Bandor 50 SW8 modules measurement

[jzagaja]

For those interested in a smoother Jordan JXR6HD modules. Here is a measurement of four Bandor 50 modules, single copper wound, eight ohms, low inductance. MLS stimulus, less than 1W, 6mm electret mic, relative dB values, cardboard as a baffle, 45 deg to the carpet.

[jzagaja]

And their picture.

[graaf]

Hi Jack!

give us more!

what can be the cause of this depression 1500<3000 Hz?
Are there any significant resonances visible in the unsmoothed response?

regards,
graaf

[jzagaja]

Hello Graaf,

Depression has two causes:

1) Very delicate suspension that result in "rim resonance".
2) Energy reflected through the cone from the carpet.

This means that one have to be careful with stored energy in the cabinet. Doreen called me one hour ago and she can straighten FR response but she feels it isn't necessary. You can get a better midrange from aluminium coil.

There are of course very high Q resonances above 10K but they are -25dB down. For evaluation I need better measurement.


I wish in this thread we compare 1000 times lighter membrane. My recent ribbon (appended picture) speaker is quite good however we have larger Q diffraction and worst transformer. In this week I'll get amorphous C core from AMS Irleand. A lot of parameters needs to be adjusted then. Ribbon also need a screen damping like in microphones.

I also made Jordan JXR6HD measurement in the same setup but response was bad so at the moment won't show anything
(I think better baffle is needed).

Cheers,
Jack

[jzagaja]

Another interesting approach is to use Bandors as very low noise and high quality directional microphones with a careful design like PJ Baxandall's differentiatior. Doreen seems to have many users of this kind.

[graaf]

Originally posted by jzagaja

This means that one have to be careful with stored energy in the cabinet.

perhaps a suitable cabinet can be a pipe like in "Yoshii 9" or in "Pluto"?

Originally posted by jzagaja
Another interesting approach is to use Bandors as very low noise and high quality directional microphones with a careful design like PJ Baxandall's differentiatior. Doreen seems to have many users of this kind.

geez! this sounds REALLY esoteric, fullranger as a microphone

best,
graaf

[jzagaja]

I like "Pluto" enclosure but only if one has suitable reflector for high frequencies. Impedance peaks (n*Fs) should be carefully damped then. With anodized Bandors you can make wonderful looking speakers. Will try in future.

Bandors play much deeper bass notes than Jordans.

[graaf]

Originally posted by jzagaja

Bandors play much deeper bass notes than Jordans.

no surprise - JXR6 Fo 80 Hz, Qts 0.45 and Bandor Fo 65 Hz, Qts 0.6

apparently at low SPLs low bass is not outside of the reach of such small drivers, perhaps this is also the case of "Yoshii 9"

best,
graaf

[jzagaja]

With acoustic music a lot of people can be satisfied. Don't forget it is only 50mm cone. I'm very comfortable with Bandors. You don't have to play music loud on them. Not only they measures well but has some magic. I've found imaging natural behind speaker line. Disadvantage is I have to give them back to the owner on Saturday

[oon_the_kid]

Hi Jack,

Since you actually have both the Bandor and the Jordan, how do you rate the sonic difference between the 2. particularly the mids and highs?

Since the Jordan are out of production for so long, i am beginning to wonder if they will ever come back online again...

So far I have tried the one from Mark Audio, they are really nice, but I guess I am curious about the rest....

Oon