Why you need room EQ even with the speaker with perfect anechoic measurements

[dshreter]

Hi

It is indeed possible to EQ the speakers for a hypothetical Listening position that shouldn't vary by a few inches or cm. It remains however, that the best solution is multiple subs followed by EQ'uing the subs. What those graphs show, is the room response: Any speaker with similar low frequency output shall present the exact same response in the low end give or take a few tenths of dB. To linearize the bass in this region, multiple subs are required, then EQ to smooth out the response or/and house curve.
I don't see this as a case for EQ rather more proof that multi subs should be used in any system regardless of the intrinsic low bass output of the mains. At this point, multi-sub is the best solution to the problem of good bass response in a given room.

Agreed. If you try to boost the response at 45Hz and 80Hz in that room, it won’t recover those dips in response. Even worse, you’ve added a ton of energy around those frequencies in an attempt to smooth the response, and if you lean forward or back just a bit, that same band will be bloated instead and you will have found a new dip in response.

My preferred approach is to place main speakers close to the front wall, and you can push the modes up into a higher frequency range that does respond to EQ. Below the low pass, it has to be solved via subs.

 

[dense]

EQ can make the graph pretty, but the flat FR doesn't always mean perfect sound.
I would rather recommend changing the room, adding a sound diffuser or anything that makes the room more like an anechoic chamber.

 

[fredoamigo]

an anechoic chamber would be a horror to listen to.
But agree with you on the first part of your message.

 

[Igor Kirkwood]

...It remains however, that the best solution is multiple subs followed by EQ'uing the subs....

According our experience with Jean-Luc Ohl , using 4 subs (SVS PC-2000), it's better to introduice the same EQ for the 4 subs.

If we try to put 4 different EQs for the 4 subs, the result is not good.

 

[RayDunzl]

If we try to put 4 different EQs for the 4 subs, the result is not good.

What goes wrong?

 

[Igor Kirkwood]

Afters first long trying use different EQ , no succefully ; the best result was One EQ only for the 4 subs .

The localisation of theses subs was Left and Right Griesinger position and one front ant the 4 th back

Your can see the patch of mesuring of Jean-Luc Ohl .

 

[jlo]

What goes wrong?

The problem is that with 4 subs, the response is not minimal phase so it is very difficult to simulate the result of EQ. Doing a global EQ on the 4 subs gave good results so I did not really try to found a better method with separate EQs.
Note that the global EQ of subs is different for each of the various configurations (you can switch between 1, 2, 3 or 4 subs while maintaining levels, switch in mono, stereo, Griesinger, M/S, etc....).

 

[Igor Kirkwood]

Notice after MMM mesuring around auditor place (0,8 meter x 0,8 meter) at 2,65 meter. We use only 3 sub EQ ( QSC Q-SYS Core 110f ) for the 4 SVS Subs .

In the first time Jean-Luc Ohl tried, a long time, 4 different EQ for 4 subs. The results was worce !

You can see the very week IIR EQ for 4 subs

 

[Joseph Crowe]

As one who's constantly striving for good off-axis response I find the Revel performa3 F208 to have an unusually excellent off-axis. Nearly all the speakers I test have very aggressive narrowing directivity starting at around 5kHz. The off-axis of the revel looks more like a really good horn since it has a nice gradual narrowing across it's entire bandwidth. I've posted the stereophile measurement to show what I mean. I'm not sure what contributes to such an excellent off-axis, perhaps it's the shallow waveguide on the tweeter controlling directivity in the 2kHz-5kHz region since normally this region has very wide dispersion (+150 degrees) creating an uneven power response. The Revel appears to have a nice 90 degree coverage pattern at 2kHZ. I'm sure this speaker sounds very nice. This is one area that EQ cannot correct. If the speaker's off-axis has a different sonic signature than the on-axis then the speaker will not have correct timbrel balance no matter how effort is placed on EQ adjustment.

 

[SECA_alan]

As a new owner of the F-208, I am astonished at the off-axis performance. In fact the overall even-handedness of this loudspeaker is something else IMO.

I do wonder if it's up for replacement very soon, as there are some great offers around at the moment. I understand the BE version to be superior, but I don't yet see a like for like replacement on the same price bracket.

 

[Joseph Crowe]

There’s a high level of probability that the beryllium will sound fantastic considering Harman’s extensive experience with the material. Any Be drivers I’ve tried have been high performing since breakup occurs much higher in the frequency range and impulse response is very quick.

 

[audiophile]

EQ can make the graph pretty, but the flat FR doesn't always mean perfect sound.

It makes some people believe they got that perfect sound.

 

[600lbs of Sin]

As one who's constantly striving for good off-axis response I find the Revel performa3 F208 to have an unusually excellent off-axis. Nearly all the speakers I test have very aggressive narrowing directivity starting at around 5kHz. The off-axis of the revel looks more like a really good horn since it has a nice gradual narrowing across it's entire bandwidth. I've posted the stereophile measurement to show what I mean. I'm not sure what contributes to such an excellent off-axis, perhaps it's the shallow waveguide on the tweeter controlling directivity in the 2kHz-5kHz region since normally this region has very wide dispersion (+150 degrees) creating an uneven power response. The Revel appears to have a nice 90 degree coverage pattern at 2kHZ. I'm sure this speaker sounds very nice. This is one area that EQ cannot correct. If the speaker's off-axis has a different sonic signature than the on-axis then the speaker will not have correct timbrel balance no matter how effort is placed on EQ adjustment.

My experience with the f208’s parallels yours. I used to run arc with an anthem avm60, also tried Dirac on my Emotiva. I was never happy with the end result. After installing a couple acoustic panels on the side walls and running direct mode was I satisfied. Then I ditched the pre pro and bought a 2 channel pre amp with a better DAC. Smooth sailing since!