Noooo, the units are too nice to look at.
A shaped front could be nice, but I like them open and free
A shaped front could be nice, but I like them open and free
Not a massive problem with the Beryllium tweeter. You can remove it by gently blowing unlike with sticky softdome units
You finally explained to me the advantage of Berilium. I will keep that in mind. Thanks!
I haven’t experienced much with bass reflex speakers, so can’t say for sure.
Any way I would believe some damping will not hurt. - but too much will make the sound lifeless/dull.
those panels migth be a plus perhaps. Any idea of mass & Young modulus? Made me think of polymer mixed wood for external plancher areas of the houses in wet environment.
Just for the reference : Earl G. at Geddes took polycarbonate from Remshape.
Ah, I like wood too and one could certainly venner anything from metal to plastic, plexiglass or glass... with the suitable glue of course. Of course no problem with hdf/mdf well braced. I talked about polymers to try to push this concept build towards the modernity it is illustrating vs classic materials. But I liked very much the woods pannel of your former thread ! I am not a fan at all of the shape and flashy colors of Wilson Audio, but their polymer migth have some structural plus : rigidity plus damping which is not easy to get sota. You don't wantas you know the panels are acoustic transducteur by themselves other than shape diffusor they are.
The sanding between two internal andexternal enclosure was about that, not to add weigth but to add damping and kill transmission by mass srping mass technic. It is llike whenn you use a glue or damping sheet of plastic or rubber between two panels : you don't want an hydrolic press to fussion them, you want the rigth amount to permit enough rigidity and enough damping..
Will you leather the alumin front panels as your last builds ? I wondered what Wilson puppy made in front of their loudspeaker frontplate, seems a sorta of dense wool some out below carpets ?
some ref among others : https://audioxpress.com/article/some-thoughts-on-plastics-for-speaker-enclosures
IMO a valid point.
@PSchut: I encourage you to spend some time learning VituixCAD
https://kimmosaunisto.net/
My experience is Proper loudspeaker simulation takes sound to the next level. You can work through a lot more promising iterations than with just trying filters. Maybe you already on the path of doing it. So just a tip.
In 2009 Albert Von Schweikert experimented the "most" damping cabinete solution.
https://www.audiocircle.com/index.php?topic=70291.0
https://www.audiocircle.com/index.php?topic=70291.0
I am planing to use that. It looks like a fantastic tool. I bought a good mic and have a decent sound card that will be used for measuring responses and DATS for impedance. And when it performs as expected it deserves a donation for sure
I do not have the time to make this a multi year project. I used what I know works, applied logic and overkill to be sure. I am very confident that 15 mm of MDF, plus 13 mm of (1100kg/m3) HDF topped with 20 mm of solid Walnut (that to me is much nicer visually than any veneer) with plenty bracing and clamped between a serious front and back of aluminum will do a good job in being a low resonance enclosure.
Can this be improved? Sure ….. but not a lot given the same dimensions and still practical executable.
This enclosure will be great.
That doesn’t mean the speaker will be great, there is work to do, but the enclosure will not be a limiting factor in my opinion.
Ohhh and yes, I will cover the aluminum with the same leatherette as the previous speaker. This material is soft, strong but for most looks great with these units.
A personal note on plastic: I don’t believe it makes good speakers. It is fantastic if you make products in volume and need to make money. Both reasons not applicable to a DIY project. Like I mentioned before a good speaker has mass.
If all elements are equal I think an 80kg speaker will sound better than a 30kg one.
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The von Schweikert "Wall" sure is a very stable construction. The most important part of this sandwich is the elastic glue between MDF and artificial stone.
The high wheight is not always needed and wanted.
You get similar results by using MDF, 3mm of an elastic glue and ca. 2mm aluminum panel. The aluminum get's a cover of Bondum, a compressed fiber, basicaly just the same as the felt used by von Schweikert, fixed by the same elastic compound. A lighter and more compact solution for the same problem.
The most important component is the 3mm layer of elastic compound, which can be easily made by using a toothed spatula. In Europe the Sikaflex line of adhesives has some well suited products that are incredible sticky, cure 100% reliable and keep elasticity for ages.
Such composite panels still need proper bracing, as they only solve a part of the problems a speaker cabinet has.
Such academically developed solutions are well suited for speakers, but are mostly developed for other uses. Passenger ships for example need thin, light and highly effective sound insulation.
The high wheight is not always needed and wanted.
You get similar results by using MDF, 3mm of an elastic glue and ca. 2mm aluminum panel. The aluminum get's a cover of Bondum, a compressed fiber, basicaly just the same as the felt used by von Schweikert, fixed by the same elastic compound. A lighter and more compact solution for the same problem.
The most important component is the 3mm layer of elastic compound, which can be easily made by using a toothed spatula. In Europe the Sikaflex line of adhesives has some well suited products that are incredible sticky, cure 100% reliable and keep elasticity for ages.
Such composite panels still need proper bracing, as they only solve a part of the problems a speaker cabinet has.
Such academically developed solutions are well suited for speakers, but are mostly developed for other uses. Passenger ships for example need thin, light and highly effective sound insulation.
Plastic are more than okay : high Young modulus can be found as well as some nearer from wood. Polymers mixed or some like PU can be okay if damping is needed (and guess : we need it). Nylon P6/6 has as good stifness as aluminium and better damping and cost way much less. Dunno about CNC cost though. Pu seems quite ideal for a front panel glued on a less thick alumin pannel (1 cm certainly more than okay, or Nylon pannel for the stifness and structural integrity. As usual it is certainly how you join the panels that maters. hence people focus on bracing to enhance that stifness of the cabinet.
Yes MDF/HDF, can be okay enough, there were some studies here.
Alumin is stidd but has poor damping vs comosites. Imo no point to make a front plate if all the structure is not made of the same material to keep the stifness everywhere.
Mass is not really needed, what is needed is stifness first and structual integrity. Mass comes because most use woods made, so stifness comes with weigth due to more thickness. People thinks it is mass, but mass here is just to avoid flex and wood panels to sing too much, or at least to sing where it arms the less.
But anyway, impressive build and drivers. Looks good to me. Better than a monkey coffin for sure.
Yes MDF/HDF, can be okay enough, there were some studies here.
Alumin is stidd but has poor damping vs comosites. Imo no point to make a front plate if all the structure is not made of the same material to keep the stifness everywhere.
Mass is not really needed, what is needed is stifness first and structual integrity. Mass comes because most use woods made, so stifness comes with weigth due to more thickness. People thinks it is mass, but mass here is just to avoid flex and wood panels to sing too much, or at least to sing where it arms the less.
But anyway, impressive build and drivers. Looks good to me. Better than a monkey coffin for sure.
Hi Forum.
Happy new year to you all, and I hope 2025 will be an inspiring DIY speaker building year in good health.
A small update after 2 slow weeks.
I have prepared the power amps, wired them, shortened the supplied ribbon cables as the DSP sits fairly close and tested the amps.
All works fine, 500W @ 4 Ohm. Also played with the DSP software that after some fiddling was quite straight forward and adding the LR4 Filter (24dB/oct) is easy. crossover frequency of course TBD.
The next weeks we will start to add the leather on the aluminium front and back, and adding the final 20mm layer of solid Walnut to the enclosure.
I hope to be done by the end of February and start listening and tweaking during Dutch Carnival 🙂
Cheers, Peter
Happy new year to you all, and I hope 2025 will be an inspiring DIY speaker building year in good health.
A small update after 2 slow weeks.
I have prepared the power amps, wired them, shortened the supplied ribbon cables as the DSP sits fairly close and tested the amps.
All works fine, 500W @ 4 Ohm. Also played with the DSP software that after some fiddling was quite straight forward and adding the LR4 Filter (24dB/oct) is easy. crossover frequency of course TBD.
The next weeks we will start to add the leather on the aluminium front and back, and adding the final 20mm layer of solid Walnut to the enclosure.
I hope to be done by the end of February and start listening and tweaking during Dutch Carnival 🙂
Cheers, Peter
Hi @PSchut
First of all congratulatiins for your well thought and fantastic build. Just two questions:
1. Why did you decided to use AT drivers? They are very good by no means, buy world has changed in last 30 years and we have new contenders from Purifi, SB Textreme, SS Ellipticotor, Wavecor and maybe few others. AT measures poorly given their price tag vs newly developed competition in terms of THD and harmonics.
And why have you not purchased the paper versions of Flexunits? They are told to be much better in bass reproduction than Poly cones.
BTW I truly love AT and what they are doing, but from some just wondering whether they are still really proving the value which they cost.
2. Why do you think butyl mats as used in cars, on internal speaker walls makes no sense? They will not damp anything?
First of all congratulatiins for your well thought and fantastic build. Just two questions:
1. Why did you decided to use AT drivers? They are very good by no means, buy world has changed in last 30 years and we have new contenders from Purifi, SB Textreme, SS Ellipticotor, Wavecor and maybe few others. AT measures poorly given their price tag vs newly developed competition in terms of THD and harmonics.
And why have you not purchased the paper versions of Flexunits? They are told to be much better in bass reproduction than Poly cones.
BTW I truly love AT and what they are doing, but from some just wondering whether they are still really proving the value which they cost.
2. Why do you think butyl mats as used in cars, on internal speaker walls makes no sense? They will not damp anything?
Thanks Kapelli, Thanks.
The reason is simple. My current speaker (see original thread, that will go to its new owner next Sunday) sounds so good that I do not want to change anything from a sound reproduction point of view. Even after 7 years, when I sit down and the first notes come out it is heaven 😎
The only problem I have a a fairly strong resonance at 32 Hz from my room.. So depending on the music piece it blooms a bit.
I did remove that with Roon, but for some reason the total magic disappears a bit.
I know the Purify has a few great drivers but the surround that looks like it has been in the sun too long just doesn't do it for me. (and no underhung models)
The ellipticor midrange measures fantastic (according to Troels Gravensen) but also no underhung engine and a bit too big for my application where I wanted a d'appolito configuration.
The SB textreme is a beautiful driver, but not underhung, and a few years back I was hired by a speaker manufacturer as independent tester in a lawsuit that uses SB drivers and proved they were over specifying the frequency response of their tweeters.
You are right, there are many good drivers, I just happen to like the AT drivers, their range, their look and feel and they sound really good
There is one other reason why I started a new build and that is its size. These speakers are massive. In the spring we redecorated our living/kitchen and suddenly their size bothered me (could also be old age and lack of testosterone hahaha)
So why change a winning team.
I did not want to start a full renewal with prototype like we did last time.
We are already going from 6" to 5" midrange, underhung voice-coil (that should have much lower distortion and is faster) and from 10" to 8" woofer.
The advantage is the DSP based LF Hypex drive that will allow some room correction only affecting the Woofer. So I can boost the sub frequency a bit and reduce the 32Hz room mode .... and the speaker (although still big for today's standard in Sonos world) is a bit smaller and less bulky.
Paper version of the Woofer .... do you mean sandwich cone? (that is not paper)
I discussed that with Per Skaaning and the 8" size with same 77mm VC does not benefit that much from it. It only increases mass and lowers speed and efficiency.
...Oh I do think butyl mats work on walls that are flimsy. and I used them on two sides of the internal midrange cabinet.
But if your wall is 15mm MDF, 13mm HD + 20mm solid walnut it has limited effect in my opinion.
The mass of this combination is approximately 0.35kg per dm2 (=10x10cm) the 4mm bitumex is 0.072kg per dm2, so it will add 17% of mass.
Taking into account that the 3 layers are glued and we will put some tension between front and back, so the enclosure is sandwiched between two massive aluminium slabs and there is bracing every 10 to 12cm we decided not to do this. It would most likely not have hurt, but I am also fighting the lower end of the possible internal volume so that is why we limited this.
Cheers,
The reason is simple. My current speaker (see original thread, that will go to its new owner next Sunday) sounds so good that I do not want to change anything from a sound reproduction point of view. Even after 7 years, when I sit down and the first notes come out it is heaven 😎
The only problem I have a a fairly strong resonance at 32 Hz from my room.. So depending on the music piece it blooms a bit.
I did remove that with Roon, but for some reason the total magic disappears a bit.
I know the Purify has a few great drivers but the surround that looks like it has been in the sun too long just doesn't do it for me. (and no underhung models)
The ellipticor midrange measures fantastic (according to Troels Gravensen) but also no underhung engine and a bit too big for my application where I wanted a d'appolito configuration.
The SB textreme is a beautiful driver, but not underhung, and a few years back I was hired by a speaker manufacturer as independent tester in a lawsuit that uses SB drivers and proved they were over specifying the frequency response of their tweeters.
You are right, there are many good drivers, I just happen to like the AT drivers, their range, their look and feel and they sound really good
There is one other reason why I started a new build and that is its size. These speakers are massive. In the spring we redecorated our living/kitchen and suddenly their size bothered me (could also be old age and lack of testosterone hahaha)
So why change a winning team.
I did not want to start a full renewal with prototype like we did last time.
We are already going from 6" to 5" midrange, underhung voice-coil (that should have much lower distortion and is faster) and from 10" to 8" woofer.
The advantage is the DSP based LF Hypex drive that will allow some room correction only affecting the Woofer. So I can boost the sub frequency a bit and reduce the 32Hz room mode .... and the speaker (although still big for today's standard in Sonos world) is a bit smaller and less bulky.
Paper version of the Woofer .... do you mean sandwich cone? (that is not paper)
I discussed that with Per Skaaning and the 8" size with same 77mm VC does not benefit that much from it. It only increases mass and lowers speed and efficiency.
...Oh I do think butyl mats work on walls that are flimsy. and I used them on two sides of the internal midrange cabinet.
But if your wall is 15mm MDF, 13mm HD + 20mm solid walnut it has limited effect in my opinion.
The mass of this combination is approximately 0.35kg per dm2 (=10x10cm) the 4mm bitumex is 0.072kg per dm2, so it will add 17% of mass.
Taking into account that the 3 layers are glued and we will put some tension between front and back, so the enclosure is sandwiched between two massive aluminium slabs and there is bracing every 10 to 12cm we decided not to do this. It would most likely not have hurt, but I am also fighting the lower end of the possible internal volume so that is why we limited this.
Cheers,
When you make speakers, if you want, record a video and compare how it plays the composition "here but i m gone" by Vanessa Fernández compared to high-end speakers Audio Physic scorpio 25. It would be interesting to hear how well your speakers play.