Recommendation on amplifier and sound card for measuring loudspeakers?

shank1207

Member
2016-03-24 12:31 pm
Hello everyone this is my first post here, I am looking for setting up small lab to measure loudspeakers that I will test in my office. This is what I have decided so far.
1.ABEC for simulation.
2.Arta+Limp for Measurement
3.Behringer ECM 8000 mic(other recommendation accepted)
Could you please suggest me suitable sound card and amplifiers?
 
I have used a Creative Tracker-Pre http://www.creative.com/emu/products/product.aspx?pid=17511 with Arta+limp and a BehringerECM 8000. I have used a Velleman Kit K4003 Power Amplifier.
Also useful is a Sound level calibrater and a Sound Level Meter.
The most anoying thing about the solution is that the measurements need calibrating.
If you want proper 'accurate' reapeatable measurements there is no way out of paying for Bruel and Kjaer or similar.
 

shank1207

Member
2016-03-24 12:31 pm
Thanks for the reply I was looking at a similar product E-MU 0204 USB but cant find it in Thomman and also will it work with windows 10 in specification it is mentioned windows 7

I think I would prefer amplifier with casing such that I just have to plug in XLR. Do you have suggestoin for that?
Bruel&Kjaer are quite expensive, could you tell me more about sound level calibrator and could Behringer give repeatable results after proper calibration.
 
I have been using the Creative Tracker Pre with Windows XP so I don't know if it is compatible with Windows 10. I don't have any other suggestions unfortunately.

I am only testing low power speakers so don't need a big amplifier. The Creative is only 'Prosumer' and has a single ended output so XLR isn't required. I don't have any suggestions, more or less anything will do as long as it can supply enough power.

I believe that the Behringer is only an electret microphone in a fancy metal case so it's not worth getting too excited about the measurement accuracy. I use a Tenma (Farnell own brand) Sound Calibrator 72-7260 - TENMA - CALIBRATOR, SOUND | Farnell element14

I have used Bruel&Kjaer equipment , quite expensive is an understatement, but there is a reason for the cost. The microphones were condensor with a 200 V bias voltage supplied with calibration plots. The Sound level calibrator had a metal diaphragm, it wasn't just an amplifier driving a standard speaker like the Tenma unit.
The microphone amplifier read SPL without having to go through an error prone and inaccurate calibration procedure.
 
I don't know why a B&K would be considered required for basic speaker measurement. A calibrated mic, yes. Without calibration you're not going to know the difference between a speaker anomaly and a microphone anomaly. I had my ECM 8000 calibrated by Kim G. It turned out that my ECM 8000 was quite flat and the cal file is hardly necessary, but you never know until it's calibrated. Mine is an older model with a different mic element supposedly, YMMV.

If you must know the absolute SPL level for some reason, sure get the Tenma, but for basic crossover design relative SPL is fine.
 

shank1207

Member
2016-03-24 12:31 pm
I don't know why a B&K would be considered required for basic speaker measurement. A calibrated mic, yes. Without calibration you're not going to know the difference between a speaker anomaly and a microphone anomaly. I had my ECM 8000 calibrated by Kim G. It turned out that my ECM 8000 was quite flat and the cal file is hardly necessary, but you never know until it's calibrated. Mine is an older model with a different mic element supposedly, YMMV.

If you must know the absolute SPL level for some reason, sure get the Tenma, but for basic crossover design relative SPL is fine.

Thank you for the information can you purchase ECM 8000 calibrated by Kim G?
 
Thanks a lot. For the calibrator it seems to be under my budget yeah with have a xp running in my virtual machine shouldn't be a problem anyway, probably in future i will get B&K mic.

I haven't had a lot of luck using USB sound cards in a virtual machine (Windows guests in a VirtualBox on a Mac using USB passthrough). I tend to get odd noise, or stuttering, try it on a speaker you don't care about if you give it a shot.
 

1audio

Member
Paid Member
2004-03-24 5:16 am
SF Bay Area
For straightforward speaker measurements I think this address at alot of the problems: Dayton Audio OmniMic V2 Computer Based Precision Room Measurement System Its a USB mike with calibration and good speaker measurement software. Its current so it should work fine with Win 10. Its not cheap but not expensive given its a system. An amp for testing doesn't need to be big and a big amp will probably fry things too easily. Even a thrift store receiver would be adequate.

More important is the space. An office will allow testing to maybe 250 Hz before reflections degrade the results. I'm a big fan of windowed ground plane measurements. I had access to a warehouse space with a high ceiling (10M) and about 30M X 30M. With this space and its concrete floor I could measure below 20 Hz in a pseudo anechoic space. Using Praxis (the precursor to the Omnimike) I could even measure with machinery running in the background.
 

shank1207

Member
2016-03-24 12:31 pm
Thanks for your suggestion, I prefer measurement mic+ARTA+sound card rather then plug and play system for measurement. I am sure it will allow a good learning curve . Yes i read about ground plane measurement it seems to provide good result, when you not measuring in anechoic. I will look more into it.
 

1audio

Member
Paid Member
2004-03-24 5:16 am
SF Bay Area
Calibrators are great when they are working right and you have the correct adapter for your microphone. The internal volume, including the location of the microphone is critical for accuracy.If the volume is a little bit off the calibration is no longer accurate. For a pistonphone the adapters even figure in the distance between the diaphragm and the retaining ring.

If you do not have the correct adapter the calibration is not very accurate.

Soundcards typically will be much flatter that the on board sound interfaces of the past, but sensitivity etc. can be all over the map and Windows can muck around with that in internal settings when you least expect it. Also they don't go into laptops. The USB cards were pretty good but even that market seems to be shrinking. The EMU cards do give good performance and you can find used examples pretty cheap. The M-audio Transit is also decent.
 

29285

Disabled Account
2010-01-17 9:20 pm
My setup is a Linux-Laptop, as small amp, a good mic and behringer UCA-202 sound card. This is a quite basic one with only 2 line inputs. There a no software knobs available thus sensivity stays always the same, independent of any system settings. With ARTA a calibration is possible, but until now I never needed this for measurements of relative frequency response.
 

shank1207

Member
2016-03-24 12:31 pm
Calibrators are great when they are working right and you have the correct adapter for your microphone. The internal volume, including the location of the microphone is critical for accuracy.If the volume is a little bit off the calibration is no longer accurate. For a pistonphone the adapters even figure in the distance between the diaphragm and the retaining ring.

If you do not have the correct adapter the calibration is not very accurate.

Soundcards typically will be much flatter that the on board sound interfaces of the past, but sensitivity etc. can be all over the map and Windows can muck around with that in internal settings when you least expect it. Also they don't go into laptops. The USB cards were pretty good but even that market seems to be shrinking. The EMU cards do give good performance and you can find used examples pretty cheap. The M-audio Transit is also decent.
Hi is there any source to learn to proper calibrate a microphone, i feel i am kinda weak in this and been neglecting it at past. Now that i may make relative measurements which should make it very essential. And yes I am inclining more towards EMU sound card for my purpose.
 

shank1207

Member
2016-03-24 12:31 pm
My setup is a Linux-Laptop, as small amp, a good mic and behringer UCA-202 sound card. This is a quite basic one with only 2 line inputs. There a no software knobs available thus sensivity stays always the same, independent of any system settings. With ARTA a calibration is possible, but until now I never needed this for measurements of relative frequency response.
Hi , yeah i gotta read the ARTA documentations seems the software is much more powerful then i thought. Which mic are you refering as a good mic?
 
Oh I didnt think about that can you suggest me usb/firewire soundcard compatible with windows 10 ?
If I used Windows 10 I would. I did just buy a Behringer UMC202HD, which works OK with Windows 7. It has built in mic phantom power, which is nice.
Hi is there any source to learn to proper calibrate a microphone, i feel i am kinda weak in this and been neglecting it at past. Now that i may make relative measurements which should make it very essential. And yes I am inclining more towards EMU sound card for my purpose.
Catch 22: you need a calibrated mic to calibrate a mic. All you need is a calibrated mic, or one that people tend to think is pretty darn flat out of the box. I haven't been in the market for a long time, so I have no idea about the latter.