Heresy or....

[Paul Carmody]

.... and I suppose that a flute would represent an acoustic instrument that is likely to have fewest harmonics).

It has TONS.
A clarinet, on the other hand, is close to a pure sine wave after the initial attack.

[romanbednarek]

It has TONS.
A clarinet, on the other hand, is close to a pure sine wave after the initial attack.

Yeah, as I was typing that statement I remembered the amount of "breath" that comes through along with the intended musical note with a flute.

On a side note, I was listening to my Sony MP3 player last night using the SensMe randomizer on "Midnight" mode and it played the version of "What Child Is This" that you and your wife recorded (you on acoustic guitar and her on flute with the second layer that she composed). I was reminded of how nice the arrangement is and well it was performed despite a few slightly muted notes from the acoustic guitar here and there (not bad for a drummer though ).

[jclin4]

I first heard pure sine waves in an electronic music course in school, working with old moog and ARP analog synthesizers. I was struck with how similar it sounded to a clarinet.

[romanbednarek]

I first heard pure sine waves in an electronic music course in school, working with old moog and ARP analog synthesizers. I was struck with how similar it sounded to a clarinet.

I guess that clarinets aren't too common in most of the types of music I typically listen to. But I do remember hooking up an oscilloscope to my CD player when I was in college and noticing that there are a lot of smooth sinewaves in the CD by Kraftwerk that my suitemate had.

I guess the point that I was trying to get at is that an instrument whose sound is dominated by the fundamental tone may be perceived (spatially) in a different way than one whose sound contains a lot of harmonic content and this may be related to the design parameters of the speaker itself. This may be a clue to why certain speakers sound good with certain types of music.

[brianpowers27]

....

From my analysis, the tone's position is most stable if the tweeter is located under the woofer.

Dave

Why?

Side note: Are producers really mixing flat on axis with speakers that have a neutral power response? Doubtful.

[Face]

Why?

Side note: Are producers really mixing flat on axis with speakers that have a neutral power response? Doubtful.

Some.

[dbe]

Why?

Side note: Are producers really mixing flat on axis with speakers that have a neutral power response? Doubtful.

Not Dave, but Dave here. I never thought about this before, but my gut tells me that it has to do with the tilt and instability of the ZDP. Since the tilt is towards the bass/mid, it makes sense. The old Mission speakers with first order networks were designed with the woofers on the bottom and were set up on dedicated stands with the tweets to the outside to use location for time alignment.

Producers generally don't mix, but the mixing and/or mastering engineers use a myriad of speakers, only a few of which are flat on axis with uniform power response. There is less concern with mixing engineers and more with mastering engineers regarding technical speaker characteristics. What they are most concerned with is if the mix translates to the real world.

One of the other Daves

[DDF]

Why?

The frequencies covered by the tweeter are localized higher by the hearing system.

Sorry, 15 hour day, too bagged to to cite exact HRTF details.

[DDF]

Could it be true that this type of "tonal spatial expansion" which allocates different tones to different places within the soundstage based on driver location and crossover slope/frequency could result in the type of speaker that I prefer as it relates to a less "crowded" soundstage since different tones will be eminating from different points in space. .

Roman, probably not as the effect I'm mentioning affects height perception only.

[dbe]

The frequencies covered by the tweeter are localized higher by the hearing system.

Sorry, 15 hour day, too bagged to to cite exact HRTF details.

Shot the crap out of my hypothesis...



Dave

[dlr]

Roman, probably not as the effect I'm mentioning affects height perception only.

My preference is for 3-ways with small mids, so the CTC of mid to tweeter is small as well. I had the 10" woofer at about midway between floor to midrange with a full passive setup, but now am using a Peerless 10" closed box from the 2002 DIY that was the old competitions with selected drivers. The design placed the driver near an edge, so it's either very close to the mid or the floor. It is run actively with a DQ-LP1.

I've been using it at the floor due to close proximity to reduce floor bounce issues. I had thought at first that I'd have issues with height and driver integration, male vocalists especially. Johnny Cash is my favorite for checking a design for these vocals. What surprises me is that I do not get an impression of his voice coming from the woofer or between drivers, though I'm crossing lower than usual at maybe 150Hz (midrange using box highpass only). The harmonics of his voice still maintain the illusion of a good image with some depth, but the height remains at the M/T box area.

I don't know what crossover Fc would start to make this an issue, but I find no discernible difference for 3-ways with a smallish midrange at this Fc.

dlr

[DDF]

My preference is for 3-ways with small mids, so the CTC of mid to tweeter is small as well. I had the 10" woofer at about midway between floor to midrange with a full passive setup, but now am using a Peerless 10" closed box from the 2002 DIY that was the old competitions with selected drivers. The design placed the driver near an edge, so it's either very close to the mid or the floor. It is run actively with a DQ-LP1.

I've been using it at the floor due to close proximity to reduce floor bounce issues. I had thought at first that I'd have issues with height and driver integration, male vocalists especially. Johnny Cash is my favorite for checking a design for these vocals. What surprises me is that I do not get an impression of his voice coming from the woofer or between drivers, though I'm crossing lower than usual at maybe 150Hz (midrange using box highpass only). The harmonics of his voice still maintain the illusion of a good image with some depth, but the height remains at the M/T box area.

I don't know what crossover Fc would start to make this an issue, but I find no discernible difference for 3-ways with a smallish midrange at this Fc.

dlr

Dave,

You're crossing low enough that you shouldn't see height wander or "bloom" issues for 3 reasons.
- the wavelengths are still very long at 150Hz
- the spectral notches that cause height wander are all way above 150Hz.
- image location will be defined more by the faster rise time components of the signal (higher frequencies)

Dave

[DDF]

Shot the crap out of my hypothesis...



Dave

You didn't stand a chance Dave. It's a pretty esoteric phenomenon.

[romanbednarek]

My preference is for 3-ways with small mids, so the CTC of mid to tweeter is small as well. I had the 10" woofer at about midway between floor to midrange with a full passive setup, but now am using a Peerless 10" closed box from the 2002 DIY that was the old competitions with selected drivers. The design placed the driver near an edge, so it's either very close to the mid or the floor. It is run actively with a DQ-LP1.

I've been using it at the floor due to close proximity to reduce floor bounce issues. I had thought at first that I'd have issues with height and driver integration, male vocalists especially. Johnny Cash is my favorite for checking a design for these vocals. What surprises me is that I do not get an impression of his voice coming from the woofer or between drivers, though I'm crossing lower than usual at maybe 150Hz (midrange using box highpass only). The harmonics of his voice still maintain the illusion of a good image with some depth, but the height remains at the M/T box area.

I don't know what crossover Fc would start to make this an issue, but I find no discernible difference for 3-ways with a smallish midrange at this Fc.

dlr

This reminds me of something that was very distracting with vocals when I auditioned my friend's B&W Nautilus 802 speakers a few months back. I was using one of my favorite crossover tweaking CD's ("Static and Silence" by The Sundays) to evaluate his speakers because I'm very familiar with that recording and find that Harriet Wheeler's voice covers a wide range of frequencies. Although her voice isn't quite as deep as Johnny Cash's, there are certain times when there is a warmth to her vocals accompanied by the fundamental note and a higher frequency "breathy" overtone. The character of her voice is great for tuning crossovers in order to balance out these frequencies.

While I was auditioning my friend's speakers in his room with this CD, I recall an odd sensation when this warmth was present in her vocals because it sounded "spatially disjointed" from the rest of the tones in her vocals. It sounded to me like there was some linear distortion associated with the lower midrange or upper bass region which made these tones sound resonant and shifted the image whenever they were present. I'm not sure if this resonance was due to the room interactions or inherent to the tuning of the speaker (or related to the crossover point between the surround-less Kevlar midrange and the dual 8" woofers) but it was quite distracting. When we swapped in my Alpheus MkII speakers which have a configuration similar to your original passive configuration (small 4" midrange, 8" woofer 18" above the floor and 2nd order slopes centered around 300 Hz), this phenomenon was not present at all (which would imply that the room wasn't the dominating factor unless the differences in driver location and crossover points/slopes came into play).

I haven't compared enough three way speakers to determine the effects of woofer location along with crossover slopes and frequency, but can surmise that these parameters might have a greater impact than most people realize not only in terms of neutrality but in terms of spatial presentation, especially with vocals. I have designed two different three way speakers which use the RS180 as the woofer crossed at 500 Hz with 2nd order slopes. One is a TMW "bookshelf" design and the other is a tower speaker with the woofer 18" above the floor and despite the higher crossover frequency I didn't find either of them distracting with vocals. Perhaps the use of shallower crossover slopes allows for better integration spatially despite the higher crossover frequency and driver location differences. I suspect that steeper slope crossovers might present a more drastic shift in the image as tones transition between the drivers relative to a design with shallower slopes which would likely place more tones between the drivers during this transition.

My choice of 2nd order slopes with three way designs has mostly been out of convenience and cost (fewer large crossover parts) but this discussion has got me thinking of possible consequences related to crossover frequency, slope and driver location with three way designs other than floor bounce interactions which is one parameter that I would usually take into consideration. I suspect that since there are so few three way DIY designs that there haven't been too many discussions on the implications of these parameters and firsthand experience is somewhat limited relative to two way speaker designs.

[MSaturn]

What Roman is describing is the reason to get the 801's instead

[dbe]

You didn't stand a chance Dave. It's a pretty esoteric phenomenon.

I had read that the ZDP was not static in larger cone drivers and was frequency dependent in the relative baffle offset. I made the assumption that interaction with the more or less fixed position of the tweeter ZDP would account for the height wander. I never thought about the pinnae issue. Knowing this makes a couple of other details clearer to me.

I need to study the physiology of the ear more.

Thanks.

Dave

[DDF]

I had read that the ZDP was not static in larger cone drivers and was frequency dependent in the relative baffle offset.

Dave, in the old days (70s) before we really understood group delay's impact on crossovers, people used to talk about the ZDP and how it moved over frequency. This was just another way of saying that the driver group delay wasn't flat over frequency.

Dave

[Deward Hastings]

I suspect that since there are so few three way DIY designs

That's only partially true (or is a matter of perspective) . . . all the "two way" designs we see are three way if they are used, *as they all should be*, with a "subwoofer" and crossed out at 100 Hz. or above. It almost always substantially cleans up the midrange to get the distortion inducing high-excursion bass signal off the midrange cone.

Other advantages are:

* One can get rid of that silly hole in the box that lets delayed reflection of the back wave out into the room

* The generally smaller "two way" box (if low bass is not part of the design) is more easily reinforced to stop panel vibrations (or it can be included in the "subwoofer" box as an all-in-one two-way+(sub)woofer)

* It encourages treating the room's behavior in the modal region and the speaker's behavior above as the two separate problems that they are

[romanbednarek]

That's only partially true (or is a matter of perspective) . . . all the "two way" designs we see are three way if they are used, *as they all should be*, with a "subwoofer" and crossed out at 100 Hz. or above. It almost always substantially cleans up the midrange to get the distortion inducing high-excursion bass signal off the midrange cone.

Other advantages are:

* One can get rid of that silly hole in the box that lets delayed reflection of the back wave out into the room

* The generally smaller "two way" box (if low bass is not part of the design) is more easily reinforced to stop panel vibrations (or it can be included in the "subwoofer" box as an all-in-one two-way+(sub)woofer)

* It encourages treating the room's behavior in the modal region and the speaker's behavior above as the two separate problems that they are

I guess that my definition of a three way speaker design assumes a completely passive crossover network. I understand the advantages of adding a subwoofer to a two-way system and actually recommend this configuration for anybody who has a home theater setup or any system that includes bass management within the receiver to remove the bass signals from the two-way speakers completely.

I still think that the complications of integrating a subwoofer to a two-way speaker are quite a bit different than what needs to be considered when choosing driver location, crossover frequency and crossover slope in a traditional passive three-way speaker design.... especially since you don't have quite as much freedom when it comes to locating the woofer as compared to a subwoofer which usually operates at frequencies whose wavelengths are so long that they don't need to be located as close to the "midrange/midwoofer" and there shouldn't be any sound that can be localized (other than harmonic distortion that might be present).

[Deward Hastings]

I guess that my definition of a three way speaker design assumes a completely passive crossover network.
. . .
I still think that the complications of integrating a subwoofer to a two-way speaker are quite a bit different than what needs to be considered when choosing driver location, crossover frequency and crossover slope in a traditional passive three-way speaker design....

Again, perspective. I have three way mains that are completely active . . .

And I don't see "subwoofer integration" as particularly different from woofer integration. If one is blessed with a room which allows (sub)woofer placement at the speaker position then one can simply use the subwoofers as speaker stands . . . and the result will be the same as a "full range" three way at the same location. There is not much complexity involved in a straightforward LR4 at 80-120 Hz. regardless whether or not the woofers are in the same box as the M and T. Even an all-in-the-same-box three way design benefits from active crossover to the (sub) woofer . . . it eliminates large and costly passive crossover components, and opens up a wider range of driver choices, since matching efficiency is no longer an issue, and one can be less concerned about the behavior of the W driver up into the midrange because more appropriate crossover slopes are easily available.