Behringer FBQ2496 manual adjustment with RTA

[Andysu]

I’ve done another frequency sweep test at 10feet distance to the listening position. Microphone is (point at the front) of the room.

So what does those (level -19db ok) mean? I assume the level is correct or near to being correct as I have had ones that said (level is low).



Headroom I assume that means I have a good clear level before clipping and my amplifier Alesis RA300 is no where near clipping, unless I’m getting some false readings here?



I’ve unplugged the ports and done the test over again. I would like to get this done right. But I having a little misdoubt with my conference with this device at the moment. Maybe you can delay me of these negative vibes I’m getting, or it could be that the, heat is getting to me, it’s rather warm today.

Thanks.

[brucek]

Maybe you can delay me of these negative vibes I’m getting

You'd have to answer these questions before I knew if you did things correctly.

Did you do a soundcard calibration routine and store the cal file in REW?

Did the measure a correct flatline response after doing the soundcard calibration of your loopback?

Did you download the microphone/meter calibration file for your mic/meter and store it in REW?

Did you do the Levels setup routine?

Did you calibrate the REW SPL meter?

Headroom I assume that means I have a good clear level before clipping and my amplifier Alesis RA300 is no where near clipping

No, the clipping is in regard to the soundcard itself. Use the scope tab to observe the input/output levels if needed.

You should be placing the mic/meter in the upright vertical position at the listening position - not ten feet away.

brucek

[Andysu]

No I assumed the basic sound car in the pc was good enough. But if you feel strongly that I should make some calibration test then I’ll do so, just show me visual idea of what to look for please, as computers isn’t my strongest point.

Hmmm, microphone meter? I’m not sure if I did can you please provided direct link to (download file) please.

(Microphone ECM8000 now placed in vertical position!) Ten feet away is the seating position.

I took another frequency sweep reading while adding a few more filters and have unplugged the ports, thou I feel, I should conduct a few of the above tests that you mentioned. Anyway mate, I’m off for walk down to the shop to get a can opener) being cocooned in the room all-day isn’t doing me any favours and I need to take a 1 hour break.

Thanks.

[brucek]

No I assumed the basic sound car in the pc was good enough.

No, the basic soundcard is quite crummy actually and needs to have its rather inadequate response compensated for by doing a calibration and creating a file that corrects it's problems.

Hmmm, microphone meter? I’m not sure if I did can you please provided direct link to (download file) please

Here is the link to the Download page

Your questions reveal that you perhaps haven't availed yourself of the knowledge that can be gained by simply reading THE REW HELP FILES. Please read these files before continuing.

brucek

[Andysu]

I’m back and they don’t even sale (can opener) imagine that.

I’ll read though the link to help absorb enough information on the REW before struggling any further.

I’ll go to download page later on this evening after I have read several pages and then, continue onwards.

Thanks again for the online forum support, I’m sure I’ll get some productive results before the year is out.

Thanks.

[thewire]

Andysu wrote:

One thing I’ve noticed is when conducting (sound check before frequency sweep) is that the sound check is never the same twice when repeating the test in the same position. That is the level is too low or it’s okay. Now is there a reason for this?

Thanks.

Your pink noise level for example when using the subwoofer level in the generator (in tools) or as when you setup the settings such as when doing the "check levels" there should = 75dB on your SPL meter and also 75dB in REW. Try lowering the wav volume then gradually (very slowly) adjust the level until your meter says 75dB. I have found it can take anywhere from 5 seconds up to 30 seconds to get this proper. Determining the proper sweep level can be indicated at the top of the bars during the check levels setup. Watch that each does not go red as this will cause clipping during the test proccess. Even better yet turn on the SPL meter in REW by pressing the red button and watch this reading costantly. During the setup proccess it will tell you if the sweep is appropriate because your reading at 75dB will not fluctuate. The different numbers bellow should be within 10dB from eachother. Then when you go to check levels watch again and if the SPL reading has not settled correctly to within at least .5 of your target (being 75dB for example 74.8 is acceptable IMO). Don't forget to calibrate the SPL meter when you begin to see it stabilize. If anything goes wrong, check your soundcard or try using different sweep levels with the generator again to see what is most stable and how smooth sounding the noise from the subwoofer has become.

Taking the time to verify the inputs accuracy and setup REW much slower than one might think to do so will result in my better testing over longer lengths of time as I have discovered spending almost full days doing so. Watching movies before testing helps also. I hope this makes since.

[Andysu]

Cheers for that brief input of information. I’ll switch everything ON later as I have just woke up too a headache, this late afternoon so I’ll get one with again later on.

Thanks.

[Andysu]

Hello evening guys. Well I think I’m starting to get some progress down here tonight. After take a few more tests and looking at the data on the REW room EQ Wizard I’ve managed to get a few smooth response from, 20Hz up to around 100Hz where I’ve gotten a bit of dip that’s giving me, headache as I’d like to get smooth roll-off down to 120Hz.

I’ll post the date before and after once I’ve finished the task.

Thanks.