The Uluwatu - another new Curt C design?!

[NyxOne]

Re: The Uluwatu - another new Curt C design?!

It looks cool, and Curt is a good designer, but I wouldn't call 92 dB high sensitivity. My current project is 98dB/ 2.83V and I would consider that high sensitivity for what it is. My little towers are 94 - 95 dB and I consider that the bottom rung of "higher sensitivity".

I think he's considering his speaker high efficiency in regard to typical "Hifi" systems. Like Loren Jones said, it's still 5dB stronger then the average 87dB speaker. Finally, he's using only a couple of 5 inch "hifi" drivers to achieve this while your Zephyr, 96dB efficient, design use a 12" pro driver with a compression driver meant for "public address"... Not everyone can manage to talk their wife into this kind thing! ;)

Chuck

[Cosmic Charlie]

Re: The Uluwatu - another new Curt C design?!

Seems the SB tweet is out of stock at Madisound. And too bad about the odd shape of the other drivers. Madisound ought to offer baffles as an add on to the kit. Perhaps make them out of baltic birch since mdf that long would be fragile to ship. We can also hope that they don't fancy up the x-over components and drive the price higher yet.

I would like to give them a whirl.

[Jeff B.]

Re: The Uluwatu - another new Curt C design?!

I think he's considering his speaker high efficiency in regard to typical "Hifi" systems. Like Loren Jones said, it's still 5dB stronger then the average 87dB speaker. Finally, he's using only a couple of 5 inch "hifi" drivers to achieve this while your Zephyr, 96dB efficient, design use a 12" pro driver with a compression driver meant for "public address"... Not everyone can manage to talk their wife into this kind thing! ;)

Chuck

But my 95dB towers don't use any prosound drivers or really big drivers either. Curt's has a lot of cone area it's just in a line, that's all. Loren is right though about the trade-offs. That Hoffman's Iron Law is pretty tough to work around. If you want deep and efficient, then you need large; small and efficient means it won't go deep. In the case of my towers, they're flat to 40hz, but that's what I have subwoofers for.




Jeff

[johnnyrichards]

Re: The Uluwatu - another new Curt C design?!

Also, he implemented very little baffle step correction and the measurement he posted was in room, boundary loaded and the tweeter is still hot up top. Good rock and roll speakers since those get pushed against the wall quite often.

[Jeff B.]

Re: The Uluwatu - another new Curt C design?!

What you say is true regarding true high sensitivity designs Jeff, but 92 db is still 3 to 6 db above many designs and that isn't nothing. It looks like these dig pretty deep in the bass for the sensitivity they do have. To reach to the 30's with 92 db sensitivity in a box that size (not that it's a small box) is doing pretty well.

Are you basing the bass extension on the Omnimic plot? You need to be aware of how that works. With the Omnimic's "blended" setting my Continuums appear to reach to 20-30Hz too. He doesn't show the gate time, but there is a point on that graph where the response isn't really valid, or at least it doesn't mean the same thing as it does above that point. I have a set of these woofers, they won't reach this deep anechoicly.

[Jeff B.]

Re: The Uluwatu - another new Curt C design?!

I think he's considering his speaker high efficiency in regard to typical "Hifi" systems. Like Loren Jones said, it's still 5dB stronger then the average 87dB speaker. Finally, he's using only a couple of 5 inch "hifi" drivers to achieve this while your Zephyr, 96dB efficient, design use a 12" pro driver with a compression driver meant for "public address"... Not everyone can manage to talk their wife into this kind thing! ;)

Chuck

He's not using a "couple" of them, he's using six of them. It's a nice design and I love the look, but it's certainly more than a couple of 5" drivers. He's really working with some pretty high sensitivity with the 6 drivers together in the bass (and quite a bit of cone area too), but giving up 6db of it for baffle step compensation. It's a well thought out design, really.

[Jeff B.]

Re: The Uluwatu - another new Curt C design?!

Also, he implemented very little baffle step correction and the measurement he posted was in room, boundary loaded and the tweeter is still hot up top. Good rock and roll speakers since those get pushed against the wall quite often.

It looks like 6+ dB of baffle step compensation / low end boost from looking at the crossover design.
Jeff B.

[johnnyrichards]

Re: The Uluwatu - another new Curt C design?!

It looks like 6+ dB of baffle step compensation / low end boost from looking at the crossover design.
Jeff B.

You're right, I was thinking of something else.

[CWH&R]

Re: The Uluwatu - another new Curt C design?!

Seems the SB tweet is out of stock at Madisound. And too bad about the odd shape of the other drivers. Madisound ought to offer baffles as an add on to the kit. Perhaps make them out of baltic birch since mdf that long would be fragile to ship. We can also hope that they don't fancy up the x-over components and drive the price higher yet.

I would like to give them a whirl.

He did his measurements with out counter sinking the drivers.

[kanemack]

Re: The Uluwatu - another new Curt C design?!

He did his measurements with out counter sinking the drivers.

that he did, but the version on the site has them countered, and look a whole lot sexier, and smoother as curt said. this is one build where a cnc company is a must. i can do irregular baffles, but ten cutouts is an exercise in imperfect.

[[email protected]]

Re: The Uluwatu - another new Curt C design?!

that he did, but the version on the site has them countered, and look a whole lot sexier, and smoother as curt said. this is one build where a cnc company is a must. i can do irregular baffles, but ten cutouts is an exercise in imperfect.

You need a pattern. Pm me.

[johnnyrichards]

Re: The Uluwatu - another new Curt C design?!

Actually, I am wondering if something less than 6db bafflestep correction is what he targeted considering the posted measurement. The room response near wall that he posted, regardless of Omnimic's weird gating, would show a lot more energy below ~800 - 1000 Hz and lower, not a relatively flat response, especially considering the 10db scale on the chart. Hmmmm... 2.5 design, I know.

http://speakerdesignworks.com/sitebuilder/images/SystemResponse2.5mNearWall112313-960x426.jpg

[Jeff B.]

Re: The Uluwatu - another new Curt C design?!

Actually, I am wondering if something less than 6db bafflestep correction is what he targeted considering the posted measurement. The room response near wall that he posted, regardless of Omnimic's weird gating, would show a lot more energy below ~800 - 1000 Hz and lower, not a relatively flat response, especially considering the 10db scale on the chart. Hmmmm... 2.5 design, I know.

http://speakerdesignworks.com/sitebu...13-960x426.jpg

Can't comment on the measurements and placement but the network is pretty straight-forward. It's a cascaded 2.5 Way. The 4 "bass" drivers have a sensitivity that's 6dB higher than the two series connected midbasses. The reason such a large inductor is used (7mH) is due to this sensitivity difference and trying to blend the six drivers together smoothly. With a cascaded network like this if the inductor value was 0 there would be no change in response and no compensation. As the inductor gets larger the lower the midrange output will be and the more baffle step compensation, or rise in the bass response you will have. Given the sensitivity difference and the size of the inductor there appears to be an 8.5 dB rise in response from the midrange to the bass range (just doing it in my head). Also the ratio between the depth of the cabinet and the width is going to require a 6 dB BSC in order to be flat in the lower midrange even if it is near a boundary. Boundary reinforcement would occur at frequencies lower than that.

[donradick]

Re: The Uluwatu - another new Curt C design?!

Seems the SB tweet is out of stock at Madisound. And too bad about the odd shape of the other drivers. Madisound ought to offer baffles as an add on to the kit. Perhaps make them out of baltic birch since mdf that long would be fragile to ship. We can also hope that they don't fancy up the x-over components and drive the price higher yet.

I would like to give them a whirl.

When I built the Galeons with the SB13 drivers, I flush mounted them - royal PITA.
I also surface mounted a pair and measured the response - pretty much no change from the recessed ones.
So I would advise people to surface mount them.

[NyxOne]

Re: The Uluwatu - another new Curt C design?!

When I built the Galeons with the SB13 drivers, I flush mounted them - royal PITA.
I also surface mounted a pair and measured the response - pretty much no change from the recessed ones.
So I would advise people to surface mount them.

Not for this design! It would change the voice coil offset between the midwoofer and the tweeter and affect the crossover...

Chuck