NEAT ULTIMATUM MF9

Posted by: vimal on 11 November 2001

First and foremost I would like to thank Mark Raggett of Naim Audio for all the help I received.

I have now had the Ultimatums in active mode for about 3 months,and it has been an experience,but also a little frustrating.
It was an experience because all the attributes you look for in going active was there,but a little frustrating, because there was one element that was difficult to get balanced and that was the bass.
I feel it could be the Naxo3-6 filter circuits that may require adjustment(not sure).As the Ultimatums are not true 3 way speakers but 2.5(two and a half),with the MF sharing the LF it was a little difficult to set the pots up for all music.I may have the Naxo modified while carrying out listening tests.I am certain this can be solved.They are still a superb listen if you are prepared to alter the setting to suit music type.

I have now received the passive crossovers from Bob Surgeoner of Neat Audio,they are encased in maple cabinets to match the sycamore speaker cabinets.Bobs cabinet maker must be a descendant of the strad violin maker, because these are beautifully finished.
I have had these hooked up passive for 5days,and they are back to what I remember when I decided to go for them.The bass seems to go even deeper than I remember and this could be due to the crossover now being external.I do miss the pin sharp imaging,and precision of the active set up.
In the next couple of weeks I will be hooking up
Alan Probin's Nap500 (very kind of Alan I just hope I dont get hooked on the 500 which could turn out costly).
In conclusion I was originally runnig active Isobariks with a sixpac, and was looking to replace the briks with a more modern speaker,
and I believe I have found them in the Neat Ultimatum MF9s.

Posted on: 11 November 2001 by Allan Probin
Vim,

I wonder if some of the frustration of the active set-up not being an all-encompasing maginitude greater than passive may be down to the fact that Neat use very simple, first-order crossovers. Maybe replacing a simple passive crossover circuit and instead forcing the signal to go through a more complex active circuit with semiconductors, attendant power supplies (you are 'only' using a hicap on the SNaxo), etc., is one of those swings and roundabouts things - you gain in some areas but lose out in others.

BTW, Bob came round a few days ago and we put a pair of Petites up on the 500. Certainly juiced them up a bit. The MF9's should be fun.

Allan

[This message was edited by Allan Probin on SUNDAY 11 November 2001 at 22:45.]

Posted on: 11 November 2001 by Martin Payne
quote:
Originally posted by Allan Probin:
(you are 'only' using a hicap on the SNaxo)


Allan,

I think he's only using a NAXO.

The SNAXO is supposed to be a major improvement. I'd change this first.

I wonder how the NAXO was configured for a 2.5 way speaker? Has the low-pass been disabled on the mid channel, or just set so low that it is effectively a low-pass rather than band-pass? Or are you using the MF9's just as a standard 3-way with the lower range of the midrange chopped off?

cheers, Martin

Posted on: 12 November 2001 by vimal
Martin
I am not sure,how the filters were setup,as it was left to Bob and Mark to sort out (Bob if you are out there please respond)
I do have a Snaxo which will be used in the final setup once all the filter mods are sorted out using the Naxo.
Posted on: 12 November 2001 by Bob Surgeoner
Vim's Naxo was set up to mirror the MF9's 2.5-way passive crossover, so both sub-bass and bass-mid sections receive full signal up to their upper roll-offs.

I hope this helps.

Bob/Neat Acoustics