Linkwitz Orion speaker project

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Linkwitz Orion speaker project

Post by MikeC » Mon Dec 07, 2015 1:31 pm

http://www.silentpcreview.com/Linkwitz_Orion_speakers

The second article in this section covers the construction of my Linkwitz Orion speakers. Article isn't quite complete; it'll be added to later.

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Re: MikeC's Audio Craft: An Introduction

Post by LostHighway » Tue Dec 08, 2015 2:55 am

Again, beautiful work Mike!

I still haven't heard any of the Linkwitz designs but when spring rolls around I'll probably make arrangements to go listen to the pair of Orions available for audition in my state. If I like the Orions I might go for the LX521 since the parts cost is about the same but much depends on money in hand when the time comes and the size and layout of the new room. The number of amplifiers involved and the fact that you sort of have to accept as a given that the ATIs aren't crippling the potential performance gives me pause but...

I like the looks of your radius on the side panels better than the original but did you run it past Linkwitz? Given the woofer frequencies I wouldn't think that change would alter performance but that is simply a guess.

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Re: MikeC's Audio Craft: An Introduction

Post by MikeC » Tue Dec 08, 2015 9:22 am

LostHighway wrote:Again, beautiful work Mike!

I still haven't heard any of the Linkwitz designs but when spring rolls around I'll probably make arrangements to go listen to the pair of Orions available for audition in my state. If I like the Orions I might go for the LX521 since the parts cost is about the same but much depends on money in hand when the time comes and the size and layout of the new room. The number of amplifiers involved and the fact that you sort of have to accept as a given that the ATIs aren't crippling the potential performance gives me pause but...

I like the looks of your radius on the side panels better than the original but did you run it past Linkwitz? Given the woofer frequencies I wouldn't think that change would alter performance but that is simply a guess.
The X521s are better than stock Orions, by all accounts. I haven't heard them but am planning a build inspired by the X521 and the NaO Note II RS. Both go all out to try and achieve controlled dispersion that is frequency-independent on both front and rear axis.

I would never use the ATI amps. Too big, too ugly, too inefficient. I'm working on putting together an 8-ch am using 8 class-D Hypex and Connex amp modules with SMPS PSUs. They all have the same voltage gain, which is nice. Roughly 70W each for the tweets and high mids, 250W for the lower mids and 400W for the bass. So about 800W per side, 1600W total. The whole thing, with power supply modules, will cost under $1000, and fit in a dual side heatsink case less than 4" tall, 17" x 15". Efficiency is over 90%. Both LX521 and NaO are 4-way designs.

The amps in an active speaker system never work nearly as hard as in a standard passive xover system. Each amp is only asked to cover a very narrow frequency band, with nothing but speaker cable between it and the driver -- no caps, coils or resistors. I've always been of the opinion that audible differences between well spec'd amps are minor at best and exacerbated only when pushed into clipping or other misbehavior by external conditions that the testers may be unaware of. The amps in an active xover speaker system simply cruise so they simply don't misbehave. It'd be very hard to hear the differences between any good amps with this setup until/unless they're driven into (even momentary) clipping.

Actually, I didn't cover this, but I recently made a switch from the electronic crossover to a programmable digital xover. The miniDSP OpenDSP-DA8. It takes only digital inputs 44-192kHz, and has 8 separate analog outputs (up to 4-way xover). So it replaces my DAC. I feed the digital signal from the coax SPDIF out on an ASUS Zen sound card in the PC, and the OpenDRC-DA8 applies the xover slopes, driver eq and driver time delays AND converts the digital signal to analog. Because the xovers are infinitely adjustable, I've been able to improve on the sound over the original electronic xover, tweaking it for my particular speakers. The filters are adjusted via software on the PC, with a USB link to the DA8. Measurements with a USB mic can be done directly through the OpenDRC-DA8 as well. Overall, it's slightly fuller & richer in the mids & high bass (say 100~300Hz) and the tonal balance seems better. I've lost the ability to play super high res DSP files in native format, which I could do with my Teac UD-501 DAC, but since I have so few of these, it's not a big deal. I can still play them downsampled. The only other price I pay is very slightly higher residual noise -- a hiss is audible from the mids & tweets from about 1.5' away, compared about about half that distance before. This when there's no signal, but of course, any music playing at any level makes it inaudible. I can live with it.

The changes in Orion side panel dimensions are too small to be measurable, certainly not audible. It would only affect the bass below 100 Hz. Our hearing is not very sensitive in that region.

The main issue with these types of open baffle dipoles is that they need lots of room around them to sound their best, so they're not suitable for smaller rooms. 4' behind & 2' on the sides are the minimum recommended distances. But then the majority of high end speakers also call for similar placement, generally, so...

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Re: MikeC's Audio Craft: An Introduction

Post by MikeC » Tue Dec 08, 2015 2:30 pm

OK, I finished the Orion 3 speaker article. Added a bit more background about open baffle vs. enclosed systems; a pic of the classic Wharfedale SBL/3 -- found a good photo! http://www.silentpcreview.com/Linkwitz_Orion_speakers

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Re: MikeC's Audio Craft: An Introduction

Post by Quinnbeast » Tue Dec 08, 2015 2:39 pm

MikeC wrote:http://www.silentpcreview.com/Linkwitz_Orion_speakers
The second article in this section covers the construction of my Linkwitz Orion speakers. Article isn't quite complete; it'll be added to later.
Whoah. I'm almost regretting that I asked whether you'd built any speaker cabinets; I now have a further half-dozen vague questions in my head. Quite hilarious that you followed up with an article as if to reply - "Speakers? You mean, like these???" :shock:

Those, are beauties. I was reading an article just recently about how there's an increasing market for narrower baffle designs (and in turn smaller drivers), partly driven by an aesthetic choice for typical home use, known to many as 'the wife factor'. Great to see some bigger woofers in there - what size are they? I think I should stop reading SPCR at this point, since I've already got one fairly expensive hobby as it is. *rubs hands together*
Today, outside the stratospherically priced exotica in high end audio, virtually all consumer speaker systems are either ported or sealed enclosure designs
This one definitely resonates (pun detected) with me. The more I read into some of the 'non-standard' designs and the near-limitless price ceiling that goes along with it all, the more that alternative solutions become an interesting proposition. Even if I had sufficient disposable income to buy into that kind of market, I'm not sure I'd ever be comfortable with that sort of extravagance. I can absolutely see the fascination with taking a more modest, more hands-on approach. Looking forward to the next installment.

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Re: MikeC's Audio Craft: An Introduction

Post by MikeC » Wed Dec 09, 2015 8:33 am

HammerSandwich wrote:THAT's the project I'm interested in! Strikes me as more power than I'd ever need, but headroom for EQ makes sense with active crossovers, etc.

Speaking of Hypex, those new Kii speakers sure look interesting.
Had not been aware of those speakers, but yea, they do sound fascinating....
http://kiiaudio.com/en/
http://www.digitalaudioreview.net/2015/ ... udspeaker/

...but for €10,000/pair you'd expect fascination!

The reduction of the back radiation by using active cancellation sounds very clever and ambitious, but surely there must be a price paid for such manipulation, least of which would have to be SPL capability with just four 6.5" bass drivers, two of which must be dedicated to the cancellation. I'd love to hear them.

PS -- These are said to have a cardioid polar pattern; the Orion's "H" frame bass loading results in a figure 8 cardioid pattern, not omni. When you stand to the side, the bass level is down 6 dB.

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Re: MikeC's Audio Craft: An Introduction

Post by HammerSandwich » Wed Dec 09, 2015 10:30 am

MikeC wrote:Had not been aware of those speakers, but yea, they do sound fascinating....
http://kiiaudio.com/en/
http://www.digitalaudioreview.net/2015/ ... udspeaker/

...but for €10,000/pair you'd expect fascination!
They're absolutely too pricey for me. But it seems relatively reasonable when you add the unique, phased-array tech to 12 channels of DAC & Ncore. Hell, the new Benchmark amp looks amazing, but it's $1500/channel. And Benchmark's pricing is hardly outrageous, at least in a high-end context.

I see Kii's approach this way: rather than spend a fortune on exotic materials, a line array of 32 ribbon tweeters or whatever; Kii has used more electronics to help solve acoustic problems. This strikes me as clever engineering, because electronics fall in price faster than any other part of the equation.

While they can always build larger, more expensive speakers, I expect this technology to trickle down. Need evidence? The Kii 3 is 60+% cheaper than the Grimm LS1, which came out only 4-5 years ago. A Moore's Law for audio gear? Yes, please!
MikeC wrote:The reduction of the back radiation by using active cancellation sounds very clever and ambitious, but surely there must be a price paid for such manipulation, least of which would have to be SPL capability with just four 6.5" bass drivers...
This page has a test from Germany's Audio magazine with measurements that support this. Bass distortion is definitely this speaker's weak spot. Of course, 4x6.5" is roughly 1x12", but you don't get the larger driver's excursion. Such a small box certainly hurts a sealed system's efficiency, too. (I'd prefer a tower that has the same footprint & price as the monitor plus stands.)
MikeC wrote:...two of which must be dedicated to the cancellation.
However, I don't believe this follows. First send the transient to the rear woofers. Less than 1ms later, reinforce the wave when it arrives at the side drivers. Fractionally later, add in the front 5". Use the same timing approach with anti-phase signals, and your DSP does a lot of the work. Note that this is just speculation, but it seems plausible. Putzeys certainly advocates negative feedback in electronics; this is just the acoustic equivalent.

Anyhow, it's a new implementation, so I expect it to improve over time.
MikeC wrote:PS -- These are said to have a cardioid polar pattern; the Orion's "H" frame bass loading results in a figure 8 cardioid pattern, not omni. When you stand to the side, the bass level is down 6 dB.
The magazine test also has off-axis measurements. :)

FWIW, LX521s & Naos are also on my want-to-hear list.

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Re: MikeC's Audio Craft: An Introduction

Post by MikeC » Wed Dec 09, 2015 11:20 am

There were discussions in the past about Live End Dead End rooms -- in which one end of the room is fully padded to absorb as much acoustic energy as possible -- and the rest of the room is live. Some favored using speakers on the live end, others on the dead end, and some advocated either, depending on speaker characteristics.

Kii speakers would seem to be like putting "normal" sealed speakers in the dead end of such a room... without the need for all that acoustic treatment.

Alternatively, remove one wall so it's open to the great outdoors and place speakers there, facing into the room.

Hmm.... I'm not sure how that would sound. Certainly, if the freq. response for the lack of back reflections was compensated with equalization, you'd more or less be removing the room from the overall acoustic equation. I've listened to speakers in my DIY semi-anechoic chamber & not liked the experience, but then that room is fully padded. I likened it to headphone listening, in a way.

And despite all the electronic manipulation, the pressure in the box still remains, with all its attendant problems.

Still the German review you linked is wildly enthusiastic.

Like I said, I'd love to hear them.

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Re: MikeC's Audio Craft: An Introduction

Post by ojg » Thu Dec 10, 2015 12:38 am

Very nice writeup about the Orion! I like your design choices like the elongated curves and the black baffle.

Just one error, the midrange driver is from SEAS, specifically the W22EX001, not Scan-Speak.

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Re: MikeC's Audio Craft: An Introduction

Post by MikeC » Sat Dec 12, 2015 2:42 pm

ojg wrote:Very nice writeup about the Orion! I like your design choices like the elongated curves and the black baffle.

Just one error, the midrange driver is from SEAS, specifically the W22EX001, not Scan-Speak.
Of course you're right -- the mid driver is a SEAS W22EX001.

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Re: MikeC's Audio Craft: An Introduction

Post by HammerSandwich » Sun Dec 13, 2015 11:45 am

MikeC wrote:There were discussions in the past about Live End Dead End rooms -- in which one end of the room is fully padded to absorb as much acoustic energy as possible -- and the rest of the room is live. Some favored using speakers on the live end, others on the dead end, and some advocated either, depending on speaker characteristics.

Kii speakers would seem to be like putting "normal" sealed speakers in the dead end of such a room... without the need for all that acoustic treatment.
You make a really strong analogy.

It does seem that a lot of recent speaker designs attempt to improve the direct/reflected ratio. What's really interesting here is how different the implementations are. Dipole (e.g., Linkwitz, Nao), waveguide (Geddes, JBL), cardioid (Kii) sure look different! I'd really enjoy being able to compare all of these designs in a couple different rooms...

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Re: Linkwitz Orion speaker project

Post by HammerSandwich » Sun Dec 13, 2015 11:51 am

Also, this:
An aside: After a lifetime of listening to both live and canned music, I've come to the realization that authentic reproduction of music cannot ignore volume. There is simply no way that even a single violin or singer can sound authentic when played at 70 dB for background music in a living room. A live violinist or singer can easily produce 90+ dB in an instant, then drop down to a bare whisper in the next instant. The dynamic quality of the music cannot be reproduced if the peaks are held to say 80 dB, which forces the pianissimo to barely audible levels. Volume defines scale, and without scale, there can be no authenticity.
Absolutely. Fletcher-Munson plays a major role here as well.

One of the best demos of this is in Pink Floyd's Time. As the clocks fade out, the grandfather's chime changes timbre radically, so it's easy to hear when the volume's correct. I really like 2 things about this example: 1) just set the volume too high & go, and 2) even people unfamiliar with the sounds of natural instruments can recognize it instantly.

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Re: MikeC's Audio Craft: An Introduction

Post by MikeC » Sun Dec 13, 2015 12:20 pm

HammerSandwich wrote:It does seem that a lot of recent speaker designs attempt to improve the direct/reflected ratio. What's really interesting here is how different the implementations are. Dipole (e.g., Linkwitz, Nao), waveguide (Geddes, JBL), cardioid (Kii) sure look different! I'd really enjoy being able to compare all of these designs in a couple different rooms...
Yes, that would be fun... and probably almost impossible to collect all those speakers in one place unless you just bought/built them all.

With Kii, they're very pointed on their site about the reasons for it: to allow greater freedom of room and placement choices while still making really good sound, especially bass, as if from a BIG speaker.

Thinking about how to achieve cardioid bass dispersion in a speaker system without all that signal manipulation, one way would be to take a modified open baffle dipole like the Orion H frame, and absorb the back wave -- lose it in something like a massive absorbent box made of concrete. It would have to be pretty thick to lose it all, of course, and pretty big not to cause too steep a bass rolloff, but as long as the back wave is down far enough compared to the front... -20 dB? -30 dB? None of the reviews or Kii's own literatures states what this is. Hmmm.... But then we might as well go back to the infinite baffle, right? lol!

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Re: MikeC's Audio Craft: An Introduction

Post by HammerSandwich » Sun Dec 13, 2015 1:50 pm

MikeC wrote:Thinking about how to achieve cardioid bass dispersion in a speaker system without all that signal manipulation, one way would be to take a modified open baffle dipole like the Orion H frame, and absorb the back wave -- lose it in something like a massive absorbent box made of concrete.
You are one of the few audiophiles who is equipped to try this. Just borrow absorbers from the chamber & pile them up behind the Orions. Is your wife planning any trips out of town? :D

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Re: Linkwitz Orion speaker project

Post by LostHighway » Sun Dec 13, 2015 3:45 pm

HammerSandwich wrote:Also, this:
An aside: After a lifetime of listening to both live and canned music, I've come to the realization that authentic reproduction of music cannot ignore volume. There is simply no way that even a single violin or singer can sound authentic when played at 70 dB for background music in a living room. A live violinist or singer can easily produce 90+ dB in an instant, then drop down to a bare whisper in the next instant. The dynamic quality of the music cannot be reproduced if the peaks are held to say 80 dB, which forces the pianissimo to barely audible levels. Volume defines scale, and without scale, there can be no authenticity.
Absolutely. Fletcher-Munson plays a major role here as well.
This has been probably the primary argument of the horn loudspeaker advocates, that extremely high efficiency is required to achieve the "jump factor" of the dynamic swings (both micro and macro) of live music. Horns also tend to measure very well with respect to distortion.

Most of my own exposure to horns has been old school designs (Klipsch, Altec and JBLs) both stock and modified but I haven't heard most of the new horn designs (the Avant Gardes excepted). I find the old school horns unacceptably colored to my ears but many people absolutely love them.

The problem I have with live levels is that they can be moderately to severely unpleasant in a home environment. Many, perhaps most, instruments designed for the concert hall (we'll exclude the clavichord and a few other specifically drawing room instruments) can play shockingly loud. Some friends of mine used to do a regular Halloween concert in a rather live 400-seat hall and just the combination of an alto sax with stiff reed and a small trap set can play louder without amplification than I'd ever want to listen a home, even two-thirds of the way back in that hall.

At the opposite end are speakers that clearly start to compress as the volume goes up and IME this is not a direct correlation with measured sensitivity, some speakers that aren't at all efficient don't compress all that much provided the amplification can keep up. Magnepans for example are entirely different animal with huge amps (think Bryston 7B-SST or the Parasound JC-1) relative to amps that supply maybe 100wpc into 8 ohms and 160 wpc into 4 ohms.

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Re: MikeC's Audio Craft: An Introduction

Post by MikeC » Sun Dec 13, 2015 4:39 pm

HammerSandwich wrote:You are one of the few audiophiles who is equipped to try this. Just borrow absorbers from the chamber & pile them up behind the Orions. Is your wife planning any trips out of town? :D
:lol: :lol:

She'd kill me & lever leave me alone in the house again! (Or leave me alone in the house for good. :shock: )

Besides, I don't think that would work. What might work is something like a long tapered folded transmission line on the back end of an H frame. The walls would have to be very inert & opaque, acoustically, and the line stuffed progressively denser so that at the end of a 9' line, all signal would be say -30 dB relative to the front wave.

The question is how low could the xover freq to this bass unit be? Too low and you'd have the bottom end of the mid driver working in omni, so... perhaps up as high as 200 or 250 Hz, with a steep slope?

You'd have to do something similar with the mid driver(s), but this would be easier, the line could be much shorter -- say no more than 1.5~3'. Above ~1kHz, if it's a cone driver, just enclose the back with enough stuffing... in an aperiodic type enclosure.
The end result would still be a pretty big speaker, but it could be narrow & deep & tall.

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Re: Linkwitz Orion speaker project

Post by LostHighway » Sun Dec 13, 2015 5:15 pm

MikeC wrote:
HammerSandwich wrote:You are one of the few audiophiles who is equipped to try this. Just borrow absorbers from the chamber & pile them up behind the Orions. Is your wife planning any trips out of town? :D
:lol: :lol:

She'd kill me & lever leave me alone in the house again! (Or leave me alone in the house for good. :shock: )

Besides, I don't think that would work. What might work is something like a long tapered folded transmission line on the back end of an H frame. The walls would have to be very inert & opaque, acoustically, and the line stuffed progressively denser so that at the end of a 9' line, all signal would be say -30 dB relative to the front wave.

The question is how low could the xover freq to this bass unit be? Too low and you'd have the bottom end of the mid driver working in omni, so... perhaps up as high as 200 or 250 Hz, with a steep slope?

You'd have to do something similar with the mid driver(s), but this would be easier, the line could be much shorter -- say no more than 1.5~3'. Above ~1kHz, if it's a cone driver, just enclose the back with enough stuffing... in an aperiodic type enclosure.
The end result would still be a pretty big speaker, but it could be narrow & deep & tall.
Severely attenuating the back wave from drivers above say 120 Hz with absorption alone shouldn't be that much of issue but the octaves below that are a different story and it gets worse the lower you go. I don't think you could accomplish it in an enclosure that would fit into a domestic environment, certainly not with just fiberglass or rock wool stuffing. Tuned mass dampers within the enclosure and either making the enclosure insanely massive or trying to decouple it at those frequencies from room surfaces might do it. I strongly suspect the general direction of the Kii design is the only practical solution.

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Re: Linkwitz Orion speaker project

Post by NeilBlanchard » Sun Dec 13, 2015 8:00 pm

I have always wanted to hear a transmission line speaker - I think the theory is solid. It is not easy to do, however.

My personal reference for bass performance is my old Snell Acoustics Type E/II - with a few mods. The main one was a bundle of plastic drinking straws in the bass port. I cut them to length, and packed them tight enough for a good friction fit. This kept the tuning the same, but dampened the output a touch. I used a program I got from Roy Allison to graph the output below 200Hz, and I used his theory that all the distance from the woofer and the port to all of the room boundaries had to NOT have any common multiples.

This tamed a +16dB peak at 40Hz (the port tuning, I think?) down to +/-4dB over that frequency range, and I had the -6dB point at about 31.5Hz. Which is pretty phenomenal for a 8" woofer - the cone actually measured ~6.5" and it had a long throw.

That suspension is what failed, and I got a kit to replace the surrounds (with neoprene) but I have not gotten around to fixing them.

The Snells have a rear firing 3/4" tweeter that helped them stay reasonable at the top. But now that I have LX5's with the Lineaum tweeter, I am spoiled for anything else. If I could use the Snell woofer and enclosure with the Linaeum, I be happy. As I wrote elsewhere, I have not heard the equal to the Linaeum full figure 8 tweeters. They act like a point source, but they have the surface area to move some air without any sign of overload. They are totally wide open at all frequencies they cover - and with you eyes closed, you cannot locate them.

The only tweeter I am aware of that could be this good is the Gallo cylindrical electrostatic unit. I'll bet it sounds fabulous.

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Re: Linkwitz Orion speaker project

Post by HammerSandwich » Sun Dec 13, 2015 9:34 pm

LostHighway wrote:At the opposite end are speakers that clearly start to compress as the volume goes up...
Soundstage's NRC measurements show this, though only the difference between 70 & 90dB. Interestingly, such tests are far more common for subwoofers (e.g., Data-bass, Audioholics).
MikeC wrote:She'd kill me & lever leave me alone in the house again!
Don't be silly, Mike. There's no reason not to trust you alone once you're dead. (And for your headstone, how about, "Keep it down up there!")
MikeC wrote:Besides, I don't think that would work. What might work is...
Before getting divorced, you should probably try the Orions outside. I'm not claiming they'd be exactly like a naturally cardioid speaker in that setting, but half space definitely removes room effects. Your subjective impressions would be interesting, though I believe that a dipole would sound closer to a point-source outside. Still have the NHTs?


So our conclusion is that the best, practical-though-expensive approach would be Kiis combined with a time-aligned, infinite-baffle, DBA sub? If I hit the lottery...

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Re: Linkwitz Orion speaker project

Post by LostHighway » Mon Dec 14, 2015 6:08 am

HammerSandwich wrote:So our conclusion is that the best, practical-though-expensive approach would be Kiis combined with a time-aligned, infinite-baffle, DBA sub? If I hit the lottery...
I haven't heard the Kii Three and I've seen a ton of exotic speakers designs that both looked good on paper and garnered one or more favorable reviews fail to deliver in actual auditioning so I'll refrain from making any guesses as to "best". I will say that given current high end audio prices the Kii doesn't seem to be completely crazily priced based on rumored pricing (I'm not sure if the mentioned prices are with or without VAT). The Grimm LS1 price, on the other hand, is very hard to justify.

When it comes to low bass (sub 60 Hz) reproduction the more I think about it the more I think multiple sources like the Audio Kinesis Swarm may be the best practical answer. Room modes are room modes regardless of your ability to control the initial radiation pattern.

Speaking only for myself I know I can live without sub 40Hz bass without feeling too deprived. I had Rogers LS 3/5As as my primary speakers for a couple years and with them I did occasionally, but not constantly, miss the bass extension. If you move the -3dB point down to 38 - 42 Hz and the roll off is relatively gradual (more likely with sealed enclosures than bass reflex/ported) I almost never miss that bottom octave, room reinforcement will typically give you some of it if the speaker roll over is semi-gradual.

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Re: Linkwitz Orion speaker project

Post by NeilBlanchard » Mon Dec 14, 2015 6:45 am

If we are talking ultimate music reproduction, then ya gotta have all or most of the bottom octave! 20-40Hz is not crazy difficult to do - it is the subsonic stuff below 20Hz that takes a LOT of effort.

Here's something though: bass is basically omnidirectional, so I have my doubts about trying to eliminate the "rear" part of those frequencies.

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Re: Linkwitz Orion speaker project

Post by LostHighway » Mon Dec 14, 2015 7:29 am

NeilBlanchard wrote:If we are talking ultimate music reproduction, then ya gotta have all or most of the bottom octave! 20-40Hz is not crazy difficult to do - it is the subsonic stuff below 20Hz that takes a LOT of effort.
I'm not sure what "ultimate music reproduction" means to you but IME it usually means really serious money.

The reason I don't miss sub bass isn't that there isn't much actual music down there (electronica and large pipe organs potentially excepted). IIRC the lowest note on a conventional acoustic double or electric bass is 41 Hz, a standard tuba doesn't go down to quite as low and excluding the big Bosendorfer the bottom cut off for a concert grand piano is 28 Hz but that note carries a considerable amount of higher harmonic energy that makes the absence of the solid fundamental not that unpleasant to live without. There are a number of specialized and not all that commonly used acoustic instruments that can get into the 30 Hz - 40 Hz range but most of my listening is jazz, chamber music, R&B, rock and other genres where those super low notes just don't exist.

There is something to sub-harmonics and to room ambiance for purist recordings in large halls that I suppose could be used to argue for 20 Hz - 40 Hz reproduction being in some sense essential for "ultimate" reproduction but I'm far more concerned that the reproducers get things right where my music really lives, which is the 40 Hz to 4kHz range. If I'm going to drop an extra grand on speakers I'd far sooner spend it improving that range than adding relatively flat 20 Hz - 40 Hz response. YMMV.

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Re: Linkwitz Orion speaker project

Post by HammerSandwich » Mon Dec 14, 2015 6:54 pm

LostHighway wrote:
HammerSandwich wrote:So our conclusion is that the best, practical-though-expensive approach would be Kiis combined with a time-aligned, infinite-baffle, DBA sub? If I hit the lottery...
I haven't heard the Kii Three and I've seen a ton of exotic speakers designs that both looked good on paper and garnered one or more favorable reviews fail to deliver in actual auditioning so I'll refrain from making any guesses as to "best".
Agreed 100%. That said, I typoed the above. I'd intended more that Kii's (<- punctuation counts!) focus tech seems potentially the best method to reduce reflections in real-world rooms above the low bass, and...
LostHighway wrote:When it comes to low bass (sub 60 Hz) reproduction the more I think about it the more I think multiple sources like the Audio Kinesis Swarm may be the best practical answer. Room modes are room modes regardless of your ability to control the initial radiation pattern.
The 1st point's excellent & well supported by Geddes & Harman.

My understanding of DBAs, however, is that they absolutely eliminate room modes (though room shape must be vital). But, while the theory seems valid, I don't recall seeing detailed results from an actual build. If anyone could post a link, I'd appreciate it.

So, this combination should be pretty good. I'll note that I first heard about Kii from Linkwitz's links, which implies he also finds it promising. He's also linked to various controlled-dispersion projects. I wonder how much he's analyzed the direct/reflected potential from each basic approach. Perhaps the LX521 won't be his final speaker.

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Re: Linkwitz Orion speaker project

Post by NeilBlanchard » Tue Dec 15, 2015 7:05 am

There is a fair amount of music in the bottom octave, between 20 and 40Hz. Drums and synthesizers have fundamentals in this range. These are audible pitches. And yes pipe organs regularly go into this range - and some even hit 16Hz with their 32 foot pipes.

SUBsonic bass below 20Hz is rare for music - but not for movies. A car door slamming is ~5Hz, for example.

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Re: Linkwitz Orion speaker project

Post by MikeC » Tue Dec 15, 2015 8:26 am

I've measured my Orions many times, and with the standard xover/eq, they go down pretty low into the bass. Here's a graph:

Image

The top more jagged curve is before room compensation software. Note each vertical step represents 5 dB. Even w/o room compensation, the output is down only around 10 dB at 20 Hz, relative to the 1 kHz signal. W/ compensation, it's a flatter curve with less drop -- perhaps 6~7 dB down at 20 Hz.

The length of the room into which the Orions fire is a bit over 30', as the dining area is open to the LR, so the deep bass does have chance to develop (a 30Hz wave being over 30' long).

But do I hear this extension as a benefit in the music I play? Nope. Mostly, I prefer jazz/blues, both traditional & modern, lounge music, lots of vocals, a bit of old rock, a bit of classical. I have many excellent live and live-sounding recordings that contain much of the acoustic space of the original performance. Virtually none of the music I play suffers audibly in the least when I apply a high pass filter that drops the output below 30Hz at 24 db/oct.

(An Aside: A digital subsonic filter is easy with JRiver & many other software. I applied this filter when I discovered that one of the 24/96 albums that I played a lot for a while, recorded live in a NY church, Dave's True Story: Sex without Bodies, had subsonic signals that literally flapped the bass drivers on the Orions -- I first noticed because one of the speakers was actually moving! -- & caused IM distortion higher up in the bass. The filter cut this & eliminated the problem.)

I guess if you want authentic car door slam sounds in your room, the sub-20Hz range might be important, but I have ZERO interest -- there's more than enough info in the film visual & audio through my 7" driver transmission lines in the TV room to convince me it's really a door slam & stay immersed in the story being told (assuming the movie/show is well done). In music, there's very little down there... and this is a statement both Linkwitz & NaO designer John K. have repeated many times. (For his latest system, John K. deliberately chose the least powerful 10" Peerless in the series (SLS), stating the audible difference between that and the XLS used in my Orions was only about a dB in the deep bass, and most folks would never even notice. Better to put the $ into a sub if you really need that super deep bass.)

This also calls the purpose of the Kii into focus -- one of their stated advantages is to minimize the "spray" of bass into unwanted areas like through the wall into your neighbor's apt, and the ability to sound good in smaller rooms. They're certainly not going for high power capability at 20 Hz.

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Re: Linkwitz Orion speaker project

Post by HammerSandwich » Tue Dec 15, 2015 11:57 am

This discussion made me go back to Linkwitz's pages, and this one's proven interesting. He links here, where you can find a lot of info about bass patterns & dipole & cardioid woofer setups. One thing's clear: you could begin experimenting & measuring with only $500 or so.

Anyhow, while I find extreme bass quite fun, I agree it's not common in music. If you're heavily into electronica or pipe organ, sure, but getting below 40Hz serves everything else pretty well.

I'll try MikeC's 30Hz highpass soon. My speakers (Dunlavy IVs) get into the 20s, but their 1st-order crossovers allow some deep bass to hit the 5" mids. The highpass might add a touch of clarity, though I probably don't listen at high enough levels to matter. At least not very often... :)

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Re: Linkwitz Orion speaker project

Post by MikeC » Tue Dec 15, 2015 4:43 pm

Thanks for that link, HammerSandwich -- http://kimmosaunisto.net/CardSub/CARDSUB.html I've read through much of the linkwitz site but never hit this link before. kimmosaunisto's "Variable volume resistance enclosure" looks like a pretty good & relatively simple way to get cardioid bass response! Hmmmm.... I can feel a new speaker project coming on! (like itchy nose before a cold :lol: ).

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Re: Linkwitz Orion speaker project

Post by NeilBlanchard » Wed Dec 16, 2015 6:29 am

All I know is extension down to ~31.5Hz is better than ~40Hz. And I do listen to some pipe organ music - and I have recorded pipe organs several times. A staple of my music collection is Peter Gabriel, and he very often has 2 or 3 bass lines at the same time, so articulate controlled bass is very important to me. Lots of music, from Emerson Lake and Palmer to Paul Simon to every symphony with a big drum have music in the bottom octave.

I also like extended high frequencies - I think that even though we can't hear pitch above ~20kHz, every percussive instrument produces overtones (nearly square wave attack) and this makes them sound right to have. My first experience listening to a 96kHz sampled digital recording was a revelation.

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Re: Linkwitz Orion speaker project

Post by HammerSandwich » Wed Dec 16, 2015 7:16 am

MikeC wrote:Thanks for that link, HammerSandwich -- http://kimmosaunisto.net/CardSub/CARDSUB.html I've read through much of the linkwitz site but never hit this link before. kimmosaunisto's "Variable volume resistance enclosure" looks like a pretty good & relatively simple way to get cardioid bass response! Hmmmm.... I can feel a new speaker project coming on! (like itchy nose before a cold :lol: ).
This new section of SPCR does seem to be having that effect. I've never been into DIY audio but have read about assorted builds for years. The internet's greatly opened up this area.

So, how about a thread on your amp project? Some of the $10-20 amp boards (TPA3116 or whatever) have tempted me, but I'm not sold on the, uh, thoroughness of their engineering. OTOH, a UcD180 build isn't THAT much more expensive, and it's a proven quantity.

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Re: MikeC's Audio Craft: An Introduction

Post by MikeC » Sun Dec 20, 2015 10:48 am

Quinnbeast wrote:Those, are beauties. I was reading an article just recently about how there's an increasing market for narrower baffle designs (and in turn smaller drivers), partly driven by an aesthetic choice for typical home use, known to many as 'the wife factor'. Great to see some bigger woofers in there - what size are they? I think I should stop reading SPCR at this point, since I've already got one fairly expensive hobby as it is. *rubs hands together*
They're 10" drivers, Quinnbeast.

My wife is perfectly ok with these speakers, though she didn't like the more rounded look of the original design.

There have been other narrow front profile speakers still integrating big woofers in the past. I was using a pair of NHT 2.9 speakers for some years, and it had great WAF, despite having a 10" woofer. Narrow & tall & deep, with woofer mounted on the side, at bottom.

Image
NHT 2.9, left; right is mirror imaged. Spkr on top is a Paradigm I reviewed a few years back -- http://www.silentpcreview.com/Paradigm_ ... a_Speakers

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