Does calibration really make a difference?

**htguy** · **05-15-08, 05:01 PM**

It may be wrong to ask this in a tweaker’s forum (and I hope I am not banned!), but how much of a difference would I notice if I calibrated my sub as compared to a non-calibrated sub? I have a very modest sub (the JBL L8400), and am not an audiophile. The sound system is used only for HT? Is there a really good chance that the difference will be noticeable, or will I not really know until I make the calibration? I don’t really want to spend $200 or so on equipment, and then not hear any difference.
Thanks

**Rambo4** · **05-15-08, 06:54 PM**

I am no expert, but I think your placement is your best advice from my own experience. If you are in a null, it'll be hard to calibrate anything properly without a lot of EQ. As far as anything else, a SPL meter measurement is a relatively cheap, quick, and worthwhile investment, combine that with the free REW software available here and you should get a good idea of where you stand acoustically. There other avenues you can take apart from EQ, such as sound absorbers and bass traps as many here know much more about than I.

Basically, I found I was able to rid myself of major nulls and peaks with the placement and SPL measurement, then I tweaked after that with EQ. Did the trick for me.

**brucek** · **05-15-08, 07:11 PM**

Quote:

Is there a really good chance that the difference will be noticeable,

No one can answer that question, because the only answer is, it depends.

You need to measure your response of your low frequencies and see how it looks.

If it follows a reasonable target, then the answer is that you don't require any changes.

If you had a +20dB peak at 50Hz, then that 50Hz is about all your hearing from your subwoofer, and you could at least benefit from moving the sub around to smooth your response.

The cost is a cheap Radio Shack meter and some cables. We know you have a computer..

brucek

**htguy** · **05-15-08, 07:33 PM**

Thanks, I really appreciate these answers. From what I have read, it seems like the Behringer ECM5000 calibration mic at $50 is my best bet. I have access to an M-audio firewire solo. I read that moving the sub even a few inches can make a difference, depending on the room.

**brucek** · **05-15-08, 08:07 PM**

Yeah, the ECM8000 is the best choice, and if you have a soundcard that has a built-in mic preamp (with phantom power), then you're good to go.

brucek

**salvasol** · **05-15-08, 08:32 PM**

Quote:

htguy wrote:

... but how much of a difference would I notice if I calibrated my sub as compared to a non-calibrated sub? I have a very modest sub (the JBL L8400), and am not an audiophile. The sound system is used only for HT? Is there a really good chance that the difference will be noticeable, or will I not really know until I make the calibration? I don’t really want to spend $200 or so on equipment, and then not hear any difference. Thanks

Where in Los Angeles???

Did you calibrated the rest of the system??? ... What I mean, Did you set up all your speakers to 75db??? ... That can be a starting point (if you haven't done it)

**htguy** · **05-15-08, 08:57 PM**

I see that you are in Fontana. I am near West LA.
I have to reveal my ignorance. What does setting up speakers to 75db mean?

**salvasol** · **05-15-08, 10:15 PM**

Quote:

htguy wrote:

I see that you are in Fontana. I am near West LA.
I have to reveal my ignorance. What does setting up speakers to 75db mean?

That's the first calibration you do to the system ... here you set all speakers to get 75db with the SPL meter so they sound the same when using a test tone (What receiver do you have??? ... some have the auto-calibration feature, that's what I mean when I said set to reference level or 75db

)

**htguy** · **05-15-08, 11:42 PM**

I used the auto calibration feature of my receiver. My next step will be the SPL to double check the receiver.

**htguy** · **05-16-08, 03:18 AM**

I have started to read the REW instruction pages. Boy, this seems confusing. It will probably make more sense once I get it running. Anyway, it seems like if I am using the Behringer mic with the REW, I will also need an SPL meter to calibrate the REW? Can use the Galaxy M130 for that purpose? Is the 130 better than the radio shack model?

**brucek** · **05-16-08, 08:03 AM**

Quote:

Can use the Galaxy M130 for that purpose? Is the 130 better than the radio shack model?

Yes (if it's a Galaxy CM-140). The CM130 has no AC output.
The Galaxy CM140 is a good all-in-one choice for use with REW.

brucek

**htguy** · **05-16-08, 11:13 AM**

Brucek- The cost of the 140 is about the same as the cost of the behringer mic and either the 130 or a radio shack meter. Since I am starting from scratch, I thought I would get the mic and a separate meter. From reading other posts, it seems like the behringer mic is slightly preferred over the 140? But, I also read on a post that the 130 is rated to only 125Hz, which makes it useless for sub measurements? Is that correct? So, if you were going to pick between the 140, and the Behringer mic/Radio shack meter combo, which would you recommend? Or, is the 130 OK for sub measurements? Thanks for your help with all of these basic questions.

**brucek** · **05-16-08, 11:58 AM**

Quote:

if you were going to pick between the 140, and the Behringer mic/Radio shack meter combo,

I personally like the (ECM8000 with the XENYX preamp) along with a Radio Shack meter for rough level setting.

brucek

**htguy** · **05-16-08, 05:25 PM**

Quote:

brucek wrote:

I personally like the (ECM8000 with the XENYX preamp) along with a Radio Shack meter for rough level setting.

brucek

I already have the M-audio firewire solo. Is that a suitable alternative to a XENYX?

**brucek** · **05-16-08, 06:24 PM**

Quote:

I already have the M-audio firewire solo. Is that a suitable alternative to a XENYX?

Yep...

brucek

**htguy** · **06-04-08, 04:15 PM**

After a lot of testing and working with the guru’s on this forum, I learned that REW won’t work with my older (non-intel) Mac computer. I would like to at least get some very basic measurements to determine if I have any severe bass frequency problems. I do have an analogue radio shack sound meter. I read someplace that is possible with a sound meter to manually do what REW does, but that would take hours. I noticed that there is a 15 Hz to 80 Hz test tone on the download page. Could I do the following as a “quick” way to test to see if my subwoofer could benefit from EQ: Play that test tone and see if the meter dips or jumps at any time?

**brucek** · **06-04-08, 04:55 PM**

Go to the downloads page and download the manual method excel file that matches your meter type and then download the sinewaves from that page and create a CD and you're set for hours of fun.

brucek

**htguy** · **06-04-08, 05:09 PM**

Thanks. I was sort of trying to avoid that.

**htguy** · **06-04-08, 05:19 PM**

I forgot to ask, what volume do I set the subwoofer at for the tests? Do I calibrate it to 75db to match the volume from my other speakers while running a pink noise test tone?

**Andysu** · **06-04-08, 05:48 PM**

Quote:

htguy wrote:

Thanks, I really appreciate these answers. From what I have read, it seems like the Behringer ECM5000 calibration mic at $50 is my best bet. I have access to an M-audio firewire solo. I read that moving the sub even a few inches can make a difference, depending on the room.

More so if you where to move a few inches like side to side forwards or backwards or downwards and slightly upwards from the original position and, you’ll hear a slight difference.

**salvasol** · **06-04-08, 10:12 PM**

Quote:

htguy wrote:

I forgot to ask, what volume do I set the subwoofer at for the tests? Do I calibrate it to 75db to match the volume from my other speakers while running a pink noise test tone?

Sorry you couldn't make REW work.

You can try playing the 80Hz test tone and set the SPL to read 75db ... then play the rest of the tones and write down the reading you're getting. I think you can input the results into REW to see a graph; I did it but I use Windows XP ...

**clausdk** · **06-08-08, 08:32 AM**

Quote:

htguy wrote:

It may be wrong to ask this in a tweaker’s forum (and I hope I am not banned!), but how much of a difference would I notice if I calibrated my sub as compared to a non-calibrated sub? I have a very modest sub (the JBL L8400), and am not an audiophile. The sound system is used only for HT? Is there a really good chance that the difference will be noticeable, or will I not really know until I make the calibration? I don’t really want to spend $200 or so on equipment, and then not hear any difference.
Thanks

In my system its like night and day with and without calibration.

I can run the bypass on the BFD and in an instant you can hear the sound with and without the BFD doing its magic.

I'm down to using 2 filters right now and thus removing a HUGE peak around 35 hz in my room.

When I run demos for people who come over I sometimes switch the BFD in and out and they are really surprised about the difference.

**htguy** · **06-09-08, 05:34 PM**

For some reason I can’t get the test tones on the download page to play. I downloaded them on a mac, and copy them into itunes, and itunes shows zero length for the file. When I download on a PC, windows media player plays the file, but there is no sound (yes, I have the vol turned up). Is there a trick to playing these tones? Can I use the signal generator in REW instead?

**brucek** · **06-09-08, 06:24 PM**

Quote:

For some reason I can’t get the test tones on the download page to play.

I can't see any reason why this is happening.

I just tried it a couple of different ways. I simply click the index.html link and it asks if I want to open or save the file.

If I click open it lists all the different tones. If I click one it plays the tone.

If I click save, it puts the index.html file in the location in my computer and it plays the tones when I open it??

OK, you're just messing with us , right?

brucek

**htguy** · **06-09-08, 06:40 PM**

I got the tones to play on my PC at work. At home I only have Macs. I am new to all of this stuff. I am embarrased to say, but I had some of my outputs muted on the sound control panel when I was learning about calibrating a sound card. I forgot that I had them checked. I am sure I am doing something equally as simple with my Mac at home.

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