I would like to test some speaker concepts. The testing doesn't have to be perfect, I would just like some scientific feedback telling me what is the byproduct of each implementation (rather than just trusting my ears). My mic would be my iPhone. I already have a sweep track. I am wondering if there is a cheap and easy way to play my 5Hz to 20kHz sweep track, record playback, and convert it to a FR chart? Any help is appreciated, thanks.
There are apps for that.
Audiotool for Android is one example.
The frequency response might not be linear due to the phones microphone and signal processing.
I use the app together with an Dayton imm-6 which is calibrated. Frequency response might still be altered because of the phone.
But as it sounds this would be a good start for you.
The app can do sweeps, pink and white noise etc.
If you wanna dive deeper into the subject I'd suggest a better mic than the imm-6, like a usb-mic from Dayton or so at least.
Audiotool for Android is one example.
The frequency response might not be linear due to the phones microphone and signal processing.
I use the app together with an Dayton imm-6 which is calibrated. Frequency response might still be altered because of the phone.
But as it sounds this would be a good start for you.
The app can do sweeps, pink and white noise etc.
If you wanna dive deeper into the subject I'd suggest a better mic than the imm-6, like a usb-mic from Dayton or so at least.
Pink noise would be the easiest. Sweeps tend to excite an infinite number of little dips and resonances and give a response that will need smoothing to be meaningful. With pink noise, the response is instantly visible using RTA (real time analyzer) software. Maybe it's possible to use a wired headset that has a better quality mic, or maybe if you have a sufficiently popular phone, there is a correction curve available.
I also use AudioTools, but on the iPhone. A Dayton iMM6 mic is inexpensive and handy for this.
EDIT: Ooops, out of stock Dayton Audio iMM-6 Calibrated Measurement Microphone for Tablets iPhone iPad and Android
EDIT: Ooops, out of stock Dayton Audio iMM-6 Calibrated Measurement Microphone for Tablets iPhone iPad and Android
REW ( REW - Room EQ Wizard Room Acoustics Software ) is a remarkably good piece of software for this application. A fairly low cost measurement mic like a Behringer ( or any fairly flat small diaphragm omni condenser mic ) with a two channel audio interface with a mic input will round out a very powerful measurement set up. RTAs are not useful measurement tools. You want to be able to compare input to output in a transfer function measurement, one that shows you the level of the sound ( frequency response ) as well as when the sound arrives ( the phase response ). Plenty of forum type advice for REW as well as good videos on youtube for more professional software like Smaart but the principles are the same.
Indeed. The sweep is preferred when an impulse is to be gated to isolate the direct response from reflections. Another benefit of the sweep is a much increased SNR.
What is your process of measuring speakers with Audiotools?
I use pink noise in combination with the peak store.
The saved files give detailed unfiltered data and 1/6 octave data.
I find the latter to be too rough to evaluate certain peaks and dips; especially with open baffle speakers.
Also do you find it measures reliably below 100Hz?
Thanks
Jens