What is your favorite house curve

[Rednaxela]

How does it sound?

 

[Acerun]

How does it sound?

It sounds incredible. Moving from the $20 android Multieq app to the $200 laptop-based Multieq-x software is a revelation. Thank you for your help and encouragement! Feels like I can now tweak and adjust to taste. I also just bought that ACM1-X calibrated Audessey microphone, so I'll take a new set of measurements with that as I hear it is even more accurate. One still can't use a UMIK with Audessey.

 

[Acerun]

After new measurements with the calibrated microphone. Added tilt, added low shelf at 60 and cut at 550

 

[Rednaxela]

To be honest since you showed the subwoofer plots as well, I’m not sure if adding this shelf is entirely right.

I’d imagine this default rolloff to in fact be part of the crossover to the sub.

Something you might want to verify.

Sorry for the confusion.

 

[Acerun]

Here it is with the low shelf removed. Didn't seem to change much? I suppose I can add more bass as needed. The Harman curve has more bass in the graph, no? Honestly I feel like I'm battling too much bass if anything.

 

[Rednaxela]

The story is getting a bit hard to follow now, I’m sorry.

1) You have subs, the response of which is (I believe) not included in these graphs. So these graphs do not fully represent what your system puts out. This makes it hard to comment on your bass response for instance, as your actual bass is something else. My apologies for not realizing this earlier.

2) What you show now is a different rolloff than the one I commented on the other day. Did you notice this yourself? Can you explain it?

3) I don’t understand how the purple line turns the green line into the orange one. Do you? What am I missing?

 

[Acerun]

The story is getting a bit hard to follow now, I’m sorry.

1) You have subs, the response of which is (I believe) not included in these graphs. So these graphs do not fully represent what your system puts out. This makes it hard to comment on your bass response for instance, as your actual bass is something else. My apologies for not realizing this earlier.

2) What you show now is a different rolloff than the one I commented on the other day. Did you notice this yourself? Can you explain it?

3) I don’t understand how the purple line turns the green line into the orange one. Do you? What am I missing?

1) Yes, I believe that is correct. I am showing just my left front channel which is not taking the subs into consideration. I think I will need to do that by ear?
2) I believe I mentioned that I took new readings today with a calibrated microphone. Perhaps that changed things? I also adjusted the tilt to +4 to -7. I am also cutting off at 550Hz.
3) Green is the before reading, purple is the filter applied and apparently the orange is the corrected output.

 

[Acerun]

In any case don't worry about me and thank you for your support. I'm like Wile E. Coyote, I need to get back to the drawing board.

 

[Rednaxela]

Green is the before reading, purple is the filter applied and apparently the orange is the corrected output.

Understood but the numbers don’t seem to add up.

Edit: for instance, have a look at the area between 35Hz and 90Hz. Green is cut entirely there to become orange, while purple shows a cut followed by a boost. Between 150Hz and 200Hz, purple shows a boost of almost 10dB, but the max green-orange difference is not more than 3.5dB there. Etc.

 

[Stefano_Milano]

OK. I thought about opening a rat's nest by doing this, because it is a simplification of what sometimes has to be done. Some of the points have been made earlier in this forum thread and elsewhere, but it might be useful to bring the key factors in the process to one place. The marketing of room EQ algorithms often presents the impression that all combinations of loudspeakers and rooms can be "fixed", "calibrated" or the like, by means of measurements, math and equalization. In reality, much of the "math" does not include the exceptionally complex, non-linear and occasionally capricious psychoacoustics of human listeners. A critical missing element is that humans adapt to circumstances, bringing our perceptions into acceptable territory. Loudspeakers reproduce sounds. Musicians produce sounds. Both do it in rooms. We don't feel the need to "equalize" - even if we could - the instruments and voices of live music. Two ears and a brain separate the sources from the venue, and adapt to aspects of what the environment contributes to the overall performance. The venues vary, and some are even not ideal, but we manage to appreciate the excellence of fine instruments and voices in most of them.

The special problem with sound reproducing systems is that flaws get superimposed on everything that is played through them. These monotonous colorations can sometimes be beyond the ability of humans to adapt, and they need to be identified and attenuated.

Therefore, the "right way" begins with choosing well designed, timbrally neutral, loudspeakers. If the loudspeakers exhibit audible resonances and/or frequency-dependent directivity issues, it is not likely that measurements in a room will reveal such problems and that equalization is capable of compensating for them. It is often the case that the solution is better loudspeakers. Fortunately these can be identified with good reliability from competently made anechoic measurements presented in a "spinorama" format, following the industry standard. Amir, on this site, makes such measurements and others can be found at www.spinorama.org.

This done, set them up in your room and make a steady-state frequency response measurement at the prime listening position - the stereo seat. We will be paying close attention to the frequencies below about 400-500 Hz, where adjacent boundary effects and room resonances are active. Because much of the bass in recordings is mono (all of it in LPs) drive both loudspeakers simultaneously to evaluate what is happening at low frequencies. Measure them individually to find out what is happening at frequencies above about 400 Hz. If you are using bass management and one or more subwoofers the process is the same, and of course all subs should be running simultaneously. Why? Because multiple sound sources couple energy to room resonances differently when they operate in unison.

You can repeat this at different seats to see how much seat-to-seat variation there is - often quite a lot. Averaging several of these curves is a common practice, making the curves look much smoother, but hiding some awkward realities at low frequencies. Superimposing the curves on one graph is a more useful display of what is happening in your setup. You can then choose which humps/peaks to attenuate, depending on which seats are affected. Remember, at this stage we are looking only at bass frequencies. Narrow dips, however deep, should be ignored. Broad dips can be filled in, but keep the EQ boosts below about 6 dB. Aim for a smoothish curve that is tilted slightly upward at lower frequencies.

The benefits of this exercise will apply only to the seat or seats exhibiting similar shaped curves. That is why multiple-sub methods have been developed aimed at reducing seat-to-seat variations so that one equalization can deliver improved bass to several listeners. These are discussed in detail in Chapter 8 in the 3rd edition of my book.

Above about 400-500 Hz the "early reflections" curve in the spinorama should be similar to what you have measured. If you have well designed loudspeakers the room curve might have some smallish ripples caused by acoustical interference between and among the direct and reflected sounds - these are not problems to two ears and a brain and equalization is the wrong method of addressing them if they were - that is an acoustics issue. Spatial averaging over several microphone locations tends to smooth the room curve at middle and high frequencies, thereby reducing the likelihood that an auto-EQ algorithm (or a person) might try to "fix" something that can't be fixed, or that doesn't need to be fixed. Remember, any EQ applied to a room curve modifies the direct sound, and it the the direct sound that is a key factor in determining sound quality. If you began with loudspeakers designed to have the desirable smooth and flat on-axis/listening window response, they will be degraded.

Finally, pay attention to the overall shape of the room curve. Usually, at least for conventional forward-firing loudspeakers, the room curve will tilt gently downward. If the shape deviates substantially from the early-reflections spinorama curve then one can suspect something is amiss in the acoustical treatment of the room. If listening confirms a problem, then one is free to try modifying the shape of the spectrum with broadband, low-Q, tone-control kinds of equalization. When listening to recordings we get into the circle-of confusion dilemma, where it is difficult to know where the problem lies: the playback system or the recording.

Don't worry about little ripples. When I see exceptionally smooth high-resolution room curves I strongly suspect that something wrong has been done. The measurement microphone is no substitute for two ears and a human brain. Happy landings!

Thanks for the very clear post. I have just one doubt. After measuring the speakers in stereo with Rew below 400Hz do I have to equalize them both in stereo? Or separately?
Thanks
Stefano

 

[Floyd Toole]

Thanks for the very clear post. I have just one doubt. After measuring the speakers in stereo with Rew below 400Hz do I have to equalize them both in stereo? Or separately?
Thanks
Stefano

I quote from the essay you read: " Because much of the bass in recordings is mono (all of it in LPs) drive both loudspeakers simultaneously to evaluate what is happening at low frequencies." Equalizing them separately is a waste of time. In the real world bass is usually deficient in modest systems, so recordings tend to make use of all woofers at all times.

 

[Floyd Toole]

I was doing some listening yesterday and again was reminded how variable recordings are in the bass frequency range. My system is essentially flat down to around 20 Hz. Most recordings sound great, but there are some that have an enormous bass "bloom/boom" at very low frequencies, as if the recording engineer needed to boost the bass because of his monitoring system - or simply didn't hear the very low stuff. Who knows? But for many people excessive bass is a "forgivable sin". Otherwise, accessible tone controls are very useful. Having a "perfect" home system does not guarantee "perfect" sound.

 

[Stefano_Milano]

I quote from the essay you read: " Because much of the bass in recordings is mono (all of it in LPs) drive both loudspeakers simultaneously to evaluate what is happening at low frequencies." Equalizing them separately is a waste of time. In the real world bass is usually deficient in modest systems, so recordings tend to make use of all woofers at all times.

thanks for the clarification!

 

[Martin]

This is the target curve I used in REW for my Von Schweikert VR5 Anniversary Speakers:

Martin

 

[Acerun]

Understood but the numbers don’t seem to add up.

Edit: for instance, have a look at the area between 35Hz and 90Hz. Green is cut entirely there to become orange, while purple shows a cut followed by a boost. Between 150Hz and 200Hz, purple shows a boost of almost 10dB, but the max green-orange difference is not more than 3.5dB there. Etc.

I see what you mean. I just took 8 new measurements from the sweet spot, and this is it with no filters. I think this looks more coherent (and it sounds really good as is...perhaps a bit too much bass and the treble is a touch high?)

 

[Rednaxela]

[…] and the treble is a touch high?

There seems to be no slope in your target, which is generally found to give too bright an overall sound.

 

[Acerun]

There seems to be no slope in your target, which is generally found to give too bright an overall sound.

Yes you are right. I suppose my post was meant to show that I think I have proper measurements now and that the software is actually working. I think the subs are filling the lower end. I'm playing with crossing over at 60Hz and 80Hz. 80Hz has a fuller sound. I think I like 60 better and that's what Audyssey recommended. Edited. Honestly, I think a +2 to -1 tilt sounds best to my ears. Maybe I had Klipsch Hereseys for too many years. I do like the higher-end air.

 

[ernestcarl]

I was doing some listening yesterday and again was reminded how variable recordings are in the bass frequency range. My system is essentially flat down to around 20 Hz. Most recordings sound great, but there are some that have an enormous bass "bloom/boom" at very low frequencies, as if the recording engineer needed to boost the bass because of his monitoring system - or simply didn't hear the very low stuff. Who knows? But for many people excessive bass is a "forgivable sin". Otherwise, accessible tone controls are very useful. Having a "perfect" home system does not guarantee "perfect" sound.

I am afraid that this is especially true for many “user generated”, youtube uploaded content.

Folks upload random video-audio without monitoring/checking the low bass levels on a spectrogram or something. Systems that have pretty good low end FR extension unfortunately highlight the unfiltered bass booms too well to the detriment of one’s listening pleasure.

Funnily enough, I placed a simple EQ tone control on the television set for my father to use. He is in his middle sixties… and I keep finding out the knobs are turned up all the way up in the HF shelving (+12dB?), mids (maybe +7dB), and low frequencies (+8dB)… I amost invariably never fail to get an “ear-ache” whenever I hear the TV system he uses. I cannot stand it, yet he seems to be quite satisfied.

 

[mhardy6647]

Favorite house curve? Probably those of the "Fred Flinstone" house in (or at least very close to) Palo Alto, CA.
Always made me smile when we'd drive past it on I-280 en route to "The City" from the Silicon Valley during our rather brief sojourn out west for my first real (post-doctoral) job.

 

[Doodski]

Favorite house curve? Probably those of the "Fred Flinstone" house in (or at least very close to) Palo Alto, CA.
Always made me smile when we'd drive past it on I-280 en route to "The City" from the Silicon Valley during our rather brief sojourn out west for my first real (post-doctoral) job.

I've done the I-280 and the route from San Jose to Monterey along the #101 and the #1 and I was gawking at all the nice houses and cool architecture that we don't see in Canada at all or very much at all. I studied drafting and so I have a appreciation for unique and exotic architecture.