indirect method to listen to the sound of other people's speakers

Hi everyone .
I would like to discuss something together.
using software and microphone like REW and with sweep or pink noise it is possible to publish graphs such as frequency response, distortion, harmonics and many other data.
unfortunately, however, only the most skilled and with a lot of experience can guess how that speaker could sound so I'll come to the point.
if I can record music directly from my speaker with a microphone I can then publish it as a .
this file can be heard on your speakers . at this point you will say that it is not possible to do it this way because the characteristics of my speakers would mix with yours (unless you have studio monitors) but it is possible to listen to that song twice, first the original one played by your speakers and then the one recorded by me.
maybe you can distinguish some differences.
obviously the piece of music must be the same for both the recorder and the listener.
this way any person building a prototype could make it feel for others to be judged even if it is an indirect method.
how about ? it can be done ? .
Hello, arivel,

It seems that I would still be left with an impossible auditory perception and memory task. Subjectively subtracting the recorded sound of your speakers, from the live sound of my own speakers. That seemingly impossible auditory task is further complicated by the fact that the sound of your speakers would be overlaid with the sound of your listening room, and much of the subjective sound of a speaker is determined by the way it's polar response acoustically illuminates a room. Perhaps, a sophisticated DSP based analysis could usefully separate the response of the two if each speaker had performed in an anechoic chamber, I don't know. Even if DSP could do that, it then doesn't provide the instrument-free communication of speaker sound character you hope to achieve. In human auditory perception terms, although I would likely hear subjective differences between the two speakers. Unless those differences were gross, however, I wouldn't think that I could determine the basis for them, and more to the point, be unable to usefully subjectively determine what your speakers sound like.
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How Crutchfield tries to do it is below. If you want to try something similar, a DIY version could be to record the speakers outside, so you can eliminate your room from the equation. The room influence being quite large, and also completely unnatural when combined with the listener's room/speakers.

I've seen other people use dummy heads to do binaural recordings of a listening space/system. To present something useful, those also have to be listened to with a neutral set of headphones.
About 15 years ago, Bill Crutchfield imagined a new type of “virtual” store, where speakers could be demonstrated online — something that had never been done before. He hired a team of engineers and built a specially designed testing facility in Christiansburg, Virginia. After more than a decade of research, this patented Virtual Audio™ technology is now available on our website.

. . .

Our engineers, led by Rick Wright, Ph.D., and Gary Gibbs, Ph.D., had to develop a process for simulating the differences between speakers online. Rick explains that it starts with the team’s anechoic chamber, an acoustically neutral room that uses sound-deadening material to eliminate reflections. The room is equipped with highly sensitive microphones to measure each speaker’s frequency response, sensitivity, power handling, and other attributes.

Next, they gather data on important details like room characteristics and how our ears work. They also carefully measure the audio characteristics of different headphones to account for any sonic coloring they may add to what you hear.

SpeakerCompare tailors your listening experience to the specific type of headphones you have, so that what you hear is comparable to auditioning speakers side-by-side in person. Gary sums up the process of comparing the relative differences of speakers virtually through headphones: “When you break apart each of these pieces, model them, and put them back together, we can simulate the experience of listening with speakers.”
How Crutchfield tries to do it is below....
I haven't tried the Crutchfield app but the idea of using an anechoic chamber measurements to simulate a speakers performance has a fatal flaw: many of the best speakers are designed for real rooms, and would not measure the same way in an anechoic chamber. Hence the simulation could be quite inaccurate for such speakers, which would be a big bias against them.
the idea of using an anechoic chamber measurements to simulate a speakers performance has a fatal flaw: many of the best speakers are designed for real rooms, and would not measure the same way in an anechoic chamber.
If they were only using anechoic on-axis data without additional processing you might have a point, but that's not what they are doing.

From a DIY standpoint, even straight anechoic information would be more useful than double reflections from the recording room and playback room. One way or another, you have to deal with this aspect if you want any kind of reasonable representation of objective performance.

The patent also covers applications beyond what they are doing on their website currently.
the virtual speaker demonstration system can include the effects of a demonstration environment by, for example, allowing a user to select from a plurality of possible room configurations (e.g., geometry and absorption parameters). In this case, the characteristic for the selected demonstration environment is processed to factor in its effects.

According to yet another aspect of the invention, the virtual speaker demonstration system can remove the effects of the reference environment (the listening room for the demonstration) by inverse filtering a characteristic for the reference environment to remove its effects.

. . .

Based on user-selected options, DSP 220 accesses characteristics 210 to retrieve appropriate characteristics and accesses samples 230 to input a sound sample. Characteristics 210 generally refer to transfer functions, impulse responses, or other mathematical descriptions that characterize acoustic performance. Characteristics 210 may be used to characterize and, therefore, account for, the effects of various components of an acoustic system on overall acoustic performance. For example, characteristics 210 may be characteristics for demonstration speakers, reference speakers, demonstration spaces (rooms or vehicle interiors), reference spaces (e.g., the listening room in a retail outlet where the virtual demonstration is presented), amplifiers, tuner/receivers, equalizers, and so forth. Additionally, in a beneficial embodiment (discussed further below) allowing the user to “build” his/her own demonstration space, characteristics 210 may include absorption parameters for various materials and geometry parameters which can be used to create a demonstration room.

. . .

The signal processing performed by DSP 220 in order to implement the invention is well understood in the art. Generally, characteristics of speakers, environments, amplifiers, and other components of the total acoustic system can be expressed as transfer functions (frequency domain) or impulse responses (time domain equivalent of the transfer function). These transfer functions can be determined analytically (through modeling and prediction, such as ray tracing) or empirically (through measurement). In a preferred embodiment of the invention the transfer functions are determined empirically.

For example, transfer functions of the various demonstration speakers supported by the virtual system can be measured in an anechoic chamber by stimulating the speakers with a basic acoustic input and the measuring the response. Preferably, the response is measured across a frequency spectrum of interest to users, such as about 5 Hz to 30,000 Hz, which goes beyond the typical range of human hearing but which will include the vibratory effects at the low and high ends. The measurement of the transfer function may be made at multiple angles with respect to the demonstration speaker (to derive a response which is a function of angle) or at a single on-axis point for simplicity.
If they were only using anechoic on-axis data without additional processing you might have a point, but that's not what they are doing.
OK, gotcha.

I went and tried Crutchfied's comparisons -- of 3-4 bookshelf & floor standing speakers from Revel, KEF & Paradigm of a wide range of prices. Crutchfied doesn't list Sennheiser HD6xx so I chose the closest match, a 660s. The differences sound quite subtle & obscure to me with many of the tracks, even between $800 and $5500 models. Perhaps this means the better brands are successfully converging towards the same end goal, and paying more just gives you incremental improvements, not a wholesale change in the presentation. Perhaps it's because the process cannot recreate the experience of hearing the speakers in real time & space next to each other.

I personally would not trust the Crutchfied virtual auditions to form the basis of any buying decision. Not without a lot more data, by which I mean technical analysis/reviews, subjective impressions by people I trust, and/or my own real time/place auditions.

This begs the question of how most people buy hifi these days, with the increasing demise of brick & mortar stores, especially the smaller high service shops?!

When I lived in Vancouver, through the 80s and 90s, there was a handful of both high end boutiques as well as big box stores that maintained listening rooms. But in the last 20 years, the specialists as well as big box stores have either disappeared or cut way back. My own purchases in the past decade have been based almost entirely on on-line reviews & discussions.
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X is well known for doing this.

But given that what you hear in the end includes the room amplifier, other kit used in the system being recorded, huge loses recording it with a microphone, then confuse matters further because of your amplifier, speakers, room, and kit.

The room is the biggest boogieman when it comes to hifi, and now you have to deal with 2 of them. Just that alone...

So not very useful IMO.