx model on mean transglottal pressures and flows.

This study introduces a mechanical model of the larynx for investigating dynamic aerodynamic effects of phonation. The model mimics the hemilarynx. The tracheal inlet section was rectangular (25-mm width, 20-mm height). The vocal fold was fabricated with precision machinery from hard plastic with an attached oscillating plunger. A speaker assembly and audio amplifier drove the plunger, mimicking one-dimensional vocal-fold motion toward a flat wall. The glottal shape was rectangular. The glottal diameter was well specified or dynamically followed with a laser system. The air was sucked through the channel using a vacuum with controlled speed. Frequency and amplitude of the glottis were varied. The mean pressure and mean flow data were recorded. For steady-flow conditions, the glottal gap ranged from 0.39 to 2.58 mm. The pressure coefficient for steady flow had a range of 3.1 to 1.3 for Reynolds numbers between 300 and 9000. For oscillation conditions (a) the frequency was varied from 75 to 150 Hz while the amplitude was held relatively constant, and (b) the amplitude was varied to 0.3 mm for a fixed frequency of 100 Hz. The results indicate that the hemilarynx model provides mean pressure-flow data similar in form to other models with two vocal folds. Furthermore, the dimensional and non-dimensional pressure coefficient is sensitive to variations in glottal gap and glottal amplitude, but relatively insensitive to the frequency of oscillation.

Modelling with gradient information

Response surface models (RSMs) can be used to model expensive simulations or real measurements [1]. An RSM is constructed by simulating solutions at systematic points in a design space and fitting a model to them. The RSM is then employed in subsequent calculations (for instance in optimization) effectively replacing the original expensive simulator, which leads to considerable savings in time and money. A novel technique is presented here which uses the gradient of a function as well as the function itself to construct the RSM. Such an approach is possible because, for many types of simulations, gradient information is simple and cheap to obtain. The design of an electromagnetic speaker assembly is used to illustrate the new approach. The finite element method (FEM), on which the simulation is based, can provide gradient information at little extra cost and hence the benefits of using gradient information are considerable, being especially marked in higher-dimensional spaces.

Audible vehicle monitoring apparatus

A new and improved audible vehicle monitoring apparatus includes a sound monitoring assembly adapted for connecting to an undercarriage portion of a wheeled vehicle. A monitor housing assembly connects to the undercarriage portion of the wheeled vehicle. A microphone assembly and a first power source are retained by the monitor housing assembly. A wave transmitter assembly is powered by the first power source and is retained by the monitor housing assembly. The wave transmitter assembly is connected to the microphone assembly and transmits waves representing sounds picked up by the microphone assembly. An audible signalling assembly is retained in a cab portion of a motor vehicle in proximity of a driver within easy hearing and easy reach of the driver. The audible signalling assembly includes a signaling housing assembly, and a second power source is housed within the signaling housing assembly. A wave receiver assembly is retained by the signaling housing assembly and is powered by the second power source. The wave receiver assembly receives the transmitted waves from the sound monitoring assembly. The audible signalling assembly includes a speaker assembly which receives audio signals from the wave receiver assembly and provides audible signals to the driver of the motor vehicle. A plurality of sound monitoring assemblies can be connected to selected locations of the undercarriage portion of the wheeled vehicle, and the audible signalling assembly includes a selector switch assembly for selecting which respective sound monitoring assembly is to be listened to by a motor vehicle driver.

Earphone-type speaker assembly

A speaker assembly for securement to the temples of an eyeglass frame, such as sunglasses, is disclosed. In particular the assembly includes an adjustable support which is detachably secured to the temples or fixed permanently thereto. The speaker is supported spaced from the frame and the particularity of its mounting is that it can be pivoted to emitt sound towards the ear of a wearer or fully away from the ear or any intermediate position. This permits the wearer to adjust the direction of the speakers to hear other important sounds that may be directed at him from his back or sideways. Accordingly, if the wearer is listening to the radio in an area where important sounds need to be heard, such as in vehicle traffic, the traffic sound will overpower the earphone speaker sound.