Hiss-trionics when Recording (2017)

Hi folks,

I’m here because I don’t know where else to go, even to ask this question. I note after a quick search of the “Mac” forum that there’s some posts from pre-2014 an couldn’t find something more recent or quite like my question.

First – tech specs for my setup:
Mac OS Sierra + iMac 24"
Audacity 2.1.2, Garageband CS5, Soundbooth CS5 Trial
Neewer NW-700 Condenser Microphone, Tascam iXZ Mic & Guitar Mobile Interface, Philips SHP1900 Over Ear Headphones.

Setup and Room:
Background ambient noise at 1m from the screen oscillates between 45-50dB. (dB measured with an iPhone App.)
The mic is set up, upside down, on a boom stand 1.5m from the computer at eye level, with a pop filter and a fluffy, cat’s tail wind filter inside an attic room with sloping roof. no other acoustic treatment has been applied (that is still to come.)

Statement of Problem:
I noticed that each time I speak in the direction of the mic (offset 45° to my right, whilst looking at the screen) the hiss in the recording noticeably increases.
The noise/hiss in the gaps of silence - active mic passive state, is soft and single level however when in operation - active mic active state the noise ramps up and apparently seems to taper off when moving back to passive state.

This bugs me like crazy.

I’ve tried changing the mic, no dice. I’ve tried changing the cables. I’ve tried changing the interface (even blew one up) still nadda. I’ve tried looking around the web, stumbled across a little bit of lots of interesting stuff about sampling rates, but… not enough for me to understand. I’ve looked for ‘youtubials’ to see if there’s a walkthrough, etc. etc.

I don’t know enough to troubleshoot this further. I’ve attached a raw recording, unedited, that gives the baseline noise and example of the problem I’ve got.

Any advice or guidance would be most welcome. I’m trying to knock as many bugs out of the system before pursuing a possible, new career as a, ‘Voice Actor.’ But if I cant sort the hardware and software out, I may be heading for ruin before even getting a followup start. Cheers, thanks for taking the time.

I’ve never met an adapter that went in via the analog connection. Fascinating. I don’t think I’d have the bal… nerve to do that. You should go into the Mac setups and make sure they’re flat and not trying to help you.

Apple (upper left) > System Preferences > Sound > Input. See that, I guess, Built-In Input is selected and [_] Use Noise Reduction is not selected if it’s available as an option.


We had a discussion about Phantom Power recently. Please note that the info sheet for the Tascam iXZ Mic & Guitar Mobile Interface doesn’t mention 48 volts anywhere. That’s also missing from the labels on the front of the unit. That’s a danger sign.

The info sheet for the microphone specifies 48 volt Phantom Power. Those are different and can cause problems.

NOTE: Sound Card, 48V Phantom Power, 1/4" to XLR Cable & XLR to XLR Cable are needed to purchase additionally.* >

This is a snap from one of my devices.

So your microphone and interface are fine as long as you don’t plug them together.

Koz

I can confirm you’re not imagining it . The hiss is in the range 100-600Hz , and reduces in volume about half a second after you stop speaking , ( as if a real-time noise-gate was in operation ).

NW-700+iXZ+Wind.png734×449 128 KB

The Tascam iXZ provides phantom power from 2 internal AA batteries. I suppose you put those batteries in?

According to Tascam, it’s only compatible with “iPhone3, iPhone3GS, iPhone4, iPod Touch 1G,2G,3G, iPad1G and 2G”.

It should work with a Neewer BM700, as this is an electret mic. But that is, providing you use the XLR to mini-jack cable. I have no idea what happens if you use the XLR-to-XLR cable.

But it also states “No battery required when used as instrument preamp”. And that baffles me. It uses pip power to power the Hi-Z amp?

BTW, I believe the Neewer also comes with an XLT-to-mini jack cable. Have you tried it directly on the Mac, without the Tascam?

I suspect between Trebor and kozikowski’s responses they’ve nailed the issue, at least in part.

First, open System Preferences → Sound, click the “Input” tab, then un-tick “Use ambient noise reduction”.

I suspect once you do this, problem A goes away - the noise is now constant and not just when you speak.

Now, problem B - why are you getting noise. The Tascam iXZ unfortunately isn’t a very good choice of mic pre-amp (it’s not really an audio interface). This is because it just uses the built-in microphone input. The Tascam iXZ itself is a bit noisy, and I suspect the microphone input of the Mac is also adding further noise (though less so).

So, if you’re going to keep using the Tascam iXZ make sure you have it setup correctly. I’d suggest you do this:

1. Make sure it is switched to the Microphone option on the iXZ
2. In the System Preferences → Sound → Input option, turn up the “Input volume” to the maximum
3. Now adjust the “INPUT” volume on the Tascam iXZ until it is as loud as you can reasonably get it, without the “Input level” meter in this Preferences window ever reaching the maximum volume.

This should minimise the amount of noise from the Tascam iXZ.

Then, you can use a noise reduction plugin on the final recording if you like to reduce the noise further.

Now, this is the crude option, but makes do with what you’ve already got.

The better option would be to buy an actual audio-interface that plugs-in to the USB or Thunderbolt ports of your Mac. This will have much less noise for the majority of devices.

I hope this helps. Let me know how you go or if you have questions.

Hi folks,

thanks for all your replies.I recently received an Audient iD4 USB audio interface. its as plug and pray a device as you can expect, for OSX. It works! with the Neewer MW-700 mic, much to my relief, I had thought that perhaps the problem lay with the mic and that it too had been fritzed.

So, as for the iXZ, yeah I’ll need to tweak that a bit further.To answer some questions:
:– 2 x AA batteries were installed.
:– the 3/8th combi headphone/mic jack was trialled with both the iMac Headphone Input AND the Line In input.
:– I tried another XLR-XLR cable with the same result
:– haven’t yet tried the iXZ with acceleration switched off.

As for the read caution above this forum on my screen, I use OS Sierra and the latest download of Audacity which was installed from a DMG

I will still try to troubleshoot this iXZ on my iPad 1.0, iPhone 6+ and my iMac/OS Sierra and see what comes of it. However, I will be moving forward with my home studio using the iD4, as it simply works.

As for studio noise level reduction, so far, I’m using a noise reduction setting of NR 9db, 12 sensitivity, and 0 bands. When I swap sensitivity and NR I get a sort of random warbling effect.

The iD4 is set at 3/4 dial gain, and max output vol of matched green-yellow leds. I don’t get any clipping even when making a loud finger snap close to the mic. I have some acoustic treatment to follow through on, its a work in progress, but I learn a little each day. Next two days work on the job days, so I won’t get to tinker until Sunday at the earliest. Cheers, and thanks for all the help, so far.

The ID4 seems to be the real thing. It supplies 48v Phantom Power and has the provisions for Zero Latency Monitoring for when you start doing overdubbing.

The step up to XLR three-pin cables is serious. Most obvious is the ability to use 48 volt Phantom Power with microphones that need it. Not so obvious is the ability to put the microphone whereever you want it. If everything is working OK, you can extend XLR cables to 50 feet or more.

It’s called Phantom Power because the ID4 is sending battery voltage (48 volts—imagine my surprise) up to run the microphone electronics and allows the microphone to send the voice voltage back down to the ID4 on the exact same wires without interfering with each other.

Even without the phantom power system, three-wire XLR cables automatically reject cable noises and interference which is what allows you to go long distances without troubles.

You may not go through any adapters in the XLR string. Any adapters or cable conversions kill the advantages. If you decide to put filters or other devices in with the microphone, they have to say clearly in the instructions that they support Phantom Power.

The common A15HP voice filter …

http://www.shure.com/americas/products/accessories/microphones/microphone-problem-solvers/a15hp-inline-high-pass-filter

…will pass phantom power and still do its job.

http://shure.custhelp.com/app/answers/detail/a_id/3872/~/a15hp-hi-pass-filter-and-phantom-power

Note that even with all those advantages, you can still have electrical noise problems if you’re trying to record next to a defective electric motor or have bad house wiring.

Koz