补两张分音器图
<p>SCAN-SPEAK Reference Monitor</p><p>单元：9900，8546</p><p><br/></p><p>SCAN-SPEAK Reference Plus</p><p>单元：8546，8545，9900</p><p> </p><br/>
Merlin Clone
<p><font face="Verdana" size="1"><strong>麦林Merlin </strong><font size="2">VSM，用的SS 8545和DY的T330D，一代名箱：）</font></font></p><p> </p><br/><br/><br/><br/>The Usher Two-Way
<p>The Usher Two-Way (Scan-speak 8545+9500)</p><p class="article">Usher Audio offers two drivers that are closely modeled on highly respected Scan Speak drivers. The Usher T-9950 resembles the SS 9500, tweeter, and the Usher 8945 looks exactly like the SS 8545 woofer. Although the Usher drivers are not quite the bargain they were at their introductory price, a pair of each will still save you about $165 over the equivalent Scan Speak drivers ($289 vs $454). They may be ordered from: <nobr><a href="http://zalytron.com/" target="new">http://zalytron.com</a>.</nobr></p><p class="article">The 8945 provides all or most of the benefits of the 8545, and also shares a common fault -- a frequency response bump in the region of 900 hz. I have ignored this problem in my past crossovers using the 8545, but extended listening has convinced me that there are audible consequences, and I have therefore opted for a more complex crossover for the current design using the Usher drivers. </p><p class="article">The woofer circuit uses an lcr trap filter to smooth the peak at 900 Hz, which unfortunately increases cost and crossover board size. I recommend saving some money and space by using a very high Ga 1.0 mH inductor in the circuit. For the 20 uF capacitor, a mylar would be fine, as would a Bennic NP electrolytic, for that matter. </p><p class="article">I used a cabinet designed for my STS kit (no longer offered). The dimensions are 19" H X 10" W X 14.5" D. It has a 1.5" front baffle, with 3/4" construction on the remaining panels. The center of the tweeter is located 5.5" from the top, and offset .5" horizontally (mirror image pairs). The woofer is center mounted, and the center-to-center distance from the tweeter is 6 inches. I used a 7" X 2" port, but this could probably be improved upon. </p><p class="article">The crossover is a Linkwitz-Riley 4th order at about 2,200 Hz. I am very pleased with the results. The speaker is very focused but not fatiguing. Bass response is excellent. </p><p class="article">Here is the woofer low pass filter:</p><p class="article"> </p><p></p><p class="article">Remember -- any resistor with a value of less than .5 Ohms does not really exist. It merely represents the approximate DCR of the associated inductor. But all the other resistors are real. You may use either 14 Ga or 16 Ga inductors in the woofer series circuit.</p><p class="article">And here is the tweeter circuit:</p><p class="article"><br/> </p><p></p><p class="article">A value of 6 Ohms for the series resistor will produce the flattest response. However, feel free to experiment with a 7 or even 8 Ohm value if the highs are too bright in your room.</p><p class="article">Here is the on-axis response:</p><p><br/> </p><p></p><p class="article">Although the on-axis response is a little elevated at l000 Hz in relation to 1800 Hz, notice that compensating changes occur off axis.</p><p class="article">Here are the plots 15, 30 and 45 degrees off axis:</p><p class="article"><br/> </p><p></p><p><br/> </p><p></p><p><br/> </p><p></p><p class="article">Finally, here is the response with the tweeter connected with reverse polarity. It shows the crossover frequency of 2.2 kHz, and also demonstrates that the drivers are in phase at the crossover point when connected properly.</p><p><br/> </p><br/>Revised Crossover for the Norh 9.0 Marble
<p>Revised Crossover for the Norh 9.0 Marble</p><p>使用单元：Scanspeak 8530K + 9900</p><p class="article">The Norh 9.0 Marble speaker looks a little like an Easter ham, and is cast out of a solid block of marble. It uses the Scan Speak Revelator 8530 woofer and the 9900 revelator tweeter. A couple of months ago, a somewhat disgruntled owner delivered a pair of these very heavy speakers (along with one of the "mini" versions that substitutes the SS 9700 tweeter for the 9900 in a smaller ham), and asked for my opinion. I liked the midbass -- thanks to the inert cabinet -- but found the sound disjointed and lacking in midrange detail. We lugged them upstairs for some measurements, and this is what we found:</p><p class="article"> </p><br/><p class="article">The tweeter clearly was connected with the wrong polarity. The other sample measured the same way, so this apparently is what the factory had in mind. I switched the tweeter polarity and remeasured. The null was gone, but the overall response was elevated above 3 kHz, and the speaker sounded edgy, smeared, and very fatiguing. I recently discovered a website that had very accurate measurements of another Norh offering -- <a href="http://www.soundstagemagazine.com/measurements/norh_sm69/" target="_blank">the SM 6.9</a>. Look familiar? </p><p class="article">Since the drivers were of such high quality, and the cabinet so solid, I decided to design a new crossover from scratch. The sloped front baffle of the 9.0 permitted 2nd order acoustic slopes, and that's what I ended up with. I think the sound from the new crossover is excellent -- very cohesive and relaxed. Here's the new on-axis response. The woofer displays the usual Scan Speak peak below 1k and the dip centered at 1500 Hz, but I don't think a fix is worth the added crossover cost and complexity. The dip at 10 kHz is probably caused by a baffle ridge around the tweeter flange due to the tweeter flange being slightly recessed when tightened properly.</p><p class="article"> </p><p></p><p> </p><p class="article">The "Mini" version of the 9.0 apparently uses the exact same crossover as the bigger brother. At least that's what I've been told, and the topology and capacitor values are identical. I haven't measured the inductors. If so, this is very strange, because the slope of the Mini front baffle is considerably smaller than the regular 9.0. This will alter the relative postition of the acoustic centers of the tweeter and woofer, and require a crossover modification. Plus, the 9700 tweeter's response and sensitivity differs slightly from the 9900. In this case, the Mini measured considerably better than the Maxi with the stock crossover:</p><p><br/> </p><p></p><p class="article">Closer -- but still no banana. I redid the Mini's crossover, and ended up with very different component values than I had used for the Maxi's crossover. Here's the on-axis response:</p><p><br/> </p><p><br/></p><p class="article">Here are the schematics for the large 9.0. Notice that the tweeter is connected with reverse polarity. This is the opposite of the factory connection. Any resistor with a value of less than 1.0 Ohm does not really exist. That's just an approximate value for the resistance of the inductor itself. I used 16 Ga air core all around. Finally, if either speaker sounds too bright in your room with your equipment and program material, just increase the tweeter series resistor by 1 Ohm.</p><p class="article"> </p><p></p><p>And here are the schematics for the Mini. The same warnings about tweeter polarity and resistor values apply.The New Vifa Tower
<p>The New Vifa Tower</p><p>使用单元：Vifa M21 8" + D25 (later D27) tweeters 或 Scan speak 9500 (9300)</p><p> </p><p><br/></p><p><table width="584" border="0"><tbody><tr><td width="343" bgcolor="#ffffff"><h1 align="center"><font face="arial" color="#000000" size="4">Opal Kit</font></h1><p align="left"><font face="arial" color="#000000" size="3">The Opal takes countless curtain calls from audio critics for it's punchy bass and amazing power and reach. It's tall and slender, with fantastic looks, and a three-dimensional soundstage. The Opal will satisfy demanding audiophiles and Videophiles.</font></p><p> </p></td><td width="227"><p align="center"><a href="http://subwoofers.cc/speakers/Opal/opal.htm"><font face="arial" size="3"><img height="215" alt="opal.jpg " src="http://subwoofers.cc/HomeAud/images/opal.jpg" width="167" border="0"/></font></a></p></td></tr></tbody></table><table width="70%" border="0"><tbody><tr><td width="100%" bgcolor="#ffffff"><blockquote><ul><li><font face="arial" size="2">Flat frequency response from 48-20kHz, 3db anechoic,</font></li><li><font face="arial" size="2">In-room usable bass response to 30-35Hz room dependent</font>
</li><li><font face="arial" size="2">Nominal impedance: 8 ohms, Sensitivity: 88.5db 1 watt/1meter</font>
</li><li><font face="arial" size="2">Recommended RMS power: 30-200 watts per channel</font>
</li><li><font face="arial" size="2">Tweeter: 1" silk dome, ferro-fluid cooled</font>
</li><li><font face="arial" size="2">Bass-midrange: 8" cast-frame, doped cone, long-throw, rubber surround</font>
</li><li><font face="arial" size="2">38 1/8" tall, 10 1/8" wide and 13 1/4" deep</font>
</li></ul></blockquote></td></tr></tbody></table></p><p><table cellspacing="0" cellpadding="8" width="100%" border="0"><tbody><tr><td id="cap">The New Vifa Tower</td></tr><tr><td valign="top" bgcolor="#ffffff"><p class="article">This design has its roots in a speaker kit called the Opal, a 2-way tower design that Audio Concepts introduced several years ago. This was before I had any measuring equipment or crossover skills, and I ordered a pair, along with their cabinets. The Opal used the Vifa M21 8" treated paper woofer and a pair of Vifa D25 (later D27) tweeters, and received a rave review in the Audio Critic. Although the sound was basically uncolored in the midrange, the overall presentation was leaden and closed in. I have since learned to mistrust Audio Critic reviews, and have also been able to develop a series of crossover designs that I think substantially improved on the original. I present here my latest, and definitely my last, take on the subject. </p><p class="article">This kit is intended for people who want a basically full-range system with a minimum of complexity and cost. The Vifa M21W039-08 woofer is good down to 32 Hz in the ported tower cabinet, and provides surprisingly satisfying midrange performance for such a large driver. The Vifa D25AG35-06 aluminum tweeter delivers very smooth response with excellent dispersion. Although the resulting sound is not quite as focused as, say, my MB0W1 3-way, the Vifa tower costs much less and the crossover is far less complex. The total cost for the drivers and crossover parts is only about $220 a pair. You do, however, have to be able to build a large cabinet. To the best of my knowledge, there are no appropriate prefabricated cabinets available from the usual hobbyist sources. </p><p class="article">There are some misguided souls who think the Vifa D25 tweeter is harsh and bright. I think that’s because it looks bright and shiny, and people hear what they see. Rather than arguing the issue, I have provided an alternative crossover using the ScanSpeak 9500 fabric dome--a unit that I don’t think anyone thinks is inherently bright. To my ears, the basic difference is $112 in extra cost. But I certainly don’t think 求一款8545+9500或MDT29/33的书架名箱设计图