Need a sound recorder, what should I get?

Hi!

How about a cheap tape recorder? You could pick up a battery operated unit very inexpensively secondhand (and for not much more brand new). It's cheap, simple and a (still) large installed base of tape players means you can play the recording almost anywhere.

What you really want to do is look at the microphone you are using. I think you'll want a microphone with an omnidirectional pickup pattern and the ability to pick up sounds from afar.

Unidirectional and "noise canceling" microphones are probably not going to work well for this application.

William

What exactly are you trying to achieve? If it is some kind of evidence that your neighbour is making noise, how are you going to tell from the recording exactly how loud the noise is?

Chances are the spillage is actually very quiet, which is why you have not so far achieved a good result.

Thank you for your reply. I fear you are correct that the front end is most important - the mike and preamp.

In defense of digital vs mechanical, the Sony has 1 1/2 hr of 'perfect' MP3 and more than 340 hours of plain recording [even speech recognition software] and the design is supposed to be for individual, conference room, or that tiny sound from the corner. However, the playback sounds more like excessive tape hiss. My wife said 'typical sony' ...she once had a walkman that was no end of trouble. Also, heads up, comes with CD Sound Editor software and a DVD with Speech Recognition SW, both will only install on OS of Win2000 or better.

As you may know, picking up high frequency is no problem so this recorder apparently shifts everything into the treble. can't hear thumps and bumps, but the slightest scritch/scritch is gangbusters. For that reason may not be the right choice.

Apologies for not being scientific, so try again. Apparently the Sony ICD SX700D is inadequate in the low frequency spectrum, below 300Hz, probably deems that not very important because that's adequate for speech. However, the higher spectrum where ruslting of paper resides, the recorder appears to enhance that sound bandwidth. As a result, I fear the unit will not fulfill the function I need.

I just realized I was playing the sound back using the built in 1 inch diameter speaker. Duh! Will try using earphones with better fidelity to see if the lower spectrum exists. I also have the capability of storing as a 16 bit .wav file, so I can do some very esoteric manipulations using a Matlab clone, octave. I'll see if I can find flatness of the recording system and the noise floor of the recorder. At least I'll find the noise density coefficient.

Robert

As mentioned above, a tape deck is cheap and effective. A second hand stereo one (be sure to get one with mic inputs) and a couple of good mikes will knock the socks off any mp3 type device, for the same or less money. see

for specs.

-B

Why on earth would anyone recommend buying a last century Cassette Deck, the OP already has a digital recorder capable of 16 bit 44.1k recordings, the same quality of CD.

You might be able to improve the recordings by using a better quality external mic plugged into the mic input jack and placed accordingly.

I suspect though that the problem is not the equipment, but rather the unrealistic expectations of the OP.

Hi!

It's going to be a good starting point. But almost any portable cassette recorder I've used did a good job of picking up sound from all the room. It's a compromise of course...the more room noise you pick up, the less chance you have of being able to focus on a specific source.

A tape won't match that, but my thought is to wait until the noise occurs and start recording immediately. Announce the time of day and then just let it roll. Or get a tape recorder with voice operated recording. I have a Realistic Minisette 20 here right now that does this with two sensitivity levels. Its built in speaker is nothing to write home about, yet the recordings are pretty good. I'd guess it was made before the heyday of microcassettes (and handily beats those in terms of audio quality).

Which would probably work from a tape recording as well, although you're likely to be able to do a much better job by transcribing it yourself if the need arises. Speech recognition is still an imprecise concept.

Consider going further than that -- play the unit into your stereo receiver.

While that sounds very interesting, why do you want to do that? It sounds like a lot of work to me, and I don't understand the value of the outcome.

William

Hi!

Because it's cheap, easy and simple?

You don't need ultra-high-fidelity to capture a record of someone's making a disturbingly loud amount of sound. The cheap point is rendered moot by the presence of the more expensive recorder, yet the simplicity and still massive installed base of playback equipment can't be argued. Plus, the tape recorder has the advantage in cost--if something happens to it, you aren't out a fortune!

William

Also for the purpose of the OP he is better off, using an old recorder, because the new ones have the nasty habit of "equalizing" the mic input. As he needs a record of sound level, that is not a very good idea.

Use a computah. Scanner recorder will only record when there is something worth hearing and doesn't gobble disk space:

--
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

Rubbish. Once his CD quality recording is made, with what he has at the moment, it can then easily be transferred to a PC via USB into free editing software like Audacity, where you can do all the equalising, level shifting, noise reduction and analysis you like. You can't do much of that with a Cassette Player.

The recorder isn't as important as the microphone and the playback loudspeaker.

Is the noise coming through in one place (e.g. hammer drilling or tap dancing) or is it diffuse? If it is diffuse, an omnidirectional mic might work best.

If the noise is predominantly low frequency (e.g. boom box) a cheap omnidirectional mic will generally have a better low frequency response than a cheap cardioid. The big problem you will have with L.F. noise is demonstrating it realistically to someone, because loudspeakers are rarely flat at such frequencies and the bass from headphones will depend on their positioning on the listener's ears.

Investment in a cheap analogue sound level meter will help; then you can calibrate the recording level and match the playback level to it when you come to demonstrate the problem. Use the dBC scale if the noise is predominantly L.F.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

Why? A recording would prove nothing. You need to measure sound levels, not record the sounds. A sensitive microphone would pick up the smallest of sounds so there would be no way to determine that the neighbor's noise/sounds were a problem or not. As well, what does your lease say on noise, and his? If it is not covered, prepair for a long hard time.

I'd use the threat of moving out at the end of my lease.

s

Thank you for your reply. Curious, why dBC, not dBA?

The sounds are being transferred through above tenant's flooring and then through our ceiling. It is possible to tell origin, but it's like a spotlight diffused onto a sheet of paper - you can tell where it's coming from a little.

I like the idea of calibrating to verify the recorded sound presentation recreates EXACTLY what was there, but may be difficult in a large courtroom...

Any recommendations for readily available sound level meters? the Sony has vu meters on it, but I think they're relative and not absolute.

I did notice that the low level sounds using this mike/preamp of the Sony appear to be sitting around the last 5 to 10 levels of digitization. I did a 'quiet' recording and was going to do a histogram to find out. But there was just enough room noise to prevent that. there's a spike around 100Hz and a lesser one again near 200Hz, but don't know where that's coming from. Too high for air/ fan noise? two PC's in the room were running. on 60Hz mains.

Naive question: does quantization cause hiss? only distortion?

Not sure, but removing the low frequency spikes the noise spectral density does appear reasonably flat, except for the what appears as 1/ f noise starting to come up around 50Hz, but who hears that, right?

Robert

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Will check out Audacity, thaks for the reference.

We have our TV on while this is going on, that makes a great reference and/or talking and living normally as a comparison.

Lease says "no tenant can operate a TV, Musical Device, of Computer Sound System in a manner that disturbs another tenant" no hours of operation, no arbitrary interpretation. That's why we moved in.

I'm a firm believer in victims should not take action, perpetrators should.

if our landlord cannot, or will not, provide quiet enjoyment, no waiting for end of lease, they have failed, and now must pay for move and all costs.

This yet another example of a question that should have had a single response, with the thread ending at that point.

You do not need a recorder, except perhaps to make a record of what is disturbing you. You need to borrow a sound-level meter to measure how loud the disturbance is. Otherwise, there is no good reason for the management to believe you.

----- The Lady from Philadelphia

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Well Put!!!

dBA was originally intended as an indicator of the potential of industrial noise to cause hearing damage, it had deliberately reduced sensitivity to low frequencies because they caused proportionately less damage (and also to make an advantage out of the fact that the microphone of the original sound meters was not very sensitive to bass anyway). The use of dBC will give you a level measuremement over the normal hearing range.

You can demonstrate the exact effect you have been suffering to any official who comes to visit you, but a meter reading in dBC, coupled with a log of the times it occurs, is often sufficient to convince them. You wouldn't normally be expected to demonstrate it in a court.

Unless the noise is of some particularly irritating character or requires specialist identification, you may not need to record it at all. The action you take will depend on three properties of the noise:

1) Its loudness 2) What time of day or night it occurs - and for how long 3) Its annoyance factor (is it a hum, intermittent banging noises, thudding bass, sounds of a murder, bagpipe practice?)

...only the third property might need a recording to demonstrate the point you want to make.

There used to be a simple SPL meter, with analogue readout, available from Tandy / Radio Shack at a very reasonable price. Its accuracy wasn't certified, but mine was spot-on when I checked it against an expensive calibrated meter.

If you are contemplating legal action, you might have to get an 'expert' to take legally-valid measurements for you.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

Excellent advice. Listen to the man...