Hi all I’d like to start of by saying what an awesome group this is, I am a complete novice to all this so please bear with me.
We originally purchased a pair of Devine artists B15 subs but found them very quiet (500w RMS) the tops just completely out powered them so upgraded the drivers to Fane 15XS the volume was instantly better obviously as they are 2x the rms but just don’t sound right (amp is crown xls3500).
I’d like to put these drivers in THAM15 enclosure’s and would like some real world input, I like the thams due to their size as we are limited for space and as I understand would be good for output, any input is greatly appreciated.
We originally purchased a pair of Devine artists B15 subs but found them very quiet (500w RMS) the tops just completely out powered them so upgraded the drivers to Fane 15XS the volume was instantly better obviously as they are 2x the rms but just don’t sound right (amp is crown xls3500).
I’d like to put these drivers in THAM15 enclosure’s and would like some real world input, I like the thams due to their size as we are limited for space and as I understand would be good for output, any input is greatly appreciated.
Okay, bing found the specifications in the datasheet for fane 15xs. Search the name & model # yourself, no sense copying all the bing gobbledigook.
Vas 149.7 L, Qt .31 Fs 37.3 hz . Plug those in any sim software and see what size box it recommends. Qt .31 suggests only vented cabs are supported. AES power 1000 w (pinknoise) frequency recommendation from the manufacturer is 30-500 hz. Freq response rolls off above 2000 hz and 6 db/octave below 90 hz. Apply appropriate frequency conttol from signal source to the power amp or LCR crossover components in the box itself. Pick your lower freq limit. Rock/pop music, few manufacturers support lower than 40 hz. Organ notes can go to 20 hz which this driver cannot.
Obviously limiting volume of box limits performance of the system. David Weems charted volume factor for Qt=.31 is 0.55. so optimum box size is .55+Vas is 82 liters. Remember when calculating box size, use inside dimensions, and subtract the driver volume, 1 L and volume of any crossover components and damping inside the box.
Mr. Weems suggest Fb (3 db point) Tuning factor per Mr. Weems is 1.2. So 1.2*Fs is 44.8 hz . A nice drop off point for rock or pop.
Port area is suggested 1/7 of cone area, so 855 cm^2 is 122 cm^2 . The biggest port chart in the book is 10 cm diameter or 78.5 cm^2. A port of that diameter should be 9 cm long to tune to 40 hz.
This is per Designing Building and Testing Your Own Speaker System by David B. Weems, 4th ed.
If your amp will really put out 1750 watts per channel on 8 ohms, then you will need to provide some sort of limiter between source and amp input to keep from blowing up or ripping the suspension of a 1000 w rated driver. Going beyond xmax 12 mm is risky, as is excessive energy in the bands outside what the speaker will reproduce, below 40 hz & above 2 khz.
If you really want to shake bellies with 20-100 hz, suggest you buy something like a Eminence lab15 in their suggest box, on a dedicated sub amp. You only need one channel of that, the room dimensions are likely smaller than the wavelength so stereo is a fantasy. Packaged crossover appliances from Peavey, Rane, Nady, sum the two channels and provide a single sub output. They also filter subsonics out of stereo top feeds to keep from ripping suspensions due to microphone drops, stage vibrations from feet, or whatever. I picked up one used for $50 and use it to prevent huge excursions of my woofer due to me walking across the wood floor with a needle on the LP of a turntable. Ripped a 10" woofer spirals that way.
Happy designing & building. If you don't want to build, your case dimensions & port size suggest what your performance will be.
Vas 149.7 L, Qt .31 Fs 37.3 hz . Plug those in any sim software and see what size box it recommends. Qt .31 suggests only vented cabs are supported. AES power 1000 w (pinknoise) frequency recommendation from the manufacturer is 30-500 hz. Freq response rolls off above 2000 hz and 6 db/octave below 90 hz. Apply appropriate frequency conttol from signal source to the power amp or LCR crossover components in the box itself. Pick your lower freq limit. Rock/pop music, few manufacturers support lower than 40 hz. Organ notes can go to 20 hz which this driver cannot.
Obviously limiting volume of box limits performance of the system. David Weems charted volume factor for Qt=.31 is 0.55. so optimum box size is .55+Vas is 82 liters. Remember when calculating box size, use inside dimensions, and subtract the driver volume, 1 L and volume of any crossover components and damping inside the box.
Mr. Weems suggest Fb (3 db point) Tuning factor per Mr. Weems is 1.2. So 1.2*Fs is 44.8 hz . A nice drop off point for rock or pop.
Port area is suggested 1/7 of cone area, so 855 cm^2 is 122 cm^2 . The biggest port chart in the book is 10 cm diameter or 78.5 cm^2. A port of that diameter should be 9 cm long to tune to 40 hz.
This is per Designing Building and Testing Your Own Speaker System by David B. Weems, 4th ed.
If your amp will really put out 1750 watts per channel on 8 ohms, then you will need to provide some sort of limiter between source and amp input to keep from blowing up or ripping the suspension of a 1000 w rated driver. Going beyond xmax 12 mm is risky, as is excessive energy in the bands outside what the speaker will reproduce, below 40 hz & above 2 khz.
If you really want to shake bellies with 20-100 hz, suggest you buy something like a Eminence lab15 in their suggest box, on a dedicated sub amp. You only need one channel of that, the room dimensions are likely smaller than the wavelength so stereo is a fantasy. Packaged crossover appliances from Peavey, Rane, Nady, sum the two channels and provide a single sub output. They also filter subsonics out of stereo top feeds to keep from ripping suspensions due to microphone drops, stage vibrations from feet, or whatever. I picked up one used for $50 and use it to prevent huge excursions of my woofer due to me walking across the wood floor with a needle on the LP of a turntable. Ripped a 10" woofer spirals that way.
Happy designing & building. If you don't want to build, your case dimensions & port size suggest what your performance will be.
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The Fane 15XS TS parameters are close enough to the B&C TBX100 that the Tham 15 tapped horn was designed around that it should work OK in that enclosure.
The Fane 15XS has less Bl (magnetic strength) than the TBX100, so the bottom may start to roll off a bit higher than 50Hz.
The Tham will give you lots of thump, but not much below it's Fb of around 45Hz.
If you want to trade more bottom end for upper output, a bass reflex tuned around 36Hz of similar size would be a good choice.
The port size Indianajoe suggested may be OK for a 15" driver with 2-3mm Xmax (typical when Weems wrote his book), but way too small for a 15" driver with 12mm Xmax, the small slug of air would blow right out of the port and whistle at high power instead of making useful bass output.
The ports in your Devine Artis B15 (if it has ports..) are made for a driver with far less excursion than the Fane 15XS, so are likely undersized for it.
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Thank you both for your excellent reply’s, Indianajo as much as I appreciate your answer it just made my head explode , Walters’s exactly what I was after, yes I understand about port size I do get a lot of port noise 4x2” ports, fane suggests 4x4” port for the 15XB so I guess that will be my first port of call, would a port length of 12” get me to 37hz I know there’s probably other variables that would effect port size for hz tuning.
Post #2 is about building a conventional bass reflex design for the Fane15xs. Further research indicates the Tham15 is something you build out of plywood, not something you have bought. https://www.diyaudio.com/community/threads/building-a-pair-of-tham15-subs.265561/
Tham15 has a long organ pipe folded up in the box for better low bass response. More complicated carpentry than I want to attempt for my first speaker project. In that case the vent is the folded channel covered in the tham15 plans, not something in the corners of the front of a simple box. Picture of plans in that link indicates Tham15 was designed by Anders Martinsson although I didn't see a link on the first page.
As I said in post # 2, 78.5 cm^2 of a 10 cm diameter port is smaller than the 122 cm^2 required for a 15" woofer by the 1/7 area rule. Two would be too big, possible Xmax violations at high power. David Weems does not say what you do for port length when you have two ports instead of one.
2" port would be 20.2 cm^2, by 1/7 area rule 6 of those would be required. 82 l box would be 2.87 cuft . Weems Table 5-2 suggest 30 hz tuning with one 2" port would be 1.34" and there is no answer for 35 hz. The 4" diameter port table 5-4 suggest one such port on a 2.75 cu ft bass reflex enclosure would be 6" long for 35 hz tuning.
Tham15 has a long organ pipe folded up in the box for better low bass response. More complicated carpentry than I want to attempt for my first speaker project. In that case the vent is the folded channel covered in the tham15 plans, not something in the corners of the front of a simple box. Picture of plans in that link indicates Tham15 was designed by Anders Martinsson although I didn't see a link on the first page.
As I said in post # 2, 78.5 cm^2 of a 10 cm diameter port is smaller than the 122 cm^2 required for a 15" woofer by the 1/7 area rule. Two would be too big, possible Xmax violations at high power. David Weems does not say what you do for port length when you have two ports instead of one.
2" port would be 20.2 cm^2, by 1/7 area rule 6 of those would be required. 82 l box would be 2.87 cuft . Weems Table 5-2 suggest 30 hz tuning with one 2" port would be 1.34" and there is no answer for 35 hz. The 4" diameter port table 5-4 suggest one such port on a 2.75 cu ft bass reflex enclosure would be 6" long for 35 hz tuning.
This is the design from Fane it doesn’t actually say a port length only the diameter, this enclosure is for the 15XB not the 15XS they don’t list anything for the 15XS I did email them but still awaiting a response from their technical team. The idea of me building THAM15 came from speakerplans.com as the compact design fitted our needs of storage but like many things the more investigation I did the more unsure I became, my plan for now is to play with the port sizes in the Devine enclosures and hopefully I can find the sweet spot and if not then I’ll build some THAM15
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https://www.yumpu.com/en/document/read/27695830/compact-125-litre-cabinet-for-1-x-15a-driver-fane
The four 100mm (4" drainpipe") cutout ports in the cabinet posted in #6 are 162mm long.
The four 100mm (4" drainpipe") cutout ports in the cabinet posted in #6 are 162mm long.
Well I’d like to give you an update, I just couldn’t get them to sound nice in the reflex cabs so got all the materials to make the tham15 and oh my days all I can say is we’re over the moon with the sound output, I’d like to thank you all for your input and this forum for giving me the confidence to build these monsters, I doff my hat to you all keep on building 👌
