Topic: [MM-HLSC-1] Distorted recording... Brickwalling ? Weak battery ? Anything else ?

[fandelive]

Hi,

I recently taped a very loud rock show in an arena and the bass drum sounds very distorded.
Here's a 1 minute mp3 sample you can download : http://cmlien.free.fr/nback_sample.mp3

My gear : MM-HLSC-1 (on hat) > SP-SPSB-6524 (no bass roll-off) > Edirol R09-HR @ 24/48 (line-in, 30/80 rec level).

The mics are said to be able to handle a 138 db SPL without a battery module, and they were powered !!!

Here's what I got from the audio editor (picture) : http://cmlien.free.fr/audioed.png

The sound should not be so distorded.


So, this leads me to 3 questions :

1. How would you call that problem (brickwalling, distortion, ...) ?

2. Where does this problem come from ?

a. electronics failure with the battery box, recorder or mics,
b. weak battery in the battery box,
c. recording level set too high,
d. show was too loud and the mics couldn't handle the SPL,
e. I stood too close to the speaker,
f. anything else ?

3. How do I get rid of that distortion problem with my next tape (getting a preamp, anything else...) ?


Thanks in advance for your help,
-Fandelive

[DSatz]

Unfortunately I don't have time to download your recordings, so this will have to be a general answer.

If you look at the waveforms of your original recording in any audio editing program (with absolutely nothing done to the signal such as "normalizing," etc.), and the peak levels are as high and/or as low as they can go in the digital realm ("0 dB" or "full scale" or "100%" or whatever you choose to call it), then you had your recording level control turned up too high. It might not be the only problem with the recording, but that much would at least be confirmed. The meters on some recorders don't always show when the signal levels are too high, unfortunately.

If on the other hand the peaks of the recorded waveforms never reach 0 dB/full scale/100%, and yet the waveforms are flattened out at the loudest points in the sound, then some piece of circuitry was overdriven or overloaded before your setting of the record level could even take effect. By "before" here, I mean "earlier in the signal path from the microphones to the recording medium." That could be the circuitry of your microphones (due to inadequate powering or connecting them to too low a load impedance), or it could be the input circuitry of your preamp or recorder.

The recording level control of most recorders isn't part of the very first stage of circuitry that the signal "sees"--generally there is a circuit stage that boosts the incoming signal voltage by a certain factor (a "fixed gain" stage) and then feeds it to the circuit stage that the level control is a part of (a "variable gain" stage). If the signal from your microphones is too high in voltage for the first stage to handle, then that signal will be distorted before it ever reaches the record level controls or the meters. If that happens, you can set any levels you want, and what you get will more or less match what the meters are saying, but the signal will still be distorted.

I suggest that you begin by seeing which of the above descriptions comes closer to what you've got in your recordings.

--best regards

[fandelive]

Hi DSatz and thank you for replying !

Without any doubt, I had my recording level control turned up too high on the second tape.

But that's not the case on the first one and you can still hear some minor distortion on bass drums.

[darktrain]

There has been plenty of documentation here on the board with the hlsc's and they will definately distort in loud spl situatioins, chris church has done the testing, unless you have a 4.7k mod done to them, i have a set and have the mod and now i just go mic in with them with great results in loud rock/metal shows and for quieter stuff i use a 9100 pre, by the way roll off is useless when using cards, if you are using omnis and it seems boomy it would probably help

[bugg100]

Please change your 35 meg samples to mp3....

[fandelive]

Post edited with mp3 sample and audio editor screenshot.

[bugg100]

I'll grab those later after I get home and contribute my 2 cents....

[Belexes]

I had those mics and had Chris Church mod them and I still had issues with them in high SPL situations.

Dump them and get CA mics. 

[fandelive]

I had those mics and had Chris Church mod them and I still had issues with them in high SPL situations.

Even when powering them with a battery box or even when using a pre-amp ??
That's sad because I like their sound much more than the CA-14's (just a matter of personal taste). 

And yes, I'm thinking about asking Chris Church to mod them.
Will this affect the sound quality (changes in highs/mids/lows restitution, adding noise...) in any way ?

[yousef]

I have a pair of HLSC-1s that the previous owner got Chris Church to mod, I don't use them often but they don't seem to have any problems with bass/volume.

If you're keen on the mics, I'd definitely consider having Chris do the mod before dumping them for another set.

[darktrain]

I had those mics and had Chris Church mod them and I still had issues with them in high SPL situations.

Dump them and get CA mics. 

I have never had a issue with them since the mod and have been i extremely loud spl situations, in fact i don't even use a bb or pre in those situations, i just go mic in on the M10 and before that the pmd620 with great results, i have owned lots of small mics(at853, at831,dpa4060,dpa4061,ca11,ca14) and think the hlsc(senn mke 40) sounds the best and clearest, some have complained that they lack bass but if you are close to the source this is not the case usually, i would say your set may have issues beyond that mod if you still have issues

[ilduclo]

sure sounds like weak battery issue to me if the mics are rated to 138. I'd go to a show that you don't care about the results (some crappy local band) and experiment with the settings on the r9 with a new battery.

[Belexes]

I had those mics and had Chris Church mod them and I still had issues with them in high SPL situations.

Even when powering them with a battery box or even when using a pre-amp ??
That's sad because I like their sound much more than the CA-14's (just a matter of personal taste). 

Yes, ran them with the CA-9100.

[fandelive]

The 4.7k mod option sounds great to me, but I really need to know if it won't alter the "sound signature" of the mics. If you can tell me I'll get the exact same high/mid/bass results than before they were modded, then I think I'll go for it !

[Belexes]

I think Chris just did his mod and lowered the noise floor.  I actually might get those mics again, but not mod them and use them for quiet stuff.