[rajesh]

Hi there,

This is my first thread.

There is this Canadian company called Newform Research. They make speakers that use scanspeak woofers in box and 4' long ribbons that are mounted on those boxes. Has anyone heard (about) them? It would be helpful if some information can be provided.

Regards


Rajesh

[walkern]

Hi Rajesh,

I've heard the model you describe.  The ribbon is a freestanding dipole, and the woofer is in a traditional box.  The sensitivity of the speaker seemed quite low, and one needed to be quite careful to place them well out into the room to avoid cancellations through the mids and highs.  They sounded very fast, very detailed and fairly neutral in tonal balance.  The transition from the cone midbass driver to the ribbon was fairly seamless.  I heard from the owner that the 'loved power' and in particular, high current solid state amps.  They did not seem happy when attempting to play them loud (much over 95 db by my best guess), flattening out dynamics and becoming congested if pushed hard.  I think they would work nicely in a small to medium sized room, and probably best with music that sounds best at reasonable listening levels (bass heavy loud rock probably not so much, and full orchestral pieces or organ music at realistic concert levels are also out).

Hope this helps.

[Rocket_Ronny]

I owned the Newform 645s for several years. Here is how I had them.





I ran them with a 15 watt tube push/pull to satisfying levels.



If you want imaging monsters these will teach you the ropes. They throw a D - E - E - P soundstage. And individual images are very focused.

Major complaint back then was the integration of the ribbon with the woofs. Overall, pretty good that way, but could be better. Perhaps they are better now.

They say they are 91 db eff. but my guess would be more like 89.

The owner is a really nice guy.

Rocket_Ronny

[zeke]

I had a pair of 645's for a few years. They sounded good to me, but maybe i am not very "picky".     :>)
I drove them with both solid state and tubes --- found no sensitivity problems.
I played lots of music genres at loud levels and did not notice any congestion.

do a search at Audio Asylum  --  lots of pro and con comments

zeke

[rajesh]

Thank you very much for the replies guys. Will check out at the suggested forum too. In fact there is another model, 630 which would suit mid sized rooms more. 645s have 45" ribbons and two scanspeak woofers whereas, 630s have 30" ribbons and one scanspeak woofer. My interest in them is because the ribbons are crossed to takeover from 1000Hz onwards and go right upto 20000 Hz.

[Duke]

My recollection is that the ribbon driver used in Newforce speakers is a monopole (closed back), rather than a dipole (open back), but I may be mistaken.   

Matching up a line-source ribbon with a point-source woofer does present a challenge.

You see, sound pressure level falls off more slowly with distance from a line source than it does from a point source (3 dB per doubling of distance vs 6 dB per doubling of distance, anechoic).  So what happens is, there will be a distance at which the woofer and ribbon have the same SPL.  If you move closer, the woofer will be louder than the ribbon.  If you move farther away, the ribbon will be louder than the woofer.   A little bit of mismatch is not a problem, but a big mismatch is.  I would suggest checking with the manufacturer to make sure the speaker will work well for your room and anticipated listening distance. 

If the relative levels of woofer and ribbon can be adjusted for your normal listening distance, that would be great.

Duke

[Rocket_Ronny]

My recollection is that the ribbon driver used in Newforce speakers is a monopole (closed back), rather than a dipole (open back), but I may be mistaken

Yes, that's right, monopole.

Matching up a line-source ribbon with a point-source woofer does present a challenge.
If the relative levels of woofer and ribbon can be adjusted for your normal listening distance, that would be great.

The NewForms are mostly used active from what I understand, so the volumes should be able to be adjusted.


Rocket_Ronny

[doug s.]

a friend of mine had the 645's.  (he may still have them; i haven't been to his place in a long time.)  yes, the ribbon is monopole.  i thought they were excellent being driven by 100wpc tube amps.  but, you had to be at least 10' away to get proper integration between the ribbons and the cone drivers.  further away is even better.  otherwise, there was poor integration between them.

doug s.

[Rocket_Ronny]

I had mine about 10-11 feet apart and I was about 9 feet away.

A buddy who came over, a real audio guru, who is sensitive to crossovers and integration repositioned the whole setup and put them about 14' apart and sat around 16' away and liked that way more. His comment was that it sounded more integrated. Sounded like a jazz nightclub. I prefered my setup as it imaged way better.

Rocket_Ronny