# Using REW with Eq that is all digital?



## regalma1 (Feb 6, 2009)

I checked out both the Behringer feedback destroyers and found that they have only analog inputs and outputs. Did I miss something?

I have two other Behringer processors, the DEQ2496 and SRC2496. Neither of their analog outputs come close to the quality of the outboard DAC I am using. The SRC isn't too bad, good for the price actually. The DEQ is much worse. Based on this I would assume their other products are similar in quality. 

Is there any other product that can utilize REW that can be used in an all digital mode?

Thanks,


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## weverb (Aug 15, 2008)

What about something like this:

http://www.yamaha.com/yamahavgn/CDA...00%26VNM%3DLIVE%26AFLG%3DY%26LGFL%3DN,00.html

There are a couple of us on here using them for subs and mains.

:huh:

Although it does say "total harmonic distortion less than 0.007% (emphasis on) 20-bit A/D and D/A convertors sampling at 44.1 kHz." I guess it is NOT pure digital.


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## regalma1 (Feb 6, 2009)

Interesting, being Yamaha it is probably pretty good. I have one of Yamaha's newest and better AVR's and it sounds pretty good, but just not quite as good as my stand alone DAC. It lacks that last bit of airiness that I love.


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## brucek (Apr 11, 2006)

> Is there any other product that can utilize REW that can be used in an all digital mode?


I'm not sure what you're looking for. 

The output signals of a DAC or processor or preamp that feeds a power amp are analog. 

The output signal that is sent to a subwoofer is analog.

What would you use an equalizer for that had digital inputs and outputs?

brucek


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## tpaxadpom (Jul 15, 2006)

brucek said:


> I'm not sure what you're looking for.
> 
> The output signals of a DAC or processor or preamp that feeds a power amp are analog.
> 
> ...


I think he wants to use equalizer in the digital domain with his transport and let his DAC do what it was designed to do. I thought DEQ2496 is capable of that but I've heard it's not very transparent even in the digital domain (most likely due to low quality clock builtin).


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## brucek (Apr 11, 2006)

> he wants to use equalizer in the digital domain with his transport and let his DAC do what it was designed to do


You mean situate the equalizer between the source and DAC? You'd need an EQ for every source.

brucek


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## Kal Rubinson (Aug 3, 2006)

brucek said:


> You mean situate the equalizer between the source and DAC? You'd need an EQ for every source.
> 
> brucek


Or a selector switch. This is a big issue for some of us. With the rise of DSP EQ, one can either rely on what is built into AVRs and prepros which keep everything digital until the output to the power amps or one can add-on an external unit. However, because there is no standard and secure HD/MCH consumer digital interconnection, all the add-ons impose on us redundant A/D/A conversions of variable competence. (I note the NeptuneEQ ad at the top of the page as I am typing this.)

I know of no solution, yet, although even HDMI would be a possibility.

Kal


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## brucek (Apr 11, 2006)

Interesting. Presumably the OP is concerned with two channel since he has the outboard DAC, so that certainly precludes use of any prepro or AVR autoEQ features as he would likely be using analog bypass to keep his pristine analog signal from the DAC untouched. This would then require a switch as you suggested. I thought the DEQ2496 had full S/PDIF digital I/O in addition to the standard analog?

brucek


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## regalma1 (Feb 6, 2009)

I think we are drifting off of my original question. I am talking pure stereo music reproduction here. I have an AVR with built in DCR for multi-channel stuff. Unfortunately it falls a bit short of my expectations for music. So I have what is called a audio/HT hybrid system. 

I feed the digital output from my PC and CD player into a DAC, then into a preamp then to my speakers and subs. The AVR analog out feeds into the HT bypass on the preamp so it can use the same outboard amps and main speakers used by the stereo. It is a pretty common setup for audiophiles who use one room for both uncompromised music listening and HT. 

I would like to like to add DCR to my stereo music reproduction. At least experiment with it. Like most of us kooky audiophiles I am willing to spend money on something that may or may not help. 

The REW plus BFD is very attractive, but I don't want to corrupt the signal by converting it into analog, feeding it into the BFD, converting it into digital inside the BFD to process it, then converting it back into analog. That is two extra conversion steps. Each one is going to degrade the music.


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## brucek (Apr 11, 2006)

> I think we are drifting off of my original question. I am talking pure stereo music reproduction here.


Yes, that is exactly what I had presumed. As I said in my post above, presumably you are concerned with two channel since you have the outboard DAC, so that certainly precludes use of any prepro or AVR autoEQ features as you would likely be using analog bypass to keep your pristine analog signal from the DAC untouched. I think we're on the same page.

The only access you have to the digital signal is between the source and the DAC. Is that not correct? You have a DEQ2496 that has full S/PDIF digital I/O. Why not use that? The signal never enters the analog world until it leaves your DAC.

brucek


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## tpaxadpom (Jul 15, 2006)

DEQ2496 may be a viable option as it has 2 digital inputs: AES/EBU and Toslink SPDIF. I don't know if your sources have these types of inputs though. It may not be very convenient to switch between those sources on DEQ2496 due to lack of remote control.
1) original post didn't say anything about how it affects the sound quality in the digital domain (though I assumed it wasn't good enough as it was eliminated)
2) with only 2 sources: CD transport and PC, you can try switching to PC only source and apply needed equalization there. There are tons of different apps from multi band parametric EQs to sophisticated room correction systems. Some seem even more sophisticated than what current generation of AV processors offer (i.e. DRC, IK Multimedia ARC). Being a purist myself I do realize all of the shortcomings when you switch from high quality cd transport to PC only solution in terms of sound quality. No I didn't try Lynx sound cards on the PC with activated word clock input and I have no plans on building dedicated music source desktop PC with water cooling system. I've been using M-Audio transit with 5-6 different laptops running XP 32/64bit, Vista 32/64bit, with dozens of different players that had very different sound.


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## regalma1 (Feb 6, 2009)

I haven't eliminated the DEQ. But I am looking for a way to do full DRC. Short of $4K or more there does not seem to be any easy answers. 

What I had hoped to do was to use REW to create the filters and upload them to a BFD so it could then apply the DRC. When I discovered that the both of Behringers FDs lack digital I/O I started to look into using my DEQ, which is a very powerful equalizer. But according to the responses I found on the forum I can't upload from REW to the DEQ. So I was hoping that there was something out there that had digital I/O which could be used in this manner. That was my original question.


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## brucek (Apr 11, 2006)

> according to the responses I found on the forum I can't upload from REW to the DEQ


That only means you don't have the ability to automatically enter the filters through a midi cable, but you can simply enter them by hand. I have a BFD and have always entered the filters by hand that REW recommends. I can enter them before you could hook up a midi cable.

REW doesn't have a selection for the DEQ, but I believe it conforms to the FBQ filters.

brucek


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## tpaxadpom (Jul 15, 2006)

I wonder if any AV receivers/processors offer corrected output over their digital out (usually Toslink). Most likely it's just a simple pass-through. Though I wonder if anyone ever bothered to check...


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## Chester (Feb 19, 2007)

get a Lab.Gruppen PLM10000q  4 channel amp (2700+ watts/channel), dolby lake processing, 96khz digital ins  if i had the cash id have one right now


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## mojave (Dec 30, 2006)

You can build one. You need to make a computer with a Windows O/S, a Lynx AES16 soundcard, and Audiolense software. You connect your sources to the Lynx's digital inputs and then connect the Lynx's digital output to your DAC. There is a good article about Audiolense at Fidelity.


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## Kal Rubinson (Aug 3, 2006)

regalma1 said:


> The REW plus BFD is very attractive, but I don't want to corrupt the signal by converting it into analog, feeding it into the BFD, converting it into digital inside the BFD to process it, then converting it back into analog. That is two extra conversion steps. Each one is going to degrade the music.


How about the Z-systems RDP-1 or RDQ-1? Digital in/out and very high quality. Two channel but limited to 6 bands per channel.


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## tpaxadpom (Jul 15, 2006)

Kal Rubinson said:


> How about the Z-systems RDP-1 or RDQ-1? Digital in/out and very high quality. Two channel but limited to 6 bands per channel.


Kal, do you have personal experience using Z-systems RDQ-1? I saw your RDP-1 review in stereophile in 98. Does it mean there will be a review of Z-Systems RDQ-1 in Stereophile? If so then when do you think it will be published? Is John Atkinson going to take measurements? Sorry for so many questions.
:mooooh:


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## Kal Rubinson (Aug 3, 2006)

tpaxadpom said:


> Kal, do you have personal experience using Z-systems RDQ-1? I saw your RDP-1 review in stereophile in 98. Does it mean there will be a review of Z-Systems RDQ-1 in Stereophile? If so then when do you think it will be published? Is John Atkinson going to take measurements? Sorry for so many questions.
> :mooooh:


AFAIK, the RDQ is a simpler version of the RDP with the same filtering but lacking the 99 memories. For room EQ, after all, you need only one. No reviews are planned and I do not think that any of those are current. I am sure there are some used ones around.


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