2-Channel Subwoofer Integration

[Spock]

It seems that when we talk about subjective perception (only the ears) we don't understand each other.
But it seems that when measurements and science come in, it gets even worse...:blush:

Why don't you illustrate your comments with what you achieved and hear?

1 (one) subwoofer, placed in the center of the main speakers (mandatory) with these reproducing the entire frequency range... And the result is a wall of sound, with a well defined stage and a fantastic stereo, it is not possible to point out the origin of the low frequencies...

N Vasilic1.mp4 on Vimeo

N Vasilic2.mp4 on Vimeo

 

[JoeESP9]

This has to be the most confused topic on audio forums. A "flat" anechoic measurement on axis is a single point in the direct output of a (typical, monopole) loudspeaker, which radiates effectively forward at HF and omni at LF. Specifically because the chamber is anechoic (like open space), the capture is effectively only the direct on axis output. A well designed speaker will be both flat on axis and "flat"/smooth off axis. The off axis can be measured separately as well.
An in room/closed space measurement is not anechoic. One can do a "quasi" anechoic measurement near the speaker by gating/ignoring the closed space reflections, but this is not the same as a listening seat "in room" measurement. That type of measurement is a sound power/single point capture of the cumulative sum of the speakers all on/off axis radiated frequency responses. Totally different from an anechoic measurement. A anechoic "flat" typical forward radiating speaker cannot measure both flat anechoic (no space) and flat in room (closed space). An anechoic "flat" speaker placed in typical listening room measured at listening seat 9' or so away, will have a downward sloping response from low to high frequency, due to the omni>forward radiating characteristics of the speaker and the absorption of the air/room reflective surfaces, objects, etc.
For this type of measurement to be remotely "flat", a massive amount of HF power would have to be added. If this same EQd speaker is then remeasured anechoically, it wouldn't be "flat", it would have a highly tilted upward response from LF>HF.
So an anechoic "flat" speaker is not perceived as bright to anyones ears, with normal hearing, in room. A massively EQd to "flat at LP" certainly would, but only a very uninformed person would do that...and not have any clue about the difference.

cheers,

AJ

IMO/E My results pretty much have the same result as you have so patiently explained. Perhaps you missed where I said I use a roll off above ~8KHz because otherwise the sound is too bright.

I don't give two "ding dongs" what the anechoic response of any speaker is. My only concern is what it sounds like in a "normal" room (mine) in the sweet spot.

IME: Dipole radiators, which I use exclusively don't respond in the same way as direct radiators (boxes).

Here is something one of the spec geeks posted on ASR.

The crux of the matter is the design intent. For any dipole or bipole radiator, the ROOM IS PART OF THE DESIGNER'S INTENDED SOUND. By discarding the room sounds and measuring only the anechoic response, you discard almost half of the expected acoustic. That's why dipole and bipole radiating speakers come with specific instructions as to room placement. If the speakers are to be measured, both the distance from the speaker and the distance from the speaker to reflecting walls, ceilings, and floors are critical. To measure a panel speaker near field or in an anechoic environment is the equivalent of placing a "bookshelf" speaker in a corner and on the floor for measurement.

For any planar-magnetic or electrostatic panel, the width of the radiating surface is also an issue. Although Amirm uses multiple averaged measurements across the panel dimensions, this (again) ignores the designer's intent. Specific peaks and dips in the frequency response ARE inherent in the physical geometry of the panel, but those irregularities are also taken into account (by the designer) in the room placement. To measure the panel characteristics in isolation (ignoring the effect of the room, again) distorts the design intent of the speaker.

And finally, the distortion characteristics of the panel speaker have been measured in isolation. In the case of the LRS, yes, the distortion may rise precipitously above 10 watts, but the average listener uses the speaker at one or less watts. Want lower distortion at higher power levels? Buy bigger panels with more radiating area!

I concede that Amirm's measurements are accurate within their (gross) limitations, but I strongly dispute, due to the way that they were taken, that the measurements are at all useful in evaluating the actual sound of the speaker in situ. Any conclusion drawn from these measurements is a disservice to any reader trying to understand the speakers' sound. You're free to argue this if you wish, but the designer would almost certainly agree with me - the ROOM is an inherent part of the design and any attempt to measure the speaker in acoustic isolation is grossly misleading.

Were I an ASR member I'd have given him a thumbsup.:thumbsup:

 

[AJ Soundfield]

IMO/E My results pretty much have the same result as you have so patiently explained. Perhaps you missed where I said I use a roll off above ~8KHz because otherwise the sound is too bright.
I don't give two "ding dongs" what the anechoic response of any speaker is. My only concern is what it sounds like in a "normal" room (mine) in the sweet spot.
2Ch: Sumiko Blackbird, Rega RB300 (modified), VPI HW-19 (modified), ARC SP-9MKIII, DBX 223SX, Dyna MKIII (radically modified), Magnepan 1.7, Dual 12" DIY TL subs, 2 bridged Crown XLS-402's, 14" HP laptop/2GB USB HDD, Emotiva XDA-2

IOW, you have no idea whether your speakers are measurably anechoically "flat" on/off axis and whether this is what you prefer in the context of your connected system/room, or not. "Flat" is a measurement.

 

[AJ Soundfield]

It seems that when we talk about subjective perception (only the ears) we don't understand each other.

Agree, since every (unread) link I posted is 100% exactly that - subjective perception (only the ears).

Unlike your MP4 videos.

cheers,

AJ

 

[AJ Soundfield]

Btw Joe, if your 1.7 is anything like the 1.6/QR, a notch, rather than shelving filter at 7-8k would probably sound better to folks with hearing > 10k, like myself.
As always, YMMV.

Magnepan Magneplanar MG1.6/QR loudspeaker Measurements | Stereophile.com

cheers,

AJ

 

[rbbert]

It seems that when we talk about subjective perception (only the ears) we don't understand each other.
But it seems that when measurements and science come in, it gets even worse...:blush:

Why don't you illustrate your comments with what you achieved and hear?

1 (one) subwoofer, placed in the center of the main speakers (mandatory) with these reproducing the entire frequency range... And the result is a wall of sound, with a well defined stage and a fantastic stereo, it is not possible to point out the origin of the low frequencies...

N Vasilic1.mp4 on Vimeo

N Vasilic2.mp4 on Vimeo

Placement along the center line of a room’s short axis will always excite multiple room nodes, making flat response from the sub impossible, even with EQ (you can dampen the peaks, but the nulls will remain). That placement only works well with multiple subs in other locations.

 

[JoeESP9]

IOW, you have no idea whether your speakers are measurably anechoically "flat" on/off axis and whether this is what you prefer in the context of your connected system/room, or not. "Flat" is a measurement.

I know exactly what flat is and means. Flat in my room not in an anechoic chamber.

And no, I don't care what my or any speakers sound like in an anechoic chamber. Please enlighten me as to how many people you know or have heard of that listen in an anechoic chamber. All I care about is the sound I get in my room. In any case, testing in anechoic chambers has little to do with how a di-polar speaker sounds in a real listening room.

My system is eq'd to sound flat to 20Hz with a roll off above 8KHz. Setting my in room response flat to 20KHz makes the sound overly bright. Hence the roll off.

I made much the same statement in an earlier post.

As a ten year head and neck cancer survivor I see my ENT doctor every six months at which time my hearing is also tested. I have much less hearing loss than the average 74 yo male. At 74 my hearing still extends above 10KHz. I also regularly attend concerts and recitals of live orchestral and organ music.

You want to hear what deep bass really sounds like? Check out the Wannamaker organ in Center City Philadelphia. They have free concerts daily.

My other musical passion, jazz, is satisfied frequently by either jamming with others (I'm a bass player) and/or listening to live jazz in a club.

I'm very thankful I still have most of my hearing, I'm also still physically (ride a bike ~80 miles a week) and sexually active.

 

[AJ Soundfield]

I know exactly what flat is and means. Flat in my room not in an anechoic chamber.

Clearly you don't understand the difference explained above, both measurements or perception. Both are measurements. Flat anechoic isn't flat in room, regardless of whether a speaker is a dipole or not.

My system is eq'd to sound flat to 20Hz with a roll off above 8KHz. At 74 my hearing still extends above 10KHz.

That is both a measurement and a correlated perceptual claim.
Please share the measurements of the 1.7 you are claiming. The 1.6 above clearly shows a notch @ 8kwould be better than shelf...if one understands the correlation between how/where/what was measured and perception, plus has >10k hearing.
The most likely culprit for a speaker like yours sounding bright would be if it measured like the 1.6.

p.s. no measurements expected.

 

[chops]

You want to hear what deep bass really sounds like? Check out the Wannamaker organ in Center City Philadelphia. They have free concerts daily.

My other musical passion, jazz, is satisfied frequently by either jamming with others (I'm a bass player) and/or listening to live jazz in a club.

My father worked on the Wannamaker organ a long time ago, and I too play bass, both upright and electric, though I haven't touched the darn thing in years now.

 

[Spock]

Unlike your MP4 videos.

cheers,

AJ

Sorry (to you all) for the interruption...

Cheers!

 

[JoeESP9]

Clearly you don't understand the difference explained above, both measurements or perception. Both are measurements. Flat anechoic isn't flat in room, regardless of whether a speaker is a dipole or not.


That is both a measurement and a correlated perceptual claim.
Please share the measurements of the 1.7 you are claiming. The 1.6 above clearly shows a notch @ 8kwould be better than shelf...if one understands the correlation between how/where/what was measured and perception, plus has >10k hearing.
The most likely culprit for a speaker like yours sounding bright would be if it measured like the 1.6.

p.s. no measurements expected.

First, please stop making posts to me as if I don't know what my own system sounds like.

Second, I'm a retired EE and know specs, testing and the results derived.

Third, you have no way off knowing whether or not I corrected for an 8KHz peak.

What part of "I measured my in room response and set my DSP accordingly to compensate for any aberrations in my room response" do you not understand?

After 50+ years with this hobby I've heard lots of systems and speakers. Fifty years ago there were plenty of emporiums for a person to audition just about everything. Needless to say I heard and experienced lots of gear. IME/O any system that's set for flat in room response sounds bright.

Those who don't agree should actually listen for themselves instead of pulling out charts and graphs from who knows where.

That's it. I'm out of this thread.:wave:

 

[AJ Soundfield]

you have no way off knowing whether or not I corrected for an 8KHz peak.

Correct, since not a single solitary measurement has been presented.

What part of "I measured my in room response and set my DSP accordingly to compensate for any aberrations in my room response" do you not understand?

IOW, you don't know the difference between single point pressure mic measurements (worse, "in room"!!) and human binaural perception, aka 2 ears and a brain. Not the same thing whatsoever...and absolutely not taught in EE programs.
"Flattening" single point pressure mic "aberrations" applied to the speaker to "compensate" for "room response" is a highly misguided idea.

any system that's set for flat in room response sounds bright.

Hmmm, I wonder why, give I explained in detail previously why that's a terrible idea.
Who would do that?

cheers,
AJ

 

[kevinkwann]

That's it. I'm out of this thread.:wave:

I thought your contributions to the thread were reasoned, wise, accurate and valuable. And your patience dealing with others who were none of those things was admirable.

 

[Mike]

First, please stop making posts to me as if I don't know what my own system sounds like.

Second, I'm a retired EE and know specs, testing and the results derived.

Third, you have no way off knowing whether or not I corrected for an 8KHz peak.

What part of "I measured my in room response and set my DSP accordingly to compensate for any aberrations in my room response" do you not understand?

After 50+ years with this hobby I've heard lots of systems and speakers. Fifty years ago there were plenty of emporiums for a person to audition just about everything. Needless to say I heard and experienced lots of gear. IME/O any system that's set for flat in room response sounds bright.

Those who don't agree should actually listen for themselves instead of pulling out charts and graphs from who knows where.

That's it. I'm out of this thread.:wave:

Don’t worry, you’re in good company. [emoji6]


Sent from my iPhone using Tapatalk Pro

 

[rbbert]

...My system is eq'd to sound flat to 20Hz with a roll off above 8KHz. Setting my in room response flat to 20KHz makes the sound overly bright...

I suspect disagreements may be due to a misunderstanding about what you mean here? Is this using a single microphone at the listening seat? Is it an omnidirectional mic with a calibrated flat response for the pre-amp you are using? Are you using a "dummy head" with spaced, calibrated omnis? Are you using an XY positioned pair of cardioids? Mid-side? Blumlein?

Any/all of the above are likely to result in different frequency response measurements, so saying "flat in room response" is meaningless without further description of what that means.

 

[nc42acc]

So if you have one subwoofer and you want to integrated into your room without weeks of tedious measuring and listening where would be the best location to locate it for a start?

 

[AJ Soundfield]

So if you have one subwoofer and you want to integrated into your room without weeks of tedious measuring and listening where would be the best location to locate it for a start?

There's no simple answer because that would depend on a multitude of factors, the mains LF extension, the means of filtering between mains/sub..if any, the room itself and where on sits, etc, etc.
For example, if the mains had to be crossed higher, 70-90hz ish, then one would want the sub somewhat centered, as localization creeps in...and so on. Too many variables for a simple, place here to start.
Btw, it doesn't take "weeks" to measure. More like seconds, in 2021.
Heck, there are ways to even use smart phones now. Especially for LF. Its far more important to understand what/how...as this thread might indicate.

cheers,

AJ

 

[Spock]

So if you have one subwoofer and you want to integrated into your room without weeks of tedious measuring and listening where would be the best location to locate it for a start?

I tried my sub all over the places in my room (except the ceiling ). To me, there is a simple answer. At the center of the mains speakers. Thank God i´am not alone

… a single sub needs to be placed equidistance from mains best is dead center to avoid localization ..
Regards

Ah, but I use only my ears! :happy:

 

[nc42acc]

That’s where it is now, center in front of rack. The big heavy black box in the middle of the room.

I tried my sub all over the places in my room (except the ceiling ). To me, there is a simple answer. At the center of the mains speakers. Thank God i´am not alone



Ah, but I use only my ears! :happy:

 

[chops]

Also keep in mind, the physical height of the subwoofer can also play a roll in the overall sound results as well, or even simple vibration isolation for that matter. Though optimal placement should be first and foremost on the list. Height and isolation should be for tweaking.