Yes. Here's a fourth order high pass at 50Hz comparison between Butterworth and Bessel, measured at 50Hz driven by a not so realistic single cycle, to show that.
OK, I get you, that makes sense. At least no cone overshoot that is somehow being damped. In that sense you are the one that has it right.
Indeed, it's fine. We integrate over a certain time so it doesn't so much matter what a single frequency looks like, we respond to the overall amount to determine loudness. For humans, one cycle of bass isn't enough to properly register it.
I can use an unrealistic single cycle to show what would happen at a sharp ending of the stimulus. Even when looking at 25Hz or 100Hz, the remainder rings out at the filter frequency of 50Hz under control of the damping, and at low level all the same.
I can use an unrealistic single cycle to show what would happen at a sharp ending of the stimulus. Even when looking at 25Hz or 100Hz, the remainder rings out at the filter frequency of 50Hz under control of the damping, and at low level all the same.
Well, if anyone was curious to have a look at the Duelund 100v capacitors, here is a post Duelund made on Facebook talking about the ones that they made for the Elsinores. It looks like they will be radial. They also look to be small enough to fit onto the PCB!
I should hopefully have mine soon. 🙂
I should hopefully have mine soon. 🙂
oooh. a nice radial cap looks so nice in an exposed crossover, with the messy point to point wiring hidden on the other side of the mounting board.
Try tell that to people who are into 1st order loudspeakers.
John Atkinson was asked about this and he said that it should not matter at all. Yet he still heard that 1st order loudspeakers done well had a sound that was "accessible" and that he really liked it.
But any answer he had, he said, was likely to be wrong. How refreshing to hear that. But what if they are looking in the wrong place, that the acoustic phase is not the reason, but rather that the answer is on the electrical side, and not the acoustic side. Then time integration is no issue at all. The answer is lower distortion, and that if we look for it we can actually measure it as distortion.
This is the step measurement of the famous/infamous Spica TC-50/60, I am sure you remember:
It is the electrical attribute of a 1st order filter that leads to the above result, that is they key. Not the step response in itself.
I have heard these Duelunds, if you look back earlier. It was 'tinned' and that does add a certain brilliant, in a nice way, character to the sound. I liked it. But I also liked the Miflex which is copper only. But Duelund also does a non-tinned version and it is less expensive. I haven't heard that one. But the Miflex can be made to just fit on our black crossover PCB because of size and it is axial. The tinned Duelund were wired off-the-board into a another pair of Elsinores here in Sydney and the owner is very happy. They were adhered to the inside wall and high quality extension wires were added.
The Duelunds did add something special to the Elsinore's. Unfortunately my Oppo 205 is currently not working, so I've been unable to truly experience the difference in my home setup. I switched from the True Copper Max. Also the Miflex capacitors in Joe's Elsinore's and in his 2-way standmounts appeared to extend
the sound stage
.
Only recently discovered this project and found it interesting, I seen there is 3 variations. The "ULD" would be out of the question for me personally with driver cost and such, however the other two are doable. If my amplifier does 150 wpc into 8 ohms and 300 watts into 4 ohms, would the NBAC version be worth it over the MFC. Outside of power requirements, what is the differences here?
Re: MFC version, a few months ago I was casting nasturtiums on the MFC’s ability to do the higher mid region well. I owe Joe & SB an apology; recently while playing tweeter roulette with some of my unused projects, I revamped the xover for my SB15MFCs, and was overwhelmed by the result, they now match the sound of my reference speakers, and their slightly lower sensitivity matches my woofers better!! Essentially, I just used a small inductor (~.3mH) to even out the peak at ~6Khz, & used a 3rd order filter on the SEAS tweeter I’m using...Cheers
Right now I don't have a pair of "MFC" and have got the "ULD" and "NBAC" here - and lately I have been listening to the "NBAC" and if anyone comes around to listen to a pair, that will be it and not the "ULD" because it is so expensive. I am really loving the "NBAC" right now and since the drivers are only a fraction of the "ULD" drivers, I can listen to both with huge enjoyment. My system right now has never sounded better. I use a 35W/channel Triode Tube amps with their soft clipping easily sounds like 100 Watt.
In your case, I would be leaning towards the "NBAC" and to describe the sound is always a difficult thing. The "MFC" I am sure you would be happy with, but the "NBAC" reminds me of listening to ribbons but without the problems. The late Allen Wright was a ribbon guy and had Apogees when he lived in Australia and also when he moved to Europe, these being dipole speakers, so I got to hear them a fair bit, but he had a large room to go with them. Maybe the "NBAC" also just shades the other Elsinores in the bass. It can really put it in the room.
One thing, you must go for the Miflex or similar quality C1 cap on the Tweeter. Not cheap, but the ribbon like comparison requires that, not just for the treble but for the soundstage as well. I just checked HiFi Collective website and the have six left. I don't know if anybody has any, but they are worth the money.
https://www.hificollective.co.uk/catalog/miflex-kpcu03-1-8uf-250v-kpcu-copper-foil-capacitor.html
The "NBAC" drivers down here is slightly more expensive than the "MFC" and I am still surprised that I have used aluminium drivers. But this driver is so well behaved when it reaches its break-up mode, so surprising and it made it possible. The crossover is also slightly lower than the others. 2.6KHz versus 3KHz. It just where it wanted to be. It means I can use a large inductor and it pays off.
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would a version with MFC for bass and NBAC for mids combine best of both? higher sensitivy and clarity.
No, that would definitely not work. This is a 2.5-Way design and the driver sensitivity must be the same for all four drivers and 3dB is a lot.
I am simply talking about the fact that I foresee difficulties and that there is no reason/incentive. The 3dB is about the difference in overall sensitivity difference between MFC and NBAC.
Now for something really intriguing and may explain something about the Elsinores.
"Seemingly Reduced Mms"
https://purifi-audio.com/blog/app-notes-2/side-effects-of-passive-crossover-filters-17
Now for something really intriguing and may explain something about the Elsinores.
"Seemingly Reduced Mms"
https://purifi-audio.com/blog/app-notes-2/side-effects-of-passive-crossover-filters-17
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You are not alone 😉
But I have never listen a SB alu cone, some trauma in the past, I avoid this cone material.
I would call this a satori version ????
I know, I thought the same.
But this driver is truly different and it was a friend that bullied me into it. That is when Troels Gravesen posted a comparison (or rather it was brought to my notice) that he had compared three SB17 drivers. In my discussion in his house, it was clear that he thought I should have gone with the MFC driver in the Elsinores and not the NRX. The MFC in his opinion suits 1st order and the Elsinores are electrically 1st order. To him the NRX needed at least 2nd order but I went with it anyway. But then the original NRX was discontinued and then had little choice and now we are actually using the MFC. But what about the NBAC then? Troels recognised with his MLS signal test (sounds like a noise) that the NBAC did not have that mechanical sizzle of metal hard cones. In fact he thought the test setup was faulty, only to realise that this was an aluminium driver without the sizzle.
Let me see if I can find the link... here it is, it makes an interesting read:
"Frankly, I never thought I'd do a speaker from all aluminium (cone) drivers. My most recent experience dates back some 10 years and the midbass was harsh on my ears. Later the manufacturer modified the drivers (cone curvature) for better performance, but I never got around to doing them again."
"When I first set up this SBA driver and turned on the MLS signal from the CLIO I thought I'd done something wrong - or was suffering temporary loss of high-frequency hearing . Well, I hadn't. Usually you can hear from the very MLS signal if a driver is trouble or if it's smooth on the ear. This SBA driver was smooth on the ear. Apparently the cone design with the ribbed imprints does its thing in reducing cone break-up. I even found a manufacturer using the 8" version as midrange driver i a 3-way system up to 1800 Hz! Quite a bold choice I'd say."
http://www.troelsgravesen.dk/SBAcoustics-61-NAC.htm
My hat's off to Ulrik Schmidt, the designer of this driver.
There is another thing, by dropping the crossover frequency just a little bit, I was able to use a series 1.8mH on the two upper drivers. This large value goes a long way to subdue a voltage inside the voice coil that leads to distortion in a similar way that "current-drive" also does subdue. Effectively all the drivers benefit as the bottom two drivers use 4mH. Not all will agree, but I reckon I am getting the results that prove it. And I am working on measurements right now that I believe proves it.
I am getting a very liquid and flowing sound from these aluminium drivers, but they need more than twice the power of the "ULD" Elsinores, but in their own way are competing. Trust me, that from me is high praise indeed.
Are the True Copper Max caps not recommended any more, I.e., better performance can be had with Miflex/Duelund? The TCM caps were in the same price range, so curious what’s missing with them. 🙂
I have gotten a nice liquid sound out of hard cone drivers before. It takes a good design to make that happen. There seems to be a fine line between liquid and harsh when it comes to hard cone drivers. When you hear a Leslie organ in a recording and the sound just floats in front of you while having a liquid texture to it, it is something else. You can feel it's grip in the room. I have listened to a lot of speakers and some do it, others just simply do not...
When you mentioned that the NBAC sounded fruity, I took that for maybe a bit more vivid sounding? Maybe a bit more holographic? I will have a pair of speakers with ribbon tweeters going fairly soon. So maybe I can get an idea of what you are trying to describe.
As far as soundstage depth, do you hear a difference between the ULD, NBAC and MFC? The soundstage on the NRX seen to me at about the depth of the speakers, maybe a bit behind the speakers in some cases. However, the midrange is detailed and bold which I think is really fun!
When you mentioned that the NBAC sounded fruity, I took that for maybe a bit more vivid sounding? Maybe a bit more holographic? I will have a pair of speakers with ribbon tweeters going fairly soon. So maybe I can get an idea of what you are trying to describe.
As far as soundstage depth, do you hear a difference between the ULD, NBAC and MFC? The soundstage on the NRX seen to me at about the depth of the speakers, maybe a bit behind the speakers in some cases. However, the midrange is detailed and bold which I think is really fun!