Full range speakers, 40"-44" max height

an old man’s advice:

When speakers are short, tilt your speakers back so that the tweeter is aimed directly at your seated ear height.

that tilt is also beneficial:

a. alters reflection angle relative to floor, ceiling, side and rear walls

b. time alignment. eh: high frequencies travel faster than low frequencies. (why many designs have sloped fronts). Many/most think not really an issue at our listening distances, but .....

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toe-in, 1 listener: works best for me: while finding distance from side and rear walls, toe the speakers in so that the tweeters are aimed at your listening position.

you will still get wide imaging, wider might be un-natural, that’s another reason to chose a cartridge with wide channel separation, and tight center balance.

toe-in two listeners: if listening with a friend, i.e. small table between two chairs both listeners a bit off center:

aim left speaker at right listener

aim right speaker at left listener

effect: decent imaging for both because you are closer to the one aimed at the other person, thus more volume by distance, however the opposite speaker is aimed at you, thus more volume by dispersion. a reasonable balance rather than just hearing the speaker near you. works, try it.

movement: wheels/slip material (hard for carpet/soft for hard floors)

I use 3 wheels on my very heavy speakers, they just roll when I get tough with them.

See my virtual system: Donna’s precious items on top of speakers, no movement even on wheels.

https://www.audiogon.com/systems/9511

 

You need tight axels to prevent wobble. I tried some pricey wheels, but found that furniture grade dual wheel castors have the tightest axels.

lighter speakers just need 3 spots of material (hard or soft) to allow movement

3 wheels/slip material: 2 in front, 1 in back because you want more weight per wheel/slip material;

AND you do not need to worry about wobble, 3 always settle.

rear corner blocks to prevent tipping when moving: I have a wood skirt that hits the floor if the speaker starts to tilt; Other speakers without a skirt: I used to have rear corner blocks, floating just above the floor, to do the same thing.

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marks on floor:

I am lucky, I have a wood grid floor. I maintain the front inside corners to retain my distances from rear and side walls, and have two positions for the front outside corner: just swing the outside corner forward: normally at me; at other chair when a friend visits.

speaker polar patterns are an issue, particularly tweeters.

tweeters disbursement is narrower than mids and lows

horns can control/enhance directivity, I have T350's in my speakers

 

dome tweeters radiate equally narrow

POLAR PATTERNS https://www.audiofrog.com/dispersion-and-reflection/ scroll down, see the diagram, gradual narrowing of dispersion pattern as frequencies rise. he’s talking about cars, but it’s the same at home excerpt: "But the real deal here is not to be hoodwinked by someone’s BS suggestion that you should aim the speaker differently to fix a reflection problem. That’s only useful at the highest frequencies a speaker will play. Below that, it makes no difference." "So, in a 3-way system, which speaker should be aimed? Just the tweeter."

 

closenplay

thanks, you made me learn more about time alignment here.

 

https://en.wikipedia.org/wiki/Loudspeaker_time_alignment#:~:text=Loudspeaker%20time%2Dalignment%20usually%20simply,cover%20a%20wide%20audio%20range.

so time alignment is about voice coil positioning, not speed of sound

excerpts

" it is of utmost importance that, at the crossover frequency the outputs of both drivers should acoustically sum so as to be seamless, without any peaks or dips, otherwise the loudspeaker is said to colour the sound."

"the radiating surfaces (at the voice-coil or the dome/dust-cap depending on design, also known as the "acoustic centre") of the drivers are not in the same plane - the tweeter’s radiating surface is usually much forward of the woofer when both are mounted to the same flat panel."

therefore:

stepped front or sloped front or tilted back: moving the tweeter voice coil somewhat back (from other drivers acoustic centers) seems to be advantageous.

Factory designs (stepped or sloped) presumably based on exact math of known drivers;

amateur tilt as I describe is a simple approximation.

 

 

Speed of Sound

I moved from Virginia to Burlington Vermont.

No proper winter clothes, 30 below zero often, and I was not going to ask the evil step father for gloves, hat, scarf, anything..

Freezing miserably, I would hear the school bus coming, and coming, and where was the damn thing? Finally, it appeared.

Someone told me later, when all the moisture is frozen out of the air, sound travels faster, so I heard the bus when it was farther away.. Sure as hell made sense to me.

Because it was the crackling of the ice on the road, it seemed to me that the high frequencies were traveling faster.

So, see sloped fronts, remember that experience, I made a poor connection of the words time-alignment.

Glad I learned about the acoustic centers of various drivers

I heard Joseph Audio speakers when Jeff first started, very impressive. Haven’t heard his speakers for a long time, but based on other people’s experiences, he is making both high quality cabinets that sound superb.

AND, among other things a unique crossover, and dual magnet woofers.

He worked at Harvey Electronics, when JSE Infinite Slope speakers were added to Harvey’s line. He became friendly with Richard Modafferi, designer of those speakers with 2 unique patents:

1. Infinte Slope Crossover 120db/octave

2. Bass Shift ..., (unique way to blend the 10" and 12" woofers, including the use of dual magnet 12" woofer.

My friend at Harvey’s was Steve, who called me and said " You have got to hear these" Doctors, Lawyers, they were selling like hotcakes, until:

JSE decided to make their own cabinets (decent but nowhere near Jeff’s quality),

AND, they couldn’t deliver on time, many clients quite annoyed, so much so that Harvey’s dropped them from their line.

Jeff bought the rights to the Infinite Slope Crossover in 1992. I checked today, every speaker he makes has a version of Infinite Slope Crossovers, no doubt modified by him as needed for each model. He also uses woofers with dual magnets.

I had no money, but Phil, my friend at Leonard Radio knew I loved the Model 2’s, and Ray had taken a pair in trade with blown tweeters (the Dynaudio D21’s burnt out easily). I made a deal with Ray, replaced the tweeters, absolutely loved them.

Point is, Jeff is the only maker that is using the unique Infinite Slope Crossover, and I suspect a key reason his speakers sound so darn good, as well as his work with his driver supplier and continued use of dual magnet woofers.

two part interview with Jeff