Reflection free (or minimised) mic setup

[Dave Bullet]

I'd never really paid much attention to mic placement and the boom and clip that holds the microphone. When Andrew Jones suspected I had some mic related ripple in my response, I switched to a long pole boom in line with the microphone. Voila!, ripple greatly reduced. A small pointer for those who want...

[Reet]

Before Christmas I had been building a test rig. Over the holidays I was sick and without energy to do much and didn't want to leave the house, what better time to run through a bunch of driver tests. I ended up testing everything I had sitting on my shelves, as well as pulled a few drivers that I'm...

[Reet]

...came from AliExpress. "Best" is a subjective of course, as I have others that do better <2kHz. But >2kHz this is of the lowest 3rd harmonic I've seen, and the lowest over a wide frequency range of anything on my shelf. Tested at 2.8V, I did test again at +5dB (~5V), 2nd order went...

[JonMarsh]

What's the oldest piece of speaker test gear you have?

I am cleaning out a storage unit in CA, and a week ago brought this back home...




This is a White Model 140 Audio Analyzer- it outputs pink noise, and then via an external microphone or mic and preamp...

REW is a powerful tool, as is EQ, but getting it right can be challenging. The first step to achieving a good EQ profile for your space is to take in-room measurements. This document will detail an easy method to achieve quick and reliable results.

For room EQ, a single measurement at your listening location will not produce a good depiction of the overall room response. An average of many measurements around the listening area should be completed to create a room response for equalization...

[DaveFred]

Hello Everyone,

I am looking to build a speaker with an 8" woofer and a 4" tweeter in 1.5 cubic feet or less. These are the constraints, please don't make suggestions on what to try outside these guidelines.

Because I do not know which are the best drivers to choose,...

Minimum phase for a speaker can be described of the phase of the frequency response of the speaker at it’s acoustic centre, or the phase without any excess phase or “time of flight” included. It can be calculated from the speaker’s frequency response using Hilbert-bode transform, or HBT. When comparing multiple minimum phase responses, we can say that the responses occur at the same point in space, ie. there is no physical distance between them. When measuring speakers and processing the...

With a simple jig, loudspeaker impedance and T/S parameters can be easily measured with LIMP. The same jig may also be used to measure component value for resistors, capacitors, and inductors, as well as measure transfer functions of passive and active filters.

The setup is quite simple, the following diagram is taken from the LIMP manual:
https://artalabs.hr/download/LIMP-user-manual.pdf

Measurement Jig

This instruction is following what...

Here's a schematic for a simple dual channel measurement jig, which can be used with ARTA, REW, or SoundEasy. This jig is made with USB audio interfaces in mind, so the use of 1/4" TRS connectors is recommended for this purpose. Main reason is that the 48V phantom power on audio interfaces is only present on the XLR pins, so use of TRS will ensure that 48V will only ever be present when a mic is connected, not when using this jig even if you leave phantom power turned on.

R1 should...

What does single channel or dual channel measurement really mean, and what are the implications of choosing one over the other? This document aims to help answer this.
Strictly speaking, a microphone is a single channel of audio input, in that it is a mono signal. USB microphones which include integrated ADC and USB codec can be considered a single channel device.

Dual channel would be a measurement which includes a second channel of signal input in addition to the microphone....

[krizork]

Hello everyone,
First time post, although I've been scrolling this forum for quite some time.

My question concerns the production change in the AST2560 (https://www.htguide.com/forum/showth...lease-chime-in).

In...

[Jim Holtz]

Just a heads up that between Curt and Efalegalo they have come up with a modification to the original crossover that works better with the new production AST2560's currently shipping. Meniscus has also committed to testing every AST2560 driver ordered to assure the correct crossover parts are included...

[Zvu]

On axis and roughly 30 deg off axis. Calibrated Behringer ECM8000, M-audio FastTrack USB, Holmimpulse. Gate is good to about 85-90Hz.

Measurement conditions



Midwoofer and tweeter





Simulation of Kef's factory crossover>...

[Efalegalo]

Hi All,

I just recently completed my build of The Bordeaux and needed help with crossover issue I'm having.

See attached picture of the frequency response. I have a massive dip in the 1.25Khz - 4.0Khz range.

I've checked the crossover a 100x.
...

[Zvu]

Measurements are done in factory cabinets, gated, at 1m distance mic at tweeter axis - gate is good to 250Hz. Holm-impulse, calibrated ECM8000, M-Audio Fast Track II USB interface Dell Inspiron notebook. Vertical grid is 40dB, with 1dB resolution.

Link to gallery:

https://...