ear to driver height alignment gauge.

[Roog]

I too readily slump making such measurements futile :0)
I sit directly on the floor sometimes when I want to take things to extremes, but not for long cos my bum gets numb. :~(

 

[ToTo Man]

Christ, my idea of crude would be a parting bead and a marker

I actually use a broomstick and a marker! A metre stick is a convenient alternative for those who sit lower than 100cm (no good for me as I sit at a listening height of 103cm-104cm thanks to my sciatica and giraffe neck!).

 

[Big Tabs]

It really depends on the speaker. Many are indeed designed to be in-phase at the crossover point when the tweeter is at ear height, but some aren't, or at least aren't unless you're listening many metres away from it.

Raising the speaker up to achieve to most in-phase response at the crossover point isn't always the best thing to do as it can make the bass response worse. A better solution is often to 'rake' (tilt) the speaker backwards as this has the same effect as increasing the height of the tweeter without affecting the bass as much.

I alter the seat, not the speakers.
Also have a couple of degrees of tilt, have done for years - my house isn’t flat anyways…
For my ears, if the tweeters are too low/high - sounds wonky.

 

[Yank]

A better solution is often to 'rake' (tilt) the speaker backwards as this has the same effect as increasing the height of the tweeter without affecting the bass as much.

This can give a sort of "balcony" perspective to the soundstage.

 

[Roog]

You could use a laser level and hold it next to your ear level, I noticed that my level beeps when level so you don’t even need to check the bubble, just look to see where the red laser dot lands on your speakers

 

[ToTo Man]

FYI - 4-way IMF loudspeaker measured at ear height (103cm) vs supertweeter height (98cm) vs tweeter height (93cm) vs midrange height (78cm):

Room measurement with 1/12 oct smoothing:

Gated measurement without smoothing:

Sitting higher than the speaker is evidently not a good idea if you want a smooth response where the tweeter crosses to the supertweeter.

Sitting on midrange axis provides the smoothest response at the MF/HF crossover point. The IMFs are not alone in this behaviour, my Ditton 66s are also best listened to on midrange axis if you want to avoid phase cancellation at the MF/HF crossover point.

 

[cooky1257]

https://audiojudgement.com/speaker-lobing-polar-response/

 

[ToTo Man]

https://audiojudgement.com/speaker-lobing-polar-response/

Interesting... I wasn't aware the crossover slope affected the vertical lobing pattern.

The following diagram shows a drive unit's dispersion pattern as frequency increases. I was under the impression that as a driver starts to beam its dispersion narrows like a flashlight, I didn't realise it developed hot and cold spots off-axis?

 

[TimF]

I think I will just nail my Duevel Venus omni's to the ceiling and sit under them.