I bought a set of 4 drivers
Aura NS6-255-8A 6" Paper Cone Neodymium Magnet Woofer
Specifications: *Power handling: 50 watts RMS/100 watts max *VCdia: 1" *Impedance: 8 ohms *Re: 6.0 ohms *Frequency response: 55-5,500 Hz *Fs: 55 Hz *SPL: 91 dB 1W/1m *Vas: 0.58 cu. ft. *Qms: 10.8 *Qes: 0.58 *Qts: 0.55 *Xmax: 3.9 mm *Dimensions: Outside diameter: 6-1/8", Cutout diameter: 5-3/8", Depth: 3-3/8".
Response attached.
That said, I've considered.
For what its' worth,
Thanks in advance
Aura NS6-255-8A 6" Paper Cone Neodymium Magnet Woofer
Specifications: *Power handling: 50 watts RMS/100 watts max *VCdia: 1" *Impedance: 8 ohms *Re: 6.0 ohms *Frequency response: 55-5,500 Hz *Fs: 55 Hz *SPL: 91 dB 1W/1m *Vas: 0.58 cu. ft. *Qms: 10.8 *Qes: 0.58 *Qts: 0.55 *Xmax: 3.9 mm *Dimensions: Outside diameter: 6-1/8", Cutout diameter: 5-3/8", Depth: 3-3/8".
Response attached.
- The basic idea is to build a pair of 2.5 way speakers for music (not home theater) using the 0.5 driver to remove the need for BSC. The listening room will probably be small to medium depending on where they end up living.
- Without considering crossover design and choice of tweeter at this point, what I'd like advice on are the possible bass alignments. Iv'e got plenty of sub drivers lying around if absolutely needed, but I'd like to extract the most from the aura's. A solid in room 40 or lower Hz IF POSSIBLE.
- Enclosure size is not an issue, as my spouse doesn't mind larger speakers.
- Ampllfier - can be built depending on the speaker requirements, but I'd like to use my 7 watt push pull 2A3 amp if possible.
- Impedance - 4 or 8 ohm nominal is accaptable.
That said, I've considered.
- Sealed - not in favour of this due to the high crossover point.
- Aperiodic - considering MAPD ( North Creek Music's new MAPD driver loading ) but haven't ever tried it before so can't comment
- Reflex - preliminary . WinISD sims indicate I can get to 40 Hz easily with a bass reflex, though I can't say what this translates to in reality.
- negative taper TL
- MLTL
- BVR
For what its' worth,
- I have a licensed version of MJK's mathcad models that I will use but before starting down that track, I'd like to solicit some opinions on the best alignment / combination of alignments. I'm leaning towards TL, MLTL or Aperiodic
- I'm considering developing a 2 way series crossover in parallel with the augmenting 0.5 driver - but that's something to be tackled at a later time
Thanks in advance
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I looked at the pdf and noted it showed a single woofer,
Knowing little about TLs, won't the 0.5 woofer demand a change to the dimensions or is it an issue?
Good to see a design for the Aurasound closeout woofers, I use their 5.25" NRT woofers in my center channel and they timber match to my Infinity Overtures very well. It is a 2.5 way design with four 5.25" woofers and a 30mm dome tweeter XO'd third order at ~1750Hz.
Looking forward to seeing the results of your 2.5 way TL, those 6" woofers have great efficiency and hope they have great sound to match.
Knowing little about TLs, won't the 0.5 woofer demand a change to the dimensions or is it an issue?
Good to see a design for the Aurasound closeout woofers, I use their 5.25" NRT woofers in my center channel and they timber match to my Infinity Overtures very well. It is a 2.5 way design with four 5.25" woofers and a 30mm dome tweeter XO'd third order at ~1750Hz.
Looking forward to seeing the results of your 2.5 way TL, those 6" woofers have great efficiency and hope they have great sound to match.
Yes, I intend to build a separate cabinet for the 0.5 woofer.
Here too, there are a couple of possibilities
- An identical cabinet alignment to the main woofer
- A complementary response to acoustically even out the peaks and dips in the main woofer response, within the 0.5 woofer's passband. Here's an example (though for an MTM dual T-Line) Nike Transmission Line Loudspeakers
Hi,
Some quick modelling in Win ISD indicates 50L for two drivers vented at
40Hz gives - 3dB at 45Hz, -4dB at 40Hz, -6dB at 35Hz and -10dB at 30Hz.
Roll off is quite shallow down to the knee at 35Hz, it an alignment suited
to low power, as it has much high efficiency in the lower bass compared
to sealed. How big ~ in box volume in the TL ?
rgds, sreten.
Some quick modelling in Win ISD indicates 50L for two drivers vented at
40Hz gives - 3dB at 45Hz, -4dB at 40Hz, -6dB at 35Hz and -10dB at 30Hz.
Roll off is quite shallow down to the knee at 35Hz, it an alignment suited
to low power, as it has much high efficiency in the lower bass compared
to sealed. How big ~ in box volume in the TL ?
rgds, sreten.
Here are a couple more simulations. The first is a tapered TL, somewhat better than the last one I posted. My concern is that despite my best efforts, it doesn't seem significantly better than the infinite baffle response trace).
The second one is an MLTL . . This curve seems more promising but the size seems unreasonable, in view of the fact that I'm considering adding another aura as a 0.5 woofer (though it may not be needed if a single driver can really dig this low with authority - though I have my doubts). This sim becomes impractical if I have to double up on the size to accommodate a 2nd 0.5 driver.
Comments / optimizations on my simulations ?
The second one is an MLTL . . This curve seems more promising but the size seems unreasonable, in view of the fact that I'm considering adding another aura as a 0.5 woofer (though it may not be needed if a single driver can really dig this low with authority - though I have my doubts). This sim becomes impractical if I have to double up on the size to accommodate a 2nd 0.5 driver.
Comments / optimizations on my simulations ?
Attachments
Hi,
Simple fact is you have a 0.55 Qts driver with an Fs of 55Hz.
This simply means it wont go low without big boxes of any sort.
Vas - 16.5L, I mentioned 50L-40Hz vented for 2 of them. Vbox > Vas
is never a good sign, it means your chasing your tail, trying to make
something do something its not ideally suited to, or designed to do.
Vented box IMO is the best "compact" solution for low driving power.
TL's may get you lower, but need more power, so here not so good.
rgds, sreten.
Simple fact is you have a 0.55 Qts driver with an Fs of 55Hz.
This simply means it wont go low without big boxes of any sort.
Vas - 16.5L, I mentioned 50L-40Hz vented for 2 of them. Vbox > Vas
is never a good sign, it means your chasing your tail, trying to make
something do something its not ideally suited to, or designed to do.
Vented box IMO is the best "compact" solution for low driving power.
TL's may get you lower, but need more power, so here not so good.
rgds, sreten.
Point taken. Been there / done that with EBS alignments before.
If I can nail down a concrete design, I hope to be building test boxes this week. Otherwise, the project will have to wait till early October, on account of some other stuff.
What parameters did you use with your suggestion (enclosure size, port dimensions)? My WinISD sims. for 2 drivers suggest 100 liter box, single 4" Dia x 3" L vent ). Deviating too much from this, things start looking boomy.
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Hi,
100L is a ridiculous volume for two 6.5" drivers total Vas around 33L.
I got a decent roll off shape for two drivers with 50L and 40Hz tuning.
(numbers given earlier). Making the box bigger makes it boomier.
rgds, sreten.
Hi Ken,
1. I got the 8 ohm versions
2. Yes, I've seen teh recommended reflex box dimensions
Huh? I didn't know there was an 8ohm 8 inch. Mind must be stuck on 6.5's I see...
Anyways I looked at them 6.5's many times as possible 4x4 with tweeter in center.
Always same conclusion, Qts and Vas too high for anything but baffles and boxes.
No Karlson, Horn, PPSLs, or anything else whats gonna load em down further...
They simply lack the motor strength to do anything more than direct radiate.
I would be bored of that configuration before a project ever started.
The 8inch Auras (not 8 ohms) have a much lower Qts, and very high BL product.
Maybe could do stuff much more interesting...
Anyways I looked at them 6.5's many times as possible 4x4 with tweeter in center.
Always same conclusion, Qts and Vas too high for anything but baffles and boxes.
No Karlson, Horn, PPSLs, or anything else whats gonna load em down further...
They simply lack the motor strength to do anything more than direct radiate.
I would be bored of that configuration before a project ever started.
The 8inch Auras (not 8 ohms) have a much lower Qts, and very high BL product.
Maybe could do stuff much more interesting...
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My bad, I was tired, but regardless, look at the upper frequency limit of the 8" driver you posted - not impressive
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