HiVi Planar Isodynamic Tweeters

[otto88]

Hi

Do or could be any of HiVi's Planar Isodynamic tweeters have open backs, i.e. dipole radiating? I know B&G’s Neo3 is, but 90.5 dB is a tad low in sensitivity for my application. I’m after at least 93 db from about 2000 Hz up.

The RT1II won’t cross below 3.5 Hz without losing sensitivity . .

The RT2E-A Overview RT2E-A Isodynamic Tweeter_HiVi, Inc. or RT8-II http://www.swanspeaker.com/product/htm/view.asp?id=18 could have their backs simply screwed off, but I can’t be certain if the backs contains the magnets . .

And would it lose sensitivity if the back were removed??

[wolf_teeth]

The central magnet is attached to the rear-plate on the larger units.

Also- the screws once removed will likely force the voice coil to become unattached with a jig to hold them fast. It happened to me:



I would not advise it. Most will lose sensitivity if made to run dipolar anyway.

Later,
Wolf

[otto88]

Thanks, Wolf

So I just bought *two pairs of HiVi RT8II.
They're slim, I'll run them back to back to give a dipole pattern like the mids (Neo10s) and rest of the system, and have about 94 db sensitivity.

I hope they sound as good as the Neo3 . .

[wolf_teeth]

The RT8 won't reach 20kHz, FYI. It's more suited as an upper-midrange.
You're welcome!
Later,
Wolf

[otto88]

According to HiVi's published FR, the RT8II is fairly flat up to about 10 kHz

have you tested it and found that it tapers off at . . . HZ?

Cheers

[wolf_teeth]

It wasn't me. It was somebody else on PE-TT forum, and I tried searching but can't find it. 10kHz is not 20 kHz, so that lacks quite a bit. And as I recall, it started to rolloff about 8kHz. It's very directional being so large, and the power response suffers off-axis. I tried PM'ing the person I think it was, and hopefully he'll right back and let me know where it was posted.

I hope to update later,
Wolf

[otto88]

PS: Your Photobucketed 61 Custom T-Bird is coool.
Is it road registered? can you see out?

[wolf_teeth]

Originally Posted by otto88

PS: Your Photobucketed 61 Custom T-Bird is coool.
Is it road registered? can you see out?

It's actually not mine, but it is my driveway. The thing ran out of gas on the way to the Kruse Auction Park.

If you want t look it up on-line, it's called the 'Thunderflight', and the guy is a local around here. He was driving it, so it must be legal.

Later,
Wolf

[otto88]

Thanks Wolf

I cant hear much above 11 KHz, but as I already have the Neo3 (displaced as "tweeter choice" by the RT8II), I could use the Neo3 as more of a super tweeter

But I'd forgotten about the limited directionality of the RT8II, which is very large for basically a tweeter, 2 - 12 kHz . .

I'll do a frame that allows me to use either or both tweeters, and the Neo10 mid. See what works best

[wolf_teeth]

You're welcome-
Please report back your results!
I'd love to see the pics,
Wolf