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Joined 2003
I'm sure you've looked at the 3rd party distortion measurements at Zaph's site?
The Peerless HDS (now a scanspeak labelled driver) is a better driver for low crossover frequencies. If you want to use the SB29, I would recommend a bit higher crossover, maybe 1.7 or 1.8kHz, however it may work well even down to 1.5kHz but you may be a bit limited by power handling. The 830875 will still be happy with a slightly higher crossover.
The Peerless HDS (now a scanspeak labelled driver) is a better driver for low crossover frequencies. If you want to use the SB29, I would recommend a bit higher crossover, maybe 1.7 or 1.8kHz, however it may work well even down to 1.5kHz but you may be a bit limited by power handling. The 830875 will still be happy with a slightly higher crossover.
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I looked at Zaph's site quite a bit, and the SB29 seems to have a lower frequency response (flat to 1k), where the HDS tweeter starts to roll off at 1.5khz. That's one reason I thought the SB29 would be a good choice for 1.5khz crossover. Is there a danger I'd blow up either one of these tweeters w/a crossover that low? The woofer I'm using seems to get very beamy above 1.5khz so I figured a crossover in that region would be best. Unless I'm missing something?
You only blow up things if you play it too loud! The good thing about the SB is they are half the price of the HDS and probably almost as good. I may be going for different end results, but I am starting to think more highly of much smaller mid-woofers or even, gasp, midranges again. That's why I picked up a pair of John's little 5 inch drivers to play with.
Yes, for good off-axis power response, it seems as though you have to either use a smaller driver than 6.5", or you have to use some type of waveguide on the tweeter.
I might end up going the same way you are, a smaller driver. I wonder how Zaph's driver compares to something like the Scan Speak Revelator 5 incher....
I might end up going the same way you are, a smaller driver. I wonder how Zaph's driver compares to something like the Scan Speak Revelator 5 incher....
As far as damage, i woudnl't think there would be much of a difference between 1.5 and 1.7k. Tweeters of this quality shouldn't fry at either of those frequencies (or even lower) at normal or even quite loud listening levels. If you're nitpicking with distortion that's a different story. I haven't heard either of them but if you can get either i'd go the HDS made by scanspeak. That's just me though. No one will be able to guess which tweeter you'll like better. Just get one and play with the x-over frequency yourself seeing as you have the dcx. Go with what sounds good to you
Zaph is quite good for the money. I like it better than the Dayton RS. ScanSpeak it is not.
Oh, I didn't run those tests, John did (he linked to them earlier in this thread. If I am reading the graphs correctly, he ran a series of test, at 1khz, 1.5khz, 2khz, 3khz, and 5khz, all with 106db bursts. Here's what I'm looking at:
Seas 27TBFC
and
Tweeter group 8
Both have marked increased distortion with 1khz signals, but are very, very clean by the time 1.5khz rolls around....
Seas 27TBFC
and
Tweeter group 8
Both have marked increased distortion with 1khz signals, but are very, very clean by the time 1.5khz rolls around....
Mark's tests are a great resource. But before any of you cross these at 1khz and crank it up to 106dB, take a look at the upper left corner of each distortion plot. It says "pt25m 106dB"--to me this means its 106dB at a distance of 0.25 meters. To normalize it to the typical 1m distance we're accustomed to, wouldn't we back off ~6dB for every doubling of distance (neglecting near field weirdness since these are tweeters)? So, those tests are being run at 94dB at 1m.
Maybe Mark can speak up again to confirm this.
Still, not too shabby at all, considering. Especially that RS28F. But if you want any power handling headroom at all, don't think about taking any of them to 1khz, though 1.5khz is totally reasonable IMO.
Cheers,
Sam
Maybe Mark can speak up again to confirm this.
Still, not too shabby at all, considering. Especially that RS28F. But if you want any power handling headroom at all, don't think about taking any of them to 1khz, though 1.5khz is totally reasonable IMO.
Cheers,
Sam
I wasn't clear before - I actually own both of these tweeters, my main concern with starting the thread was to see if one (or the other) would be better from a distortion/damage standpoint for a very low crossover like 1.5khz.
Having said that, I've listened to both tweeters extensively with 2khz crossover points and there's no real contest - the SB Acoustics is a better sounding tweeter. The HDS is more "revealing", but it's pretty cold and sterile sounding when judged against the SB29.
Having said that, I've listened to both tweeters extensively with 2khz crossover points and there's no real contest - the SB Acoustics is a better sounding tweeter. The HDS is more "revealing", but it's pretty cold and sterile sounding when judged against the SB29.
Rs28f
For the benefit of anybody else reading the thread who doesn't already have the tweeters (as Tyson who is just looking for advice to choose between which of the two models he alread owns) I'll point out another option:
Parts-Express.com:*Dayton RS28F-4 1-1/8" Silk Dome Tweeter
For the benefit of anybody else reading the thread who doesn't already have the tweeters (as Tyson who is just looking for advice to choose between which of the two models he alread owns) I'll point out another option:
Parts-Express.com:*Dayton RS28F-4 1-1/8" Silk Dome Tweeter
An externally hosted image should be here but it was not working when we last tested it.
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