Dipole vs Box speakers

[TurtlePaul]

I did ‘t have LX521 in mind when I said dipoles have little bass. But 4x Seas L26RO4Y (!!!) with DSP to get to 30 hz kind-of proves the point in a way.

 

[JustJones]

Then there's Janszen A8 Electrostatic which isn't dipole, uses hybrid approach (with woofers for bass) and can be Omni with the SE (Stereo Everywhere) option. Have no idea what they sound like but they look interesting.

Valentina A8 (Active)

Introduced in 2021 along with a new passive version, the Valentina A8 is a substantial upgrade to the original Valentina Active. If you've already read about or heard the original, what's new in the sound is Deeper bass Stronger impact Louder playback Sharper imaging Wider soundstaging There's...

janszenaudio.com

Option, Stereo Everywhere

We now offer the Stereo Everywhere option, which is signified by the SE in the model name. This converts the Valentina A8 into perhaps the ultimate expression of what this loudspeaker is capable of. For those who are already familiar with both directive and omnidirectional sound, there's not...

janszenaudio.com

 

[Duke]

Most big dipoles like Quad ESL, Soundlab, Magnepan etc. fail on radiation pattern, bass extension and SPL since they try to cope with all of it at the same time, and those requirements are contradictory.

Imo SoundLabs actually have the best radiation pattern behavior I am aware of. I'll use the older (but still available) 90-degree pattern to explain why, and will come back to the newer 45 degree pattern later. Disclaimer: I have been a SoundLab dealer since late 1999, when I bought my first pair unseen and unheard, largely based on my analysis of its radiation pattern.

The faceted-curved array of the SoundLabs is exceptionally uniform within its pattern width of 90 degrees front and back. As we go down in frequency the panel width gradually becomes inadequate to control the radiation pattern width, and the pattern begins to widen... all the way out to the familiar dipole figure-8. So the variation in pattern width across the speaker's bandwidth goes from figure-8 in the bass region to 90 degrees front-and-back across the rest of the spectrum, and that's only a little bit narrower than the dipole figure-8. To the best of my knowledge, only a true omni has less radiation pattern variation across the speaker's passband.

Ime a true omni results in a lower direct-to-reverberant sound ratio than what I believe to be optimim, also a true omni calls for greater distance between speakers and sidewalls than is practical in many if not most home audio listening rooms. The dipole SoundLabs have no such sidewall distance requirements, but they do have significant distance requirements to the "front" wall, as is normal for dipoles and bipoles and omnis.

In the bass region, subjectively speaking imo SoundLabs lack the impact of a good box speaker but have better pitch definition than a good box speaker. Staying with the subjective, imo if you want to hear every nuance in an upright or electric bass, SoundLabs convey that very well.

Swiching to the objective, I've seen a pair of SoundLab A-1's measure "flat" down at 20 Hz in-room in a customer's home. It was effectively a pretty big room at low frequencies, as his house had a largely open floorplan.

But I do have to concede that very high SPLs are not within the capability of a pair of SoundLabs, and their low-to-moderate efficiency and capacitive impedance curve place heavy demands on the amplifier.

The newer 45-degree pattern SoundLabs are more efficient because their narrower pattern concentrates the energy into a smaller region, sort of like what happens when you tighten up the spray pattern on a garden hose with an adjustable nozzle. Imo this is a worthwhile net improvement, BUT it does increase the radiation pattern discrepancy between the region where the panel's faceted-curved arc controls the pattern width, and the region where the pattern shape is the typical dipole figure-8.

A listening test that ime is predictive of long-term fatigue-free enjoyment is "listening in another room" ("L.I.A.R."??). Assuming the speaker sounds good when you listen in the normal listening area, try this: Walk into an adjacent room and listen through the open doorway with no direct line-of-sight to the speakers. All you can hear through the open doorway is reflections. Does it still sound convincing? If so, that's an indication the reflection field is spectrally correct, which ime correlates well with long-term fatigue-free listening.

 

[Deleted member 21219]

A listening test that ime is predictive of long-term fatigue-free enjoyment is "listening in another room" ("L.I.A.R."??). Assuming the speaker sounds good when you listen in the normal listening area, try this: Walk into an adjacent room and listen through the open doorway with no direct line-of-sight to the speakers. All you can hear through the open doorway is reflections. Does it still sound convincing? If so, that's an indication the reflection field is spectrally correct, which ime correlates well with long-term fatigue-free listening.

Yes, this is a fantastic trick! I call it the "mono door" test, because for orchestral recordings it mimics the position of a listener standing just short of a doorway in the long side of (or in the back of) the symphony hall.

I tried it some years ago with a friend who had high-output speakers. He was often heard to say, paraphrasing a description I used to hear a lot, "With some speakers, you are there. With these speakers, they are here." We backed up to a doorway at the end of the room and listened for a few minutes, He then turned to me with a sad look on his face and said despondently, "Damn ... they left!"

Those were interesting years. Good memories.

Jim

 

[Blumlein 88]

Yes, this by the door, or in another room effect is something nothing other than dipolar panels seem to do so well. At times it can sound very much like there are real musicians just inside the room. I've had a few people who came to my door and were transfixed it sounded so real. Non-audiophiles who were surprised by it.

Some of my friends decided this was a good quick test to see if a speaker was much good at all. It varies among other speaker types with some doing better than others. Usually if it is horrible in this test it is rather poor in the room. Dipoles have nulls to the sides, don't put out huge bass, and even fail to much engage other room modes because they are rather directional. Box speakers tend to have some lumpy bass that leaks out, muffled highs and midrange. Generally not very good. It is in particular a good way to hear if your bass is too lumpy. A couple of my friends would use this test with their box speakers to decide if they needed to experiment more with speaker positioning. Now we can just run an REW sweep.

I've found that speakers like Revels or those designed with the controlled directivity in mind do better at this test. Better than most other box speakers. I've not heard anything that does this as well as open panels however.

 

[moonlight rainbow dream]

The most obvious performance attribute of the dipole to me is the figure-8 radiation pattern with reduced interaction with the sidewalls. An interesting quirk that arises is that by placing the speaker the same distance to the front wall as the MLP to the back wall, you can "delete" reflected sound from the front wall. All the other things that dipoles do can be compensated for with equalization/driver selection/system design, depending on the competency of the designer.

 

[jim1274]

Most big dipoles like Quad ESL, Soundlab, Magnepan etc. fail on radiation pattern, bass extension and SPL since they try to cope with all of it at the same time, and those requirements are contradictory. They are typically wide to get some low end, but then the baffle gets way too wide for a good dipole radiation pattern. The Linkwitz LX521 is a good example of the opposite, where the radiation pattern is very good, and the low end kind of OK by using high excursion woofers.

The physical size of the Soundlabs I’m working on shipping solution for is a negative in my situation for sure. At 6’ tall, 3’ wide, and 150#, these are not something you easily move into place in the living room and back out when not using them. My solution is to make some platforms with nylon roller ball “flying saucer” transfers and store in an adjacent room, not a trivial thing. Everything I’ve been experimenting with so far is easy to move in an out of place, small enough to store out of the way in the living room.

 

[jim1274]

Then you will like this tip. Starting on page 26, #504, Floyd Tools enters the discussion. He then answers and discusses various questions in the following pages.

omnidirectional loudspeakers = best design available

Happy to be shown examples and discuss. I think you missed the point that I was responding to someone saying Toole’s cartoon was “too smug”, so the teacher’s conundrum is about what style to use, eg humour “too smug”, math “too specialised/unintelligible to many”, short and pithy “lacking...

audiosciencereview.com

Thanks, and I have read that, just again now for a refresher. It’s the “spaciousness” he refers to that I’m trying to achieve, without too many other sonic characteristics “penalty”. After more listening to the ESS AMT 1b dipoles the last couple days, mainly for the soundstage and envelopment comparison to onmis, I also noticed the excellent transient response, low level detail, clarity and such. The Enterprise Omnis did not seem lacking, but this will require a direct A/B at some point. These AMTs have come the closest so far to the Omnis in the envelopment, spaciousness, 3-D soundstage, or whatever term best captures the effect, better than the Def Tech bipolars rotated out.

 

[jim1274]

In my experience, none who actually listen to the LX-521's describe their low-end as "kind of OK". A more typical response is "that's the most realistic bass I've ever heard". Of course, that's anecdotal and subjective.

The low end performance is important, and everyone will have a different view on that, especially depending on what they listen to. For me personally, i can live with some compromise in extension. The Duevel Enterprise Omnis I’m working with have enough extension on maybe 90% of what I listen to that I’ve never thought lacking enough to not enjoy. For me, things like timbre, detail and such are more important and not willing to compromise much on.

When listening in the far field, for my musical preferences (mostly chamber music, solo instrumentals, occasional electronic, ambient and rock), the sound stage, impact and and tonality produced by the LX-521 4.0 system rivals my 7.3.6 home theater. The LX-521 experience is better for some recordings, worse for others but always fun and engaging. Only specific Atmos-mastered music can provide a superior experience on the 7.3.6 system.

I’m not comparing these HEIL AMTs to the LX-521 in any way other than noting that they sound pretty good on some recordings, quite a bit worse on others. The AMTs are being evaluated in context of soundstage, but noticed when playing “Jazz at the Pawnshop” and Brubeck’s “Take Five” just a while ago, the resolution, low level detail, transient response and such made me not even notice the shortcomings. Other material with a lot of hot high end material do not work.

My 7.4.1 ATMOS rig in the living room never did it for me on stereo source material, even when using the DSP functions to create a surround effect.

When listening to music at my audio workstation in the near field (< 1m), I am very satisfied with a 2.1 system and desire no artificial sound-stage augmentation. The ambience within recordings is less contaminated by room effects and a simple full-range system is sufficient. Another identical 2.1 system in my den doesn't sound nearly as good for far-field listening due to room acoustics.

Surely, my equipment preferences are linked to my music preferences. Other musical preferences likely influence alternate gear selection. To each their own.

I agree with your comments on workstation and den situation. The only 2 “rooms” that are soundstage relevant here is the living room and my deck/pool area outside. A lot of this testing and learning will be very useful out in the back yard. The whole Omni adventure actually started in the context of outdoors, trying to achieve good sound across a wide area. I had purchased several Omni portable Bluetooth speakers for using when working around the house and yard where listening position is constantly changing, thinking a more capable regular Omni might be perfect for the large outdoor area.

 

[Ron Texas]

With a box speaker you can always burry a monkey in it. With dipoles, if you have a dead monkey, you are out of luck.

 

[jim1274]

Yes, this by the door, or in another room effect is something nothing other than dipolar panels seem to do so well. At times it can sound very much like there are real musicians just inside the room. I've had a few people who came to my door and were transfixed it sounded so real. Non-audiophiles who were surprised by it.

That commented really resonated with me, something I almost mentioned several times. I noticed that immediately with the Omnis and also with the ESS AMT dipoles, just to a little lesser extent. In fact, I found that the sound in my adjacent long and narrow highly reflective kitchen has better sound just turning up the living room Omnis than any speaker in the room tried so far.

Somewhat related is a similar comment on what actually was my very first Omni, at least a close approximation. When I was getting my garage door replaced, I always ask contractors “want tunes or no tunes?” So I threw an Omni near the middle of the action, and after a short time, the lead guy asks “all that sound isn’t just coming from that speaker? Where are the other speakers?” He said “I MUST get one” stopping work for a bit and ordering one on the spot.

Limited-time deal: Harman Kardon Aura Studio 3 - Elegant, BT Wireless Speaker with Premium Design and Ambient Lighting- Black https://a.co/d/9srUJfR

Some of my friends decided this was a good quick test to see if a speaker was much good at all. It varies among other speaker types with some doing better than others. Usually if it is horrible in this test it is rather poor in the room. Dipoles have nulls to the sides, don't put out huge bass, and even fail to much engage other room modes because they are rather directional. Box speakers tend to have some lumpy bass that leaks out, muffled highs and midrange. Generally not very good. It is in particular a good way to hear if your bass is too lumpy. A couple of my friends would use this test with their box speakers to decide if they needed to experiment more with speaker positioning. Now we can just run an REW sweep.

Your comment about “rather directional” on dipoles made me wonder if other dipole designs will match the soundstage of the AMT tweeters given their extremely wide horizontal dispersion front and rear? I’ll need to look at the Linkwitz in that regard.
Since the AMT is not a true dipole, only from 700hz and up crossover point, maybe not really a valid comparison?

I've found that speakers like Revels or those designed with the controlled directivity in mind do better at this test. Better than most other box speakers. I've not heard anything that does this as well as open panels however.

 

[jim1274]

Then there's Janszen A8 Electrostatic which isn't dipole, uses hybrid approach (with woofers for bass) and can be Omni with the SE (Stereo Everywhere) option. Have no idea what they sound like but they look interesting.

Valentina A8 (Active)

Introduced in 2021 along with a new passive version, the Valentina A8 is a substantial upgrade to the original Valentina Active. If you've already read about or heard the original, what's new in the sound is Deeper bass Stronger impact Louder playback Sharper imaging Wider soundstaging There's...

janszenaudio.com

Option, Stereo Everywhere

We now offer the Stereo Everywhere option, which is signified by the SE in the model name. This converts the Valentina A8 into perhaps the ultimate expression of what this loudspeaker is capable of. For those who are already familiar with both directive and omnidirectional sound, there's not...

janszenaudio.com

Since that is also a hybrid approach, thought I would throw this out, a speaker that I’ve almost bought several times over the last 15 years or so, only deterred by having several cats until recently that were “climbers”, not a cat friendly design.

If not for the prospect of a pair of Soundlabs, they would be in my living room, now so crowded with “test speakers”, even the wife asked “how many more speakers are you planning to bring in here?”, then pointing down the maze of speaker wires,
now with the added power cords to power the Def Tech built in subwoofer, adding “looks like a lot more wires to trip over too now”

https://www.eminent-tech.com/index.html?fwd=LFT8.html

 

[Blumlein 88]

With a box speaker you can always burry a monkey in it. With dipoles, if you have a dead monkey, you are out of luck.

The sturdy boxes you ship dipoles in will hold several monkeys if need be.

 

[Ron Texas]

The sturdy boxes you ship dipoles in will hold several monkeys if need be.

Then what do you do with the dipoles?

 

[jim1274]

Imo SoundLabs actually have the best radiation pattern behavior I am aware of. I'll use the older (but still available) 90-degree pattern to explain why, and will come back to the newer 45 degree pattern later. Disclaimer: I have been a SoundLab dealer since late 1999, when I bought my first pair unseen and unheard, largely based on my analysis of its radiation pattern.

The faceted-curved array of the SoundLabs is exceptionally uniform within its pattern width of 90 degrees front and back. As we go down in frequency the panel width gradually becomes inadequate to control the radiation pattern width, and the pattern begins to widen... all the way out to the familiar dipole figure-8. So the variation in pattern width across the speaker's bandwidth goes from figure-8 in the bass region to 90 degrees front-and-back across the rest of the spectrum, and that's only a little bit narrower than the dipole figure-8. To the best of my knowledge, only a true omni has less radiation pattern variation across the speaker's passband.

If the Soundlab creates a large soundstage comparable to these ESS AMTs I’m testing now, that’s enough for me. These AMTs are not as enveloping as my Omnis, but close enough and a far cry from “box” speakers.

Ime a true omni results in a lower direct-to-reverberant sound ratio than what I believe to be optimim, also a true omni calls for greater distance between speakers and sidewalls than is practical in many if not most home audio listening rooms. The dipole SoundLabs have no such sidewall distance requirements, but they do have significant distance requirements to the "front" wall, as is normal for dipoles and bipoles and omnis.

If one is placing a speaker in a permanent fixed position, that requirement for front wall distance is not practical in many instances. Since in my case this is a 2 channel system seperate from my home theater 7.4.1 system, it will be “mobile” and easy to place anywhere in the room. Well, easy depending on what you are moving into postion. The “mobile” part is going to be another “audio adventure” for a 6’ tall 150# speaker…

In the bass region, subjectively speaking imo SoundLabs lack the impact of a good box speaker but have better pitch definition than a good box speaker. Staying with the subjective, imo if you want to hear every nuance in an upright or electric bass, SoundLabs convey that very well.

I personally would rather better pitch and nuance than impact. Speaking of nuance and detail, I think listening to these AMT dipoles now make me think that is one area the Omnis can’t match. I didn’t find the Omnis necessarily lacking, actually surprised how well they performed in that area, but not at the level of these AMTs even without a direct A/B comparison, something I plan to do next. The AMTs are flawed in many ways the Soundlabs and other speakers are not, but still useful for comparative testing.

Swiching to the objective, I've seen a pair of SoundLab A-1's measure "flat" down at 20 Hz in-room in a customer's home. It was effectively a pretty big room at low frequencies, as his house had a largely open floorplan.

But I do have to concede that very high SPLs are not within the capability of a pair of SoundLabs, and their low-to-moderate efficiency and capacitive impedance curve place heavy demands on the amplifier.

The newer 45-degree pattern SoundLabs are more efficient because their narrower pattern concentrates the energy into a smaller region, sort of like what happens when you tighten up the spray pattern on a garden hose with an adjustable nozzle. Imo this is a worthwhile net improvement, BUT it does increase the radiation pattern discrepancy between the region where the panel's faceted-curved arc controls the pattern width, and the region where the pattern shape is the typical dipole figure-8.

A listening test that ime is predictive of long-term fatigue-free enjoyment is "listening in another room" ("L.I.A.R."??). Assuming the speaker sounds good when you listen in the normal listening area, try this: Walk into an adjacent room and listen through the open doorway with no direct line-of-sight to the speakers. All you can hear through the open doorway is reflections. Does it still sound convincing? If so, that's an indication the reflection field is spectrally correct, which ime correlates well with long-term fatigue-free listening.

I commented on that “another room” in a previous post, something the Omnis did quite well, in fact even down the hall and into the bathroom sounded not bad at all. The “listening fatigue” comment is one of the things that impressed me with the Omnis after listening for 14 hours a day about 10 straight days, never any fatigue. By contrast, these AMTs are already fatiguing me, the prior Def Tech bipoles fatiguing, but to a lesser extent.

 

[Blumlein 88]

Then what do you do with the dipoles?

Listen to them. They sound better than monkeys.....

 

[StigErik]

In my experience, none who actually listen to the LX-521's describe their low-end as "kind of OK". A more typical response is "that's the most realistic bass I've ever heard". Of course, that's anecdotal and subjective.

It depends on your point of view and other references I guess. I have heard the LX521, and don't think it has great bass . Yes, it's quite good at low volumes and above 40 Hz or so.

 

[DanielT]

Thanks, and I have read that, just again now for a refresher. It’s the “spaciousness” he refers to that I’m trying to achieve, without too many other sonic characteristics “penalty”. After more listening to the ESS AMT 1b dipoles the last couple days, mainly for the soundstage and envelopment comparison to onmis, I also noticed the excellent transient response, low level detail, clarity and such. The Enterprise Omnis did not seem lacking, but this will require a direct A/B at some point. These AMTs have come the closest so far to the Omnis in the envelopment, spaciousness, 3-D soundstage, or whatever term best captures the effect, better than the Def Tech bipolars rotated out.

Testing a good pair of dipoles or omnis is high on my to do list. I've had a few different box speakers, good and bad, so with one of these, I know approximately how a couple of new box speakers will sound in my room. Thus, it would be interesting to test something new, a new design principle. I can easily imagine compromising a lot on pin point accuracy in the sound in favor of spaciousness, if it stands between those choices. Most important, however, is that the speakers "disappear". I really dislike when I can localize the sound to the speakers.

So a pair of good dipole, omni speakers would be nice to have. Maybe even rig up with an AVR and buy a number of used KEF eggs and test how it sounds then. My guess is good with music with many instruments. Big band jazz for example, but worse, compared to two speakers, with music that has few instruments when pin point accuracy is of greater importance. Please note I am only guessing and that solely based on my subjective opinion of how I think I want it to sound.

I have also moved to a new apartment and so far do not have much furniture. Then placing a couple of omnis in my living room I don't think, so far, is the most optimal thing to do. But sometime in the future, absolutely.

Incidentally, I now have a pair of vintage 10 inch Tannoy coaxials. Sounds surprisingly good I must say. Now I can tick it off my list, test coaxials that is.

Speaking of AMTs. Check here, I heard these at a vintage DIY fair a few years ago. DIY AMT. That's probably the best thing I've ever heard:

More on that build in the thread below:

Hifi Vintage DIY fair with pictures

I visited this fair yesterday! DIY & Vintage meeting in Mölnlycke Here is a short report. When: 6 November 2021 Where: Country: Sweden City: Gothenburg I took pictures myself BUT most were so damn blurred so I borrow pictures from this thread, taken by other participants. Pictures taken from...

audiosciencereview.com

 

[StigErik]

I can only speak for myself here - but here's two very different pair speakers I had in my room 15 years ago. One of them totally blew the other away when it came to pure listening enjoyment. Both were using active crossovers/DSP. Which ones would you vote for? The dark red closed box ones in the rear, or the flimsy pinewood dipoles in front?

 

[Blumlein 88]

I can only speak for myself here - but here's two very different pair speakers I had in my room 15 years ago. One of them totally blew the other away when it came to pure listening enjoyment. Both were using active crossovers/DSP. Which ones would you vote for? The dark red closed box ones in the rear, or the flimsy pinewood dipoles in front?


View attachment 342258

Are the upper woofers on the red ones bigger than the lower woofers or is that some distortion of the photo?