My DCX2496 replacement for bass equalization

[mojave]

Last night I replaced my Behringer DCX2496 with a new parametric equalizer. The new one has the following specifications:

• 64 bit audio engine and signal path end-to-end
• 116dB SNR
• Extremely low latency
• Unlimited Band IIR based equalization
• Support for any number of many types of filters (shelfs, bands, LPF, HPF, notch, bandpass, allpass)
• Frequency range from 0-22,500 Hz
• Gain from -150db to +24db per band
• Bandwidth from .01 octave to 4 octaves
• Digital input so there is no extra A/D and D/A conversion
• Save and Load almost unlimited configurations
• Complete computer control for quick setup

I opened up Room Equalization Wizard (REW) and loaded my last frequency sweeps. I changed the equalizer type in REW to FBQ2496 so I could get the bandwidth as BW Oct instead of Q values. I then entered four filters into the equalizer. This all took less than five minutes. The new equalizer works great. :applause:

[Jason]

Last night I replaced my Behringer DCX2496 with a new parametric equalizer. The new one has the following specifications:

• 64 bit audio engine and signal path end-to-end
• 116dB SNR
• Extremely low latency
• Unlimited Band IIR based equalization
• Support for any number of many types of filters (shelfs, bands, LPF, HPF, notch, bandpass, allpass)
• Frequency range from 0-22,500 Hz
• Gain from -150db to +24db per band
• Bandwidth from .01 octave to 4 octaves
• Digital input so there is no extra A/D and D/A conversion
• Save and Load almost unlimited configurations
• Complete computer control for quick setup

I opened up Room Equalization Wizard (REW) and loaded my last frequency sweeps. I changed the equalizer type in REW to FBQ2496 so I could get the bandwidth as BW Oct instead of Q values. I then entered four filters into the equalizer. This all took less than five minutes. The new equalizer works great. :applause:

Cool, what did you get? I eventually want to add the DCX, but mainly as a x-over

[dvenardos]

What it is a secret? :D
Do you have digital out from your processor to give it a digital signal or are you using some kind of splitter from your source to go to your processor and the PEQ unit?

[mojave]

My source is an HTPC with the analog outs going to my Outlaw 7100. My soundcard also sent a digital PCM stereo signal to the DCX2496 so I could use it for bass management.

I use J. River Media Center (JRMC) as the front end for my HTPC and play, rip, organize all my music, movies, and photos with it. Yesterday, JRMC added support for VST plugins. I downloaded and tried about five different parametric equalizers. There are plugins for instruments and for effects and the VST plugins are used primarily for professional audio mastering. They range in price from free to thousands of dollars.

I found that I like the ReaEQ plugin the best for the reasons stated in my first post. Now my HTPC can perform the equalization itself and send the signal directly to the dual MFW-15's. Also, if using a lower crossover such as 60Hz, you can EQ the mains at 80 Hz if there is a peak at that frequency. This way you can still eq below the Schroeder frequency regardless of whether or not your mains or subs are playing the problem frequencies.

By the way, the 116dB SNR mentioned in the first post is soundcard dependent. Your results may vary. ;)

[Jason]

I thought the Schroeder freq was much higher than what most of us cross our subs over at....(I know it's room dependent, though)

[Eric D]

I thought the Schroeder freq was much higher than what most of us cross our subs over at....(I know it's room dependent, though)

:no clue: I thought that's why he said the following:

... This way you can still eq below the Schroeder frequency regardless of whether or not your mains or subs are playing the problem frequencies....

I took that as he's able to eq the midbass in all of the speakers, even above the subwoofer crossover. Or did I miss something?

Anyway, cool! But is that the only source for the system? Or how do you eq the system for DVDs, HDTV, or other sources?

enjoy,

[mojave]

I took that as he's able to eq the midbass in all of the speakers, even above the subwoofer crossover. Or did I miss something?

Anyway, cool! But is that the only source for the system? Or how do you eq the system for DVDs, HDTV, or other sources?

enjoy,

You are correct regarding EQing below the Schroeder frequency. From what I've read, this is usually from 100 to 200 Hz depending on the size of the room and room treatments and you only want to EQ below this frequency. Using traditional EQ methods, you can only EQ the subs. If you have a low crossover, you are limited in the frequencies you can EQ. With my method, you can EQ everthing below 100-120 Hz regardless of whether it is the mains or the subs playing that frequency.

The HTPC is my source for DVD's, HDTV (OTA), CD's, and other media. I don't have satellite or cable service. I also don't watch Blu-rays yet. I can use JRMC for all these sources and configure whatever directshow filters I want for decoding. About the only HDTV I watch is football and I record the games. I then start watching about half way through and skip commercials and the time between plays. I catch up to live by the end of the game.

[Jason]

Ahh...I was just perceiving it bassackwards.


I still think I want the DCX unit for x-over purposes. I've got some older Cambridge soundworks 12's that I'd like to try as MBM's so I need a bandpass x-over, and of course a hp for my mains as well as a lp for the pb13.

Anyway, congrats...and I'll be looking forward to your further impressions.

[nwboater]

Hi Mojave,

Sounds like a great approach, but I'm missing something. Do you have two analog outputs that are equalized separately - one for the MFW's and one for the mains? Otherwise it seems that you can't have a crossover function.

I recently started using Jriver MC13 and it's great. I just looked on their forum for some info about VTS plugins, and didn't find much; only someone have difficulty with one. Are their any instructions on their site for installing?

Thanks,
Rod

[dvenardos]

This sounds very interesting.
Oh, no. I feel another project coming on. :dizzy:

[mojave]

Hi Mojave,

Sounds like a great approach, but I'm missing something. Do you have two analog outputs that are equalized separately - one for the MFW's and one for the mains? Otherwise it seems that you can't have a crossover function.

I recently started using Jriver MC13 and it's great. I just looked on their forum for some info about VTS plugins, and didn't find much; only someone have difficulty with one. Are their any instructions on their site for installing?

Thanks,
Rod

The soundcard's drivers handle the crossover. I use a Creative Labs X-Fi Elite Pro and can set the crossover from 10 to 200 Hz.

To install the plugins, you have to download one (such as the ones I linked to above) and unzip it or install it. You then go to Tools > Plugin Manager > DSP and click Add Plugin at the bottom. Browse to the plugin file (it is a dll file) and select the file and then click Open. The plugin will now be loaded with the other DSP effects.

You can also click the DSP effects button (upper right to the right of the Repeat and Shuffle buttons) and then click DSP. You can load the plugin there and make changes live while the music is playing.

[mojave]

I got ready to do some more testing this evening and realized I'm not sure how to route the REW signal through JRMC to check the effect of the filters on the frequency response. Any suggestions?

[nwboater]

Mojave,

That's quite an impressive soundcard! No wonder you can eliminate the DCX.

Thanks for the info on the plug JRiver plugin. Will have to download it and try it out.

Rod

[nwboater]

The soundcard's drivers handle the crossover. I use a Creative Labs X-Fi Elite Pro and can set the crossover from 10 to 200 Hz.

To install the plugins, you have to download one (such as the ones I linked to above) and unzip it or install it. You then go to Tools > Plugin Manager > DSP and click Add Plugin at the bottom. Browse to the plugin file (it is a dll file) and select the file and then click Open. The plugin will now be loaded with the other DSP effects.

You can also click the DSP effects button (upper right to the right of the Repeat and Shuffle buttons) and then click DSP. You can load the plugin there and make changes live while the music is playing.

Mojave,

I finally got some time to try this out. Have tried several times on 2 different computers to install the rea ex plugin in Jriver. It always says "Failed to install Plugin". I have updated both machines to the most current version of JRiver.

Any ideas what could be wrong? Did you find any others that were close to this one in the features you want?

At this point I'm not looking for crossover, just want to do some low end equalization with my Klipschorns. Later will have a subwoofer or two. I'm using the EMU 0404USB DAC FWIW.

Thanks,
Rod

[mojave]

I thought I’d give an update to this thread. I am now using an Asus Essence ST soundcard with the H6 daughtercard for 7.1 channels. My media player is J. River Media Center 15 with the following VST Plugins: VoxengoBMS, Sound Delay (by Voxengo), and GlissEQ (by Voxengo). All these plugins are 8 channel. To use them, I have my output in MC15 set to 7.1 with unused channels silent. For two channel music, this sends the original two channels and opens up the other channels so I can use channel 4 for bass management. I am using ASIO output with bit-matched drivers, but could also use WASAPI or Kernel Streaming. Only ASIO provides automatic bit matching.

VoxengoBMS
This plugin is very flexible and allows the bass to be moved, mixed or monitored. Moving removes bass from one channel and combines it with the LFE channel. It is like a Small speaker setting. Mixing keeps the original channel fullrange and copies the bass to the LFE channel. It is like a Large speaker setting with duplicated bass. Monitoring allows you to listen in the original channel to just the bass that is being moved. This is useful for comparing the bass in the mains to the subwoofer to hear audible differences and to listen how each reproduces it. The original LFE and the redirected bass can have their gain changed separately even though both end up in the same channel.
The crossover can be set from 40-150 Hz with a 1 to 48 db/octave rolloff. The rolloff on the high pass is set at 12 db/octave. The crossover has a linear phase design so the frequency response and the phase remain flat.



Sound Delay
This plugin allows for delay to be set for each channel in msec, meter, or foot. It has a granularity of .01. You can also set the gain separately for each channel. Using the group delay function in V5 of Room EQ Wizard, you should be able to dial in the exact acoustic distance setting for all speakers.



GlissEQ
Although this has many dynamic filters for mastering, the Peaking Plain and Hi/Lo Pass filters are not dynamic. The Peaking Plain is what is used to reduce peaks in the bass response. It can go down to 1 Hz, has a bandwidth of .01 to 7, and a gain of +/1 15 dB.




With these plugins you can do the following:

• Route all bass below the crossover to the LFE channel
• Use some speakers as Large and some as Small
• Route all bass below the crossover to the LFE channel and put Hi-Pass filters on other channels at a different frequency so you can cascade bass in those channels over the LFE channel (similar to Geddes method)
• With a 5.1 system you can use the extra channels of a 7.1 soundcard for more subwoofers. You could then use Hi or Lo-Pass filters for each subwoofer. You could also EQ all subs together.
• Perform parametric EQ on individual channels or you can group channels together for EQ.
• Accurately set your distance (delay) and gain for all channels
• You can A/B between various settings and listen to the bass either in its original channel or in the subwoofer channel. This is helpful for determining slope and crossover frequency.

I haven't setup any filters yet in GlissEQ. I'm waiting for the Turbo kits for my MFW-15's. However, using these plugins has made the bass sound the best it ever has on both my home system and my office system. I listened to several methods of crossovers (soundcard's drivers, MC15, VoxengoBMS, DCX2496) and the VoxengoBMS crossover made the bass sound much better in the subwoofer. The other methods seemed distorted and muffled by comparison. I started a thread about The Bass Crossover’s Affect on Sound Quality at AVSForum, but it didn't get much response.