New Hi-Res Toys

[planet10]

At those frequencies the driver is close enuff to the floor.

Given real rooms, there is a lot of squish room in the estimates.

dave

 

[Salas]

Τhe width is 2,98 m.

That's even closer to a 60Hz halfwave resonance.

 

[Salas]

Fortunately the Bliss shows ~50Hz box resonance giving out enough bass just before that small room's 40Hz suck out. Further away in the room 30Hz comes up but this closed box has no resonance there to sustain a drone like a lower tuned bass reflex would.

 

[Siberia]

That's even closer to a 60Hz halfwave resonance.

I had to look up the formula. Let me write it down here for myself and for those who are feeling lazy. Assuming your graph shows a resonance of ~58Hz, we can calculate the half wavelength using the formula:

λ = v / f,

Where λ (wavelength) = v (the speed of sound in air – approximately 343 meters per second at room temperature) / f (frequency in Hz).

By plugging in the values for v and f:
λ ≈ 343 / 58
λ ≈ 5.914 meters

Half-wavelength = λ / 2
Half-wavelength ≈ 5.914 / 2
Half-wavelength ≈ 2.957 meters

This is very close to the provided room width of 2.98 meters.

 

[Salas]

The new EAD spares vs an original JORDAN spare

The original driver's Fs changes in box because it lacks a spider
Free air 2.83V SPL of new one measures about same as the old

 

[Salas]

A step response* chart is interesting to add. Highlights the time coherence of a Woofer Assisted Widerange (WAW). The 8" woofer takes over from the (polarity inverted) Jordan in timely fashion.

For perspective here's what the Stirling LS3/5a V2 gave me in the same room with the same mic.

The tweeter hits first. An undershoot before its fast rise confirms LS3/5a's HF polarity flip. The woofer starts after a distinct time gap. Being mounted behind the baffle and using a complex filter network doesn't help synchronicity. This nicely agrees with Stereophile's measurement of the same Stirling "BBC" model.

*About step response (by John Atkinson)

 

[Salas]

EAD Sweden markets an affordable enough descendant driver that fits. The E60HD MKII. Has larger voice coil and a traditional spider. Its wise to get a pair for future spares security and possibly more power handling. If it can also perform alike the original E.J. Jordan JX6RHD in the Aluminum Bliss speaker, that will be a win win move.

Its been tried yesterday as a modern replacement, and it is a success. Remains in original character but it sounds calmer and compresses less at higher SPL.

 

[Salas]

A close up picture of the mounted EAD. Virtually indistinguishable from the original Jordan. Just a wee bit more recessed in the baffle due to its not having as thick a chassis rim, but it comes with a quite thick gasket that allows for some decoupling through mounting compression.