Nautaloss enclosure for 8in Dayton Sub?
Hi X,
Time for the next FC build. I have a Dayton SD215A-88 8" DVC Subwoofer that I'd like to put to use. I like the idea of the Nautaloss enclosure, but based on some discussion in previous posts I'm not sure how suitable this driver would be: Fs=31, Qts=0.39 and Vas=1.35. It would be used for music, not HT and no need to shake the house. Your thoughts?
Cheers!
Hi X,
Time for the next FC build. I have a Dayton SD215A-88 8" DVC Subwoofer that I'd like to put to use. I like the idea of the Nautaloss enclosure, but based on some discussion in previous posts I'm not sure how suitable this driver would be: Fs=31, Qts=0.39 and Vas=1.35. It would be used for music, not HT and no need to shake the house. Your thoughts?
Cheers!
Dayton DVC woofer in Nautaloss
Grandcalmar,
The driver actually can produce some decent bass in a Nautaloss. You are limited by what SPL you can achieve due to the moderate sensitivity and 6 mm of xmax. if you are OK with a max SPL of 90 dB at 45 Hz (peak SPL is 97 dB, and -3 dB point is 67 Hz) then this can work. It makes very smooth clean bass, and some attenuation EQ from 50 Hz on up to keep it around 92 dB can work.
Here are is the SPL at 12 volts rms corresponding to xmax, cone displacement, impedance, and impulse. If interested I will get you dimensions for Nautaloss spiral.
Grandcalmar,
The driver actually can produce some decent bass in a Nautaloss. You are limited by what SPL you can achieve due to the moderate sensitivity and 6 mm of xmax. if you are OK with a max SPL of 90 dB at 45 Hz (peak SPL is 97 dB, and -3 dB point is 67 Hz) then this can work. It makes very smooth clean bass, and some attenuation EQ from 50 Hz on up to keep it around 92 dB can work.
Here are is the SPL at 12 volts rms corresponding to xmax, cone displacement, impedance, and impulse. If interested I will get you dimensions for Nautaloss spiral.
Attachments
Grandcalmar,
I revised the design a bit to reduce the size and volume which actually gives a little more max SPL. Here is the profile of the sealed TL, your task is to take this linear profile and roll it up to a spiral however you can. This gives you some room for creativity with how you want to make the final outer envelope.
Starting from the driver face.
10 in tall x 4 in long
7 in tall x 6 in long
5 in tall x 24 in long going to a point (sealed tail end for 34 in long TL)
The internal width is 8.5 in
This design can take max of 14 volts rms. Here is SPL at 14 volts, and I think it improved the impulse response somewhat.
I revised the design a bit to reduce the size and volume which actually gives a little more max SPL. Here is the profile of the sealed TL, your task is to take this linear profile and roll it up to a spiral however you can. This gives you some room for creativity with how you want to make the final outer envelope.
Starting from the driver face.
10 in tall x 4 in long
7 in tall x 6 in long
5 in tall x 24 in long going to a point (sealed tail end for 34 in long TL)
The internal width is 8.5 in
This design can take max of 14 volts rms. Here is SPL at 14 volts, and I think it improved the impulse response somewhat.
Attachments
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Hi guys, interesting thread!
I have one off-topic question, if I may: the name Nautaloss, where does it come from? I know the Nautilus speakers of course - is this some kind of wordplay?
Not trying to troll, but this has buzzed in my head several days now, I just want to know! 🙂
Jan
I have one off-topic question, if I may: the name Nautaloss, where does it come from? I know the Nautilus speakers of course - is this some kind of wordplay?
Not trying to troll, but this has buzzed in my head several days now, I just want to know! 🙂
Jan
If you build it and it doesn't work out it's "not a loss". No big deal. 😉
The resemblance to a marine animal called the chambered nautilus is also the inspiration.
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Byrrt,
Have you had a chance to so the tests with the DEQ2496, the different filters in Jriver, and I think you were going to try a dual USB DAC as a XO with Jriver?
Where can I hide 😡... NO xrk971 and others sorry have overloaded myself (mostly my job
). More excuses is i haven't used REW before therefor short time spent only done setup and exercised until now (wonna report serious) + cables under construction 
because very weird 
plug combinations needed for these setups. Expect tomorrow 
some or most will be posted.
If interest, speaker setups/drivers doing squarewaves.
01 - Download and read the attached Square_Wave.pdf (Midfi/lowfi driver doing squarewaves).
02 - Read the link and/or maybe download http://www.bodziosoftware.com.au/Attributes_Of_Linear_Phase_Loudspeakers.pdf
03 - Download and read the attached three zipped XPS documents to be read from no 1 to 3. (Huge 18" doing 20Hz squarewaves).
04 - Read the link and/or maybe download http://www.bodziosoftware.com.au/Pre_Post_Ringing_IR_And_Pulses.pdf
More goodies at Bodzio Software.
01 - Download and read the attached Square_Wave.pdf (Midfi/lowfi driver doing squarewaves).
02 - Read the link and/or maybe download http://www.bodziosoftware.com.au/Attributes_Of_Linear_Phase_Loudspeakers.pdf
03 - Download and read the attached three zipped XPS documents to be read from no 1 to 3. (Huge 18" doing 20Hz squarewaves).
04 - Read the link and/or maybe download http://www.bodziosoftware.com.au/Pre_Post_Ringing_IR_And_Pulses.pdf
More goodies at Bodzio Software.
Byrtt,
Really interesting work in these papers. Are these your studies? In the first paper I saw the ringing in the IR and it reminded me of the ringing in my Nautaloss sub woofer when I only had 2 drivers mounted conventionally. When I added to more drivers in a face-to-face (isobaric config) it removed the ringing and cleaned up the IR quite a bit. It sounds much better - and I wonder if it would reproduce a square wave better?
Here is the data - red is open baffle, blue is sealed spiral TL with conventional driver arrangement, green is the 4 drivers in isobaric mount:
I need to do some square wave tests...
Really interesting work in these papers. Are these your studies? In the first paper I saw the ringing in the IR and it reminded me of the ringing in my Nautaloss sub woofer when I only had 2 drivers mounted conventionally. When I added to more drivers in a face-to-face (isobaric config) it removed the ringing and cleaned up the IR quite a bit. It sounds much better - and I wonder if it would reproduce a square wave better?
Here is the data - red is open baffle, blue is sealed spiral TL with conventional driver arrangement, green is the 4 drivers in isobaric mount:
I need to do some square wave tests...
xrk971 No no not me at all it's all studies by Bodzio Software. Like you i think it's very interesting and even without having the cpu power and software used, one can use the knowledge to good understanding and bring best from what one have and dream for rest, those pulse response and square waves pictured are impressing and must be right way. Would have made links to his web for all four points but in hurry could only find two of them, but maybe my local docs are downloaded from his many posts at the REPHASE thread. Yes green IR is winner there, i have a closer look at your FR / IR plot tomorrow. Will return tomorrow when done some test to present.
A little thought mic + preamp amplitude/phase specs must influence much at how true the squarewave can be measured on a PC screen but neverless a compare between some tweaking is possible (which is best). Don't know yet if REW has oscilloscope, else suggest try free version TrueRTA from www.trueaudio.com which has both oscilloscope and generator, and developer is indeed a speaker builder.
A little thought mic + preamp amplitude/phase specs must influence much at how true the squarewave can be measured on a PC screen but neverless a compare between some tweaking is possible (which is best). Don't know yet if REW has oscilloscope, else suggest try free version TrueRTA from www.trueaudio.com which has both oscilloscope and generator, and developer is indeed a speaker builder.
Nautaloss Dayton Sub
X,
I finished the sub based off your design leads. I must say it was a lot more difficult not having your step by step play book for this one - but a good learning exercise.
I struggled with working out how to wrap the spiral until I came up with using a piece of rope and FC offcuts cut to the width of the channel. I used a lot of bracing and this was a rather time consuming step. Next time I would make use of the marked out first side to plan out and pre-cut the bracing pieces. This would save time as well as aid keeping the spiral sections perpendicular to the sides.
I packed the central hole (where the spiral terminates) with rockwool thinking this would help sound dissipation. I also contemplated perforating the sides on this central portion as is done with the tubes inside mufflers - do you think this would have any benefit?
I planned on using 3 thickness FC for the baffle, but low and behold I found a piece of 3/4 inch ply of exactly the right width in the basement - couldn't believe my luck!
I've only managed to fire it up once, but oh la la it rocks! No strange sounds and somewhat surprisingly there appears to be less enclosure resonance than the FC cornus so I think the innards are held together well. I'm looking forward to giving it a work out with the dual B3N Karlsonators.
Cheers!
X,
I finished the sub based off your design leads. I must say it was a lot more difficult not having your step by step play book for this one - but a good learning exercise.
I struggled with working out how to wrap the spiral until I came up with using a piece of rope and FC offcuts cut to the width of the channel. I used a lot of bracing and this was a rather time consuming step. Next time I would make use of the marked out first side to plan out and pre-cut the bracing pieces. This would save time as well as aid keeping the spiral sections perpendicular to the sides.
I packed the central hole (where the spiral terminates) with rockwool thinking this would help sound dissipation. I also contemplated perforating the sides on this central portion as is done with the tubes inside mufflers - do you think this would have any benefit?
I planned on using 3 thickness FC for the baffle, but low and behold I found a piece of 3/4 inch ply of exactly the right width in the basement - couldn't believe my luck!
I've only managed to fire it up once, but oh la la it rocks! No strange sounds and somewhat surprisingly there appears to be less enclosure resonance than the FC cornus so I think the innards are held together well. I'm looking forward to giving it a work out with the dual B3N Karlsonators.
Cheers!
Attachments
Grandcalmar,
I stand behind what I said earlier - you are a FC master craftsman! Beautiful work! Those spirals are so precisely laid out and clean. Glad it sounds great - good idea about laying out bracing before hand. That was indeed a time consuming step. I like how you integrated the plate amp! Very cool, very nice. Congratulations!
I stand behind what I said earlier - you are a FC master craftsman! Beautiful work! Those spirals are so precisely laid out and clean. Glad it sounds great - good idea about laying out bracing before hand. That was indeed a time consuming step. I like how you integrated the plate amp! Very cool, very nice. Congratulations!
Fountek FE85
X,
Thanks for the compliments. I'm having lots of fun but fear I'm heading down the Cal "Speakerholic" slippery slope - a FC slope of course!
I have a pair of Fountek FE85's that I'd like to work with next. Something wall mounted. The spec sheet indicates a relatively flat FR, but with a fairly steep roll off at ~ 130Hz, and decent sensitivity. Would the wall mounted MLTL work or would I need to go for a cornu for that bit of extra umph?
Cheers!
X,
Thanks for the compliments. I'm having lots of fun but fear I'm heading down the Cal "Speakerholic" slippery slope - a FC slope of course!
I have a pair of Fountek FE85's that I'd like to work with next. Something wall mounted. The spec sheet indicates a relatively flat FR, but with a fairly steep roll off at ~ 130Hz, and decent sensitivity. Would the wall mounted MLTL work or would I need to go for a cornu for that bit of extra umph?
Cheers!
Turbon,
Thanks. If you do try and have any questions, please don't hesitate to ask.
Cheers!
Grandcalmar,
Why don't you put the FE85's in a Nautaloss I fullrange top and use it with the Nautaloss Dayton sub? If you are looking for a wall mounted design - the flat MLTL reaches deeper in frequency than the Cornu but its output of bass SPL is less. I just measured mine with the TC9FD's and was surprised to find that it produces a flat bass shelf down to 40 Hz! I tuned it for 55 Hz but the Accidental MLTL effect brings it lower even. There is a 6 to 8 dB drop from the flat response which goes from 90 Hz to 18 kHz and there is the lower shelf from 40 Hz to 90 Hz. There is also the flat BIB wall mount.
Why don't you put the FE85's in a Nautaloss I fullrange top and use it with the Nautaloss Dayton sub? If you are looking for a wall mounted design - the flat MLTL reaches deeper in frequency than the Cornu but its output of bass SPL is less. I just measured mine with the TC9FD's and was surprised to find that it produces a flat bass shelf down to 40 Hz! I tuned it for 55 Hz but the Accidental MLTL effect brings it lower even. There is a 6 to 8 dB drop from the flat response which goes from 90 Hz to 18 kHz and there is the lower shelf from 40 Hz to 90 Hz. There is also the flat BIB wall mount.