[avahifi]

Dennis, you might want to take a look at this article.

http://www.birotechnology.com/articles/VSTWLA.html

The writer is a personal friend of mine.  He has done a lot of our more recent engineering work.

Regards,

Frank Van Alstine

P.S.  Are you come to the RMAF?  Hope to see you there again.

[satfrat]

I played the same track, put my ears 2 feet away from the tweeter/midrange and listen.

I was talking about the mid and high, I am not talking about attributes like soundstage, imaging, bass, etc etc that's more room independent.

Even if my comparison is not valid by your "superior" standard, it's still my conclusion based on what I heard, I cannot say what my ears didn't hear.

I'm not sure how you can compare 1 set in your home, another set in a motel room and yet another set in a store and be able to make any sort of accurate comparison between the 3. Too many variables imho.

Sorry to have rattled your cage but I'm sure there's many who will tell you that a set of speakers heard in a hotel room possibly won't sound the same in their own home. That's was my only point and I wasn't trying to question your ears. My apology's to you sir. 

Robin

[DMurphy]

Dennis, you might want to take a look at this article.

http://www.birotechnology.com/articles/VSTWLA.html


Thanks Frank.  That looks really interesting.  I can't make RMAF this year because my orchestra is playing its first concert next weekend.  I'll be interested in your reaction to the SongTowers.   You've got the best ear on the block.

[jsalk]

In terms of listening to speakers in different settings, I think both writers have a point and are possibly in greater agreement than it may first appear.

There are definitely speaker attributes that are extremely room dependent.  Bass response, soundstaging and imaging fall into this category.  But there are also attributes that are not room dependent.

We build many types of speaker designs, most of which are our own, but some are designs developed by others that we are asked to build.  If I want to get the best idea of how one of these designs performs, I need to take them to my listening room and spend some time with them.  But I can listen to them anywhere for attributes that are immediately evident regardless of what room the speakers are being played in.

For example, if I play one of my very detailed test tracks, I can tell immediately how much detail is being reproduced in the midrange (or how veiled they are if I cannot hear material I know is present in the tracks themselves) and how transparent the tweeter is.  These attributes are not room dependent.  This, of course, does not necessarily tell you how well the speakers might perform overall.  But it is a good place to start as they do provide an indication of driver and crossover design quality.  If they fail this test, there is no reason to take them home for further listening.

I believe the latter is what 95bcwh was referring to.

- Jim

[95bcwh]

According to your logic, one should not even talk about speaker comparison until he can have the two speakers in one room, power them with exactly the same upstream electronics.

In other words, no one has any business telling me which speakers sound better after attending RMAF, because each room is different, all electronics are different, and hence no conclusion whatsoever should be made.

Why don't you start writing to all the review magazines and start trashing their reviews because they have absolutely no credibility of telling people which speaker to buy, unless the readers have exactly the same electronics + the same room as the reviewer?


 

Jim,
Your reply sounds as sensible as can be, but I'm wondering how much attention you would pay to what kind of electronics are feeding a pair of speakers, i.e. are the non-room-dependent attributes possibly gear-dependent in your mind (or can you evaluate whether a speaker is worth taking home for further auditioning pretty much regardless of what's powering it).

[jsalk]

Brian -

Jim,
Your reply sounds as sensible as can be, but I'm wondering how much attention you would pay to what kind of electronics are feeding a pair of speakers, i.e. are the non-room-dependent attributes possibly gear-dependent in your mind (or can you evaluate whether a speaker is worth taking home for further auditioning pretty much regardless of what's powering it).

In short, for this type of analysis, source gear and room acoustics are not material.  (But in my case, I am always listening with the same sets of source gear and the same rooms.  In my shop, I have a Sqeezebox feeding a DEQX unit feeding a Bryston 4B.  So I am very used to the sound (and room acoustics).  At home I have all top-line AVA gear - DAC, pre and amp and am very much used to that sound.  So I do have a benchmark to go by.)

The basic level of detail and transparency are pretty much going to be evident no matter what is driving the speaker and what room they are located in.  I am not listening for overall quality here, just the general level of detail and transparency (and a few other performance attributes).  For example, I also have a Panasonic DX45 digital amp laying around.  While all three set-ups sound slightly different, the relative level of detail (or veiling) and transparency are very evident on all three set-ups.

Obviously, source equipment can make a difference.  But this difference is dwarfed by the difference in speakers.  For example, speaker frequency response is generally rated at +/- 3db.  You wouldn't even consider source equipment rated within similar tolerances.

While the tonal balance of source gear is clearly audible, any source gear in any room will provide a pretty good idea of the detail and transparency of a given speaker design.  In fact, listening to just the drivers themselves will give you a pretty good indication of the performance in these two areas that you will likely hear in a finished design.

There are other performance attirbutes that are not necessarily room or source equipment dependent.  For example, bass extension is also an area that I would evaluate without regard to source equipment.  In this case, I am only listening for the lowest frequencies the speaker will reproduce, not the quality of the resulting bass (which is highly room dependent).  A speaker will exhibit a given level of bass extension regardless of room or source gear considerations (with the exception, pershaps, of an EQ unit). 

I hope that makes sense.

- Jim
 

[randybessinger]

Brian -

Jim,
Your reply sounds as sensible as can be, but I'm wondering how much attention you would pay to what kind of electronics are feeding a pair of speakers, i.e. are the non-room-dependent attributes possibly gear-dependent in your mind (or can you evaluate whether a speaker is worth taking home for further auditioning pretty much regardless of what's powering it).

In short, for this type of analysis, source gear and room acoustics are not material.  (But in my case, I am always listening with the same sets of source gear and the same rooms.  In my shop, I have a Sqeezebox feeding a DEQX unit feeding a Bryston 4B.  So I am very used to the sound (and room acoustics).  At home I have all top-line AVA gear - DAC, pre and amp and am very much used to that sound.  So I do have a benchmark to go by.)

The basic level of detail and transparency are pretty much going to be evident no matter what is driving the speaker and what room they are located in.  I am not listening for overall quality here, just the general level of detail and transparency (and a few other performance attributes).  For example, I also have a Panasonic DX45 digital amp laying around.  While all three set-ups sound slightly different, the relative level of detail (or veiling) and transparency are very evident on all three set-ups.

Obviously, source equipment can make a difference.  But this difference is dwarfed by the difference in speakers.  For example, speaker frequency response is generally rated at +/- 3db.  You wouldn't even consider source equipment rated within similar tolerances.

While the tonal balance of source gear is clearly audible, any source gear in any room will provide a pretty good idea of the detail and transparency of a given speaker design.  In fact, listening to just the drivers themselves will give you a pretty good indication of the performance in these two areas that you will likely hear in a finished design.

There are other performance attirbutes that are not necessarily room or source equipment dependent.  For example, bass extension is also an area that I would evaluate without regard to source equipment.  In this case, I am only listening for the lowest frequencies the speaker will reproduce, not the quality of the resulting bass (which is highly room dependent).  A speaker will exhibit a given level of bass extension regardless of room or source gear considerations (with the exception, pershaps, of an EQ unit). 

I hope that makes sense.

- Jim
 

Great post Jim.  Good luck at RMAF.  Wish I could have attended this year, but next year for sure.  Have a great show.

[DMurphy]

Hello again     I gave the paper a good read tonight.  I knew someone must have put all that together.  I have two reservations about the otherwise excellent analysis.  First, there is an implicit assumption that the ear processes delayed reflected information in much the same way as it processes, or weights, on-axis arrivals.  I don't think we have a model of human hearing that confirms that.  If on-axis arrivals, or near-on-axis arrivals, are weighted more heavily, then all bets are off.  The MTM may still have an advantage over MT's.  Second, purely from a subjective viewpoint, I can't agree that mtm's typically have a "cupped" coloration in the midrange.  At least the ones I've worked with haven't.  But I do agree the midrange presentation is different.  To me, the sound is actually more open, although that could be the artifact of a depression in the area.  But you can judge for yourself in Denver.   On a more nuts and bolts level, I've measured a lot of mtm's above the tweeter axis, and did some more measurements tonight on the SongTower.  I was able to get useful resolution almost at the 2 meter measuring distance.  I couldn't replicate the predictions even though the ST roughly meets the spacing and crossover assumptions in the article.   There is a deep null, but it occurs at around 2 kHz, and is very symmetrical.  The 45-degree off-axis response is very even from 800-1500 Hz.

[DMurphy]

Hmmmmm     That was supposed to have included a quote from Frank's quote.  Anyhow, I'm replying to Frank. 

[Sparks]

Thanks for the MTM recap Dennis.
It did jog my aging memory.
One of the listening session was in nice open room.
In addition to the Dalis we listened to the Nufurce MTMs, very nice.
The amps were a Cary tube, Nuforce monos, a NAD and Rega cd player.
In all honesty, the NAD held it's own very well.
I had never heard the Nuforce gear before. Very nice and an intriguing design.
I feel the HT2s have a slight advantage in the imaging over the Dalis.
Certain recordings are so "there" I just can't help but perk up a little bit.
I really like the HT2s ability to fill my room with sound.

[JohnR]

Hmmmmm     That was supposed to have included a quote from Frank's quote.  Anyhow, I'm replying to Frank. 

Dennis, would you mind setting your signature in accordance with our guidelines please:

http://www.audiocircle.com/index.php?topic=41871.0

(Posted in this forum since you did not respond to my first request sent by PM.)

Thanks, and glad to have you here

[DMurphy]

Just checking to see whether I got my signature changed to show party affiliation.

[avahifi]

Dennis, for your info, the HT2s would be considered to be an MTM design, and I like them VERY much, no matter what some electrical theory might say. Nobody has all the electrical theory right yet, when that happens, we can all quit work.

Regards,

Frank

[DMurphy]

Can't argue with that--well said.  But the issue of how the ear-brain processes on-axis vs delayed off-axis information is one of the bigger unanswered questions in loudspeaker design.  It's really hard--pretty much impossible in most cases--to get flat on-axis, horizontal off-axis, and vertical off-axis response smooth at the same time, and it sure would be great if we knew just how important or unimportant that goal is.

[Woolz]

Hi, I have a 6 week old pair of HT2s.  I hesitate to respond because I have not heard the Dalis.  I can only tell you they are quite remarkable.  When Jim says they are designed for a person expecting world class sound, he's not just putting out advertising hype.
They are capable of playing with tremendous tonal fidelity, reproducing fine micro detail and expanding to fill my 1000 sq. ft. room with a convincing and mesmerizing soundstage.
I am a relative old timer to audio and have owned lots of stuff.  You are on the right track wanting ribbon high frequencies particularly if you like to listen to music with strings.  These speakers are wonderful playing classical music where many speakers fall short in my opinion.  Although jazz is my first love and big bands in particular.
I am using a CJ Premier 140 amp and Dehavilland Ultraverve preamp with them and love the combination.  I do however think a good high current amp would drive them more authoritatively playing loud dynamic stuff.  But I have a big room.
I know this is just another rave, but I can't imagine you not being thrilled with the HT2s. 
Also, I have always liked the midrange of an MTM. I think it is more open and expansive.
If you go back to Jims post Steve's HT2s you'll see my speakers.

[Sparks]

Woolz(Steve),
I checked out your speakers.
Veerrry nice.

[randybessinger]

Can't argue with that--well said.  But the issue of how the ear-brain processes on-axis vs delayed off-axis information is one of the bigger unanswered questions in loudspeaker design.  It's really hard--pretty much impossible in most cases--to get flat on-axis, horizontal off-axis, and vertical off-axis response smooth at the same time, and it sure would be great if we knew just how important or unimportant that goal is.

An opinion question(s)-do you think it is possible for different people to process differently?   I am thinking of the Toole DB studies that did seem to indicate that flat off-axis response is important.  Do you have a disagreement with the study or think it just was not conclusive?

[DMurphy]

I suspect that study was dealing with horizontal off-axis response, which is a lot easier to get smooth than vertical.  That's because the relative position of the tweeter and woofer to the ear doesn't change as you go off axis to the side, but it does as you go up or down.  And that relative change means that the woofer and tweeter arrival times (relative to each other) will change, causing a change in the phase relationships that will create destructive interference. Also, if you listen with the speakers pointed straight ahead, and you're in the middle, the direct sound will be off axis horizontally--so peaks and holes may be directly audible.  With vertical off-axis response, it's all literally going over or under your head and then bouncing around.  I always try to get the horizontal off-axis response as smooth as I can without messing up the on-axis.  But there's not much to be done about vertical response once you've got the woofer(s)  and tweeter as close together as possible and decided on a crossover point and slope.  Anyhow, I think I've come up with an experiment that will tell whether MTM's have an inherent coloration in the midrange due to the cancellation between the two woofers vertically off-axis.

[randybessinger]

I suspect that study was dealing with horizontal off-axis response, which is a lot easier to get smooth than vertical.  That's because the relative position of the tweeter and woofer to the ear doesn't change as you go off axis to the side, but it does as you go up or down.  And that relative change means that the woofer and tweeter arrival times (relative to each other) will change, causing a change in the phase relationships that will create destructive interference. Also, if you listen with the speakers pointed straight ahead, and you're in the middle, the direct sound will be off axis horizontally--so peaks and holes may be directly audible.  With vertical off-axis response, it's all literally going over or under your head and then bouncing around.  I always try to get the horizontal off-axis response as smooth as I can without messing up the on-axis.  But there's not much to be done about vertical response once you've got the woofer(s)  and tweeter as close together as possible and decided on a crossover point and slope.  Anyhow, I think I've come up with an experiment that will tell whether MTM's have an inherent coloration in the midrange due to the cancellation between the two woofers vertically off-axis.

Yes, I think you are correct on the study but as I recall it was a DB test of speakers using their Harmon facility that allows very rapid changes of speakers in the same position, etc, and they identified certain measurement parameters that the participants preferred-one of several being horizontal off-aixs flatness.  I don't remember if vertical off-axis performance was a factor or mentioned-just remember horizontal.

[TomW16]

Just to add a little credibility to the fact that people prefer a flat off-axis (horizontal I suspect) dispersion pattern, the Canadian government conducted a number of double blind experiments through the National Research Council (NRC) and the results were consistent in that listeners ranked speakers with wide and flat dispersion patterns higher than speakers that did not. 

It makes sense from a common sense perspective in that any reflected sound would be similar to the source sound.  Since the results were consistent with a number of listeners, it seems to support that people process sounds similarly.

Cheers,
Tom