greenmachine

They're somewhat less prone to memory than nickel-cadmium but still suffer from it, so it's not a bad idea to drain them at least from time to time.

These Visivox mics seem to be very good on the technical side and well built, but somewhat too large for stealth / eyeglass mounting. It woud be hard to hide them. Try to build microphones as small as possible, you won't regret it afterwards.

SP-BMC-2s seem to be very nice little mics, suited mainly for medium SPLs, limited by their relatively high self noise (like virtually all miniature mics) and a not optimally configured FET amplifier stage at very high SPLs. If you don't record in extreme situations (very quiet or brutally loud), they should give you very good results if set up properly (placement, recorder settings, etc.). You can't know if you'll need attenuator or battery box, these mics could be significantly more sensitive than your current ones (especially in the low frequency region) and thus overload the preamp sooner. Although they seem to be relatively inexpensive at first glance, there are pretty high shipping costs (and maybe other taxes) that make them expensive for the non-north-american rest of the world (ask The Low Volta about actual costs). A solution? DIY.

Not yet, it's just a wet dream at this point.

These suggestions seem to be very well thought out. I have to agree.

A marketing trick: "Fit 45 CDs (in horrible quality) onto one HiMD." or "Transfer music with up to 100x speed (again, in horrible quality)."

Sorry, some registrations, topics, posts & personal messages got lost due to a recent series of unfortunate events. Yes, you can use NiMH rechargeables in the external battery case without problems and no, the voltage does not have to be higher. I think you're confusing it with the power adaptor dc input, which indeed needs a higher voltage (3V).

It totally depends on the sensitivity of your microphones what settings suit you best for certain locations. All you can do is to experiment. The scale is just useful for comparison. If you have used 15/30 in a certain location for example, have peaks at -20dB and want to have peaks at -6dB next time recording under the same circumstances, you'll use 23/30 to amplify by roughly 14dB according to the scale. (24-10dB)

I think The Low Volta had the same problem of unresponsive buttons with his nh900 and had to replace/repair it. Maybe he'll appear here and offer some advice.

You can't improve sound quality by transcoding from a lower to a higher bitrate, in fact you'll loose some. If you re-rip from a lossless source directly to a higher bitrate, the quality can be significantly improved though.

I can't await to upload some of my new recordings to the gallery as soon as it's working. Never touch a running system until it's proven to work.

You should patent these sentences.

'soundalike' bought a DIY microphone and battery module from me. Both times fast and reliable payment. Recommended without reservations. Happy recording.

There was a question about headroom and the dB scale from 'MDnewuser' before the 'accident' happened. He asked me to mail him the dBscale for the NH700, which i've tried but couldn't reach his email address and got a Delivery Status Notification (Failure) message instead. So i'll bring it up here again. Maybe he'll appear here and repeat his specific question. Anyway, here's the scale, taking level 30/30 as 0dB reference: Values below approx. level 10/30 are of no practical use and increasingly inaccurate. 30 / 0dB 29 / -1.80 28 / -3.61 27 / -4.18 26 / -5.97 25 / -7.77 24 / -9.57 23 / -10.14 22 / -11.94 21 / -13.74 20 / -15.54 19 / -16.11 18 / -18.10 17 / -20.08 16 / -22.06 15 / -24.05 14 / -26.02 13 / -29.59 12 / -30.97 11 / -32.96 10 / -34.95 09 / -37.94 08 / -40.95 07 / -43.92 06 / -47.84 05 / -51.80 04 / -57.67 03 / -61.48 02 / -65.26 01 / -72.91

How to build a miniature battery module / box: What do you need it for? The battery module is used to power electret (pre-polarized conenser) microphones. Electret microphones need a small bias voltage of approx. 2-10 Volt for operation (with a tendency to work cleaner close to the upper limit). MiniDisc- and other recorders often provide such a voltage at the microphone input ('plug in power'), but not at the line input. If you want to record high Sound Pressure Levels (like amplified music/instruments, concerts, everything you would call 'loud') without noticeable distortion, you should use the line-in of your recorder. The line-in uses a significantly lower pre-amplification than the mic-in, which would overload soon at high SPLs. The line-in provides no bias voltage ('plug in power') for the microphones though, thus the microphones need to be powered externally, which is the task of this module. Usage: The module is operated by a commonly used 9 Volt battery (MN1604 / 6LR61). The microphones' connector belongs to the battery module's jack - the module's connector belongs to the recorder's input jack. No harmful voltage will enter the recorder. The current draw is usually very low (about 0.5-1 mA), thus the long battery life of about 500 - 1000 hours with an alkaline battery (recommended). it's not necessary to unplug the battery after use, just disconnect the microphones and there will be no current flow. It is advisable to wrap some tape around the gap between battery and module to avoid accidental touching of the battery poles with metallic objects like keys. Clean the stereo connector from time to time with a damp cloth. How to do it: Find a 9V battery (MN1604 / 6LR61), no matter what condition, open it as seen in the pictures. All we need are two outer plastic shells. Recycle the batteries. Other parts needed: A small piece of circuit boardTwo polarized or non-polarized capacitors (doesn't really matter, though some audiophiles swear on non-polarized ones, which are usually significantly larger). The capacity should be at least 1µF (micro Farad), otherwise you will get an audible low frequency roll-off. The voltage rating needs to be at least as high as the battery voltage. Two resistors, preferably 1% metal film for low tolerance and thus better channel matching. Carbon resistors tend to have tolerances of 5%. If you have a multimeter, you can match them yourself. Most electret mic capsules work best with resistors in the 2-10kΩ (kilo Ohm) range. A lower value (close to 2k) will deliver more power to the mics, but the channel separation will suffer. With a higher value (close to 10k) you will have a good channel separation, but the mics will get a bit less voltage. The difference is hard to notice though - if you have the choice, use something from the middle, otherwise use anything that's available between 2-10kΩ.One 1/8" / 3.5mm stereo jackOne cable with a 1/8" / 3.5mm stereo plugSolder the parts to the circuit board, as seen in the schematic, the stereo jack belongs to the side of the mic input, the cable with connector to the output side. If the jack is not a closed type, wrap some tape around it to prevent glue entering the inside. Solder the board to the battery connector. Fill the gap with hot melt glue. Cut a piece off the top plastic shell so that there's place for the jack. Loop the cable around to the opposite side of the jack so that there's no stress on the connections when in use. Put the top shell on it and fill the gap with hot melt glue. Because of its (lack of) size, this is a rather advanced design. If you don't feel handy with the soldering iron, you should probably head for a larger design, but you'll get the idea. Update: Alternative design - no need to disassemble batteries, which might not contain required parts, all you need is a (disassembled) standard 9V connector from an electronics store and some more hot melt glue. It perfectly covers the battery connectors: Update 2008-03: Here's a new idea: battery box built into the lead of the microphone. Uses diodes to forward the plug-in power from the recorder's mic-in jack. Can be used with or without battery. The battery clip should not be touched if used without battery.

You don't even need to disconnect the battery. There is no current flow if you disconnect the mics, thus Volta's 'box' can be taped.

No serious abuse yet since i use them only ocassionally and virtually exclusively for recording. I treat non-mechanical mp3 flash players way less carefully (they've been built for rough use as opposed to the rather delicate MD technology). LOL @ KJ.

For the mixing part - i'd really do it afterwards unless your two sources are very different in volume. There's a large variety of audio editors, including the free, but some kind of limited in its capabilities Audacity. For the schematics, this site should be helpful: http://www.minidisc.org/homemade_mics.html

With a separable 'binaural' microphone you could also use one channel for the guitar, one for the voice if you plan close miking and mix it later in some kind of editing software. For far miking it's also preferrable if set up properly IMO. Clipping can occur if you record loud music (with highly sensitive mics) through the mic-in of the recorder. In this case an attenuator or a 'battery box' through line-in usually helps. For recording acoustic guitar and unamplified vioce there should be no problem with clipping though. The SP-BMC-2 seems like a (very) good deal in your price range if you don't feel like to DIY.

Now that's a real 'box'. Does it really have to be that sturdy? Looks like a tank could drive over it.

Although not exactly my kind of music, i always liked this site for all sorts of ambient/electronic music, it also has a subcategory for 'industrial techno', check it out: http://www.artistserver.com/area.cfm?area=1

Had a Kyuss song in mind when choosing mine.

My favorite pianist Keith Jarrett in one of his (in)famous poses, propably also humming along while at it.

Caught this guy recently in a tunnel. You can clearly hear him walking from the left to the right while playing his pipes if you're listening with headphones. Have been using HRTF microphone placement (mics attached to glasses, facing forward). Doubt a one point mic could capture room acoustics in such a realistic way. --> click here <--

You'll run into (distortion) problems if you plan to record loud music through the mic input, propably even with an attenuator, since the mz-r700 lacks a low sensitivity setting. You'll need either very low sensitive microphones and/or preferrably record through line-in at high SPLs.