Do I need an equalizer?

[mojave]

I have a VTF-2 Mk-3 and MBM-12 with Atlantic Technology System 170 speakers. Below is a picture of my frequency response with the satellites crossed at 150 Hz and the VTF-2 crossover set to 50 Hz. I have a dip from 30-40 Hz. To see if this was related to the MBM-12/VTF-2 combo, I also turned off the MBM-12 and set the crossover on the VTF-2 to out. I also turned off my amplifier so just the VTF-2 was outputting sound. The second picture is the VTF-2 by itself receiving 150 Hz and below. The dip is still there.

I don't have any room for bass traps. Should I add a Behringer equalizer? Will there be a noticable difference? Should I turn up the volume on the VTF-3 so that there will be a rise from 45-20 Hz?

The pictures are from Room Equalization Wizard with no smoothing.

[mojave]

Here are some more frequency response charts:

#1 - VTF-2 MK-3 by itself with the crossover set to 50 Hz
#2 - MBM-12 by itself with the crossover set to 150 Hz
#3 - Speakers by themselves with the crossover set to 150 Hz

[cschang]

What is the X and Y scale? How many dB between markings? Hard for me to tell.

Looks like 15dB.

[mojave]

The x axis starts at 10 Hz and increases by 10 Hz at each line until it reaches 100 Hz. It then increases by 100 Hz per line.

The y axis is spaced at 15 dB intervals.

[xcjago]

Have you tried adjusting the phase on the VTF-2 MK3?

[mojave]

Yes, I adjusted the phase. With REW I was easily able to tell which phase produced the best frequency response.

[TAllen01]

I would also try moving the sub from its present location if you have an alternate location(s) and see what REW shows with the sub in various places.

[mojave]

I have moved the sub and MBM-12 to the various available positions in my living room. The chart I attached was the best frequency response I was able to obtain.

[cyberbri]

Did you get those with REW?

At any rate, you need to change the scaling on that. Try 45~50Hz for the bottom number, 100~105 for the top, and do the tests at a lower volume (say around 80dB).

[xcjago]

If you are looking to flatten your sub's frequency response, then a BFD definately can help. I have one for my VTF-3 HO and it definately sounds better than without one.

[mojave]

Did you get those with REW?

At any rate, you need to change the scaling on that. Try 45~50Hz for the bottom number, 100~105 for the top, and do the tests at a lower volume (say around 80dB).
Yes, I used REW. I have just started playing around with it in the past few weeks. I will change the scale the next time I use it. However, my volume was at 75-80 dB during the test. I probably won't have time to retest until Sunday at the earliest.

If you are looking to flatten your sub's frequency response, then a BFD definately can help.I have ordered a Berhinger DCX2496 (http://www.behringer.com/DCX2496/index.cfm?lang=ENG). It was recommended to me by Mark Seaton over on avsforum. The DCX2496 has 3 inputs and 6 outputs.

I use an HPTC with an X-Fi Elite card. From my understanding, if the card is set to decode, it will output the 7.1 channels via analog. It will also combine all channels and output a stereo digital signal via s/pdif. Both analog and digital outputs are always live.

The DCX2496 has a AES/EBU digital input that supports s/pdif. I plan to connect the digital out on my X-Fi to the Digital in on the DCX2496. I will then split the signal to three of the outputs. I can perform parametric equalization both before and after the signal is split. One output will go to my Buttkicker amp, one to the MBM-12, and one to the VTF-2 MK-3. I can then set crossovers, equalization, phase settings, and delays for each output.

I can also set dynamic equalization based on dB level. At volumes below 50 dB, for example, I can boost the bass frequencies. After the volume goes above 50 dB, the boost is turned off. This is helpful for quiet listening when you need to hear a little extra bass.

The DCX2496 has DACs with a 112dB signal to noise ratio. These same DACs are used in the Parasound Halo C2 Surround Controller. By going digital in, I am eliminating a D/A conversion and A/D conversion.

Using a microphone (which I ordered), the DCX2496 can also perform auto time delay and auto equalization. It is not currently compatible with REW, but it does have software that allows you to completely set it up using a computer. It is very easy to input the REW filter values into the software and send the changes to the DCX2496. It can store 60 different configurations internally.

I downloaded and played with its software yesterday. It looks like I can do 6 channels of equalization on the input signal and 9 channels per output signal. Since I am splitting the bass between the MBM-12 and VTF-2 Mk-3, I will actually have 18 channels of equalization available on the output plus 6 on the input.

The price for the DCX2496 is $250. I also spent another $120 on RCA to XLR cables and the ECM8000 microphone/cable. The DCX2496 connects to the computer via a serial cable or serial to USB cable. Because the s/pdif output on the soundcard is a different impedance than the AES input on the Behringer, I may have to purchase a $40 signal converter, too. However, I did read that some are using a RCA to XLR cable with no problems.

I'll let you know how things work out.

[spyboy]

Yes, I used REW. I have just started playing around with it in the past few weeks. I will change the scale the next time I use it. However, my volume was at 75-80 dB during the test. I probably won't have time to retest until Sunday at the earliest.

I have ordered a Berhinger DCX2496 (http://www.behringer.com/DCX2496/index.cfm?lang=ENG). It was recommended to me by Mark Seaton over on avsforum. The DCX2496 has 3 inputs and 6 outputs.

I use an HPTC with an X-Fi Elite card. From my understanding, if the card is set to decode, it will output the 7.1 channels via analog. It will also combine all channels and output a stereo digital signal via s/pdif. Both analog and digital outputs are always live.

The DCX2496 has a AES/EBU digital input that supports s/pdif. I plan to connect the digital out on my X-Fi to the Digital in on the DCX2496. I will then split the signal to three of the outputs. I can perform parametric equalization both before and after the signal is split. One output will go to my Buttkicker amp, one to the MBM-12, and one to the VTF-2 MK-3. I can then set crossovers, equalization, phase settings, and delays for each output.

I can also set dynamic equalization based on dB level. At volumes below 50 dB, for example, I can boost the bass frequencies. After the volume goes above 50 dB, the boost is turned off. This is helpful for quiet listening when you need to hear a little extra bass.

The DCX2496 has DACs with a 112dB signal to noise ratio. These same DACs are used in the Parasound Halo C2 Surround Controller. By going digital in, I am eliminating a D/A conversion and A/D conversion.

Using a microphone (which I ordered), the DCX2496 can also perform auto time delay and auto equalization. It is not currently compatible with REW, but it does have software that allows you to completely set it up using a computer. It is very easy to input the REW filter values into the software and send the changes to the DCX2496. It can store 60 different configurations internally.

I downloaded and played with its software yesterday. It looks like I can do 6 channels of equalization on the input signal and 9 channels per output signal. Since I am splitting the bass between the MBM-12 and VTF-2 Mk-3, I will actually have 18 channels of equalization available on the output plus 6 on the input.

The price for the DCX2496 is $250. I also spent another $120 on RCA to XLR cables and the ECM8000 microphone/cable. The DCX2496 connects to the computer via a serial cable or serial to USB cable. Because the s/pdif output on the soundcard is a different impedance than the AES input on the Behringer, I may have to purchase a $40 signal converter, too. However, I did read that some are using a RCA to XLR cable with no problems.

I'll let you know how things work out.

Thanks for this post.

How difficult did you find it to use the DCX2496? My receiver has enough inputs and outputs to handle one of those. Not a very experienced computer user.

Thanks in Advance.

[mojave]

The DCX2496 arrived 2 hours ago at my office. I just grabbed it from the receiving dock. Unfortunately, the cables I ordered won't arrive for another week.

I have read through the manual and downloaded the software. The software seems easy enough to use, but you can set everything up manually without using a computer. I suggest reading through the BFD (Behringer Feedback Device) Guide (http://www.hometheatershack.com/forums/bfdguide/) to understand how to set up parametric filters and to understand the theory behind equalization.

If you can use Room Equalization Wizard (REW) (http://www.hometheatershack.com/roomeq/) with a Radio Shack SPL meter it will greatly facilitate the setting up of the DCX2496.

Once I get everything, I will start a new post regarding the DCX2496.

[Kingrsl]

Have you had a chance to play with your new EQ? I picked up a used Behringer EQ for a deal this weekend but haven't set it up yet.

[mojave]

I have only played with the software for the DCX2496. The cables were to ship in 7 to 10 days. Today is 7 business days, but I have not yet received notification of shipment. As soon as the cables arrive, I will hook it up. I did receive a Behringer ECM8000 measurement microphone and cable.

Last night I ran a new frequency response chart from 15-200 Hz and 45-105 dB per the REW forum requirements. I have posted it below.

[Kingrsl]

Did you use the Behringer mic with REW to get those readings or your RS meter? Hopefully, I can get REW working tonight.

[mojave]

I used the RS digital meter connected to my X-Fi Elite soundcard. I downloaded the correction file from the REW forum and loaded it prior to taking measurements.