What Do You Think . . . and How Does It Work?

But the claim was that Linkwitz was a brilliant speaker designer. You would think his speakers would be well known and sought after. That just isnt the case. What makes him so brilliant if few audiophiles care about his speakers?

Those Pluto’s would be handy, being able to move them about as you want (unlike the Martin Logan’s I have that weigh 60-some lbs. each and have spikes that I have to pull up from the carpet.  Who was it that posted that their speakers each weigh 130+ lbs?  Oh, my aching hernia!)

Kenjit wrote: "[Siegfried Linkwitz] obviously had a few designs that were available as DIY projects but i dont know of any that stereophile reviewed."

Liinkwitz had several commercial designs which were manufactured by a company called Audio Artistry. One of them received Stereophile’s 1998 Loudspeaker of the Year award.

Here’s the review:

https://www.stereophile.com/floorloudspeakers/328/index.html

Duke

Kenjit, you just named six brands of box speakers. What? You argue with everyone about box speakers. Are you new to audio?
Read more, argue less is my suggestion. I won’t do the google searches for you.

I thought this was an interesting video about the speakers in question!  Check it out

I checked the setup. Its obviously not a state of the art system. It would be ok for background music. 

Seigfried Linkwitz was brilliant as a speaker designer.

completely disagree. There were no commercial speakers made by him as far as i know. He obviously had a few designs that were available as DIY projects but i dont know of any that stereophile reviewed. I rarely see audiophiles mention his name on forums. I hear names like B&W, Dynaudio, Wilson, Magico, Harbeth, Kef. But Linkwitz? No chance. 

Bob540, the Linkwitz speakers disappear and present music in a natural, organic way. Since they are lightweight, you can keep them against a wall then move them closer to your listening seat when you want the best sound. 
Seigfried Linkwitz was brilliant as a speaker designer. Checkout Linkwitz Labs website for an education. (Kenjit)

They may not have brand appeal, (magico), but they sound better IMHO.

Would you please share with us again the perfect design?  32’ wide concrete side panels, correct?  Speakers mounted flush with ghe side of the house cut out and an anechoic chamber for as a listening room, correct?  Or was Bose and Sonos. And cheap ear buds? 😂


LoL, you on the other hand are prime for stand up!  You’ll be happy to know you aren’t my least favorite here though anymore!

I thought this was an interesting video about the speakers in question!  Check it out 👍

https://m.youtube.com/watch?v=X-jPWrGUjEs

Be fair kenjit, ATC started introducing curved slightly tapered side panels to their domestic cabinets a few years back. You can be sure they did it for good sonic reasons.

It looks like ALL their professional speakers are boxes. We all know boxes are bad. 

http://atcloudspeakers.co.uk/professional/loudspeakers/

Having curves doesn't stop it being a box. Its still a box. You gain nothing from having slightly tapered side panels. Its just cosmetic. Hence they do it on their hifi speakers because appearance is important to audiophiles. 

@darkstar, More realistic that Magico?  But I thought those were supposed to be near-best?

Built Linkwitz Orions in 2006. Still my main speakers. Built the PVC Plutos in 2008. Stunningly good, odd looking, speakers. Small footprint. Lightweight and easy to move. Work best somewhat near field. The Pluto sound more like real music than magico IMHO. 

I just finished building a pair of LXMinis (Plutos are the old version). But I'm not ready to give an opinion on sound because I don't have them in the best location at the moment. And heaven forbid, I'm using a cheap pair of Chinese stereo Class-D amps (I'll worry about switching to another amp later if they measure poorly in a good location. I've been in blind amp tests, so I don't worry too much about amps, but some of these cheap amps do have FR problems.). But I will say I played the Chesky Ultimate Demonstration Disc and they did everything the disc said they were supposed to.

As always with DIY, expect it to take longer and cost more than you think. My first impression is that they'd be better with subs, but subs require an upgrade to a $500 DSP and programming, whereas the regular kit from Madisound comes with a preprogrammed MiniDSP. And the plans are an extra $100+. Also the plans aren't 100% clear and don't perfectly match the Madisound kit (but close enough).  Another point of contention is that the plans don't tell you how to connect the MiniDSP to which amp channels. I had to figure that out from reading the LXMini build forum.

Keep in mind that the concept of active crossovers is a whole different animal. It may not be just plug-n-play like passive crossovers, which I've had experience building before. If you need to adjust the programming you're going to need a measurement microphone and REW, and the time to learn how to use that. So at least another $100. I already have those. And you'd need to learn how to program the MiniDSP if it needs adjustment.

You're also not going to make perfectly straight cuts in 3-4" PVC unless you have a miter or radial arm saw. My 10" miter wouldn't cut all the way through the 4", so I had to fiddle with trimming it a bit. And cutting PVC makes an absolute mess. The dust settles on everything like a magnet.

If you do decide to go this route, start with a simple source. My system runs wirelessly from a laptop running Amazon Music HD and MusicBee into a Paradigm PW Link preamp into a MiniDSP 2x4 HD into each channel of the amps (each driver gets its own channel). But first I tested using a CD player straight into the MiniDSP. It cut down on the points of failure.

And obviously looks are subjective. My buddy says it looks like a combination of an ashtray and a pipe bomb. I wrapped mine completely in black woodgrain with silver undertones vinyl, which provided its own set of problems. I like the quirky looks simply because they are so different, and they're about function over form. But I don't expect these to supplant my next project that I'm building for my new media room - Bill Fitzmaurice David w/upgraded drivers in charcoal auto paint. Another quirky looking, function-over-form speaker from a brilliant designer.

kenjit,

"Even ATC use box shapes and yet they are regarded as the finest speakers. It is all a hoax."


Be fair kenjit, ATC started introducing curved slightly tapered side panels to their domestic cabinets a few years back. You can be sure they did it for good sonic reasons.

http://atcloudspeakers.co.uk/hi-fi/loudspeakers/entry-series/scm40/


Tapered cabinets must be a nightmare to produce consistently. Others like Sonus Faber have been doing it for decades.

The big exception is Harbeth but then they follow the BBC research which identifed these issues some 50 years ago. To keep the accepted box cabinet they came up with the almost unique concept of carefully constructed thin walled lossy cabinets as an answer.

As far as I know only Harbeth and Spendor currently do this.

You’re not quite ready for standup but keep working at it. 

The whole reason for OB, right, boundaries, and boxes are not the first choice, of a seasoned speaker builder.
I’m not a commercial speaker builder, seasoned, oh yea..

I build what I know works, for over 45 years, now. The 120 to 130 pairs, I’ve put out...Not a round one in the bunch. Though I did do an underground concrete vault one time.. that is still working fine.. 1/2 ton

OB Lattice structure, with ribbon and planar drivers are my thing.

NO BOX, NO TUBE, it’s not round, event the driver openings are rectangle, not round...

Time to go feed the chickens.. and George... the goat. and  Junior the rabbit, and  Bubs the dog.


Regards..

The industry? Good grief!

I think it’s generally agreed in the industry that a box is the worst possible shape for a loudspeaker cabinet.

The main reasons why most are built this way seems to be consumer expectations of domestic acceptability and manufacturing convenience.

yep. We are being duped. Most audiophiles dont want to hear that though. Even ATC use box shapes and yet they are regarded as the finest speakers. It is all a hoax. 

This design gets the benefits of a spherical design, but also adds a tapered tube at the back to eliminate all internal resonances.

Shape Variation
Cube +-5.0 db
Rectangle +-3.0 db
Cylinder +-2.0 db
Beveled Cube +-1.5 db
Beveled Rectangle +-1.5 db
Sphere +-0.5 db

Interesting, for a complete speaker system, round. smooth, tapered interiors, are a way to reduce pocket resonance. It can also be used to incorporate a resonance into an enclosure also.. That was my point, the GAIN factor, for BASS is a real issue for distortion in the bass region 250hz<

You have to use it or lose it, but you can't keep it.. 

When speaking of spectral decay effects on enclosure vs mechanical distortion (GAIN based) there is no comparison in how much one increases over the other. (The 20% bass distortion crowd, and don't even know it)
Interiors that are rough inside, not smooth are a much quieter enclosure.. The SQ is always better..

Remove the Highlands Scottish wool from behind the mids, let that blister your ears a bit..
or Remove the VERY coarse fiberglass from the bass enclosure...
BOOM....forever........

INSIDE, Smooth is bad.
OUTSIDE, Smooth is good, but just for the dust factor.
if it wasn't for that rough would be better.

Regards

Schedule 40/6" is 7mm thick. Schedule 80 is 11mm thick. I am rusty on my structural eng.

Cylinders echo and gain? ... no, they behave pretty much like any other "tube" whether it is square or rectangular, but more consistent and easier to deal with.

All materials "ring". If you have a material that does not ring (at all), then it is probably not stiff (or only stiff in one dimension). You can always add dampening. Open the hood of your car and knock on the likely aluminum block. Tell me if it "rings".

not really. it rings like a bell.

Yes it can, when used for TT platers, and is forged, but there is a reason for that too. Galvanization issues.

With Metal housed planars. Forged, won't GROW Barnacles (as fast) as cast will. Cast alu without a treatment, can get flakey in less than 5 years..
Double in thickness in 15 years. Aviation shot peen, stress relieves and removes, pocket resonance, issues, also..

Most speakers that use Aluminum, use it for it's milling ability.
EX: GR Research LS9 (Beta) and a few other.
Infinity Infinitesimal  v.5 and 1.0 (cast)

CAST.. is actually the best , Highly porous, (to a point) dead silent.
Light, strong, easy to cast, easy to mill. A lot like a cast aluminum
engine block (neutralizing agent required)
Cast, Alu/Mag (no barnacil alloy) rims, dead silent. There is a reason they cast rims.. A lot quieter than a steel or spoke.

Columns.....

Regards..

To those who think it's ugly, put your creative hat on and build a nice wood veneered cabinet over it. The guts doesn't have to change and your can be tailored to your visual preference.

I think it’s generally agreed in the industry that a box is the worst possible shape for a loudspeaker cabinet.

The main reasons why most are built this way seems to be consumer expectations of domestic acceptability and manufacturing convenience.

The following extract is taken from diyaudioandvideo.com


What is the best shape for the box?

Internal reflections in the box combined with the vibration of the box itself can cause spikes in the frequency response of the system.

Different box shapes have different effects, with perfect cubes being the worst and spherical or egg shaped boxes being the best.

Although spheres have advantages, it is very difficult to create a spherical speaker box that is as strong as a typical rectangular box.

One good example of a spherical speaker is the Gallo Nucleus Solo above on the left which is made of rolled steel or brass.

An even better design is the sphere/tube concept by B&W shown on the right.

This design gets the benefits of a spherical design, but also adds a tapered tube at the back to eliminate all internal resonances.

Shape Variation
Cube +-5.0 db
Rectangle +-3.0 db
Cylinder +-2.0 db
Beveled Cube +-1.5 db
Beveled Rectangle +-1.5 db
Sphere +-0.5 db

https://www.diyaudioandvideo.com/Guide/BuildSpeaker/

" NOBODY has done any comparisons to check if a $2 PVC pipe beats a $50k high end Wilson."

Nobody is claiming that either.

But somebody is committing a straw man argument fallacy.

Duke

These PVC pipe speakers are all hearsay. NOBODY has done any comparisons to check if a $2 PVC pipe beats a $50k high end Wilson. 6mm is a joke. Even cheap box speakers use at least 15mm mdf. Do not be duped by this cheap PVC hogwash. 

Actually...

The PVC pipes used would have a minimum wall thickness that well exceeds 6mm.

DeKay

Here the thing though, cylinders, have an inherent characteristic to ECHO
and GAIN... not disappear, or blend like you want.. They're usually have pretty high mechanical distortion. Even with a lot of baffles..
Concrete pipe... ECHO, even long square tubes echo, and GAIN..

which is why im saying its not good. 

At the same thickness PVC is similar in strength to MDF

We are talking about the linkwitz pluto speakers. They are not concrete pipes. They are not 2 inch thick PVC. They are PVC pipes that are about 2mm thick. I dont want to hear any more excuses. Do you know how bendy 2mm thick PVC is? Theres nothing rigid about it 

Aluminum is actually one of your softer metals. Way down ⬇️ on the Mohs scale of hardness. 2.75 to be specific. It’s still an interesting material when thick, like 2-3”.

Aluminum, is a good material for low resonance, and great strength.

not really. it rings like a bell. 

Aluminum, is a good material for low resonance, and great strength.

The problem is cost. Oh my. 

MDF
13-15 ply plywood, void free 3/4"
Hardwood
Aluminum

As far a cost, lowest to highest. 
Some hardwoods can exceed Aluminum for sure, but normally they are veneers.

There were a few companies that used PVC enclosures. Advent, 
Same era, Infinity was using cast Aluminum/magnesium at 10 times the cost, and 5 time the Retail. 

I'd like to say my speakers were CNC from marine aluminum, but paying for them, is a whole different story..

Here the thing though, cylinders, have an inherent characteristic to ECHO
and GAIN... not disappear, or blend like you want.. They're usually have pretty high mechanical distortion. Even with a lot of baffles..
Concrete pipe... ECHO, even long square tubes echo, and GAIN..

Big BASS Yes especially loading a tube inside a tube, and porting both enclosures. That's a 6th order, band pass. Home use.. OH my, you couldn't do it. Pictures would be falling off walls.

Columns... They work. Less real estate, less distortion, more bass, BASS, B A S S..

At the same thickness PVC is similar in strength to MDF. With the "bend" forces exerted on a speaker enclosure, a tube is a significant advantage over a box making the comparative thickness higher but that would be compared to an unbraced box.

PVC tubes are great for building Helmholtz resonators. There’s a simple formula for figuring out the resonant frequency Fr based on volume, nozzle length and nozzle diameter. I built a 60 Hz resonator out of 6” PVC pipe sections and PVC elbow joints. The trick is using the purple prep stuff just before applying PVC cement. My resonator was 15 foot long folded S shape.

The downside of using PVC tubes for conventional speakers include the difficulty of the manufacturing process and cost of adding adaptations for stands, speaker mounting interfaces, speaker terminal interfaces and finishes.

Its not really difficult. All you need to do is attach the tube to the driver. Takes about 2 minutes. You are wrong. 

from an engineering standpoint a tubular shape is inherently the most rigid and deflects the least under pressure than a box shape.  

It depends. A pvc tube can be bent easily by hand if you squeeze it across the width. But its harder to bend lengthways. The material matters more than shape. An mdf box is still more rigid than the pvc pipe used for the linkwitz speakers. 

kenjit,

from an engineering standpoint a tubular shape is inherently the most rigid and deflects the least under pressure than a box shape.  
that's why pressure vessels are cylindrical- e.g. pressurized gas, liquid nitrogen storage dewars, compressed air cylinders and HVAC boilers.  
as a speaker enclosure this translates into ultra low resonance and coloration.  Magico in fact sees the value in ultra rigid enclosures by making theirs from aluminum.  
The downside of using PVC tubes for conventional speakers include the difficulty of the manufacturing process and cost of adding adaptations for stands, speaker mounting interfaces, speaker terminal interfaces and finishes.  
The higher end B&W diamond towers mimic this to some extent- they remind me of trash receptacles. 

Kenjit, um... concrete pipe?
And yeah, certainly competitive with other devices claimed as state of the art. A cabinet's audible colouration (coloration) has a significant signature to the overall sound, a tube will do well in such a situation as the tube itself lends to withstand pressure from the driver.

Let's face facts though, best engineered for sound quality, isn't necessarily aesthetically the most pleasant.

Kenjit, explain to me why it wouldn’t work??

of course it would work. It just wouldnt be state of the art. Look at all the other high end speaker companies and the great lengths they go to with their cabinets. There are no PVC speakers out there among them. Only PVC speakers out there are the cheap ones on amazon. 

Kenjit, I’d say millercarbon is correct and the effects of pressure on the inner walls of a tube (incidentally, specifically engineered to uniformly hold pressure) is a great idea. Cabinet resonance would be low using this material and geometry, especially if you used schedule 80. Talk about inexpensive DIY!

If designing a tube shaped cabinet, it would be logical to use at least an inch or two larger radius (inner dimension of the tube) than the ports on the driver basket to allow the driver to breathe correctly, with a beveled edge on the baffle to allow unrestricted airflow from the back pressure of the driver.

The bazooka style used in car audio worked well.

Kenjit, explain to me why it wouldn’t work??
(Oh and I don’t specifically think it’s not the material so much as the geometry of a tube that makes it such a good idea).

alymere

Thanks for the clarification.

Many of us are only familiar with using the 2 channel amplifiers that the advertising branch of high end audio (the press) prefers to talk about.

Habits and all that...

https://homemedialimited.co.uk/product/ati-at6012-12-channel-power-amplifier/

It’s a little late for an April Fool’s Day joke. 

@mickeyb, I was going to suggest those inexpensive Crown amps — you could buy 3 of those and not have too much money in it.  The 12 amps alymere mentioned would be interesting too.  Maybe one of you guys with plenty of room and some loose change could put this together and video the result.  That would be a hoot.  Too bad Dr. Linkwitz isn’t still around to serve as technical consultant. 

@soix, too funny!  It does look like a periscope, doesn’t it?   Add a lens and play the theme song through it for “Twenty Thousand Leagues Under the Sea”.  ☺️

@mickeyb You don’t need 3 amps. What amp were you listening to with the Orion’s you heard? What you do need is at least 3 channels per side for a total of 6 minimum. You could use the amp that Linkwitz recommends on his website which is the ATI AT6012 which has 12 60 watt channels. Use a couple of extra channels in bridge mode for the woofers if you wish. I bought Orion’s, built the Lxmini, Lx subs, and the Lx 521.4. I love them all. I use a mix of analog and minidsp boxes for eq/xover. Buy or build any one if you like fussing around with gear. They are not plug and play but for my ears the time invested to get them set up right has been well-rewarded.

I've made copies of the Bose Cannon for movie theaters.  Used Sono tubes in 8, 10 and 12 inch diameter.  At about 14 foot long, rather hard to hide.  Thought about using the attic space above the living room ceiling, just never did that.  still have a 10 inch model in the attic.  Open at both ends, no build up of air pressure.  Back then, when testing it, was watching a movie and a fog horn went off, very loud and realistic sound.  Nelson tried a pair of 15 inch diameter Sono tubes in Grass Valley.   Quite eleaborate with a thick marble base and the 15 firing up into what appeared to be a 10 foot tall tube.  There are many roads to subwoofer nirvana.  Currently using a swarm of 10s and a 12 for bass.

I have an opportunity to by a linkwitz Orion speaker Right now. The problem is it needs 3 amps to run it. The sound is amazing. The bass astonishing. It’s the 3 amps I’m not nuts about. Supposedly, the amps don’t even need to be that great. My energy bill is already high. 

I use a SVS Sound Cylinder (round tall sub) for my home theater room. It hits pretty hard and tight, but then again I’ve not heard the best in class, etc.

It beats a poke in the eye with a sharp stick, as we say in these parts!

I love it..Rollin' on the ground...

Regards

no

Have you heard it?