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I finally figured out how to power the Sennheiser MKH-104, 404, and 804 from 48 V phantom power (P48) which is very common on professional and many prosumer mixers and recorders. The MKH-X04 series requires -8V for operation. Please note that some portable recorders do not generate P48 even on their XLR connectors. This will not work with P12 or P24 inputs. It works like a charm on P48 inputs (at least from Mackie, Yamaha, and Sound Devices). Thanks to everyone for their input and assistance.
Today, 48 V phantom powering is almost universal. In phantom powering the positive voltage is fed through a pair 6k81 ohm resistors, one to each modulation lead. The matching of these resistors is often done to 0.1% to maintain common mode rejection. The negative power runs on the mic shield. XLR: Pin 1-shield; Pin 2-audio hot, +48 V; Pin 3-audio low, +48 V. Tuchel: Pin 1-audio hot, +48 V; Pin 2-shield; Pin 3-audio low, +48 V. This was standardized in the 1960s in DIN Standard 45596. //
Prior to standardization, in 1964, Schoeps produced the CMT-20 microphone which used negative 8.5 V phantom power. The CMT-200, according to Schoeps drawing SB316, dated 1964-10-14, used the same -8.5 V phantom. Later this was broadened to negative 8-12V phantom followed by the switch to positive phantom at some later point. With vintage microphones, at least from Schoeps, be very careful as they might be negative phantom.
(free) 333-page technical document on sound restoration titled "Manual of Analog Sound Restoration Techniques." It's written by Peter Copeland of The National Sound Archive in England (part of the British Library Board), and it's a remarkable and interesting document.
I don't agree with everything Copeland says, but he makes a number of good points in his report, and there's a lot of very good information in it, particularly on vinyl restoration techniques. Apparently Copeland died in 2006 without finishing the manuscript; parts of it are in desperate need of editing, and the info is dated in sports, but there's still a treasure-trove of good information there. Note that Copeland's approach is very scientific and engineering-based; subjective audiophiles may take issue with some of his opinions.
It's available as a free PDF at this link:
http://www.bl.uk/collections/sound-archive/pdf/analoguesoundrestoration.pdf
Copeland reportedly put about ten years of research into writing the document, and it's very well-done. Anybody who's trying to do restoration and mastering of vinyl, 78RPM discs, and analog tape should read it.
The late Peter Copeland wrote a handbook concerning analogue sound restoration. It is required reading. When Peter died in 2006, I despaired that this would ever see the light of day. In 2008-09, the British Library released it as a free PDF file available here.
The IASA “Green Book” TC-04 Guidelines on the Production and Preservation of Digital Audio Objects can be purchased from IASA. The Second Edition is available online.
The CoOL (Conservation On Line) site has many resources. In particular, read Gilles St-Laurent’s 1996 article on The Care and Handling of Recorded Sound Materials.
The National Recording Preservation Board of the Library of Congress and the Council on Library and Information Resources March 2006 Capturing Analog Sound for Digital Preservation: Report of a Roundtable Discussion of Best Practices for Transferring Analog Discs and Tapes
This Tape Timing Chart is approximate. Most reels will contain a bit more tape than indicated time implies, typically about 6%. The footage is actual.
These timings are for one program. There can be as many as four mono programs on one 1/4-inch tape.
This document discusses the speeds used for most analog magnetic tape recording.
See the tape timing chart to convert speeds and lengths into times.
Note throughout most of the rest of this document we are using the correct ISO form of in/s instead of i.p.s. which is the traditional way of stating "inches per second".
One of the challenges for good sound reinforcement or speech recording is keeping the speaker “on mic”. There are many ways of handling this, but some work better than others. Here are my favourites:
- If the room is quiet and you can do a proper setup, a pair of Sennheiser MKH-416 short shotgun mics, one for the interviewer and one for the interviewee, gives very natural and unselfconscious results.
- For larger groups, I’ve had good results with an Audio Technica AT-822 (or the phantom-powered AT-825) stereo microphone, but the actual voice quality of that mic is inferior to the MKH-416. The high-end is harsher, but, used at a greater distance that is often not as noticeable. The room needs to be very quiet for this to work well, however. This is currently my least favourite approach (of those listed).
- So far, some of the best pickup I have found is a headworn mic–the main subject of this post.
At our church, they had tried headworn mics from Shure and they really were uncomfortable. Whoever selected the units, selected dynamic units and they did not sound all that good. They were retired in favour of the Countryman E6 units (also available from Shure, although I prefer the direct-from-Countryman version with the 2mm cable for robustness).
The Countryman units were working reasonably well, but never seemed to stay in the same place. It was frustrating as it was causing a widely varying sound quality, so we decided to try a DPA 4066 headworn mic on our head priest. The results were outstanding. The unit is comfortable (no more sore ears), it stays put, and it sounds better!
It is no surprise that these are taking over the religious and theatre markets.
A New Year’s view of at-risk audio formats
2024-02-20
2015-01-11
This article was first written in January 2015, with minor revisions in 2018. The revisions made in 2024 are highlighted, like this line. The deletions are struck through.
There are many factors that affect the ability of people like us to digitize tapes for you, our clients.
One of the most difficult issues to balance is the physical space that different formats take up, the ongoing maintenance of these formats, and, to be brutally honest, their return on investment.
What we discovered is that some of the machines we were archiving for future use would not work when they were brought out of storage. Rubber parts, capacitors, and lubrication are probably the most prevalent causes of failure. We have said to clients more than once (with a wry smile), “Yes we can probably restore your tape, but first we need to restore a machine.”
Manufacturer and maintenance depot support for various formats is waning or fully discontinued. Parts are hard to come by, and good machinists with an interest in doing this are either non-existent or very expensive.
So, what formats are at risk:
The benefits of using a voltage audio transmission system in broadcast facilities is investigated. State of the art microphone preamplifier requirements and an ideal voltage system distribution amplifier are outlined. The application of the Peak Program Meter to the new systems and the modified installation at WABC-TV are covered.
Introduction
Over the years, many audio practices have been followed without anyone asking WHY? or IS THERE A BETTER WAY?
The [then (i.e. 1980)] present [but now deprecated] standard for Broadcast Audio Systems is EIA Standard RS 219 [1]. In light of the fact that the [then] current standard was published in 1959 (and this was merely a reaffirmation of an earlier standard), one might imagine that in relation to today's common audio practices, it is somewhat archaic.
The Antioch Broadcasting Network (ABN)
Playing today's date in history when available
Conyers Old Time Radio
Streaming the Widest Variety of Programs from the 1930s, 40s and 50s!
Technical Bulletin No: 1101 – The Lattice Splitting Pad
601 Heron Drive, Logan Township, NJ 08085
Phone: 856-467-8000 • Fax: 856-467-3044
http://www.radiosystems.com
The lattice splitting pad may be used to combine two audio sources into a single audio output or to derive two separate outputs from a single audio source. A characteristic of the lattice pad that makes it very desirable for audio work is the port to port isolation. When used as a splitter, output port to output port isolation is theoretically infinite if the pad resistor values match the input port source impedance. In combiner applications, input port to input port isolation is also theoretically infinite if the pad resistor values match the output port load impedance.
HTTPS for Roku SoundBridge M1001
The SoundBridge M1001 has a lot of protocols the device can work with. But being 15 years old, HTTPS is not implemented. So the radio is dying in slow motion - each time a station is changing from HTTP to HTTPS it passed away for owners of a SoundBridge. Until now. Cause I love my M1001 I made a workaround. So have a look at https://mind.work/2021/01/18/rescue-of-the-soundbridge-m1001/
Years in service: 2004-2008
The Roku SoundBridge Network player allowed you to stream your music library, including iTunes and Windows Media libraries, from your PC to your stereo. The player also made it easy to listen to a variety of Internet radio stations without even turning on a computer. The stylish aluminum SoundBridge was compatible with a customers speakers or stereo and had built-in support for Roku's free Roku Radio tuning service, making it easy to listen to radio from around the world or across town.
- In Winamp, select Media Library. Right-click file to convert > select Send To: > Format Converter.
- Click Encoding Format to choose the format > OK.
- Follow the steps above to convert an entire playlist.
Android Audio Recorder
Android friendly!
Audio Recorder with custom recording folder, nice recording volume indicator, recording notification, recording lock screen activity.
5.0 out of 5 stars Held its own against competition!
Reviewed in the United States on September 10, 2013
Verified Purchase
I was recently in need of closed headphones and curious about what the market offers. I thought I might share my findings with someone in a similar situation. The Tascam TH-02 turns out to be an excellent value among the eight headphone models that I have compared. Below is my review of these headphones. //
Shure SRH440
Without doubt, these are the best of the bunch. In terms of clarity, they are in a different league---perhaps, the KNS6400 is close but also with weaknesses (see above). Treble is sometimes a little on the bright side, but not as bright as the KNS6400's. Some people may find them bright with bright recordings, but the headphones should not be blamed for that. These produce very neutral and accurate sound. Bass is sufficient and often pleasantly strong in the mid- and upper bass regions, but deeper bass is not covered by these cans. Most music recordings do not contain this deep bass, anyway.
I summarize my findings with the following top two picks:
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Shure SRH440: These are the headphones you can safely choose under $100 if what you are looking for is accurate, neutral sound.
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Tascam TH-02: This is a secret gem. At $30, you get really good closed cans. Its overall presentation is not as clear as the SRH440's, but with their price factored in, you cannot complain. They are definitely in the same league as the AKG K518LE (foam pads removed) and the Creative Aurvana Live. It may depend on personal preference, but among the three, my pick is the Tascam. The Creative has a better look and feel, but I'd choose the Tascam for its sound.
If you don’t have Western Electric transformers, you can pick up easy-to-wire isolation transformer boards from Newman-Kees RF Measurements & Engineering, as shown here:
This Audio Hum and Lightning Isolator board from Newman-Kees uses high-quality transformers to isolate lines.
This Audio Hum and Lightning Isolator board from Newman-Kees uses high-quality transformers to isolate lines.
They provide lightning isolation to 1200 Volts and can be strapped for various applications as shown in the schematic. Features include 600 Ohms in and out, primary and secondary center taps, board traces for attenuators and 1/8-inch mounting holes. Cost: $35.50. Email newman-kees-hertel-rf-eng@twc.com.
Frank selected two Electro-Voice 635A omnidirectional mics. Imagine your reporter holding the top microphone within about 2 or 3 inches of their mouth, while the bottom microphone is pointing away from the mouth. Crowd noise is picked up equally by each 635A mic, thus the crowd noise is suppressed — virtually canceled!
You can experiment with pattern types; Frank finds that it works best with identical omnidirectionals, and the 635As are inexpensive, under $150 each.
The first photo shows the parts you’ll need to construct this project. Once you’ve gathered them, follow Frank’s step-by-step instructions.