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If you're going to do a 3 way speaker, then a small dome midrange is the way to go, IMO. It gives you a number of advantages that a larger cone doesn't. First, it keeps the same shape/radiating surface as your tweeter. So it's easier to integrate and get a seamless sound from a tonal standpoint. Second, since it's small, you can place it physically closer to the tweeter on the baffle, which makes it easier to get smooth vertical off axis response. Third, since it's smaller, it will typically be able to cross over to the tweeter a bit higher than a typical midrange driver, while still keeping more even polar response in the crossover region. I'd recommend to build separate sub-unit inside your speaker that houses the mid/tweeter only, so it's sealed off acoustically from the back pressure waves of your bass drivers. The other thing I've noticed is that with a 3 way speaker, you end up with more (and larger) parts in the signal path, so quality of those parts become even more important. Cheap parts are fine for the design portion and the fine tuning, but for the final speaker, splurge on good quality caps and coils.
Ideally I want a 10-12" driver that extends down to 30-40Hz, but also needs to be capable of reaching up to 400-500Hz, cleanly for a dome mid? (impossible?).
I never said it was easy.You were the first person to reply to my very first thread here on Audio Circle. Next time you reply to a 'newbie', maybe check your own prejudices and keep your presumptions to yourself? From what I can gather, it doesn't exactly stimulate the Audio Circle spirit - an inclusive, knowledge-sharing community.No harm done though, Mr. Clark! I'll be happy to learn from you, if you have anything worthwhile to add here?
The original JBL L100 has minimal parts, the 12" woofer is run full range.
Ideally I want a 10-12" driver that extends down to 30-40Hz
Excellent post Norman, a plethora of great info. Referencing your post, what would you think about the Allison dome midrange used in Roy's model One through Three speakers? I thought they were the best midrange driver I've ever heard.
Peak midrange dome was to me circa 1976 I credit to the Yamaha NS-1000...*Who’s got your dad’s pristine NS-1000s you’ll sell me for $500? I’ll pick ‘em up. Come-ooon man you need that attic space.
Can I just play peacemaker here and suggest that I see your point but can you concede that there is little in your OP that gives any indication of your journey so far?Audiocircle is a good place overall and I (and others I'm sure) welcome you here. We are not the only resource out there though, and don't overlook the other ones, especially DIYaudio.com, there is a DIY contingent here but it is not the main focus of this site. You may get more useful answers there. Don't give up on us though! We like to see builds too!As to T-Love's point about interaction with newbies. This is something to be mindful of. I remember one new person who joined the site because he was restoring a pair of old Bozak speakers that he had come across and he was looking for guidance/ inspiration/knowledge. Someone with a large presence on the site chimed in on the thread and said that Bozak speakers couldn't be any good because (insert baffling rationale here). The fact that Bozak speakers were very well regarded in their day, and that the individual in question admittedly had never even heard of the brand, let alone heard any, didn't prevent him from having an 'opinion' about them and posting responses that seemed to be based on the saying 'if you can't dazzle them with brilliance, baffle them with BS'. Perhaps as a result of being told by a prominently involved person that his speakers (theretofore unknown to the person) weren't any good, he posted a few more times and then basically went away. So a welcoming attitude does count for a lot. Just my 2¢.
Why specifically do you want a dome? A cone driver would give you more flexibility to try different things during the learning process. As far as inter-driver spacing, the domes you linked are 130 and 200mm in diameter.
Instead of advice, let me ask a few questions. Do you plan to measure your results? If so, how?
Hi T_love16, welcome to AudioCircle and the chronic hobby/passion/disease that is Hi-Fi speaker design and building.Wow, as the saying goes “that escalated quickly”. I started writing this yesterday and would have been the third reply but pesky day job interfered. Now on page 2 of the thread it is clarified you’ve completed the plebe stage of building some kits and getting grounded in what a good Hi-Fi speaker sounds like.There is a joke among amateur and professional speaker designers that illustrates where we are as sophomore designers.Question: What is the best speaker you have ever heard?Answer: The latest one I just finished designing. That illustrates what I find as a honeymoon period with new speakers that applies for both DIY and commercial designs. First our attention is captured by what this one does that the last one didn’t. As that new wow factor subsides a mature trained (most of us self-trained by putting in the hours) listener begins to hear the big picture both the good and the bad. For me it helps to have some benchmark designs to contrast and compare to my latest effort. For example I spent 2020 being blown away (sometimes literally https://www.diyaudio.com/forums/multi-way/352063-exploring-purifi-woofer-speaker-builds-post6244079.html) by the Purifi PTT6.5 woofers and matching passive radiators in a couple of speakers I have designed using them. For those systems the crossover is presently at line level based on Marchand Electronics PCBs with bi-amping power from ACG 1000 series amplifiers. When I compare the textbook 2nd order crossover to my friend Michael’s Uilleam Audio X-LS Encore the superior crossover by Danny R is apparent in the smoothness and integration evident. So I have a goal post to work towards labeled “Purifi stunning bass and midrange transparency meets refined crossover 2.0”.I presume you are aware of the resources at diyAudio.com with 1000s of posts of varing signal to noise ratios in the speaker forums. Three perhaps less well known resources I suggest are:http://www.htguide.com/forum/forumdisplay.php?6-Mission-Possible-DIYhttp://www.troelsgravesen.dk/Diy_Loudspeaker_Projects.htmhttp://www.humblehomemadehifi.com/archive.htmlAnd, finally, back to your original query “Now there seems to be some promising midrange dome options, with high sensitivity and great freq/HD measurements. Maybe they've always existed, and I've just missed the boat?” here is my two cents worth.Set the way back machine to 1958 and Edgar Villchur’s Acoustic Research introduced the AR-3 adding to his acoustic suspension bass loading system (introduced in AR-1) the world’s first dome tweeter and midrange drivers. By the time I was hanging out in Hi-Fi shops late 1960s early 1970s it was the AR-3a and JBL L100 competing with the Advents for most sold Hi-Fi speaker. The prevailing wisdom was AR-3a for classical music and jazz, for rock JBL L100 (b.t.w. FANTASTIC post on the L100 by WGH above). Three ways with dome midranges persisted into the 1980s. I wanted SO BAD the ADS (Braun in EU) 710 or 810. And over in England we have PMC keeping the dome midrange alive on the UK scene. Peak midrange dome was to me circa 1976 I credit to the Yamaha NS-1000 (https://www.stereophile.com/standloudspeakers/yamaha_ns-1000_loudspeaker/index.html) and its host of Japanese (often domestic market only) competitors from Technics, Sony, JVC, Diatone, et.al. that brought high tech materials to the 3-way woofers + domes monitor architecture. Note that what these have in common is the volume and proportions of the by 2021 standards large wide AR-3a/L-100 ‘monitor’ style cabinet. By the late 1980s and early 1990s the dome midrange had largely disappeared from the home Hi-Fi market. I believe three factors contributed. First style along with manufacturing and shipping costs led to abandoning the hefty ‘monitor’ cabinet in favor of slim mini-monitor and narrow floor standers. Of course late generation ADS designs and current NHT and PMCs demonstrate nothing physically stops using a dome midrange on a slim speaker. (As an aside why not more market love for the NHT C4 and C3 dome 3-ways?) There the second factor hits. Unless someone can point me to an exception when I compare candidate dome vs. cone midranges the dome mid always has a narrower bandwidth, specifically less lower mids/bass reach. As WGH’s L100 post clearly illustrates what is considered an adequate 3-way crossover 1971 vs 2021 has A LOT more parts on its bill of materials (BOM). And in 2021 we are likely to consider these should be more expensive parts. So…add a dome midrange and my BOM cost just went up 5x to cover/enhance 500-4k (Volt VM572) or 800-6k (Satori MD60N-6). Of course with the Looney Toons pricing possible in 2021 a 500% increase in BOM costs are often absorbed. Now combine factors one and two to get factor three, baffle step correction. If I am springing for a 3-way expensive BOM and using a narrow baffle I need to supply baffle step correction up to some hundred Hz. Comparing cone vs dome midranges the cone will often reach lower. If it gets down to a couple of hundred Hz the baffle step correction is as easy as turn the woofers up 2-4 dB and done. With a dome mid reaching its limits 500-800 Hz BSC will likely require more complex shaping of the woofer response (more complex = more parts = more BOM $$) to meet the mid and upper ranges.Now given T_love16 has clarified he is ready and looking for a challenge and some of my favorite commercial speakers ever* sported dome mids I say if dome mids attract then go for it!*Who’s got your dad’s pristine NS-1000s you’ll sell me for $500? I’ll pick ‘em up. Come-ooon man you need that attic space.
Recently noticed an ad in Stereophile - Yamaha is back!But at a price, these aren't your Dad's NS-1000'sYamaha NS-5000 - ZYLON 12" woofer, dome mid-range and tweeterhttps://usa.yamaha.com/products/audio_visual/speaker_systems/ns-5000/index.html$14,999.95I did similar bracing to my JBL L100's. Internal side-to-side braces, 3/4" plywood glued to the recessed back panel and a brace from the back panel to the woofer magnet. The braces, 1-1/2" thick back panel and locking the woofer in place really tightened up the bass, low notes were lower and punchier and male FM radio voices has less lower mid-range resonance.
I don't always have access to an anechoic chamber (I used to have weekend access to one at my old university), so I measure time-gated. Clio measuring system.Like I mentioned before, if you have anything worthwhile to add here, I'm all ears.
