At this price point you should expect good measurements and consistency between the driver units. The chosen drivers for this design fulfills that more than enough.<\/p>\n
<\/p>\n
<\/p>\n The response dip centered at 1250Hz for the mid-woofer sure does look nasty, but despite some higher second-order distortion it doesn\u2019t affect the sound quality of the driver and is actually only a beauty spot in the frequency measurements.<\/p>\n There is a very nice consistency between the two mid-woofer samples. They have a very flat frequency response from the mid-range to the upper mid-range 1.5-4kHz. The driver has a very nice off-axis behavior and starts \u201cbeaming\u201d as high as 3.3kHz. The rising top-end is easily tamed with a response shaping circuit in the filter design and there is no severe and nasty cone-break-ups that needs to be treated.<\/p>\n This mid-woofer just begs for to be crossed-over high up in the mid-range and the listening test confirms it.<\/p>\n For further details see: After using my DEQX system for a while in order to break-in the drivers and to get a feel of the driver units behavior and sound characteristics, I\u2019ve decided to cross-over the drivers at a fairly high frequency, around 3kHz.<\/p>\n One might argue that a tweeter like the ScanSpeak AirCirc driver is over-kill for such a design and why not use a small \u00be\u201d tweeter instead, but in this design I want to use a true symmetrical LR2 cross-over slopes.<\/p>\n Using a true LR2 cross-over slopes requires some robust tweeters to handle the shallow frequency response slopes as well as a well-behaved mid-range without frequency anomalies above the cross-over frequency.<\/p>\n The AirCirc tweeter has an extended low-end frequency response and has the distortion numbers to back it up.<\/p>\n <\/p>\n The two tweeter samples have almost a perfect consistency between each other. It simply doesn\u2019t get better than this.<\/p>\n The rising top-end above 15kHz is nothing that needs to be corrected for. If it at all can be heard it gives the high frequency a bit more air.<\/p>\n For further details see: I think these two mid-woofer and tweeter drivers complement each other perfectly. \ud83d\ude42<\/p>\n <\/p>\n When using a symmetrical Linkwitz-Riley 2nd order cross-over filter topology, the mid-woofer and the tweeter “acoustic center off-sets” is a very important factor to consider for a successful design.<\/p>\n The acoustic center off-set between the drivers in the Sequence Two \u2013 Monitor<\/strong><\/span> design is about 26mm, when measured at tweeter-axis and at a 2.5m distance.<\/p>\n There are several solutions to adjust the acoustic center off-sets between the mid-woofer and the tweeter and here\u2019s the most commonly used techniques:<\/p>\n 1.\u00a0\u00a0 \u00a0Use an asymmetrical cross-over slope. Each technique has its pros and cons. The most commonly used \u201casymmetrical cross-over slope\u201d technique can often cause poor phase tracking around the cross-over point.<\/p>\n Using a \u201cstepped baffle\u201d can cause additional baffle diffraction and using a \u201cslanted baffle\u201d cause added enclosure building complexity.<\/p>\n In my prototype design I will use the option 4 and 5. The \u201cladder delay network\u201d adds complexity to the filter design, but doesn\u2019t have the same issues in the vertical off-axis response roll-offs as the option to \u201ctilt\u201d the enclosure back-wards.<\/p>\n Listening tests will decide which of the solution 4 and 5 that performance the best. If they are equally good, I will publish both options as a part of the design.<\/p>\n <\/p>\n The first (left<\/strong>) prototype mid-woofer cross-over section is very simple and consist of an electrically first-order section (L1<\/strong>) and a response shaping circuit (C1+L2+R1<\/strong>) to achieve a full \u201cbaffle step correction\u201d and an acoustical LR2 cross-over slope with a cross-over point at 3000Hz.<\/p>\n The tweeter cross-over section consists of an simple electrically second-order section (C2+L3<\/strong>) and an adjustable tweeter level attenuation (R2<\/strong>) together with a \u201cnotch filter\u201d (C3+L4+R3<\/strong>) to flatten out the sharp impedance peak at the resonance frequency of the tweeter.<\/p>\n The tweeter \u201cnotch filter\u201d is a must in order to achieve an acoustical LR2 cross-over slope with a cross-over point at 3000Hz and to avoid audible distortion and “ringing” at the tweeters resonance frequency.<\/p>\n The second (right<\/strong>) prototype cross-over filter has the \u201cladder delay network\u201d (L4+C3<\/strong> and C4+L5<\/strong>) circuit connected between the cross-over filter and the \u201cnotch filter\u201d section.<\/p>\n Observe!<\/strong> In this filter the tweeter isn\u2019t directly connected to ground.<\/p>\n","protected":false},"excerpt":{"rendered":" To readers of the AudioExcite blog, there should be no surprise that I like two-way stand-mount loudspeakers and here is another one and most likely not the last one. \ud83d\ude42 With the Sequence Two \u2013 Monitor we take a step up in both the price, but also in sound quality. At this price point […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"class_list":["post-1746","post","type-post","status-publish","format-standard","hentry","category-blog"],"_links":{"self":[{"href":"https:\/\/www.audioexcite.com\/index.php?rest_route=\/wp\/v2\/posts\/1746","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.audioexcite.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.audioexcite.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.audioexcite.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.audioexcite.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1746"}],"version-history":[{"count":17,"href":"https:\/\/www.audioexcite.com\/index.php?rest_route=\/wp\/v2\/posts\/1746\/revisions"}],"predecessor-version":[{"id":1749,"href":"https:\/\/www.audioexcite.com\/index.php?rest_route=\/wp\/v2\/posts\/1746\/revisions\/1749"}],"wp:attachment":[{"href":"https:\/\/www.audioexcite.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1746"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.audioexcite.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1746"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.audioexcite.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1746"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"\"](\"https:\/\/www.audioexcite.com\/wp-content\/uploads\/2012\/02\/Woofer-TW-axis-0deg-1L-vs-2R-.jpg\" "\\"Woofer")
<\/a><\/p>\n
\nAudioTechnology 15H520613SDK<\/a><\/p>\n<\/a><\/p>\n
\nScanSpeak D3004\/660000<\/a><\/p>\n
\n2.\u00a0\u00a0 \u00a0Use a stepped baffle.
\n3.\u00a0\u00a0 \u00a0Use a slanted baffle.
\n4.\u00a0\u00a0 \u00a0Tilt the enclosure back-wards.
\n5.\u00a0\u00a0 \u00a0Use a ladder delay network circuit.<\/p>\n<\/a><\/a><\/p>\n