No surprise, another opinion based on data or experience. The new speakers are a different animal.Originally Posted by 3LockBox
No surprise, another opinion based on data or experience. The new speakers are a different animal.
Artists and dreamers and thinkers
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Reaching for the far skies - David Longdon
Surely, "opinions based on data or experience" are superior to those based on reading reviews?
That’s what you said. Making claims without knowledge = 0.0.
Artists and dreamers and thinkers
Are right here by your side
Reaching for the far skies - David Longdon
Well, unless these speakers are using onboard electronic processing they are deploying passive circuitry. In past SDA models the crossover network had the SDA components built in. There used to be a speaker design webpage that had a good description of how Polk SDA networks worked, but I can't find it anymore. Suffice to say it worked very well, but the speakers were still subject to placement and room anomalies, not to mention the additional cable stretching between the speakers. Yes, these speakers have angled front baffles where the old ones didn't, but I didn't read anywhere in that advertisement that described a completely different speaker. In fact, setup for the SDAs (then) specifically eschewed any kind of toe-in, so interesting that these introduces toe-in by design . If I were in the market for stereo floor monitors I'd defo pick these up because I am partial to Polks (or was rather).
Regardless of the circuitry that will EQ a room, you still need to properly set things up "mechanically" first. Sure EQ can help, but why make the electronics do all the heavy lifting. The best sound is achieved with as little signal manipulation as possible. The more things that can get in the way the more the sound has a chance to deteriorate. The best systems have none because they have treated the room and set up the speakers as precisely as possible. If you hear a room treated and set up properly and compared it to the same room set up improperly but EQ'ed you will likely hear good sound in both, except the small nuances of air and space will likely be missing in the EQ'ed room. Why? Because more electronics in the way of the signal. Now for home theater it might be the only way to go to get those 3D spacial effects sounding proper.
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A gentleman is defined as someone who knows how to play the accordion, and doesn't.
Maybe it's just me/ I struggle finding a copy of Queen 2 where i like the sound. Sounds muffled to me.
There is still a webpage for the Polk SDAs. I sold mine back in the 80’s and got Snell EIIs after listening to my neighbor’s Acoustats. I have wondered if the narrow beamwidth of those helped isolate each ear from the other channel in the midrange. The Snell’s rear firing tweeter help expand the dispersion of the highs which would beam out the front tweeter. The Polks just didn’t sound as accurate, likely having resolution issues. The new Polks are very high resolution and received help in design from the new Sound United engineering environment which uses folks pulled from all of their brands.
https://www.soundunited.com/aboutus
Artists and dreamers and thinkers
Are right here by your side
Reaching for the far skies - David Longdon
I will have to vehemently disagree with your first statement.
Yes, the vast majority of the "big" speakers on the market, are variations of big enclosures, with multiple drivers mounted them, and various x-over technologies. But concerning the advancements amed within each of these categories, there have been some pretty major advancements.
Enclosures that are made of materials besides wood (Magico's aluminum, Wilson's proprietary material, Von Schweikert's advanced CLD, and some others), make a substantial difference in measurable and audible improvements. Speaking of enclosures, with CNC techniques, building non rectangular enclosures has become easier and cheaper, which also account for audible improvements. Decreased standing waves, curved sides do not flex like straight sides (decreasing resonance and improving damping), and better diffraction.
Then there are the drivers themselves. Ceramic cones, honeycomb cone construction, metals, advanced cone damping materials, better magnets, improved tolerances, etc. These can drastically decrease cone weight, without sacrificing rigidity, and improve resonance and damping. Less distortion, faster transient response, less dynamic compression, easier to crossover, etc are the results.
And also crossovers have improved. Better caps (faster charge/discharge cycle) make a difference, as do air core coils, and flat wire coils. More advanced computer aided design software also helps.
So, some of these improvements are small, some not so small. The thing is, once all the more obvious changes are made, the smaller changes become more obvious, because they are less masked by the bigger problems.
I've been listening to high end audio for decades, at: audio shows, in people's houses (I belong to the biggest audio club in the world here in LA, I get a chance to hear quite a few high end systems on a regular basis), my own more humble system, in brick and mortar stores (the LA area has some great stores). And I can speak from experience, speakers have improved quite a bit in the last few decades in almost every audible respect.
And let me add, that a lot of the technology developed by the high end over the last few decades, has trickled down to budget products. Speakers like those from: Tecton, ELAC, the budget Klipsch, the budget JBLs, Fyne Audio, and others have really stepped up the sound quality of speakers at very reasonable, if not down right cheap prices, very recently.
Last edited by simon moon; 11-09-2019 at 10:08 PM.
And if there were a god, I think it very unlikely that he would have such an uneasy vanity as to be offended by those who doubt His existence - Russell
I think the difference between speakers of yore and current models is the way they are voiced. Ever since Magico hit the stores it seems everything is geared toward a clear, precise and somewhat up tilted top end. Maybe it was the trend in slim designs that preceded that, with multiple smaller bass drivers instead of one large cone. Maybe it was the desire to design a speaker with faster and punchier bass to keep up with the modern tweeter. I don;t know, but at every show I see these stellar looking speakers that don;t have much warmth to them. Precision over musicality.
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A gentleman is defined as someone who knows how to play the accordion, and doesn't.
Your post reminds me of when I compared the Polk LSi flagship towers to B&Ws (don’t remember the model number but most have a similar top end). The Polk LSi was reviewed by Cordesman over 16 years ago and it’s nipple tweeter was admired and said to support an accurate but softer high end. Several friends of mine who listened to the B&W’s high end said they were unforgiving. I say they were just unnatural to the point of being nails on a chalkboard. We listened Patty Griffins latest 1000 kisses which was beautifully produced. On her voice the Polks sounded awesome and I had just heard her in a Borders music/book store live. The B&Ws were unlistenable even though a bit more intelligible on the lower midrange. I bought the Polk LSi and eventually expanded to a 5.1 matched system. However it wasn’t until I bought the Pioneer Elite receiver with microphone calibration did I feel the the Polks were not too soft. That EQ left the system very balanced in the high end, and opened up the soundstage because of delay matching.
Last edited by Firth; 11-10-2019 at 09:31 AM.
Artists and dreamers and thinkers
Are right here by your side
Reaching for the far skies - David Longdon
Speaker wires above a certain gauge have been scientifically proven to have zero effect.
I agree with you 100% on all of these. Except for the fact that they were ALL available to speakerbuilders 40 years ago.
Always on the lookout for great "show-off recordings" I sampled this album on iTunes.
The bass is boomy. The voice is recorded monaurally, in a heavily-baffled sound booth, so there's no sense of space around it. Almost all the instruments are mixed monaurally, right on top of the vocal, except the 2nd guitar on "Making Pies" and "Long Ride Home." It has neither extreme highs nor extreme lows. The only exception is "Mil Besos" which sounds like it was recorded live -- but who wants a thousand heads of Amazon?
"Beautifully produced" it ain't.
For a beautifully produced album of similar material check out "Mi Tierra" by Gloria Estefan.
True, true. I think the trend toward two 6" drivers instead of one 12" woofer is mostly driven by WAF -- smaller footprint speakers are easier to fit into most room configurations. Since MOST content doesn't go below 50Hz most consumers will never miss that first octave.
And for those who do want a lot of bass, there's plenty of modern pop & hip-hop with a +20dB hump in the 50Hz octave to make it sound like there's lots of bass.
When you say, "Ever since Magico hit the stores" are you speaking of these?
I was referring to the SDA cable which connects the left and right speakers. And the wires were only 18 guage. To be as simple as I can (and relying on my memory) a narrow band of midrange was mixed twix the speakers, phase opposite, which was meant to cancel out crosstalk and widen the soundstage while creating a phantom center channel. It worked! But you still had to follow careful set-up protocol, room treatments, etc. The type of room played a major role as it does with all speakers. And of course the SDA effect was minimal off axis but I'd say the SDAs did have a bigger 'sweet spot'. And the speakers sounded great without the SDA cable anyway and I wound never really using it in the latter years simply because my last house never had a room in it conducive to proper setup.
They wound up in the family room (remodeled basement) where they were integrated into a 5.1 system. There, the SDA effect was a bit superfluous considering the existence of a dedicated center channel speaker and surround speakers.
Too bad Polk ditched passive radiators in their designs. I love the way they sound, and no, I couldn't care less about whether they color something or they're not accurate or whatever. I liked the way they sounded.
Speaker cables can easily change the sound.
Don't know about the gauge, but material, configuration matters.
Try !
https://www.polkaudio.com/discover/sda-technology
I'm not sure about this concept. I must admit I haven't heard it in person, but adding out-of-phase signal to a stereo pair of speakers sounds counterproductive to me. When the video talks about "interaural crosstalk" it assumes your speakers are as close together as shown in the video -- otherwise there'd be no IAC. Years ago, Carver Audio used to market something they called a "sonic hologram generator" (inserthere) which fed out-of-phase signal into the soundstream, causing some elements to appear to pop out of the soundstage, as they literally were out-of-phase. It wasn't a good idea then either.
Last edited by rcarlberg; 11-10-2019 at 06:15 PM.
Tried. Disproved. As has every other scientific double blind listening test. But hey, don't take my word for it: look it up for yourself.
https://www.stereophile.com/content/...arison-tests-0https://www.soundandvision.com/conte...ear-differenceSince no statistical tests of significance have been applied to the results it is not possible to demonstrate that one set of cables was found to be superior to any others in an objective sense.Note these comparisons are 16-gauge and 24-gauge -- not something equivalent to Monster, which would be about 12-gauge.the measurable differences in electrical characteristics and performance between audiophile cables and cheaper, 16-gauge zip cord seem too small to explain the apparently huge audible differences that are sometimes reported. It seems that tests with real music signals decrease the ability of listeners to distinguish small sonic differences between cables. Although three panelists heard a difference between 16-gauge and Monster Cable with pink noise, the panel as a whole was unable to hear any significant difference between them with choral music (Comparison No. 5). Even when Monster Cable was compared with 24-gauge using choral music (Comparison No. 6), only three panel members had psychoacoustically significant scores (twelve out of fifteen or better), though the group’s score in this non-level-matched comparison did reach the less strict level of “statistical significance.” It seems likely that the differences between 24-gauge and Monster Cable would be even harder to hear (if audible at all) if the levels were matched and typical music, not pink noise, were used.
http://www.aes-media.org/sections/pn...s/2000/lampen/Or your choice of Google. It's not even in dispute.
Last edited by rcarlberg; 11-10-2019 at 07:23 PM.
I'm not sure if the signal shared between the two stereo speakers are 180deg out of phase or just slightly phase shifted, but it was a narrow, mid-frequency bandwidth. It sounded better with particular stereo recordings. Modern music of the '80s had so much reverb it that didn't lend itself well to the SDA effect. The older music, with dryer mixes, were much less colored and the SDA effect was more pronounced, at least to my ears anyway.https://www.polkaudio.com/discover/sda-technology
I'm not sure about this concept. I must admit I haven't heard it in person, but adding out-of-phase signal to a stereo pair of speakers sounds counterproductive to me. When the video talks about "interaural crosstalk" it assumes your speakers are as close together as shown in the video -- otherwise there'd be no IAC. Years ago, Carver Audio used to market something they called a "sonic hologram generator" (insert
Interesting. I guess I'll reserve judgment until I hear it.
In general though I agree with BobM above: reproduction is best when it is most accurate to the source material. Adding shit to try to make it sound better -- rather than fixing the underlying problem(s) -- is a fool's errand.
Maybe I should clarify: "above a certain gauge" means 14 or 12 gauge or even 10-gauge -- not standard 16-gauge or mini-stereo 24-gauge.
About the SDA. Some these brochures clearly show Polk’s thinking about the beaming characteristics of speakers. I now understand where Polk came from, the sonar and ultrasonic domain of John Hopkins APL where the founders cane from. I know ideally one would want each speaker to form an acoustic beam at each ear, a left beam pointed are the left ear and vice versa for right. Beams also avoid energy directed toward non desirable reflecting surfaces and the SRS was a huge array that minimized vertical dispersion like Maggies. More later but here is the site:
https://polksda.com/pdfs/SRSTLBrochure1990.pdf
The top level website though has all the info.
Artists and dreamers and thinkers
Are right here by your side
Reaching for the far skies - David Longdon
The diagram from the brochure seems to indicate 180º out of phase:
Screen Shot 2019-11-10 at 6.17.23 PM.jpg
By putting two drivers side-by-side, one wired backwards from the other, I'd think you'd get all kinds of nasty phase cancellations -- not a "true stereo signal" -- but what do I know.
The advertisement doesn't go into depth with regards to how the signal is passed twixt the two speakers. There is a cable that connects the two speakers to each other (seperate from the speaker wires). The SDA cable passes a signal form one channel to the other (left to right/right to left); exact frequency range escapes me but I do remember it is not a full range signal. The SDA effect requires the extra cable and is not present when not in use; the speakers will operate like normal speakers without the SDA cable. None of the drivers are wired out of phase.
Unless that cable has some electronics built into it to alter the phase, and an equalizer in it to limit the frequency response.... all the cable is doing is connecting one midrange (or row of midranges) in opposite polarity to the others. Now, granted, because you add a cable between the speakers what the cable is undoubtedly doing is wiring the LEFT-HAND "Dimension Crosstalk Drivers" out-of-phase from the RIGHT-HAND midranges, and the RIGHT DCDs out-of-phase from the LEFT mids. What you are therefore creating with is a L+R and L-R configuration.*
Question: without the SDA cable, do the "Dimension Crosstalk Drivers" put out any sound at all? Or are they, as I suspect, disconnected?
*- I have some digital editing software on my computer. I can do L+R (mono) and L-R (difference between the channels, only) and the result is not, shall we say, "true stereo." L-R is what cheap equalizers use for removing vocals (which tend to be center, both channels) or for isolating vocals (L+R minus L-R), which tends to decrease everything but the center mono channel.
So, by adding an out-of-phase L+R signal, what you're doing is apparently widening the stereo image, because you're canceling out the mono in the middle. It would work better for recordings with a lot of stereo separation. On mono recordings it would effectively cancel everything
Last edited by rcarlberg; 11-10-2019 at 11:14 PM.
I'd like to return to this discussion for a sec, if you don't mind. Speakers "beaming to each ear" is indeed a thing -- we do that with headphones for instance -- and I've heard several megabuck stereo systems set up to do exactly this.
To some extent, this may be the most pure, most isolated, least "room effect" way to set up a speaker system.
But I'm not convinced it's the best.
For one thing, it gives you a "sweet spot" that is not just a finite plane, but a finite POINT. There is one perfect spot, equidistant from the speakers, a certain distance from the walls, a certain height -- and if you move your head one inch to the left or right, or an inch up or down, your sweet spot disappears. It's like wearing REALLY BIG headphones. In a huge room, there might be only one place to sit to hear music....
With many speakers, particularly speakers that are not bilaterally symmetrical, there is a sweet spot (a vertical plane in front of the speaker) where all the drivers are in perfect alignment. Dahlquists are a perfect example. Off-axis they don't sound nearly as good. Where these two planes intersect in the room -- left speaker and right speaker -- is where your "sweet spot" ideal listening distance exists. "Toeing in" your speakers reduces that distance, if your room is too small.
With many other speakers, speakers where the drivers are not time-aligned, there is a sweet spot (a horizontal plane) where the drivers are in alignment. If you stand up or sit on the floor, the sweet spot disappears. (Some designs never do align, vertically, unfortunately...)
Combine the vertical plane(s) with the horizontal plane and you get the worst of both worlds: a sweet spot literally an inch in diameter.
The solution? Bilaterally-symmetrical time-aligned phase-coherent speakers. They put out a unified stereo waveform that fills the room, from any angle, at any height. There is no "sweet spot." The whole room becomes the sweet spot.
The downside of course is that the room must be tuned properly, to reinforce uniform frequency dispersal. You don't want it too dead or too reflective. You don't want it too small (or too big I suppose). You don't want too many reflective surfaces in it.
But the room is as important as any other component in your system, and should be treated with the same respect.
Just my 2¢.
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