duf astudiu
Test report
Clint:
BBC complex studios in cairo
Test date:
June 14, 2014
Location:
Test method
It is based on ASTM E 90 standard
Project discretion
This is hotel based in Cairo Egypt and unique place in Cairo nile view in agouza
outside noise was normally 85 db and when the rash hour begging it measurers 88 db and it is vary hi noise
And that use technique of wall damping construction for sound isolation
Test object
Description of test
Instruments: sound level meter paa3 S/N 00380650
ACOUSTICAL calibrator B&K S/N 1897713
PAA3 SOFTWARE
HP I7 laptop
Test procedures
Closing all the doors and start test with
SPL meter
RT 60
Space and time average
Test investigation
Audio booth
First test inside the door of the studio and location of test in center of the space and open the window
it measures
And measuring the back ground noise in the same place . with closing the window and Curtin
And measuring RT60
Second
Test outside lobby area (rooms)
Measuring in the rooms in third floor with dynamic range testing
Third
Test outside lobby area ( garage ) after lobby door to garage and with full loudspeaker power
Measuring that following
And RT60 for the air volume
And after closing the door of garage outside ( street)
Measuring as following ( with dynamic rage )
And that is show it noise from 100 hz to 1 khz related to traffic noise
The code and testing comparing
Project Design :: Hotel
Goal: To create an aesthetically pleasing and calming environment, which encourages guests to feel relaxed and comfortable so that they enjoy their stay and are more apt to return. To minimize noise from other guest rooms, the corridor and mechanical equipment.
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Codes & Testing :: Sound Transmission Class (STC)
Code: STC rates a partition’s or material’s ability to block airborne sound.
Enforcement: Appendix Chapter 35 of the ’88 and ’91 UBC, Appendix Chapter 12, Division II of the ’94 and ’97 UBC will be contained in the forthcoming IBC. Although not all municipalities have adopted this appendix chapter, it is still recognized as an industry standard.
General Information: The Uniform Building Code (UBC) contains requirements for sound isolation for dwelling units in Group-R occupancies (including hotels, motels, apartments, condominiums, monasteries and convents).
UBC requirements for walls: STC rating of 50 (if tested in a laboratory) or 45 (if tested in the field*).
UBC requirements for floor/ceiling assemblies: STC ratings of 50 (if tested in a laboratory) or 45 (if tested in the field*).
* The field test evaluates the dwelling’s actual construction and includes all sound paths.
Definitions:
STC Strength: Classifies an assembly’s resistance to airborne sound transmission in a single number.
STC Weakness: This rating only assesses isolation in the speech frequencies and provides no evaluation of the barrier’s ability to block low frequency noise, such as the bass in music or the noise of some mechanical equipment.
Recommended Isolation Level
An assembly rated at STC 50 will satisfy the building code requirement, however, residents could still be subject to awareness, if not understanding, of loud speech. It is typically argued that luxury accommodations require a more stringent design goal (as much as 10dB better – STC 60). Regardless of what STC is selected, all air-gaps and penetrations must be carefully controlled and sealed. Even a small air-gap can degrade the isolation integrity of an assembly.
Codes & Testing :: Impact Insulation Class (IIC)
Code: IIC rates a floor/ceiling assembly’s ability to block impact sound.
Enforcement: Appendix Chapter 35 of the ’88 and ’91 UBC, Appendix Chapter 12, Division II of the ’94 and ’97 UBC will be contained in the forthcoming IBC. Although not all municipalities have adopted this appendix chapter, it is still recognized as an industry standard.
General Information: The Uniform Building Code (UBC) contains requirements for sound isolation for dwelling units in Group-R occupancies (including hotels, motels, apartments, condominiums, monasteries and convents).
UBC requirements for floor/ceiling assemblies: IIC ratings of 50 (if tested in a laboratory) or 45 (if tested in the field*).
* The field test evaluates the dwelling’s actual construction and includes all sound paths.
Definitions:
IIC Strength: Helps to rate structure-borne noise such as footfall, a chair dragging on the floor, or other realistic sounds in a single number.
IIC Weakness: Due to the nature of the testing procedure, almost any assembly with carpet will meet the IIC requirement. Meeting the IIC requirement does not ensure the control of footfall noise. Conversely, if an assembly does not meet the IIC requirement, it does not necessarily mean that there will be a footfall noise issue.
The tapping machine frequently used for this test is not designed to simulate any one type of impact, such as a male or female footsteps, nor to simulate the weight of a human walker. Thus the subjectively annoying creak or boom generated by human footfalls on a limber floor assembly may not be adequately evaluated by this method (American Society for Testing and Materials – ASTM, E 1007, 5.2).
Recommended Isolation Level
An IIC rating of 50 will satisfy the building code requirements. As with STC, it is typically argued that luxury accommodations require a more stringent design goal. Bare in mind, some floor assemblies rated as high as IIC 70 could still transfer noticeable footfall noise.
Recommended Isolation Level
An IIC rating of 50 will satisfy the building code requirements. As with STC, it is typically argued that luxury accommodations require a more stringent design goal. Bare in mind, some floor assemblies rated as high as IIC 70 could still transfer noticeable footfall noise.
ANSI (recommendation) .
Hotels/Motels | |
Individual rooms or suites | 40-45 (db) |
Meeting/banquet rooms | 40-45 (db) |
Halls, corridors, lobbies | 45-50 (db) |
Service/support areas | 60-65 (db) |
And for the clubs
The noise levels in clubs ranges between 95-98 dB(A) region
Ground type., the exposure times and frequency of exposure and the proportion of attenders vs. non-attenders . According to all the previous factors a test must be retake Loud speakers will be relocated according to the wind direction , to reach the standards levels .
Conclusion
*The test result apply to the time of test (from 5 pm to 10 pm ) we will not be responsible for any other test done out of the above time frame.
This study made under American standard test method
Dr. Ibrahim Elnoshokaty.
Acoustical consultant
Eng. Eslam Youssef Eng. Mohamed hamdi
R & D engineer Test and measurement
Engineer
introduction
A one-way audio transmission over a data network. It is widely used to listen to audio clips and radio from the Internet on computers, tablets and smartphones. In addition, computers at home are commonly set up to stream a user’s music collection to a digital media hub connected to a stereo or 5.1 . Listening to momentary blips in music or a conversation is annoying, and the only way to compensate for that over an erratic network such as the Internet is to get some of the audio data into the computer before you start listening to it. In streaming audio, both the client and server cooperate for uninterrupted sound. The client side stores a few seconds of sound in a buffer before it starts sending it to the speakers. Throughout the session, it continues to receive audio data ahead of time.
High-resolution audio
The industry has been transformed by digital downloads from sites such as iTunes, marking a shift away from physical media like vinyl, tapes and CDs. Formats including MP3 and AAC make it easy to buy, listen and store our tunes. With regards to sound quality, however, these formats just don’t cut the mustard. The use of lossy compression means that data is lost in the encoding process, which means resolution is sacrificed for the sake of convenience and smaller file sizes.
encoding process
Lossy codecs: Many of the more popular codecs in the software world are lossy, meaning that they reduce quality by some amount in order to achieve compression. Often, this type of compression is virtually indistinguishable from the original uncompressed sound or images, depending on the codec and the settings used.[4] Smaller data sets ease the strain on relatively expensive storage sub-systems such as non-volatile memory and hard disk, as well as write-once-read-many formats such as CD-ROM, DVD andBlu-ray Disc. Lower data rates also reduce cost and improve performance when the data is transmitted.
Lossless codecs: There are also many lossless codecs which are typically used for archiving data in a compressed form while retaining all of the information present in the original stream. If preserving the original quality of the stream is more important than eliminating the correspondingly larger data sizes, lossless codecs are preferred. This is especially true if the data is to undergo further processing (for example editing) in which case the repeated application of processing (encoding and decoding) on lossy codecs will degrade the quality of the resulting data such that it is no longer identifiable ( audibly or both). Using more than one codec or encoding scheme successively can also degrade quality significantly. The decreasing cost of storage capacity and network bandwidth has a tendency to reduce the need for lossy codecs for some media.
achievement of lossless codec’s and bandwidth
It’s basically a protocol allowing media to be streamed from any bog-standard HTTP server whilst keeping some of the functionality provided by dedicated media servers. For example; HLS allows you to adjust the video quality in real-time, based on the bandwidth available to the client.
It can be used for ‘Live’ broadcasts and Video on Demand, and it’s file based nature means that it plays really well with Content Distribution Networks. Once prepared for delivery, the content needed to provide a stream is static (though a ‘Live’ stream, but it’s very nature, won’t be), so the stream can be served from any HTTP(S) server.
Great news for those in the creative industry – HLS also supports (incredibly) basic DRM in the form of AES-128 encryption. We won’t be covering that though as it’s outside the scope of this piece
The HLS Output File Structure and Codec
HLS is a truly adaptive bitrate technology. When audio is encoded to HLS multiple files are created for different bandwidths and different resolutions. The files are encoded using the mpg2_ts codec. The streams are mapped to the client in real time using an .M3u8 index file based on screen size and available bandwidth.
To make the system scalable and adaptable to the bandwidth of the network, the video flow is coded in different qualities. Thus, depending on the bandwidth and transfer network speed, the video will play at different qualities.
To implement this, the system must encode the video in different qualities and generate an index file that contains the locations of the different quality levels.
The client software internally manages the different qualities, making requests to the highest possible quality within the bandwidth of the network. Thus always play the video the highest possible quality, viewing lower quality on 3G networks and highest quality in Wi-Fi broadband.
sharedin Live Streaming
consists of three parts: the server component, the distribution component, and the client software.
1- server component
The server requires a media encoder, which can be off-the-shelf hardware, and a way to break the encoded media into segments and save them as files, which can either be software
1-1 Media Encoder
Encoding should be set to a format supported by the client device,
1-2 Stream Segmenter
sharedin stream segmenter is software can reads the Transport Stream from the local network and divides it into a series of small media files of equal duration. Even though each segment is in a separate file, audio files are made from a continuous stream which can be reconstructed seamlessly. also encrypt each media segment and create a key file
1-3 File Segmenter
The segmenter also creates an index file containing references to the individual media files. Each time the segmenter completes a new media file, the index file is updated of equal length
2- Distribution Components
The distribution system is a web server or a web caching system that delivers the media files and index files to the client over HTTP. No custom server modules are required to deliver the content, and typically very little configuration is needed on the web server.
sharedin Client Component
sharedin begins by fetching the index file, based on a URL identifying the stream. The index file in turn specifies the location of the available media files, decryption keys, and any alternate streams available. For the selected stream, sharedin client downloads each available media file in sequence. Each file contains a consecutive segment of the stream. Once it has a sufficient amount of data downloaded, the client begins presenting the reassembled stream to the user.sharedin client is responsible for fetching any decryption keys, authenticating or presenting a user interface to allow authentication, and decrypting media files as needed.This process continues until the client encounters the #EXT-X-ENDLIST tag in the index file. If no #EXT-X-ENDLIST tag is present, the index file is part of an ongoing broadcast. During ongoing broadcasts, the client loads a new version of the index file periodically. sharedin client looks for new media files and encryption keys in the updated index and adds these URLs to its queue.
Protection against errors
In this case is generated a different flows with the same quality video and locations are listed in the index file.
The management of all files is done from the client, so that if it fails the first flow, use the next and successively.
content can be easily encrypted. Currently sharedin supports AES-128 encryption using 16-octet keys. There are three ways in which encryption can be applied: using an existing key, using a randomly generated key, or using a new key that’s generated for every X number of video segments. The more video segments that have unique encyrption, the greater the overhead and the less the performance. Keys can be served over SSL for an added layer of encryption.
All iOS devices running 3.0 and later support sharedin
Android 4.0 (Ice Cream Sandwich).
Android 4.1+ (Jelly Bean)
Android 4.4+ (Kit Kat)
Most new top-of-the-line Androids now support High Profile level
Desktop shardin Support
all web browser has native support
concolusion
sharedin tech are made for internet radio to get good quality of audio signal without cutting or buffering at all bandwidth from gsm mobile traditional bandwidth to broadband and that tech has alot for development and enhancement and the development of sharedin tech only in the stream sigmenter and the Clint player that all not success without HLS technology . sharedin add new stone at the pyramid of HLS
presnted by
Dr. ibrahm noshokaty
april 2015
MTI
400 Bed General Hospitals Project |
Enoshmink Technology & Media Services |
12/19/2013 |
Project Acoustical Design :: Auditorium/Theater
Goal: To properly balance absorption and reflection to provide a favorable acoustical environment. One must address both the need to hear and understand speech, and the desire to have a pleasant space for music.
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Auditorium sound transmission loss:
Wall 1 and 3
Wall 2 and 4
Ceiling
Wall sound Isolation Thickness ( wall damping concept ):
Recommended ANSI Levels for Large auditoriums, (for very good speech articulation) : 35 db
Used material : Rock wool
Material density: 80 m3/Kg
SPL: 85 db
WALL NAME |
THICKNESS |
|
|
|
|
Wall 1 |
0.0120975198718746 m |
|
|
|
|
Wall 2 |
0.0217294161921501 m |
|
|
|
|
Wall 3 |
0.0120975198718746 m |
|
|
|
|
Wall 4 |
0.0217294161921501 m |
|
|
|
|
Ceiling |
0.00532148967971023 m |
|
|
|
|
2- Reverberation time before sound treatment calc
Reverberation time of the auditorium before sound treatment
Frequencies (HZ)
|
125 |
250 |
500 |
1000 |
2000 |
4000 |
RT 60
|
1.79830407258774 |
2.37372022535858 |
1.11229061289745 |
0.829339416874118 |
0.7816360567047 |
0.764687873972774 |
Length: 24.5 m
Width: 13.64 m
Height: 6 m
Volume: 2005.08 m3
Wall |
Material |
||||
Front Wall |
gypsum_board |
||||
Back Wall |
gypsum_board | ||||
Right Wall |
gypsum_board | ||||
Left Wall |
gypsum_board | ||||
Ceiling |
Enosh | ||||
Floor |
floors,wooden |
3-Reverberation time after sound treatment calc
Enosh Ceiling:
Length: < enosh_ceiling> m
Width: 9 m
Material: 1” m
Eonsh pallet:
Number: 10
Area: 37.5 m2
Material: 2”
RT 60 at different frequencies (after adding enosh materials):
Frequencies (HZ)
|
125 |
250 |
500 |
1000 |
2000 |
4000 |
RT 60
|
1.16485073560508 |
0.688448147242969 |
0.383563617180037 |
0.323910429879985 |
0.326120568218462 |
0.329313120258735 |
4-Critical area after sound treatment
5- calc of Standing Waves:
Frequency | Length | Width | Height | ||
F1 | 7 | 12.5733137829912 | 28.5833333333333 | ||
F2 | 14 | 25.1466275659824 | 57.1666666666667 | ||
F3 | 21 | 37.7199413489736 | 85.75 | ||
F4 | 28 | 50.2932551319648 | 114.333333333333 | ||
F5 | 35 | 62.866568914956 | 142.916666666667 | ||
F6 | 42 | 75.4398826979472 | 171.5 | ||
F7 | 49 | 88.0131964809384 | 200.083333333333 | ||
F8 | 56 | 100.58651026393 | 228.666666666667 | ||
F9 | 63 | 113.159824046921 | 257.25 | ||
F10 | 70 | 125.733137829912 | 285.833333333333 |
6- the shape of the diffuser to remove standing wave
Diffusers:
Length: 1.5
Width: 0.3
Depth:
0.0571666666666667 0.228666666666667 0.228666666666667
0.0571666666666667 0
The application of the diffuser will be in the wall panel
7-Codes & Testing :: Sound Transmission Class (STC)
Code: STC rates a partition’s or material’s ability to block airborne sound.
Enforcement: Appendix Chapter 35 of the ’88 and ’91 UBC, Appendix Chapter 12, Division II of the ’94 and ’97 UBC will be contained in the forthcoming IBC. Although not all municipalities have adopted this appendix chapter, it is still recognized as an industry standard.
General Information: The Uniform Building Code (UBC) contains requirements for sound isolation for dwelling units in Group-R occupancies (including hotels, motels, apartments, condominiums, monasteries and convents).
UBC requirements for walls: STC rating of 50 (if tested in a laboratory) or 45 (if tested in the field*).
UBC requirements for floor/ceiling assemblies: STC ratings of 50 (if tested in a laboratory) or 45 (if tested in the field*).
* The field test evaluates the dwelling’s actual construction and includes all sound paths.
Definitions:
STC Strength: Classifies an assembly’s resistance to airborne sound transmission in a single number.
STC Weakness: This rating only assesses isolation in the speech frequencies and provides no evaluation of the barrier’s ability to block low frequency noise, such as the bass in music or the noise of some mechanical equipment.
Recommended Isolation Level
An assembly rated at STC 50 will satisfy the building code requirement, however, residents could still be subject to awareness, if not understanding, of loud speech. It is typically argued that luxury accommodations require a more stringent design goal (as much as 10dB better – STC 60). Regardless of what STC is selected, all air-gaps and penetrations must be carefully controlled and sealed. Even a small air-gap can degrade the isolation integrity of an assembly.
8-Codes & Testing :: Reverberation Time (RT60)
Test: RT60 measures the reverberance within a room.
Related Code: RT60 is soon to be adopted under ADA for classroom acoustic criteria.
General Information: Reverberation Time is the time required, in seconds, for the average sound pressure level in a room to decrease 60 decibels after a source stops generating sound. This test is standard on certain projects, such as “THX” movie theaters and various government buildings. Normally, in the design phase, you must demonstrate (through calculations) that a space will achieve the stipulated reverberation time. Often times, measurements are required to verify results.
Strength: Because RT60 is void of variables, unlike many other tests, it is straightforward and clear-cut.
Weakness: RT60 does not account for problematic and potentially annoying reflections. Often times, there is still a need for expert analysis.
9-Codes & Testing :: Noise Criteria (NC)
Code: This industry standard (also an ANSI standard) usually pertains to HVAC or mechanical noise impact.
Enforcement: This standard is often required for certain certifications (such as government medical facilities) or included in client specifications/standards (for example, some companies have NC standards that their buildings must meet).
General Information: An NC level is a standard that describes the relative loudness of a space, examining a range of frequencies (rather than simply recording the decibel level). This level illustrates the extent to which noise interferes with speech intelligibility. NC should be considered for any project where excessive noise would be irritating to the users, especially where speech intelligibility is important. There are a few spaces where speech intelligibility is absolutely crucial, including:
For some areas, such as machine shops or kitchens, it is not essential to maintain a particularly low NC level.
NC Level Strength: It is important for design professionals to specify NC ratings to protect their designs (within reason – specifying an acceptable NC level does not have to be a burden on the budget). Doing so speaks to your reputation as a responsible architect or designer and limits your liability.
NC Level Weakness: NC does not account for sound at very low frequencies. In spite of numerous efforts to establish a widely accepted, useful, single-number rating method for evaluating noise in a structure, a variety of techniques exist today. The vast majority of acoustic professionals use the NC standard, but it is still important to be aware of the other acceptable methods that do account for low frequency levels, including (but not limited to):
Conclusion
1- Wall damping system theckinss 14 to 15cm
2- Wall treatment using acoustics panel NRC UP to 1.15
3- Ceiling treatment using acoustics panel NRC up to .80
4- Floor treatment using bright surface to balance the RT of room
5- Standing wave are detect by 10 frequency
6- Must diffuse all wall by two thickness panel
7- theater seats must be foam injection not
sponge
this stady according to American standard
ASTM E90-2009″ Standard Test Method for Laboratory Measurement
Of Airborne Sound Transmission loss of Building Partitions”
ASTM E4I3-2004″ Classification for Rating Sound insulation”
Dr. Ibrahim elnoshokaty
Member acoustical society of America
Member acoustical society of Egypt
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