New Floorstander Project

[ralphs99]

A quick look at what I'm working on currently.
Volt B250.8, ATC SM75-150S, Eton ER4.

The boxes are just test boxes at the moment. They're sealed, but may end up as dipoles. On the other hand they may just stay sealed because the bass is just fantastic as is. Smooth, tight and controlled. Extension to the lowest octave is missing, but I may add a sub-woofer or try a Linkwitz transform profile. The Volt's have a small glitch in the FR and impedance plots signalling the beginnings of breakup modes at about 550Hz. But I'm croosing to the ATC at 375Hz at 24dB/oct, so it's already well down.

The ATC's are amazing drivers, superb, expolsive, attack and control. Almost horn-like in their rendition of snare drums and brass. Strings and vocals are smooth and detailed.
But the SM75-150S isn't easy to apply, requiring some EQ and careful integration. They start getting too directional above about 3.5kHz, so at the moment they're crossed out at 3.35kHz.

The ER4 has an interesting character. I haven't heard better reproduction of cymbals, especially ride cymbals. But sometimes it can sound a bit confused. I haven't flush mounted the drivers yet, and the protective HPF has been cobbled together with parts I had on hand. It's highly variable directivity is causing some issues with the power response, so I will be doing some experiments with waveguide loading the ER4 to manipulate the power response. I'll also be trying out some AC ribbons and maybe a dome as well.

It's all sounding very impressive considering the development is only in it's early stages.

Cheers,
Ralph.

[george a]

Hi Ralph
Nice looking setup...
Where are you getting the AC ribbonds from? (and where did you get the ATC??)

Cheers from Sth OZ

[wintermute]

All I can say is those are test boxes!!

very nice work

Tony.

[inertial]

(sorry for my english)
Nice!
IMHO Er4 is one of the best and absolutely not-confused at all!
Maybe it haven't the max SPL possible and it has medium spl with 2,83 volt ......but it sound great. What type of rear load have you applied
in your test box for the tweeter?
Cheers,

[David Gatti]

Nie setup ralph!
BTW, from that photo, it looks like your enclosure is made from bricks !

[69stingray]

What species of wood is that on the side?

[Landroval]

Originally posted by 69stingray
What species of wood is that on the side?

Man, it's a reflection of the brick wall. I think the whole speaker is painted with high gloss black.

[Audiophilenoob]

Originally posted by Landroval

Man, it's a reflection of the brick wall. I think the whole speaker is painted with high gloss black.

ultra high gloss... simply stunning work

[Stocker]

Originally posted by Landroval
high gloss

No kidding. Nice.

[ralphs99]

Thanks for the good words everyone.

Yeah, they are looking better than I was expecting. And they're certainly sounding great too.
You guys picked up on the reflection of the bricks pretty quick. I didn't even notice when I took the picture!
The whole box is a high-gloss black finish. I can't take any credit for the boxes though, I got them from another guy who made them for his now abandoned project. I figured it would be easier to use these rather than make my own. I'd still prefer a wood grain finish, but do they do look kinda cool - if a bit evil- in black.

IMHO Er4 is one of the best and absolutely not-confused at all!

I won't disagree with you at this stage Inertial. I've only had them running a couple of weeks and there's still lots of development work to do. I've already made several experiments with the rear loading, and haven't yet found what I'm looking for. But I have discovered they're tricky to integrate. At the moment they are firing into the top half of the enclosure which is loosely stuffed. Please let me know if you have some suggestions.

Where are you getting the AC ribbonds from? (and where did you get the ATC??)

I got the ATC mid from Ebay in Germany. Got lucky on that one! Another abandoned project. I bought them with some other drivers including another pair of Volt B250.8's I've had shipped here to Melbourne and some PHL2460's and Raven R2's still with my sister in Holland. More drivers than I know what to do with at the moment!
I'm still waiting for the AC ribbons from a group buy through here. I paid for them in April, but there's been some problems with delivery and I'm still waiting. Not too much longer I hope!

Cheers,
Ralph.