Maz4bz Posted February 13, 2023 Posted February 13, 2023 (edited) Dear all, I've had a lot of fun building a few tapped horns now, including the THAM10HTL and a couple of LAB12's. They're all awesome subs. Some time back I developed a tapped horn subwoofer with the aim of meeting the performance of the legendary Danley TH50 tapped horn cinema subwoofer. I don't know how much a TH50 retailed for but the last time I enquired on its little brother the DTS20 that model retails for $9,990 AUD! I felt it might be useful to share my design for anyone interested in building something to put a 15" driver into. I've titled this post as the versatile tapped horn because I loaded it with four different drivers with very different specifications and all performed admirably in this enclosure. I don't think this is unique, it seems to me with a tapped horn the enclosure is dominate. I had a similar experience with the LAB12's too. It should be noted that my design is certainly not a copy of the Danley product. The driver Danley used is no longer available and the path design for the TH50 is unique. My design instead utilises an optimised path generated by the excellent MTH Tapped Horn workbook freely available on DIYSubwoofers.org. My design had to fit into a space at the rear of my room which set the footprint. I iterated the design height of the enclosure until I had hit the desired passband response I was chasing. So here's the published TH50 response: Here's the modelled response of the four woofers i had on hand at the time: The design is 266 litres so its a substantial enclosure. Of all the tapped horn models on DIYSubwoofers this one gives the deepest/lowest output (longest path length, in this case 446cm) for a given outside dimension. Here's the optimised Box Plan fold: For comparison, I estimate the path length for the TH50 as approximately 436cm... Sadly, this forum won't allow uploads of xls files so here's a screen shot of the panel cuts from two sheets of 17mm ply: Her's the path during build.... I highly recommend extensively bracing these kinds of enclosures. The energy generated at high levels is quite significant and can result in substantial cabinet panel resonances.... I tried both an end opening (first pic below with Celestion AD15H loaded) and side opening (with Alpine SWS-15D4 loaded) and settled for the side so that I could stand the enclosure up and minimise floor space.... Measured impedance is bang on for the predicted Hornresp model so the build was a success. I used the advanced semi inductance model from DIYAudio to ensure that the Hornresp model and subsequent build was as accurate as possible... The testing and listening to me showed that I really couldn't pick the difference between the four drivers I tried in this enclosure. Yes they measure a little differently but it wasn't audible in any meaningful way. What was clear was that despite there being big differences in efficiency between the two car subs and the two PA live music drivers it was excursion that determined ultimate headroom and max SPL. It's for this reason that I stuck with the Alpine SWS. Suffice to say the bass output from this enclosure is monumental! Here's the measured (with Omnimic) outdoors ground plane response of the Alpine SWS... So in summary I think you can have very near Danley performance for the price of a few sheets of ply and a fairly affordable 15" driver. Edited February 16, 2023 by Maz4bz 5
Janus77 Posted February 16, 2023 Posted February 16, 2023 Always enjoy your builds Maz, nice work! I don't think i'd get a sub that size approved for our living area, but flat to 25hz or so it must add some fill to the room!
Maz4bz Posted February 16, 2023 Author Posted February 16, 2023 Gday Janus, yes it's a great design if I may say so myself. The learning for me with prior builds is that room gain down low means that the LAB12 size subs aren't always necessary. Trading extension for efficiency has definite benefits too. I guess Danley already knew that! 2
davewantsmoore Posted February 16, 2023 Posted February 16, 2023 2 hours ago, Maz4bz said: I guess Danley already knew that! It's also got to be front of mind when designing for stadiums and millitary applications. 2 hours ago, Maz4bz said: a great design if I may say so myself It looks pretty good. DIY rules these waters. 1 1
Andrew Tilsley Posted March 7, 2023 Posted March 7, 2023 Have built all of Volvotreter's tapped horns, including the big 20Hz model. I've also built a couple of the Bill Fitzmaurice horn subs, including the Tuba (thin profile), and the Table Tuba. Great options. With the Table Tuba, you can dress it up and disguise it...or tuck it behind a lounge. It uses an 8 inch woofer. Don't be fooled by the output/depth though given the long horn path. The baby 6 inch horns are good also...I used a pair. See pic. Tang Band woofers. The Tuba is out of this world for HT applications...I used SB Acoustic 12-inch. 4
Magician1981 Posted September 6, 2023 Posted September 6, 2023 (edited) Interesting. By the looks of it this is a +- 20Hz design right? Can you share the hornresp par please? And would you have be any chance a design of this TH that is tuned lower? Edited September 6, 2023 by Magician1981
davewantsmoore Posted September 14, 2023 Posted September 14, 2023 On 6/9/2023 at 6:18 PM, Magician1981 said: Interesting. By the looks of it this is a +- 20Hz design right? Can you share the hornresp par please? And would you have be any chance a design of this TH that is tuned lower? http://wp.volvotreter.de/projects/th-2/the-eminence-horn/
Magician1981 Posted September 14, 2023 Posted September 14, 2023 3 hours ago, davewantsmoore said: http://wp.volvotreter.de/projects/th-2/the-eminence-horn/ Already knew about that one. Thank you anyway. I've decided to go for the lilwrecker 17hz tapped horn. It's on the avs forum.
Rrobot Posted October 11, 2023 Posted October 11, 2023 (edited) Loving all these tapped horn builds Maz - you wield the software with aplomb! I've learned heaps following your posts, cheers! I'm circling tapped horn options myself for a pair of small PA subs to stick a top-hat in - I don't need a tune nearly as low as yours here and I want to keep the size down so probably a THAM12 is looking like a decent option. To also keep cost down I've tried modelling a few mid-priced pro drivers like a high excursion Lorantz which seemed to model just OK (rolls off a bit high maybe) assuming very optimistically that I haven't totally fluffed hornresp. However from your experience maybe high xmax car subs could be a fruitful path to explore? Maybe I'm not looking hard enough or have unrealistic expectations but seems we're a little limited downunder for affordable pro drivers that can survive horn loading at decent SPL? Keep sharing all your experiments, its awesome! Edited October 11, 2023 by Rrobot
tuyen Posted December 14, 2023 Posted December 14, 2023 Grabbed this tapped horn enclosure from Matt recently. Very well solidly built and designed. Props to Matt. Definitely not a small unit. Stuck a Goodmans audiom bass 81 15” woofer. Driven by a crown xls1000 50hz low pass (24db). Even at low listening levels, that boost in 20-50hz range really brings an extra level of musical engagement that is very enjoyable. Cheers again Matt! 2 1
Maz4bz Posted December 15, 2023 Author Posted December 15, 2023 So glad it worked out for you Ty. TBH I was sad to let her go, but really happy to hear it sounds great to someone that doesn't have confirmation bias! Would be great to see some measurements outdoors to see how your vintage driver is performing. Cheers. 2
Rrobot Posted September 24, 2024 Posted September 24, 2024 (edited) Just circling back to this thread after a time, partly to big up our Aussie pro driver manufacturer Lorantz. I eventually built a THAM15 loaded with the highest xmax 15" Lorantz make. It simmed pretty well and measured reasonably close to the predicted. Definitely more a pro audio oriented tuning rather than a home theatre or hifi extension but the THAM15 has always been a bit more of a kick bin than a true subwoofer. I'm really happy with it for the occasional small backyard DJ stuff and with the appropriate high pass should theoretically take close to the rated 700 watts before running out of excursion. Edited September 24, 2024 by Rrobot 2
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