Questions about using active EQ and the right gear

G

gus6464

Audioholic Samurai
While doing some surfing around the net I came across this article about the tower version of my speakers and how simple EQ smoothed out the FR quite a bit so I want to try and do the same with my bookshelves.

Here is the article on the speakers
http://www.regonaudio.com/DALI Ikon 6 speakers.html

I have read the following post at AVS about using TrueRTA and what gear is needed:
http://www.avsforum.com/avs-vb/showthread.php?t=572477

I will be purchasing the Behringer ECM8000 ($50) mic and UB502 ($30) mixer with a copy of TrueRTA lv.4 w/ 1/24 octave resolution.

Now the thing is I don't know anything about which EQ to get and how exactly does one go about in hooking it up to my AVR. These are the ones I found on the Behringer website.

ULTRACURVE PRO DEQ2496
http://www.behringer.com/DEQ2496/index.cfm?lang=ENG

ULTRAGRAPH DIGITAL DEQ1024
http://www.behringer.com/DEQ1024/index.cfm?lang=ENG

ULTRAGRAPH PRO FBQ6200
http://www.behringer.com/FBQ6200/index.cfm?lang=ENG

ULTRAGRAPH PRO FBQ3102
http://www.behringer.com/FBQ3102/index.cfm?lang=ENG

Now all of these range from $150-170 but like I said I am lost because I don't which one is better than the rest for my application.
 
M

markw

Audioholic Overlord
You would need to insert the equalizer between the preamplifier output and the main amplifier input.

In order to do so, you may need to convert the receivers preamp's RCA (unbalanced) output to match the XLR (balanced) I/O connection scheme of the amplifier's input, and possibly do the exact opposite for the main amplifier's input.

This would need to be done for each channel you wish to equalize.

I know your receiver has preamp outputs, but I'm not too sure about main amplifler inputs. Without main amp inputs, unless you're planning on running external power amplifiers with your unit, this implementation could be problematic.
 
Last edited:
F

fmw

Audioholic Ninja
If the receiver has a tape loop, you can insert an equalizer there but that's a solution only for stereo, not for any kind of surround mode. Making up cables to connect the units is necessary but fairly trivial. Modern A/V receivers have EQ built in. I assume you know that.
 
G

gus6464

Audioholic Samurai
If the receiver has a tape loop, you can insert an equalizer there but that's a solution only for stereo, not for any kind of surround mode. Making up cables to connect the units is necessary but fairly trivial. Modern A/V receivers have EQ built in. I assume you know that.
The AVR in my office is very old and while it has an EQ all it does is bass and treble and nothing very fancy at all. Also it does not have pre-outs but I think it has a tape loop. I only run it in 2ch anyway so using tape loop would work. So do I just connect the tape in to the outs on the EQ and then tape out to the in on the EQ?
 
M

markw

Audioholic Overlord
Maybe, maybe not.

...it does not have pre-outs but I think it has a tape loop. I only run it in 2ch anyway so using tape loop would work. So do I just connect the tape in to the outs on the EQ and then tape out to the in on the EQ?
To insert an equalizer or similar in-line processing device, one needs to insert it somewhere in the circuit path. You must break the circuit, send the signal out to the device, and then return it into the circuit exactly where it left it.

In the good old days of analog two-channel stereo, adding an equalizer was as simple as pie. You simply located the tape monitor output on the back panel, ran an interconnect from there to the eq’s input, and then ran another interconnect from the eq’s output back to the tape monitor’s input on the receiver. You turned on the eq, a pushed the “Tape Monitor” button on the receiver in, and, voiola!. Your eq is now in the circuit!

Likewise, to take the eq out of the circuit, you just pushed the “Tape Monitor” switch again to restore the internal signal path

If one is talking about one of the current AVR's, simply having tape out and tape in jacks on the back panel does not guarantee that it will create the needed "monitor loop" configuration of the old days where the signal was sent out and to a device and then returned immediately to the same point in the circuit path where it left via the push of a button.

While many AVR’s might have “tape out” jacks on the back to allow you to send an analog two-channel signal out to an external device, it’s generally a one-way trip.

Likewise, they might have a “tape input” on the back to allow you to play tapes through your system, but odds are it must be selected via the input selector, which makes it worthless for the purpose of inserting an eq into the circuit.

The key is to scour the front panel for a "tape loop" or "tape monitor" button. Without that, these two sets of jacks simply allow a signal to be sent out to an tape deck but that tape deck's input must be selected as another input, not the out/in loop, as many have discovered.

So, if you do indeed have the needed "tape monitor loop" then you'e good to go but, be aware that it will only affect two channels, most likely the front two.

One way to verify you do have what's needed is to take one stereo interconnect and connect the tape output to the tape input in question. Switch the receiver to FM, CD or some other source besides tape, and press the tape monitor switch. It should sound exactly the same. If you lose the signal, there's a problem. Likewise, not being able to find the "tape monitor" button/switch on the front panel is also a problem.
 
Last edited:
G

gus6464

Audioholic Samurai
To insert an equalizer or similar in-line processing device, one needs to insert it somewhere in the circuit path. You must break the circuit, send the signal out to the device, and then return it into the circuit exactly where it left it.

In the good old days of analog two-channel stereo, adding an equalizer was as simple as pie. You simply located the tape monitor output on the back panel, ran an interconnect from there to the eq’s input, and then ran another interconnect from the eq’s output back to the tape monitor’s input on the receiver. You turned on the eq, a pushed the “Tape Monitor” button on the receiver in, and, voiola!. Your eq is now in the circuit!

Likewise, to take the eq out of the circuit, you just pushed the “Tape Monitor” switch again to restore the internal signal path

If one is talking about one of the current AVR's, simply having tape out and tape in jacks on the back panel does not guarantee that it will create the needed "monitor loop" configuration of the old days where the signal was sent out and to a device and then returned immediately to the same point in the circuit path where it left via the push of a button.

While many AVR’s might have “tape out” jacks on the back to allow you to send an analog two-channel signal out to an external device, it’s generally a one-way trip.

Likewise, they might have a “tape input” on the back to allow you to play tapes through your system, but odds are it must be selected via the input selector, which makes it worthless for the purpose of inserting an eq into the circuit.

The key is to scour the front panel for a "tape loop" or "tape monitor" button. Without that, these two sets of jacks simply allow a signal to be sent out to an tape deck but that tape deck's input must be selected as another input, not the out/in loop, as many have discovered.

So, if you do indeed have the needed "tape monitor loop" then you'e good to go but, be aware that it will only affect two channels, most likely the front two.

One way to verify tou do have what's needed is to take one stereo interconnect and connect the tape output to the tape input in question. Switch the receiver to FM, CD or some other source besides tape, and press the tape monitor switch. It should sound exactly the same. If you lose the signal, there's a problem. Likewise, if you can't find the "tape monitor" button/switch on hte front panel, there's a problem.
Ok the unit does indeed have a tape loop in the back but there is not a "tape loop" or "tape monitor" button in the front. So I guess I am screwed unless I get a hold on an old school fully analog integrated or go with separates?
 
M

markw

Audioholic Overlord
Ok the unit does indeed have a tape loop in the back but there is not a "tape loop" or "tape monitor" button in the front.
No, you don't have a tape loop. You have two totally separate and unrelated inputs and outputs. That's the whole point that my last post was trying to make. I can't see how much more clearly I could have stated it.

So I guess I am screwed unless I get a hold on an old school fully analog integrated or go with separates?
Sure sounds like it to me.
 
G

gus6464

Audioholic Samurai
No, you don't have a tape loop. You have two totally separate and unrelated inputs and outputs. That's the whole point that my last post was trying to make. I can't see how much more clearly I could have stated it.

Sure sounds like it to me.
Ahh ok so I guess it's time to start looking at separates. I was searching online for a SS preamp and amp which have balanced inputs to make my life easier and I came across these. Now I would rather pay more now so I can buy the last amp I will ever in the power department. Here are some finds in the used department.

Sunfire 300x2 $800 Discontinued
http://www.sunfire.com/300TwoFrontPR.htm
This beast apparently doubles it's power at 4ohms can drive 2 and 1ohm loads for a limited time.

Parasound Halo A21 ~$1200
http://www.parasound.com/halo/a21.php

Bryston 4B ST ~$1300
http://www.bryston.ca/4bst_m.html

These are the only 2 preamps I found

Parasound Halo JC2 ~$2500 used
http://www.parasound.com/halo/jc2.php

Parasound Halo P3 $500 used
http://www.parasound.com/halo/p3.php
 
T

tbewick

Senior Audioholic
While doing some surfing around the net I came across this article about the tower version of my speakers and how simple EQ smoothed out the FR quite a bit so I want to try and do the same with my bookshelves.

Here is the article on the speakers
http://www.regonaudio.com/DALI Ikon 6 speakers.html

I have read the following post at AVS about using TrueRTA and what gear is needed:
http://www.avsforum.com/avs-vb/showthread.php?t=572477

I will be purchasing the Behringer ECM8000 ($50) mic and UB502 ($30) mixer with a copy of TrueRTA lv.4 w/ 1/24 octave resolution.

Now the thing is I don't know anything about which EQ to get and how exactly does one go about in hooking it up to my AVR. These are the ones I found on the Behringer website.

ULTRACURVE PRO DEQ2496
http://www.behringer.com/DEQ2496/index.cfm?lang=ENG

ULTRAGRAPH DIGITAL DEQ1024
http://www.behringer.com/DEQ1024/index.cfm?lang=ENG

ULTRAGRAPH PRO FBQ6200
http://www.behringer.com/FBQ6200/index.cfm?lang=ENG

ULTRAGRAPH PRO FBQ3102
http://www.behringer.com/FBQ3102/index.cfm?lang=ENG

Now all of these range from $150-170 but like I said I am lost because I don't which one is better than the rest for my application.
The measurements cited in the article you referred to [1] are of insufficient accuracy to be useful for correcting loudspeaker and room FR deviations. As the forum you linked-to said, you need at least 1/12th octave resolution measurements to identify resonances in the FR of speakers and rooms. Low-resolution, 1/3rd octave RTA is not a useful tool to correct speaker and room resonances. Dr Floyd Toole has written on this subject [2,3].

I think some caution is necessary when using a equalizer. Equalization can't correct the FR of a poor loudspeaker. It may be used to correct speaker resonances, but to do this, you need high-quality measurements of the loudspeaker's FR, combined with the ability to interpret these measurements. I am doubtful whether equalization is suited to correct loudspeaker FR deviations in the mid- and treble ranges. In saying this, eq. is still useful to make simple tonal adjustments according to your own preferences.

There is also the question of getting good bass for several listeners, and this is something eq may not be able provide by itself. For this, you may need multiple subwoofers [4].

I have Audyssey automated room correction on the amplifier I'm using. I don't know how good Audyssey is compared to knowledgeable manual room correction/equalization. The Audyssey version I'm using lacks the ability of applying a customised electronic crossover (i.e., a crossover of adjustable slope and frequency) suited to the acoustical crossover of my loudspeakers and subwoofer. The most expensive version of Audyssey does do this, however.

[1] http://www.regonaudio.com/DALI Ikon 6 speakers.html
[2] 'The Acoustical Design of Home Theaters', Dr Floyd Toole, Harman/Infinity.
http://www.infinitysystems.com/home/technology/whitepapers/acoustical_design.pdf
[3] See Dr Toole's other articles:
http://www.infinitysystems.com/home/technology/technology_whitepapers.aspx?test=1&Language=ENG&Region=EUROPE&Country=GB
[4] 'Subwoofers: Optimum Number and Locations', by Todd Welti, Research Acoustician, Harman International Industries, Inc.
http://www.harman.com/wp/pdf/multsubs.pdf
 
Last edited:

Latest posts

newsletter

  • RBHsound.com
  • BlueJeansCable.com
  • SVS Sound Subwoofers
  • Experience the Martin Logan Montis
Top