Taking the shout out of piezo tweeters [message #39973] |
Tue, 21 January 2003 05:58 ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
Oscarl
Messages: 20 Registered: May 2009
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Chancellor |
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There was a recent post on this subject, with reference to the two pi. I recently came across this website, while I'm not technically minded, it may prove useful. Share your opinion. http://misty.com/people/don/pzfix.html
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In my Studio 2 Pi's, it (or some other flaw) is real. [message #39978 is a reply to message #39974] |
Tue, 21 January 2003 10:53 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
Patrick Kopson
Messages: 26 Registered: May 2009
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Chancellor |
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Something is wrong with the sound of my recently completed Studio 2 Pi's. Call it "shouty" or "harsh" or "shrill", but it IS there. It is irritating enough to my wife that she is willing to let me build different speakers already. That will be fun, but I am not giving up that easily--I am going to try isolate the problem and fix it first. I am investigating three posible causes: 1. The 1038 is just more efficient than the Alpha 10-A. This can be corrected with just a cap in series with the piezo--as Wayne already explained below. 2. The plastic housing of the 1038 is resonating. This might be cured by applying a mixture of silicone calking and sand to the extrior of the back side of the 1030 for damping. 3. The Alpha 10-A and the 1038 may overlap a bit too much. The Alpha 10-A has fairly flat response up to 5KHz while the 1038 is prety flat from 3.5KHz up. I make this comment based only on the published response curves of the drivers and my intepretation of them. Any feed back on this posibility will be most appreciated. Items one and two are simple to experiment on. Item three, however would be difficult to "fix" or even verify. I'll borrow a real time analyzer to check it out.
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wonder how much it relates [message #39984 is a reply to message #39974] |
Tue, 21 January 2003 16:27 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
Sam P.
Messages: 307 Registered: May 2009
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Grand Master |
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to sound inside the enclosure bouncing back thru the cone, and muddying things up. I've noticed that a lot of the time a project involves a narrow baffle, and no padding on some of the surfaces next to the cone. Also, if the box tuning, however closely to plan you build, comes out wrong, an early lowend rolloff may be percieved as a tonal balance with the MIDS "in your face". I call that "tv" sound more than shouting, hey wait, my tv shouts at ME all the time, where's Elvis when you need him:) . Look in BOXPLOT at the effect of variations in Vb or Fs, sometimes a few Hz. off will really move you away from "flat" to dropping off or peaking. . Hmmn, might mean, turn those wires over to the tweeter and give it a listen:) Even with no crossover...the tweeter motor is behind the woofer...at 5kHz. 1/2 wave is pretty small:) . ARE YOU GUYS USING THE INDUCTOR that Wayne mentioned for trimming the midrange rise? Sam
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Fifty bucks buys a lot of speaker [message #39988 is a reply to message #39974] |
Tue, 21 January 2003 22:54 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
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Wayne Parham
Messages: 18756 Registered: January 2001
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Illuminati (33rd Degree) |
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The Motorola KSN-1038 is the best sounding piezoelectric tweeter I've found. For that matter, it's the best sounding ten dollar tweeter I've found. Everyone is entitled to their own opinion, that's fine. But I've used lots of them and found the KSN-1038, 1041 and 1056 to be the most pleasant, both by specifications and by my ear. The KSN-1005 with its long snout is the one I never really liked. It is more efficient, but sounds noticably different. There are some others that I don't like, such as the versions that aren't horn loaded and most of the generic knock-offs. But I like the Motorola KSN-1038 and I've stuck with them for the low cost two-ways for over twenty-five years. There's just a sound that I like and a simplicity of the design that appeals to me. There is a slight rise in both the current Alpha 8 and the Alpha 10 in the upper vocal overtone region, around the 2kHz to 4kHz octave, just before upper cutoff. That's what the 0.5mH coil is for. I find the one π and two π speakers to be very pleasant, and I've always been proud of them. But if you want to build a more expensive speaker, you can always make different choices. As for me, I think the one π's and two π's are perfect, just the way they are. I can't think of any better set of parts that gives so much satisfaction for fifty bucks.
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parts vary in their specs [message #39994 is a reply to message #39988] |
Wed, 22 January 2003 06:51 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to previous message](/forum/theme/AudioRoundTable/images/down.png) |
Sam P.
Messages: 307 Registered: May 2009
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Grand Master |
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more than some people realize between production lots. The last 4 drivers I ordered, I specifically asked that they be taken from the same carton. I got 3 the same, and one different lot number...the bastards:) DCR of all 4 was 6.3 ohms, Fs was a uniform 41Hz., but the free air Z peak of the oddball was 48.3 ohms, 10% higher than the others(44.0, 44.0, 44.6 ohms). The pair I have from a couple of years ago measured 37.2 ohms/40Hz. and 37.8 ohms/42Hz. PE measured Fs of 43.13 last year. Pioneer still claims 36Hz... . My POINT, that even within the same lot, the manufacturers only try to hit a certain tolerance. One year something comes marked taiwan, the next time china, etc. Then "rooms" differ alot, and why the heck would anyone drive a ford? So an EXPECTATION that a speaker can be built and be "turn key perfect" in every room for every person is ludicrous. I am sure after suitable break in, listening sessions and trying different room positions and/or treatments improvements will be heard. If not, get out the soldering iron, add a choke to the woofer, maybe pad the tweet slightly, or at $10 a pop, why not try a pair from a different BATCH of the same item. Or a different part number within the same "family"? Sam
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