I'm going to perform the full set of Horizontal and Vertical measurements needed by Vituixcad for designing a crossover for a TPL-150H + AE TD12M (will use a Monacor DSM-48Lan for Active crossover), following the process described here.
I have a Cross Spectrum Labs UMIK-1 bought in 2017, which i has going to use for this, but given that the Vituixcad advises against it, i was considering buying a cheap Behringer ecm8000, and use the UMIK-1 to create a calibration file to it.
I contacted CLS to inquire about how accurate the UMIK-1 should be given it was bought 4/5 years ago, to which they respond:
So i've been researching and trying to understand what to do, and this basically sumarizes my options:
1 - Accept that 1db is not relevant, buy the ecm8000, and use the UMIK-1 to calibrate it: Total cost = 40€,
2 - Buy the ecm8000, and send it to hifi-selbstbau, they offer a calibration service for both 0º and 90º, available here: Total cost = 40€ (ecm8000) + 40€ calibration + 30€ shipping (both ways) = 120€,
3 - Buy a EMX-7150 from isemcon, available here for 250€: Total cost = 250€ +15€ (shipping) = 265€,
4 - Sell the UMIK-1 (should be able to get at least 50€), and get a new UMIK-1 from CSL (and use to calibrate the ecm8000), it has a total cost of 160€ imported from the USA: Total cost = 160€ - 50€ + 40€ (ecm8000) = 150€.
5 - Calibrated UCM800 - Don't know how good the calibration is: Behringer ECM8000 calibrated
On 2), i don't know how accurate the calibration from hifi-selbstbau is, or how it compares to the CSL or the isemcon, but i assume it won't be as accurate.
On 3) Isecon now only calibrates their own microphones, and does it for a 38€ cost.
Basically i think i only have two options, either accept the potential drift from the UMIK-1 and just buy the ecm8000, or if i go with a calibrated option, it makes sense to invest in the long term, get the EMX-7150 and calibrate it every few years.
How much impact does a non perfect microphone has in the final result? Maybe it doesn't matter, maybe it does, i simply don't have the experience to know it.
I have a Cross Spectrum Labs UMIK-1 bought in 2017, which i has going to use for this, but given that the Vituixcad advises against it, i was considering buying a cheap Behringer ecm8000, and use the UMIK-1 to create a calibration file to it.
I contacted CLS to inquire about how accurate the UMIK-1 should be given it was bought 4/5 years ago, to which they respond:
So i've been researching and trying to understand what to do, and this basically sumarizes my options:
1 - Accept that 1db is not relevant, buy the ecm8000, and use the UMIK-1 to calibrate it: Total cost = 40€,
2 - Buy the ecm8000, and send it to hifi-selbstbau, they offer a calibration service for both 0º and 90º, available here: Total cost = 40€ (ecm8000) + 40€ calibration + 30€ shipping (both ways) = 120€,
3 - Buy a EMX-7150 from isemcon, available here for 250€: Total cost = 250€ +15€ (shipping) = 265€,
4 - Sell the UMIK-1 (should be able to get at least 50€), and get a new UMIK-1 from CSL (and use to calibrate the ecm8000), it has a total cost of 160€ imported from the USA: Total cost = 160€ - 50€ + 40€ (ecm8000) = 150€.
5 - Calibrated UCM800 - Don't know how good the calibration is: Behringer ECM8000 calibrated
On 2), i don't know how accurate the calibration from hifi-selbstbau is, or how it compares to the CSL or the isemcon, but i assume it won't be as accurate.
On 3) Isecon now only calibrates their own microphones, and does it for a 38€ cost.
Basically i think i only have two options, either accept the potential drift from the UMIK-1 and just buy the ecm8000, or if i go with a calibrated option, it makes sense to invest in the long term, get the EMX-7150 and calibrate it every few years.
That's what i'm trying to understand
How much impact does a non perfect microphone has in the final result? Maybe it doesn't matter, maybe it does, i simply don't have the experience to know it.
Last edited:
A broadband (low Q) 1dB high frequency delta is definitely audible. I prefer to start voicing with a design that accurately follows my target curves as close as possible therefore I consider 1dB to be relevant.
Why does Vituixcad not work with the Umik? The big change over time will be sensitivity and a smaller change in HF response. The transfer calibration will most likely be +/- 1 dB at best.
The ECM8000 also exists as several other brand mikes from the same Asian manufacturer. They will all be similar.
Good luck with your project.
The ECM8000 also exists as several other brand mikes from the same Asian manufacturer. They will all be similar.
Good luck with your project.
The umik is a usb mic, and the usb interface doesn't support timing critical applications. It's otherwise a convenient interface for acoustic measurements where timing isn't critical.
REW has improvised a workaround for this. kimmosto is advising people on the preferred method.
You'll notice that people defending this position will over-play the word 'calibrated'.
REW has improvised a workaround for this. kimmosto is advising people on the preferred method.
You'll notice that people defending this position will over-play the word 'calibrated'.
I agree that a USB mic is not the right choice for your needs.
Looking at your list of options in the first post, I'd recommend to go with the Isemcon. The cheaper mics do drift over time. I had several ECM8000 mics (because I tried to save money), and they all drifted a lot after a few months, such that they became useless to me after a year or two.
Proper cross-calibration of two microphones can be a bit of work. I offered this service for a while, but I stopped. The "work/money" ratio just was not right for me anymore (see here http://hifibau.ch/wp-content/uploads/2015/09/HiFi-Bau_Mikrofon_Kalibrierung_201509.pdf / in German).
Looking at your list of options in the first post, I'd recommend to go with the Isemcon. The cheaper mics do drift over time. I had several ECM8000 mics (because I tried to save money), and they all drifted a lot after a few months, such that they became useless to me after a year or two.
Proper cross-calibration of two microphones can be a bit of work. I offered this service for a while, but I stopped. The "work/money" ratio just was not right for me anymore (see here http://hifibau.ch/wp-content/uploads/2015/09/HiFi-Bau_Mikrofon_Kalibrierung_201509.pdf / in German).
Another option is to simply get the mic freshly calibrated. Cross Spectrum Labs will calibrate almost any mic for you and provide fresh cal files compatible with REW. I have used them many times and they are excellent. They did both my UMIK-1 and UMIK-2.
Cross·Spectrum Labs - Sound | Vibration | Engineering
Cross·Spectrum Labs - Sound | Vibration | Engineering
Thanks for posting the link to your note. I had been thinking about offering the calibration service but not sure if it makes any financial sense. I have the necessary stuff (B&K references with recent cal) and the other stuff to maintain the calibrations but would DIY'ers pay a reasonable fee for the work? Cross Spectrum charges $55 for the service. I would need to see if its worth my time to do it for that. And if there is enough interest.
I guess that all depends on room conditions when the measurement is taken. In an anechoic environment it might be important depending on what one is trying to achieve.
Generaly, we DiYers do not have those conditions and the rooms we manage to prepare have far greater reflexion/dispersion to worry about 1dB.
Generaly, we DiYers do not have those conditions and the rooms we manage to prepare have far greater reflexion/dispersion to worry about 1dB.