Hi percevel
I agree this has been a great rebirth. I like how EVA can be both routed into shapes if thick, or bended if thin.
The blue EVA looks pretty good. It is definitely better than the orange mats I have and looks similar to my 80kg/m3 yoga blocks. The kayak foam does look like EVA or PE (poly ethylene) and does look high density especially if it can be routed. And honestly EVA and PE are very close and share most of the same benefits with EVA being a bit more rubbery. Ultralon Foams | Ultralon Foam Group
I think if you can get over 100kg/m3 it should be good. My white foam is 110kg/m3 and Mattes black is 125kg/m3.
I was actually in Washington DC last week for some workshops and seminar and met up with XRK. I bought the RSS265hf from parts-express and XRK helped take delivery and then I brought it back in my suitcase. Hence only the one. If it works I might just pay for the $60 shipping to Japan next time. But it was great to meet XRK in person!
Cheers jeshi
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That's a great feel good internet story! 
For the Dayton, I do something similar when I go back to Canada, but now, they are starting to charge for even your first checked luggage. It's starting to look less interesting if I need to pay $50 for checked luggage. I might not even bother carrying some heavy boxes next time, and just let shipping do it for me!
Another name for MiniCell is cross linked polyethylene. It has this plush leather feel when sanded. Yes, less rubbery than EVA.
For the Dayton, I do something similar when I go back to Canada, but now, they are starting to charge for even your first checked luggage. It's starting to look less interesting if I need to pay $50 for checked luggage. I might not even bother carrying some heavy boxes next time, and just let shipping do it for me!
Another name for MiniCell is cross linked polyethylene. It has this plush leather feel when sanded. Yes, less rubbery than EVA.
EVA is a cross-linked form of ethylene. Ethylene vinyl acetate. In fact I think the white foam board I get here in Japan is actually a custom blend of PE and EVA. Some people call it EVA but the company keeps the actual formula a secret so it's probably not sure PE or pure EVA. I also think that depending on the manufacturer what you get that's called PE or Eva can be quite different both in terms of density and the actual chemical composition.
The low density EVA that I've seen like those cheap orange mats I bought or Crocs are very rubbery, while higher density EVA foams are more velvety. Maybe to construct the higher density they have to increase the ethylene content. But I've also seen cheap PE that is more rigid and approaching PET bottle like materials. You want flexibility and that velvety feel.
So that MicroCell is probably the same stuff that I and Mattes are using. But check the density. Sounds like a great material to explore if you can still get your hands on it.
Cheers jeshi
The low density EVA that I've seen like those cheap orange mats I bought or Crocs are very rubbery, while higher density EVA foams are more velvety. Maybe to construct the higher density they have to increase the ethylene content. But I've also seen cheap PE that is more rigid and approaching PET bottle like materials. You want flexibility and that velvety feel.
So that MicroCell is probably the same stuff that I and Mattes are using. But check the density. Sounds like a great material to explore if you can still get your hands on it.
Cheers jeshi
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Dear all,
judging from the pictures, the black microcell looks good. If it´s sandable and has a nice density, it should work well. Another simple test to look for material properties would be to simple press something into the material, does it come back to the original shape (after some time) or remains?
The velvet/suede finish finely sanded makes, in my opinion, for a very luxurious surface, feels and looks a lot more expensive than it is, and was one of the reasons to persuade me using this material. The suede surface should also be fine for any small reflections.
Personally, I would stay away from any brittle and rigid material.
All the best
Mattes
judging from the pictures, the black microcell looks good. If it´s sandable and has a nice density, it should work well. Another simple test to look for material properties would be to simple press something into the material, does it come back to the original shape (after some time) or remains?
The velvet/suede finish finely sanded makes, in my opinion, for a very luxurious surface, feels and looks a lot more expensive than it is, and was one of the reasons to persuade me using this material. The suede surface should also be fine for any small reflections.
Personally, I would stay away from any brittle and rigid material.
All the best
Mattes
New 6.5 and 8" coax drivers from TB.
Some are getting their hands on them right now... hoping to see some measurements soon.
TB new line of Coax FR drivers
Some are getting their hands on them right now... hoping to see some measurements soon.
TB new line of Coax FR drivers
Hi Perceval,
nice drivers, for sure. Someone has clearly been thinking about diffration from rings, steps, suspension etc., but has somehow given up at the basket, if I look at the false screw heads or whatever that is. Otherwise the attempt to have no mechanical problems on the path from tweeter to baffle seems logical. KEF does it in a quite similar way.
Looking forward to see real measurements of these devices, for sure our German magazines will have those in a short time.
Hi Jeshi,
I have attached some screenshots of OB simulations with an old AJ-Horn program (sadly, I´m not so savvy with all that software, but this old program has proved to be quite realistic on several occasions), with the RSS 265, the SLS 10, the Dipole 10 and finally, my Dipole 18 in a larger baffle, just as my flowers, to put things into perspective.
In no way this is intended to disencourage your use of the Dayton, or is intended as offense... I was interested myself in finding out how the Dayton compares to others.
Obviously, it was not intended for OB use... but for small subwoofers, as visible by the high MMS. The 2 other 10-inch candidates have only half the moving mass...
So, sorry for posting this, but of course these are only simulations...
All the best
Mattes
nice drivers, for sure. Someone has clearly been thinking about diffration from rings, steps, suspension etc., but has somehow given up at the basket, if I look at the false screw heads or whatever that is. Otherwise the attempt to have no mechanical problems on the path from tweeter to baffle seems logical. KEF does it in a quite similar way.
Looking forward to see real measurements of these devices, for sure our German magazines will have those in a short time.
Hi Jeshi,
I have attached some screenshots of OB simulations with an old AJ-Horn program (sadly, I´m not so savvy with all that software, but this old program has proved to be quite realistic on several occasions), with the RSS 265, the SLS 10, the Dipole 10 and finally, my Dipole 18 in a larger baffle, just as my flowers, to put things into perspective.
In no way this is intended to disencourage your use of the Dayton, or is intended as offense... I was interested myself in finding out how the Dayton compares to others.
Obviously, it was not intended for OB use... but for small subwoofers, as visible by the high MMS. The 2 other 10-inch candidates have only half the moving mass...
So, sorry for posting this, but of course these are only simulations...
All the best
Mattes
Hi Mattes,
Thanks for the simulations and no offense was made so no need to be sorry. I guess I am approaching my OB differently than yours. I am following the Linkwitz and gainphile approach where they will use a DSP to correct for bass loss rather than relying on a passive cross-over and the inherent parameters of the driver (mms, qts...). So for a DSP approach (like Linkwitz and gainphile) the important parameters are low distortion and large xmax to give room for bass correction without creating distortion.
Here are some simulations I did on the RSS265HF-4 and P830668. I am not trying to simulate baffle effects, just the driver properties. I use unibox and set a sealed box to 2000 liters. This should approximate the rear air volume of an open baffle in a room. I read about this trick a couple years ago, but I can't remember who told me it. I've done the same with 10,000L and 64,000L boxes (2m x 4m x 8m room) and unibox gives the same numbers as 2000L. Without DSP correction the RSS265HF and 830668 both give similar responses with an F3 of 42-43hz. But the RSS265HF-04 has much more xmax to allow for bass boosting via DSP correction. I've also include my actual measurement of my RSS265HF-04 in a baffle-less, no DSP, open-baffle configuration (bare driver) and it is not far off from the simulation with an F3 (3db down) around the 42-45hz point. And the distortion measurement is very well behaved.
With a linkwitz correction I should be able to recover the lost bass on the RSS265 and get 100db of flat response down to 30hz and an F3 of 25hz with still 100db of output. For my applications (nearfield monitor) I only need about 88-92db before my ears hurt, and for my room I will be happy with 40hz so I am well within the specification I am targeting and this should give me lots of headroom to keep very low distortion. The only thing bad about the RSS265HF compared to the 830668 is that it needs more power to get to 100db, but 5watts will give me 91db which should be about right for me.
Linkwitz had previously recommended the 830668 for his open baffle speakers but then switched to the SEAS L26RO4Y which has lower distortion and greater xmax. Gainphile followed after Linkwitz and searched for a cheaper solution and found the RSS265HF. I am certain the Acoustic Excellence drivers are excellent, but I honestly did not hear about them until you told me and they are 3-4x more expensive than the RSS265HF when I factor in shipping. My main nearfield monitor speakers are a 2way Satori MW16P with tweeter and the RSS265HF + fullrange is just an experiment. My previous experiments with fullrange drivers didn't convince me that I preferred it for my nearfield application (I preferred the Satori + tweeter 2way with perfect time alignment and phase crossover).
So I absolutely agree that your simulations and approach favor the low moving mass, but I think for my application the RSS265HF will give me extremely low distortion within the DB and LF extension I am targeting. I honestly don't think that either approach is better or worse than the other. Some people don't want a DSP and want Caps and Coils crossovers others are very happy with DSPs (when done properly).
cheers
Jeshi
Thanks for the simulations and no offense was made so no need to be sorry. I guess I am approaching my OB differently than yours. I am following the Linkwitz and gainphile approach where they will use a DSP to correct for bass loss rather than relying on a passive cross-over and the inherent parameters of the driver (mms, qts...). So for a DSP approach (like Linkwitz and gainphile) the important parameters are low distortion and large xmax to give room for bass correction without creating distortion.
Here are some simulations I did on the RSS265HF-4 and P830668. I am not trying to simulate baffle effects, just the driver properties. I use unibox and set a sealed box to 2000 liters. This should approximate the rear air volume of an open baffle in a room. I read about this trick a couple years ago, but I can't remember who told me it. I've done the same with 10,000L and 64,000L boxes (2m x 4m x 8m room) and unibox gives the same numbers as 2000L. Without DSP correction the RSS265HF and 830668 both give similar responses with an F3 of 42-43hz. But the RSS265HF-04 has much more xmax to allow for bass boosting via DSP correction. I've also include my actual measurement of my RSS265HF-04 in a baffle-less, no DSP, open-baffle configuration (bare driver) and it is not far off from the simulation with an F3 (3db down) around the 42-45hz point. And the distortion measurement is very well behaved.
With a linkwitz correction I should be able to recover the lost bass on the RSS265 and get 100db of flat response down to 30hz and an F3 of 25hz with still 100db of output. For my applications (nearfield monitor) I only need about 88-92db before my ears hurt, and for my room I will be happy with 40hz so I am well within the specification I am targeting and this should give me lots of headroom to keep very low distortion. The only thing bad about the RSS265HF compared to the 830668 is that it needs more power to get to 100db, but 5watts will give me 91db which should be about right for me.
Linkwitz had previously recommended the 830668 for his open baffle speakers but then switched to the SEAS L26RO4Y which has lower distortion and greater xmax. Gainphile followed after Linkwitz and searched for a cheaper solution and found the RSS265HF. I am certain the Acoustic Excellence drivers are excellent, but I honestly did not hear about them until you told me and they are 3-4x more expensive than the RSS265HF when I factor in shipping. My main nearfield monitor speakers are a 2way Satori MW16P with tweeter and the RSS265HF + fullrange is just an experiment. My previous experiments with fullrange drivers didn't convince me that I preferred it for my nearfield application (I preferred the Satori + tweeter 2way with perfect time alignment and phase crossover).
So I absolutely agree that your simulations and approach favor the low moving mass, but I think for my application the RSS265HF will give me extremely low distortion within the DB and LF extension I am targeting. I honestly don't think that either approach is better or worse than the other. Some people don't want a DSP and want Caps and Coils crossovers others are very happy with DSPs (when done properly).
cheers
Jeshi
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and I should say that my main living room system are Acoustat 1+1 fullrange electrostatic speakers (no crossover, fullrange single driver, 35hz-ish extension) driven by a single-ended tube power amp (GoldenTube SE-40), a solid state preamp (BalancedAudio Technologies VK20) and sourced mainly by a Victor direct drive turntable with MicroSeiki MA505 tonearm and various cartridges. So while my living room system is pure analog, my music-workstation is pure digital: Satori diy nearfield 2way monitors, TPA3116d2 class-D chip amps, miniDSP crossover/correction, focusrite firewire-audio interface, music workstation pc running DAW/DJ software like AbeltonLive or FLstudio). So I can appreciate many approaches to reproducing good sound and music.
cheers
jeshi
cheers
jeshi
follow up on my post #410. I did some quick linkwitz correction sims for the RSS265HF-4 OB. Decided a 20hz Q0.6 target (F3 24hz) might be a reasonable target since it only performs about a 5db lift. Here is the Linkwitz-transform bi-quad spreadsheet and then applying this correction in unibox. Even at 100db output it would get to 25hz before exceeding xmax and starting to induce distortion. I would never push that far, and with my typical 92db output I would be well below the xmax and probably keep the very low distortion that I measured even with the linkwitz correction bass lift added in.
Unfortunately things are getting busy for me (work, oboe concert coming up, Christmas season) so I'm not sure how much I will be able to devote to my speaker building, but I will let everyone know when I make some progress.
cheers
jeshi
Unfortunately things are getting busy for me (work, oboe concert coming up, Christmas season) so I'm not sure how much I will be able to devote to my speaker building, but I will let everyone know when I make some progress.
cheers
jeshi
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They celebrate Xmas in Japan?
They have decorations over here, but it's mostly the stores, trying to sell more stuff.
I'm the only house in my village with Xmas decorations and a tree.
Yes it's huge here, but it's not about Christianity, it's just the decorations, music and feelings. Lights and trees everywhere. It's really pretty. Yes it's also in the stores, but most stations will put up lights and trees. They even have a weihnachtsmarkt near Yokohama.
Not much snow in Tokyo but we usually get some in January.
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perceval, if you decide to come to Tokyo send me a message and we can meet up and I can show you around. January is also nice since Tokyo basically keeps the Christmas decorations up from Nov to about spring time in March (end of ski season). About the only strange thing about Christmas in Japan is that everyone (and I mean everyone) gets KFC chicken for Christmas dinner. Somehow the American Thanksgiving turkey (and some clever marketing by KFC) established the KFC-Christmas connection back in the 1970s. If you want KFC on CHristmas you have to go register, preorder (weeks ahead of time) and then you get a pickup window (like 1-2pm). And even then we see crazy queues at KFC around Christmas time. Strange and wonderful Japan Christmas tradition.
http://www.bbc.com/capital/story/20161216-why-japan-celebrates-christmas-with-kfc
http://www.bbc.com/capital/story/20161216-why-japan-celebrates-christmas-with-kfc
Hi Jeshi,
yes, different approaches, and of course this is a good thing. I also noticed your Acoustat´s being mentioned long ago, this must be a very nice system... also good to hear that you´re using a record deck and the nice MA 505!!! Which cartridges do you use?
I´ve also had large ESL fullrange panels (Capacity E 3, which will be mostly unknown out of Germany...) but, after the sad failure of same (by the way: someone needs a pair of failed Capacity ESL, to pick up in Northern Germany, to exchange with a few bottles of red wine?), decided to go the fullrange/basshelper direction.
Your goals, Jeshi, are not so far away from mine, quoting your 100 dB/25 Hz number. The difference is maybe that I would like to have that at listening distance, 2,5 metres, and some headroom above. Probably I didn´t succeed with 25 Hz, but with 30 Hz. I need a realistic level of acoustic instruments (piano, drums, upright bass) for the perfect illusion, and yes, a piano played full force will be very loud (and very difficult to reproduce...).
So, I needed a pair of 18-inch bass drivers in OB´s of app. 94 cm (acoustic) diametre, driven by a few hundreds of watts to achieve this and have some headroom, too.
The point is that I have a hard time to believe that a single 25 cm driver could do this as well, or could do the 100 dB at 1 m at 25Hz, no matter how much power you´re sending into it...
But of course, as you´re listening at low levels in the nearfield, a pair of 10-inchers, even in OB, appropriately corrected, will most probably fulfil your needs, and this is the important thing, all else are numbers (ahhh, still with the numbers: I believe that you´ll have to correct your infinite baffle simulations with OB baffle effects, namely the -6 DB slope downwards, depending on baffle size, and then our numbers match suddenly. My simulations predict the RSS265 to be at 85 dB max at 25 Hz at max excursion, without the baffle loss 100 dB don´t seem inappropriate...).
A good time to all christmas decoration devotees!!! If someone in this house decides to put lametta on my speakers, I will leave...
All the best
Mattes
yes, different approaches, and of course this is a good thing. I also noticed your Acoustat´s being mentioned long ago, this must be a very nice system... also good to hear that you´re using a record deck and the nice MA 505!!! Which cartridges do you use?
I´ve also had large ESL fullrange panels (Capacity E 3, which will be mostly unknown out of Germany...) but, after the sad failure of same (by the way: someone needs a pair of failed Capacity ESL, to pick up in Northern Germany, to exchange with a few bottles of red wine?), decided to go the fullrange/basshelper direction.
Your goals, Jeshi, are not so far away from mine, quoting your 100 dB/25 Hz number. The difference is maybe that I would like to have that at listening distance, 2,5 metres, and some headroom above. Probably I didn´t succeed with 25 Hz, but with 30 Hz. I need a realistic level of acoustic instruments (piano, drums, upright bass) for the perfect illusion, and yes, a piano played full force will be very loud (and very difficult to reproduce...).
So, I needed a pair of 18-inch bass drivers in OB´s of app. 94 cm (acoustic) diametre, driven by a few hundreds of watts to achieve this and have some headroom, too.
The point is that I have a hard time to believe that a single 25 cm driver could do this as well, or could do the 100 dB at 1 m at 25Hz, no matter how much power you´re sending into it...
But of course, as you´re listening at low levels in the nearfield, a pair of 10-inchers, even in OB, appropriately corrected, will most probably fulfil your needs, and this is the important thing, all else are numbers (ahhh, still with the numbers: I believe that you´ll have to correct your infinite baffle simulations with OB baffle effects, namely the -6 DB slope downwards, depending on baffle size, and then our numbers match suddenly. My simulations predict the RSS265 to be at 85 dB max at 25 Hz at max excursion, without the baffle loss 100 dB don´t seem inappropriate...).
A good time to all christmas decoration devotees!!! If someone in this house decides to put lametta on my speakers, I will leave...
All the best
Mattes
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