Turbon,
Great news about the Vifa's arriving. Yes, they are nicely made little drivers with copper shorting ring, vented pole piece, vented spider basket, etc. Wait till you hear them. You need a helper woofer or sub woofer XO at about 150 Hz to 200 Hz for the Nautaloss to sound complete - as the sealed TL alignment has very little bass below 150 Hz. What will you use for the sub? Is Kapa board same as foam core?
Regards,
X
One more thing, if you do not plan to use them in a bi-amp config with DSP where you can tweak things at-will, having a baffle step compensation/shelf filter will be needed. Something like ~1 mH + 5 ohms + 0.47 uF all in parallel and then the whole thing in series with the positive terminal of the driver should work well.
Great news about the Vifa's arriving. Yes, they are nicely made little drivers with copper shorting ring, vented pole piece, vented spider basket, etc. Wait till you hear them. You need a helper woofer or sub woofer XO at about 150 Hz to 200 Hz for the Nautaloss to sound complete - as the sealed TL alignment has very little bass below 150 Hz. What will you use for the sub? Is Kapa board same as foam core?
Regards,
X
One more thing, if you do not plan to use them in a bi-amp config with DSP where you can tweak things at-will, having a baffle step compensation/shelf filter will be needed. Something like ~1 mH + 5 ohms + 0.47 uF all in parallel and then the whole thing in series with the positive terminal of the driver should work well.
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Hi X.
Yes, the Kapa board should be the same as your foamcore but the paper part seems to be a bit thicker almost cardboard...
I haven't thought a lot about how the setup will be in the end but Grandcalmars Dayton sub seems to be very nice - yes, something similar... Do you have a good woofer to recomend for use in such a design? We never listen at a volume much higher than ordinary speaking level. I do when I'm alone but that's not very often but then I wish the SQ is at its best at those occations
...
A vague plan is to use them in a 5.1 or 5 if the woofer part turns out right with cornus at center/back and nautalosses as front R/L including the woofers. The nautalosses should be possible to listen to in stereo - or I might use 5 cornus and nautaloss woofers - as you see nothing is decided yet - it is in a virgin state for now
Regards
Yes, the Kapa board should be the same as your foamcore but the paper part seems to be a bit thicker almost cardboard...
I haven't thought a lot about how the setup will be in the end but Grandcalmars Dayton sub seems to be very nice - yes, something similar... Do you have a good woofer to recomend for use in such a design? We never listen at a volume much higher than ordinary speaking level. I do when I'm alone but that's not very often but then I wish the SQ is at its best at those occations
...A vague plan is to use them in a 5.1 or 5 if the woofer part turns out right with cornus at center/back and nautalosses as front R/L including the woofers. The nautalosses should be possible to listen to in stereo - or I might use 5 cornus and nautaloss woofers - as you see nothing is decided yet - it is in a virgin state for now
Regards
Boards in southern Sweden...
Sorry to threadjack for one post...
Is there someone who is willing to split a pakage of 25 boards with me?
They are white, 100*70cm 5mm thick. I will keep 9 of them so two lots of 8 boards are to take and pay for. Thats 600 per lot. Pickup in Lund and nothing will happen until I got the money and this is a one time happening
PM me...
Regards
Sorry to threadjack for one post...
Is there someone who is willing to split a pakage of 25 boards with me?
They are white, 100*70cm 5mm thick. I will keep 9 of them so two lots of 8 boards are to take and pay for. Thats 600 per lot. Pickup in Lund and nothing will happen until I got the money and this is a one time happening
PM me...
Regards
Turbon,
I don't know what drivers are easily obtainable in Sweden, but I imagine much of the inexpensive woofers we can get from Parts Express and MCM may not be available there.
For budget version - I would look for something around 6.5 in to 8 in with a rubber surround, a Qts of at least 0.9 and an xmax of at least 3 to 4 mm. I would not spend more than $15 per driver. Something similar to this GRS:
https://www.parts-express.com/grs-8pr-8-8-poly-cone-rubber-surround-woofer--292-428
For nice version, get a Peerless 8 inch Nomex HDS 830869. It has a lower Qts but lower fs and lots of xmax that lets you EQ it.
https://www.parts-express.com/peerless-830869-8-nomex-cone-hds-woofer--264-1098
I don't know what drivers are easily obtainable in Sweden, but I imagine much of the inexpensive woofers we can get from Parts Express and MCM may not be available there.
For budget version - I would look for something around 6.5 in to 8 in with a rubber surround, a Qts of at least 0.9 and an xmax of at least 3 to 4 mm. I would not spend more than $15 per driver. Something similar to this GRS:
https://www.parts-express.com/grs-8pr-8-8-poly-cone-rubber-surround-woofer--292-428
For nice version, get a Peerless 8 inch Nomex HDS 830869. It has a lower Qts but lower fs and lots of xmax that lets you EQ it.
https://www.parts-express.com/peerless-830869-8-nomex-cone-hds-woofer--264-1098
Better system is to make it big to handle a 15 in pro audio woofer like this one with 12.5 mm xmax and 96 dB efficiency. Faital Pro 15HP1030. Foam core need not apply here - 3/4 in thick ply with bendable ply channels and lots of bracing.
https://www.parts-express.com/faitalpro-15hp1030-15-professional-woofer-8-ohm--294-1280
https://www.parts-express.com/faitalpro-15hp1030-15-professional-woofer-8-ohm--294-1280
Got the FC and drivers, plus made a slow start on the build. Hoping my Mum can find her Hot-glue gun, rather than me having to go buy one...
Picture 1: Cut and joined a few pieces of FC for the spiral. Stripped one side of the paper and foam leaving a single 1/2" strip on each panel to be joined. PVA takes a while to fully dry but creates a strong bond...Pre-curved FC & Faital Pro 4FE32 and Vifa TC9FD.
Picture 2: Dagger shape is 32" long and a ~4" base, giving 5.3L. It took about 3hrs to create the spiral shape using the circles from the dagger. However, its spot on with 15mm walls and can be used to make an MDF template... From the centre of the red circle to the straight edge [baffle front] is ~4.5", giving a 36" path length once the baffle is in place. Baffle height is ~9"... Overall depth & height ~10.75" x 12" ... X, your 9" x 12" is a pretty good sizing, the Fibonacci spiral and normal spiral come close [one under, one over] ... Visually, I prefer the normal spiral shape.
Picture 1: Cut and joined a few pieces of FC for the spiral. Stripped one side of the paper and foam leaving a single 1/2" strip on each panel to be joined. PVA takes a while to fully dry but creates a strong bond...Pre-curved FC & Faital Pro 4FE32 and Vifa TC9FD.
Picture 2: Dagger shape is 32" long and a ~4" base, giving 5.3L. It took about 3hrs to create the spiral shape using the circles from the dagger. However, its spot on with 15mm walls and can be used to make an MDF template... From the centre of the red circle to the straight edge [baffle front] is ~4.5", giving a 36" path length once the baffle is in place. Baffle height is ~9"... Overall depth & height ~10.75" x 12" ... X, your 9" x 12" is a pretty good sizing, the Fibonacci spiral and normal spiral come close [one under, one over]
... Visually, I prefer the normal spiral shape.Attachments
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The sizing of the circles in the dagger shape are used to generate the shape of the spiral... Imagine all the other drawn circles within the spiral behind the red one, it just gives a known volume and a constant expansion of the spiral from point to end... Now it's laid out on the computer, I can just pull the dimensions needed to generate the template with no guess work Just me being ultra over the top
Just me being ultra over the top
BMS,
Ok I think I understand what you are doing - generating a linear expansion spiral ? Maybe not available in sketch up but any cad program lets you generate a linear spiral by specifying angular rotation span and rate of radial expansion and it makes it in one command. Just in case you need to make more in the future. Did your Mum find the hot melt glue gun?
Ok I think I understand what you are doing - generating a linear expansion spiral ? Maybe not available in sketch up but any cad program lets you generate a linear spiral by specifying angular rotation span and rate of radial expansion and it makes it in one command. Just in case you need to make more in the future. Did your Mum find the hot melt glue gun?
Now roughly 1/2 way through building the two FC speakers, using PVA at points really slows things down... Already cut one baffle for the Faital Pro 4FE32.Though not sure whether to build a matching pair, or the second with the Vifa TC9FD first. Then mod for the 4FE32 after measurements are made... hmm 
Will be interesting to see the polar plots for the 4FE32. It's cone is deeper than the Vifa's, so I'd guess it'd start to beam earlier than the TC9FD. Time will tell
Will be interesting to see the polar plots for the 4FE32. It's cone is deeper than the Vifa's, so I'd guess it'd start to beam earlier than the TC9FD. Time will tell
BMS,
I only use PVA on the last step of gluing the final side on. Otherwise it is hot melt glue all the way. Goes pretty quickly. You really should make a stereo pair so you can actually listen to them in stereo because the imaging is very eye opening. Go for the dual 4FE35's - that is what I would do. The TC9fD is nice but you will really get a good amount of airtime on them in the OB. Their polar performance will in all likelihood be better than the Faital's just because they are smaller. What are you using for the subs?
I only use PVA on the last step of gluing the final side on. Otherwise it is hot melt glue all the way. Goes pretty quickly. You really should make a stereo pair so you can actually listen to them in stereo because the imaging is very eye opening. Go for the dual 4FE35's - that is what I would do. The TC9fD is nice but you will really get a good amount of airtime on them in the OB. Their polar performance will in all likelihood be better than the Faital's just because they are smaller. What are you using for the subs?
Using PVA on a few joints that might look a little messy with the hot glue. Just about to reinforce the baffle on one, then it's ready to be wired, sealed and driver mounted. Second speaker isn't too far behind
A stereo pair with the 4FE35's it is... will be using the 8" Peerless sealed, with limited SPL, it'll do 20-250Hz... Furthermore, if I turn the cab upside down [driver closer to the floor] there should be a gain of ~6dB, rising from ~70Hz through to 350Hz and allow for a higher XO point
A 10" Nautaloss perhaps!?
A stereo pair with the 4FE35's it is... will be using the 8" Peerless sealed, with limited SPL, it'll do 20-250Hz... Furthermore, if I turn the cab upside down [driver closer to the floor] there should be a gain of ~6dB, rising from ~70Hz through to 350Hz and allow for a higher XO point
A 10" Nautaloss perhaps!?
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Why stop there? I think early in the thread I was helping someone else with an AE TDM15H driver for a woofer in a Nautaloss - it is pricey but would make a killer woofer with 14 mm xmax and fs of 20 Hz. AE Speakers --- Superb Quality, Unforgettable Performance, Definitely.
Although, now I see that there are other good candidates with lower price and the required specs: lots of xmax, a low fs, and a strong motor with shorting rings. Here is one with 14 mm xmax and an fs of 25 Hz, Qts of 0.49, in a 4 ohm 12 inch cast frame with triple shorting rings for $150. May be tough to get in UK though: https://www.parts-express.com/dayton-audio-rss315hf-4-12-reference-hf-subwoofer-4-ohm--295-464
Either of these in the stated sealed alignment volume but with Nautaloss spiral sealed TL and additional EQ in the low end to get the deep grunt bass at 25 Hz would work very well. Definitely need 18 mm side walls and probably bendy plywood or MDF for the curved channels.
This morning tried & measured one Nautaloss with a Faital PRo 4FE32... a slightly different spec to the 4FE35. Don't think the '32 is quite as suited to this enclosure as the '35 should be... will swap drivers and try the '35 tomorrow. Should have the second enclosure ready tomorrow also
Faital Pro 4FE32: IR wasn't as good as I was expecting, but the polar response looks good up to 4K then starts to become more directional, very similar to the Vifa TC9FD in the 14cm x 21cm OB. However, the '32 would need baffle step compensation and has a large peak at 8K.
Faital Pro 4FE32: IR wasn't as good as I was expecting, but the polar response looks good up to 4K then starts to become more directional, very similar to the Vifa TC9FD in the 14cm x 21cm OB. However, the '32 would need baffle step compensation and has a large peak at 8K.
BMS,
Great progress you are making - any photos? Yes, the FE32 is a lower Qts design and perfect for a more compact vented alignment as the Vb can be smaller. It will not have as good bass extension, however, if XO is at 200 Hz it should be good? I am surprised that the IR was not good though - are you getting reflections somewhere internally? Are you using stuffing inside the spiral towards the rear 2/3rds? It needs it to absorb that sound energy of the back wave.
Great progress you are making - any photos?
Yes, the FE32 is a lower Qts design and perfect for a more compact vented alignment as the Vb can be smaller. It will not have as good bass extension, however, if XO is at 200 Hz it should be good? I am surprised that the IR was not good though - are you getting reflections somewhere internally? Are you using stuffing inside the spiral towards the rear 2/3rds? It needs it to absorb that sound energy of the back wave.
For those wanting to build the budget Nautaloss sub, the 6.5 inch polycone woofers (https://www.parts-express.com/6-1-2-poly-cone-midbass-woofer-4-ohm--299-609)are now in stock at PE $3.99 ea for 25 or more (that will be a circa $100 order with free shipping). These drivers are great for a bunch of project including the slot loaded OB in this thread: http://www.diyaudio.com/forums/full-range/249984-cheap-fast-ob-literally.html.
Get them while they last - a great deal on a very nice sounding driver.
Get them while they last - a great deal on a very nice sounding driver.
No photo's yet, will make sure to take some before sealing the second enclosure. I've added stuffing and it looks close to your pictures, just wondering if I need to make it denser.
Plus something noted from the mMarS speakers I did. What looked like an early internal reflection in the IR was reduced somewhat as the driver's mounting screws were tightened, making the driver more secure. To tight and the LF HD increased as the basket was stressed. Possible that some of what was measured on my Nautaloss was down to the driver not being mounted firmly enough.
Few things to try
Plus something noted from the mMarS speakers I did. What looked like an early internal reflection in the IR was reduced somewhat as the driver's mounting screws were tightened, making the driver more secure. To tight and the LF HD increased as the basket was stressed. Possible that some of what was measured on my Nautaloss was down to the driver not being mounted firmly enough.
Few things to try
Having a down day today, feeling really tired so just chilling and trying to perk up a bit before work this afternoon...
Swapped out the drivers last night, so the 4FE35 is fitted, plus the second enclosure is ready to be sealed.
IR is from the 4FE32 at 50cm ... good but doesn't settle down as quickly as I'd expect. See how things look once I measure the 4FE35
Swapped out the drivers last night, so the 4FE35 is fitted, plus the second enclosure is ready to be sealed.
IR is from the 4FE32 at 50cm ... good but doesn't settle down as quickly as I'd expect. See how things look once I measure the 4FE35
