# Help on BFD



## TNTTNT (Nov 2, 2008)

Hi all,

I am new to the forum, and am really getting into AV, Hi-fi and Subs.

I bought a BK Monolith, and before long a sound meter. I now want to EQ my sub, and am finding it hard to choose between DCX2496 and DEQ2496 from Behringer. I think the pros for DCX2496 are: -

- Can independently adjust mains and sub if I wished
- Can bypass the sub's crossover, and use DCX2496

I am not sure what the benefits of the DEQ are, but there must be some or Behringer wouldn't have released in addition to DCX2496.

Could the community help me decide which is the best for EQ primarily, and may offer useful options and features.

I am using mains and sub mainly for Stereo reproduction using hi-fi amp, but use the stereo amp to also drive mains in AV set up, so also use sub for AV.

I hope I can get some advice.


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## TNTTNT (Nov 2, 2008)

TNTTNT said:


> Hi all,
> 
> I am new to the forum, and am really getting into AV, Hi-fi and Subs.
> 
> ...


I have found one Benefit so far for the DEQ2496. I think you can plug a mic into this unit and take advantage of the analysis features. I am not sure if you can plug a Behringer ECM800 straight in, or if you need a pre-amp with phantom power. I am not sure if I can use the line out from the RS SPL meter either for this.

Any help given on these questions would be received with gratitude.


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## brucek (Apr 11, 2006)

> I am not sure what the benefits of the DEQ are, but there must be some or Behringer wouldn't have released in addition to DCX2496.


Have you not downloaded the user manuals for each device from Behringer?

The DCX is a loudspeaker management system, while the DEQ is an equalizer that also offers RTA ability.

The DEQ would be the better equalizer, since it has a graphic equalizer, a parametric equalizer, and a variety of shelf filters etc.



> I am not sure if you can plug a Behringer ECM800 straight in, or if you need a pre-amp with phantom power. I am not sure if I can use the line out from the RS SPL meter either for this.


The ECM plugs directly into the DEQ. No, the RS meter is a line device and won't work.

brucek


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## TNTTNT (Nov 2, 2008)

Brucek, Thank you very much for some of the guidance. I hadn't downloaded the instructions because given the knowledge base I have on these devices, I thought I would generate more confusion in my head than answers. To show my initial ignorance, I couldn't understand why the Feedback Destroyer was used for subs. I realised recently that the feedback function is ignored, and it is only the EQ filters which are used by sub bass fans.

Do I need to account for the phantom power of the ECM, or is it literally plug and play? Also, would the measurement accuracy be better using ECM and DEQ2496, as opposed to REW and RS SPL meter? I am focusing on 20hz to 6hz range. The first part to test sub, and the non sub range to check for integration.

I know that the advantage of REW is you can do post measurement analysis, where the DEQ will be as it happens. I was just wondering about accuracy. If I want to use the ECM with REW, I would need to buy a preamp with phantom power, and if DEQ works as well it would save the budget a bit.

The Sub, REW, RS SPL, pending EQ and possibly now an ECM is really driving my interest in Audio set up. I am finding the pursuit of pefection (An endless journey) almost as interesting as the music itself.

I am limited with placement options, so I am trying to see if EQ will meet my aims.

Thanks again Brucek.


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## TNTTNT (Nov 2, 2008)

TNTTNT said:


> Brucek, Thank you very much for some of the guidance. I hadn't downloaded the instructions because given the knowledge base I have on these devices, I thought I would generate more confusion in my head than answers. To show my initial ignorance, I couldn't understand why the Feedback Destroyer was used for subs. I realised recently that the feedback function is ignored, and it is only the EQ filters which are used by sub bass fans.
> 
> Do I need to account for the phantom power of the ECM, or is it literally plug and play? Also, would the measurement accuracy be better using ECM and DEQ2496, as opposed to REW and RS SPL meter? I am focusing on 20hz to 6hz range. The first part to test sub, and the non sub range to check for integration.
> 
> ...



I took Brucek's advice and downloaded the DEQ manual. While I find some it initially heavy going, I have picked up some info. Firstly, yes, the DEQ can deal with phantom power ecm8000 directly.

Does this mean I can tap out from the DEQ into a sound card, and into REW?


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## brucek (Apr 11, 2006)

> Do I need to account for the phantom power of the ECM, or is it literally plug and play?


The DEQ supplies phantom power to the ECM. Plug and play.



> would the measurement accuracy be better using ECM and DEQ2496, as opposed to REW and RS SPL meter? I am focusing on 20hz to 6hz range. The first part to test sub, and the non sub range to check for integration.


The Auto EQ in the DEQ is really not to be used for sub frequencies (from the manual), so you would want to use REW for the sub equalization, while utilizing the DEQ's PEQ filters for those frequencies manually.



> I was just wondering about accuracy. If I want to use the ECM with REW, I would need to buy a preamp with phantom power


Yes, you would if you wanted to use the ECM with REW. But a Radio Shack meter (along with the correction file) is fine for sub EQ, and that's exactly what you are doing. The ECM can be used with the DEQ for >100Hz along with the DEQ's own Auto EQ.



> Does this mean I can tap out from the DEQ into a sound card, and into REW?


Nope...

brucek


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## TNTTNT (Nov 2, 2008)

Thanks.

I am nearly there. I have ordered a DEQ2496, and am very excited. In this case the journey will be as good as the destination.

I am in the process of ordering cables and thought XLR would be the best option for a 10m run. This sort of cabling would be insensitive to long runs, and give a better signal.

However, the BK monolith only has one mono XLR input. I rang BK about connection to the DEQ. They were as puzzled as me because if I only connect one half of the image, I might lose some instruments slightly. Is there a way of forming a mono combined signal from the DEQ?

Out of interest, why did you say connection to a soundcard and REW wouldn't work? I would have thought the DEQ would output a line level signal, which could be fed into the line-in of a sound card. The other line-in of the sound card going to the soundcard line-out, to form a calibration loop. I was hoping that this would work, so it could save me buying a phanton pre-amp.


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## brucek (Apr 11, 2006)

> because if I only connect one half of the image, I might lose some instruments slightly. Is there a way of forming a mono combined signal from the DEQ?


Why, your receiver or processor doesn't have a single mono sub out jack?



> why did you say connection to a soundcard and REW wouldn't work?


Because the DEQ doesn't break out the mic signal after the mic preamp before it enters the business end of the DEQ.



> I would have thought the DEQ would output a line level signal


It does. The signal is the audio from the line-in after processing. It is not the mic signal.

If you want to use the ECM you need a preamp. They're as cheap as a couple of large pizzas.

brucek


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## TNTTNT (Nov 2, 2008)

I take your point on the mic out issue. 

I am not using a receiver to drive the mains and sub. I am using a Primare stereo amp to drive the mains, and feed a pre-out signal to the active sub.

When I want to watch a film I have the receiver's pre-out feeding the stereo amp's line in. This way the receiver drives the rears, the stereo amp drives the fronts and feeds the sub with info.

The stereo amp is 10m from the sub. I was hoping that I could use short unbalanced leads to the DEQ2496, and then find a way of getting a mono signal over a single 10m xlr cable to the sub. The reason I was hoping to use xlr over the 10m was because this sort of cable is better for carrying signals over a long distance.

The sub has two unbalanced line inputs. If the XLR can't be done, can I feed the 1/4 balanced outputs to a unbalanced RCA connection?


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## brucek (Apr 11, 2006)

> I am using a Primare stereo amp to drive the mains, and feed a pre-out signal to the active sub.


Yep OK, so you need to _combine_ that signal into a mono signal for the sub. Passively this can be a problem, since the crosstalk is quite high, but since you have the DEQ as an active buffer, you could get away with a simple passive combiner after the DEQ.



> I was hoping that I could use short unbalanced leads to the DEQ2496, and then find a way of getting a mono signal over a single 10m xlr cable to the sub. The reason I was hoping to use xlr over the 10m was because this sort of cable is better for carrying signals over a long distance.


As I said above, you can get away with a passive combiner between the DEQ and the sub, so it will likely be an unbalanced situation. I don't know how far your sub will be away from the DEQ, but unbalanced shouldn't be a problem for a sub signal. There are also active combiners (mixers) available that accept unbalanced stereo in and balanced mono output.

brucek


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## TNTTNT (Nov 2, 2008)

I think I'm nearly there. I read somewhere that you can mix the stereo channel to mono in the DCX2496. I have gone through the manual but am not clear. Could this be the answer - use unbalanced RCA to a convertor balanced 1/4 jack to get the signal into the EQ device; mix the channels in the DCX2496 and then outputting balanced mono signal to sub?

Could someone be kind enough to let me know. I can ring and switch to a DCX if I do it tomorrow, as the order has not been dispatched.


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## brucek (Apr 11, 2006)

For such a simple thing of combining two signals, I don't know why you would change to a device that isn't suited to the job you require?

A simple passive resistive mixer available here placed next to the sub would work fine... This one accepts balanced in and out.

brucek


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## TNTTNT (Nov 2, 2008)

I hear what you are saying. You say combining is a simple task, but after hours of searching, the only device I could find in the UK was this:

http://www.proav.co.uk/Audio-Equipment/Audio-Converters/p19039_sc535.aspx


It looks a bit pricey. It costs the same as what I paid for the DEQ.

The other option is use convertor jacks and go unbalanced in and out of the DEQ. I was hoping to avoid unbalanced from DEQ to sub, as this is a 10m lead.

Do you have any links for the passive device you referred to, in the UK?


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## brucek (Apr 11, 2006)

> It looks a bit pricey. It costs the same as what I paid for the DEQ.


That's because it's active. You don't require an active one. A simple passive resistive mixer will do. If you were good at soldering, you can make one for about a dollar, and it will contain the same parts that the store bought one will contain.

If that's not your bag, you'll have to hunt for a passive stereo to mono mixer.

brucek


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## Wayne A. Pflughaupt (Apr 13, 2006)

TNTTNT said:


> The stereo amp is 10m from the sub. I was hoping that I could use short unbalanced leads to the DEQ2496, and then find a way of getting a mono signal over a single 10m xlr cable to the sub. The reason I was hoping to use xlr over the 10m was because this sort of cable is better for carrying signals over a long distance.
> 
> The sub has two unbalanced line inputs. If the XLR can't be done, can I feed the 1/4 balanced outputs to a unbalanced RCA connection?


Well, 10m doesn't really qualify as a "long" cable run. A good-quality unbalanced RCA cable would do fine.

Sounds like maybe you should have got the DCX instead of the DEQ. I think it will do mono summing (check the manual).

If you want to stick with the DEQ, the Behringer Xenyz 802 brucek linked before will combine two XLR inputs to a mono unbalanced output. If the price of a new one is too much to add to what you've already spent, you can find them on eEay for half-price, if you're patient.

Regards,
Wayne


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