Equalizers: Behringer UltraGraph FBQ6200

[Big Daddy]

I am sure most of you already know why room correction and equalization is important in audio. It may still be helpful to read Why Do We Need Equalization and Room Correction? and check the Phonic PAA3 Audio Analyzer thread.

Room correction and equalization was missing from my two-channel room. After spending some time investigating the different options, I decided to buy the Behringer UltraGraph Pro FBQ6200 stereo one-third octave graphic equalizer. The PEQ6200 is Behringer's top-of-the-line UltraGraph equalizer. It is a 31-band graphic equalizer with FBQ feedback detection System. Because the equalizer uses only pro balanced input/output, I have already ordered the proper cables.

• Audiophile 31-band stereo graphic equalizer for live and studio applications
• Revolutionary FBQ Feedback Detection system instantly reveals critical frequencies and can also be used as audio analyzer
• Dedicated Limiters with gain reduction meters for each channel protect your sound system from overload and distortion
• Pink noise generator provides test signals to adapt your sound system to any room acoustics
• Mono subwoofer output with dedicated level control and adjustable crossover frequency
• Additional sweepable high and low-cut filters for each channel remove unwanted frequencies e.g. floor rumble, hiss etc.
• Highly accurate 8-segment LED input/output metering and input gain controls for easy level setting
• Ultra-low noise audio operational amplifiers for highest signal integrity
• Relay-controlled hard bypass with an auto-bypass function during power failure (failsafe relay)
• Servo-balanced inputs and outputs with 1/4" TRS and gold-plated XLR connectors
• Shielded toroidal power transformer for ultra-low noise performance
• High-quality components and exceptionally rugged construction ensure long life
• Conceived and designed by BEHRINGER Germany

Specification Sheet:
http://www.behringer.com/EN/Products/FBQ6200.aspx

Manual:
http://www.behringer.com/assets/FBQ6200_P0230_M_EN.pdf

Most online dealers sell it for $180 to $197. I managed to buy it from UniqueSquared Ebay store for $165. The price was too good to be true and I jumped on it. This is the fifth Behringer product that I have purchased in the past two years. I already own three Behringer amplifiers (EP4000, EPX3000, and EPX4000) and a Behringer ECM8000 Condenser calibration microphone. I bought the three amplifiers from the same Ebay dealer. They have by far the best prices and are very reliable in shipping the products within twenty four hours.

UniqueSquared Store: $197
http://www.uniquesquared.com/behring...-limiters.html

UniqueSquare Ebay Store: $165
http://www.ebay.com/itm/Behringer-UL...item5647210e40

The equalizer is expected to be delivered by the middle of next week. I plan to run one third octave test tones through each speaker and measure the response with a couple of SPL meters and then equalize each speaker separately. It will be a long and laborious process. I will keep you posted.


The following is a list of all the equipment in my two-channel room:

1. Panamax M4300-PM power conditioner.
   
   
   
   
   
   
2. Onkyo C-7030 Compact Disc Player with Wolfson 192/24 DACs.
   
   
   
   
   
   
3. Carver TFM-45 stereo amplifier.
   
   
   
   
   
   
4. XiangSheng 728A Vacuum Tube Pre-Amplifier.
   
   
   
   
   
   
   
   
   
5. Denon DP-300F Turntable with Denon DL-103 Cartridge.
   
   
   
   
   
   
6. Technolink TC-760LC MM/MC Phono Pre-Amplifier
   
   
   
   
   
   
7. Behringer EUROPOWER EPX4000 Stereo Amplifier
   
   
   
   
   
   
   
   
   
8. Two Large DIY Super Tower Speakers with 15" built-in subwoofers as described in Post #948 and Post #965 of my gallery thread. The two built-in subwoofers are powered by the Behringer EPX4000 amplifier.
   
   
   
   

[Big Daddy]

As I explained before, I tried to use the equalizer with test tones and two SPL meters. Unfortunately, the results were inconsistent and not very reliable. After I wasted several hours, I finally gave up and ended up buying the Phonic PAA3 analyzer.

Fortunately, FedEx delivered the unit in one day as it was mailed from Northern California. After I spent an hour becoming familiar with the little instrument, I did not hesitate and started the equalization process. You have the choice of running pink noise from the included CD or you can connect the PAA3 to the pre-amplifier with an XLR to RCA cable and run the internal test tones generated by PAA3. I decided to use the CD as I play CDs most of the time in my two-channel room. My thinking is that any effect that the CD player, other equipment, and the cables may have on the sound will also affect the test tone CD.

This little gadget is amazing. After you run the pink noise for less than a minute, it generates the SPLs for all the thirty one (31) one-third octave frequencies from 20Hz to 20,000Hz. You can save the results in one of the ten different memory locations numbered from 1 to 10. You can put the microphone in as many as ten or less locations and take measurements. Afterwards, you can tell it to average the measurements saved in whatever memory units you want and it does that almost instantaneously. Additionally, it calculates the offsets by which you should increase or decrease the levels on the equalizer. All the averages can be saved in six different memory units labeled A, B, C, D, E, and F. It really makes the job of using an equalizer very easy.

Anyway, I first set the stereo system to flat without any equalizations and took measurements for each speaker independently and then both speakers combined. After I took three sets of measurements for several locations and averaged them, the Phonic analyzer gave me all the offsets I needed. I used those numbers and adjusted the Behringer equalizer and took additional measurements after equalization and did a few more adjustments until all the frequencies were within +/-3dB. You can see some of the results generated by the Phonic PAA3 analyzer in the following:

In the following table, the numbers in the columns two, three, and four are the recommended offsets as calculated by the Phonic PAA3 for the left, right, and both speakers. These numbers were calculated after measurements were taken for three locations and averaged. Column four represents the offsets after some preliminary equalization was performed and measurements were taken again for the same locations. The Behringer equalizer was adjusted some more and measurements were taken again for both speakers. The recommended offsets are included in column five. Asa you can see, there weresome improvement.

The following graphs represents the frequency response of the unequalized speakers and after equalization with additional adjustment:

These are the equalization offsets as calculated by the Phonic PAA3 for the both speakers.

The final frequency response of the two speakers after equalization and additional tweaking is exhinited in the following diagram. I may do some more adjustments in the future when I have more time.

This is how the Behringer equalizer looks like after all the final adjustments are made.

Was all this work and expense worthwhile? The answer is a big YES. After I was finished, I played a few CDs that I am very familiar with. There was a significant improvement in the sound that I heard. I could hear details in the music and singing that I had a hard time hearing before. I believe I have doubled the value of my DIY speakers.

[rpatt]

I'll be watching this with great interest. I'm not clear on how you will equalize each speaker separately though.

[Big Daddy]

Originally Posted by rpatt

I'll be watching this with great interest. I'm not clear on how you will equalize each speaker separately though.

I have a couple of CDs with test tones on them. My plan is turn off the right speaker first and run one-third octave test tones through the left speaker and take readings with an SPL meter. Then I will do the same with the right speaker. After I have all the dB readings, I will adjust all the knobs on the equalizer to get fairly flat response from each channel.

Then I will turn on both speakers and run the test tones again and take more readings on the SPL meter to fine tune the equalizer so that the combined output for both speakers is approximately flat. I hope the equalizer has a memory to save the information. Otherwise, I will have to write it down manually.

I realize that a flat frequency response is not always appropriate and the most pleasing. That is why the final step is to experiment and adjust the equalizer according to taste and the room environment. Initially, I may try the so-called House Curve. Since the room is relatively large with a ceiling of approximately 17ft high, I may try a flatter house curve as opposed to a steeper one. Anyway, it will be a long and boring process.

If I am not satisfied completely, I may throw everything in the recycling bin and buy a multi-channel receiver with Audyssey and use only the two front channels.

Perhaps, I shouldn't sell my Denon 4308CI receiver.

[crazyBLUE]

Originally Posted by Big Daddy

I have a couple of CDs with test tones on them. My plan is turn off the right speaker first and run one-third octave test tones through the left speaker and take readings with an SPL meter. Then I will do the same with the right speaker. After I have all the dB readings, I will adjust all the knobs on the equalizer to get fairly flat response from each channel.

Then I will turn on both speakers and run the test tones again and take more readings on the SPL meter to fine tune the equalizer so that the combined output for both speakers is approximately flat. I hope the equalizer has a memory to save the information. Otherwise, I will have to write it down manually.

I realize that a flat frequency response is not always appropriate and the most pleasing. That is why the final step is to experiment and adjust the equalizer according to taste and the room environment. Initially, I may try the so-called House Curve. Since the room is relatively large with a ceiling of approximately 17ft high, I may try a flatter house curve as opposed to a steeper one. Anyway, it will be a long and boring process.

If I am not satisfied completely, I may throw everything in the recycling bin and buy a multi-channel receiver with Audyssey and use only the two front channels.

Perhaps, I shouldn't sell my Denon 4308CI receiver.

If you throw it in the recycling bin let me know

[Big Daddy]

Originally Posted by crazyBLUE

If you throw it in the recycling bin let me know

They pick up the trash on Friday mornings.

[Big Daddy]

UPS delivered the Behringer equalizer today. The preliminary results are very positive. However, I need to run test tones and equalize the system more appropriately. Perhaps, I will have more time over the weekend.

[sandman922]

Originally Posted by Big Daddy

UPS delivered the Behringer equalizer today. The preliminary results are very positive. However, I need to run test tones and equalize the system more appropriately. Perhaps, I will have more time over the weekend.

i used to have a 12 band per channel technics with a spectrum analyser i could sit a listen to music for hours and watch it dance to the music sure wish i hadn't sold it

congratulations big daddy on your purchase and thanks for bringing back the memories

[Big Daddy]

Originally Posted by sandman922

i used to have a 12 band per channel technics with a spectrum analyser i could sit a listen to music for hours and watch it dance to the music sure wish i hadn't sold it

congratulations big daddy on your purchase and thanks for bringing back the memories

Thanks Sandman.

This is a one third octave stereo equalizer. I plan to run one-third octave test tones and flatten the misbehaving frequencies. Doing it for each channel and then for the combined channels will take a very long time and I need to get really focused to do it. My hope is that I will have the time to do it over the weekend.

[DangeRuss]

Good morning BD

As you know I just pick up an equalizer myself (which was the easy part ). Now comes the hard part (tedious part really ) Calibration. Since my other 2 eq's have built in analyzers and pink noise generators ( ADC SS-325X & 525X) setup was a relative breeze. Although I like to tweak...I'm not looking forward to manually setting up this puppy like I had to with the eq's I owned before those ADCs . So I'm entertaining the thought of buying a calibrated mic (more accurate than my SPL meter) and mic amp to run through my laptop with either TrueRTA or REW software. Have you ever considered going that route (remember I'll be calibrating six channels) ?

[Big Daddy]

Originally Posted by DangeRuss

Good morning BD

As you know I just pick up an equalizer myself (which was the easy part ). Now comes the hard part (tedious part really ) Calibration. Since my other 2 eq's have built in analyzers and pink noise generators ( ADC SS-325X & 525X) setup was a relative breeze. Although I like to tweak...I'm not looking forward to manually setting up this puppy like I had to with the eq's I owned before those ADCs . So I'm entertaining the thought of buying a calibrated mic (more accurate than my SPL meter) and mic amp to run through my laptop with either TrueRTA or REW software. Have you ever considered going that route (remember I'll be calibrating six channels) ?

Good day to you DangeRuss,

I spent some time last night and did some initial tweaking and set the equalizer for each channel. There are basically three types of problems:

1. Running test tones and measuring the response with an SPL meter is very tedious. The biggest problem is the unreliable SPL meters. I have two different SPL meters and that helped a little. Also, I use the Rives Audio test tones. It has two set of one-third octave test tones. The first set is raw and the second set is corrected for the inaccuracies of the Radio Shack SPL meter. The main difference is in the ultra low and ultra high frequencies.
2. When you fix the frequencies of each channel and then run both channels together, the frequencies interact and you have to do a lot of additional adjustment.
3. The frequencies are inter-dependent. When you raise the dB level of any frequency, it may affect other frequencies and you need to go back and adjust the other frequencies and run test tones again.

I do own the calibrated Behringer microphone, M Audio USB Powered Preamp and Audio Interface, and REW. I have used them before in my HT room. If I have some more time, I may use them again in my two-channel room. You can find useful information about the equipment in Post #2 of the https://forum.blu-ray.com/speakers/1...ubwoofers.html thread.

[DangeRuss]

Sooooo it would seem I have some more purchases to make (but I still really want these speakers <------- ). But in the interest of getting a better picture of my room response and setting a rough eq curve. Is there or what type of cable could I use to connect my SPL meter (analog RS) directly to my laptop ? Or will I have to buy a mic-amp ? And could I use pink noise along with the analyzer just to get that rough estimate ? I'll then do a more accurate calibration once I get the mic / mic-amp you've suggested (I hate to sound like a newbie )

BTW I'll be ordering the Rives disk momentarily and thanks for your continued assistance

[Big Daddy]

Originally Posted by DangeRuss

Sooooo it would seem I have some more purchases to make (but I still really want these speakers <------- ). But in the interest of getting a better picture of my room response and setting a rough eq curve. Is there or what type of cable could I use to connect my SPL meter (analog RS) directly to my laptop ? Or will I have to buy a mic-amp ? And could I use pink noise along with the analyzer just to get that rough estimate ? I'll then do a more accurate calibration once I get the mic / mic-amp you've suggested (I hate to sound like a newbie )

BTW I'll be ordering the Rives disk momentarily and thanks for your continued assistance

I own the digital version of the Radio Shack SPL meter. It has an RCA output. Computer sound cards generally have 3.5mm inputs and outputs. If you want to connect the SPL meter to a sound card, you probably need an RCA to 3.55mm cable.

If you have a high quality sound card inside your computer with proper input and output, you probably don't need a microphone preamp. My sound card is pretty basic and that is why I used a preamp.

[DangeRuss]

Originally Posted by Big Daddy

I own the digital version of the Radio Shack SPL meter. It has an RCA output. Computer sound cards generally have 3.5mm inputs and outputs. If you want to connect the SPL meter to a sound card, you probably need an RCA to 3.55mm cable.

If you have a high quality sound card inside your computer with proper input and output, you probably don't need a microphone preamp. My sound card is pretty basic and that is why I used a preamp.

I own a bunch of those cables shown but they're stereo RCA's to a stereo mini jack. I thought it would be better to find a mono mini jack to a single RCA jack (I don't want to introduce interference ).

And the onboard soundcard is probably run of the mill

What do you think of this.......

[rpatt]

I'm interested in getting an RTA system. What do you think of these three?

http://www.trueaudio.com/

[Big Daddy]

Originally Posted by rpatt

I'm interested in getting an RTA system. What do you think of these three?

http://www.trueaudio.com/

The TrueRTA sytems are very good. The best part is that you can start with the basic 1/3 octave system and then upgrade and only pay the difference in price. Alternatively, you can buy the 1/6 octave or the 1/24 octave and forget about upgrading.

The most important thing is the microphone. If you are serious about equalization, you should buy the Behringer calibrated microphone. Parts Express sells a microphone that looks exactly like the Behringer, but it is a few dollars cheaper. It gets very good reviews.

[Big Daddy]

Originally Posted by DangeRuss

I own a bunch of those cables shown but they're stereo RCA's to a stereo mini jack. I thought it would be better to find a mono mini jack to a single RCA jack (I don't want to introduce interference ).

And the onboard soundcard is probably run of the mill

What do you think of this.......

That adapter can work can work. Monoprice has both the stereo and mono version.


Stereo:

http://www.monoprice.com/products/pr...seq=1&format=2

Mono:

http://www.monoprice.com/products/pr...seq=1&format=2

[Big Daddy]

I spent several frustrating hours running one-third octave test tones in my two-channel room and taking measurements with my two flawed SPL meters ( a digital Radio Shack purchased over fifteen years ago and an American Recorder Technologies SPL meter purchased a couple of years ago).

I was not satisfied with the results of either SPL meter and finally got fed up and decided to invest in something better. After spending hours online, I found a little instrument that I expect to satisfy my needs. The regular price of this little gadget is as much as a medium-priced receiver, but I managed to find an open box unit at a discount.

The identity of this gadget shall remain a mystery until it is delivered and I have had a chance to use it.

[DangeRuss]

Originally Posted by Big Daddy

I spent several frustrating hours running one-third octave test tones in my two-channel room and taking measurements with my two flawed SPL meters ( a digital Radio Shack purchased over fifteen years ago and an American Recorder Technologies SPL meter purchased a couple of years ago).

I was not satisfied with the results of either SPL meter and finally got fed up and decided to invest in something better. After spending hours online, I found a little instrument that I expect to satisfy my needs. The regular price of this little gadget is as much as a medium-priced receiver, but I managed to find an open box unit at a discount.

The identity of this gadget shall remain a mystery until it is delivered and I have had a chance to use it.

Can't wait to see what it is.........But I have an idea (I bet it's something I have my eye on right now )

[Big Daddy]

Originally Posted by DangeRuss

Can't wait to see what it is.........But I have an idea (I bet it's something I have my eye on right now )

This picture is just to tease you.

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