Hello all,
I am looking for advise on a version of Thors that I have built. I will start by saying that I am a Civil Engineer and know absolutely nothing whatsoever about electrical engineering or speaker building. I appreciate there are hundreds of threads on this website on the subject but to be honest, it is difficult to find definite information and as time has gone on, advice seems to have changed.
Firstly, the reason for the project. I have a Cyrus system including a Streamline 2, DAC XP+ and two Stereo 200 amplifiers. I had Dali Ikon 6 speakers for years which I always enjoyed as they were detailed and entertaining, but were too bright for my room, which is unsuitable for a hifi, being a large conservatory with hard glazed and wooden walls/ ceiling with a high apex and a stone floor to top it all off! I bought some PMC 20/24’s and although it solved the bass problem, they just weren’t powerful enough to fill the room and I always felt that the midrange was too quiet when compared to the Dali’s. Therefore, as you do, I came to the very obvious and sensible conclusion to build my own speakers…
So to cut a long story short, I’ve been in the process of building my own version of Thors over the last 10 months and due to the time that it has taken, I have taken bits of information from this forum, knitting it together and ended up with the speakers that I have. Now I look back at the notes I made, mostly on scrap bits of paper, it’s not always immediately apparent why I made certain decisions and finding my way back to the original posts has proved impossible, partially as my research was often undertaken whilst travelling on trains on the way to work etc etc.
Anyway, in summary, I have built the following:
• Thor cabinets to the dimensions shown on the attached ‘Cabinet dims’ pdf although I’m still to fix the angled bits at the bottom. As you can see from the photo, I've created a separate compartment at the top of the speaker which contains the crossover for ease of access!
• Seas W18EX001 midrange drivers (note the ‘X’ i.e. not the W18E001 and I’ve attached the datasheets for both versions)
• Seas Millennium T25CF002 tweeters
For the crossover, I looked at various versions of jimangie1973’s as follows:
• I have built the crossover shown on the attached ‘Thor XO’ pdf (I think this was taken from the thread ‘Clarity on Seas Thor kit’, post 998
• I note that there were earlier version(s), which I assumed were superseded by the above
• I have subsequently found an even later version from 2015ish, thread title ‘Curved Small Thor Redux’ post 1 (attached 'Thor XO circa 2015' pdf)
They have been up and running now for about 3 days and I am fairly pleased with the sound, they are definitely improving with use and I’m not doing a comparison against the PMC’s until they have run in properly. However, it feels that I’m not getting the full spectrum of music if I can put it that way, there are parts of the music that are too quiet. And there isn’t the soundstage that I was really hoping for.
Also, having initially stuffed them with the metric equivalent of 0.75lb/ft3 of sheeps wool following advice from the forum, the bass completely disappeared, which seems similar to other people’s experience. I played around with this and currently have only 150g (0.33lbs) of insulation in the first half length and nothing in the last half, the result being plenty of bass, particularly as both speakers are close to a solid wall, one of which being tight into a corner.
My queries are as follows:
1. Which is the correct version of the crossover, or perhaps a better question;
2. Do the crossovers needs adjusting to the incorrect midrange drivers that I purchased
3. Does the reduced quantity of stuffing cause problems with the transmission line effective length and am I best not touching this until I have everything else sorted out
4. I’m sure that the only way to analyse this is to take measurements but
I have no idea what equipment (hardware and software) that I need to purchase. Obviously I don’t want to spend a fortune
I would be very grateful for some advice.
Thanks
Alex
I am looking for advise on a version of Thors that I have built. I will start by saying that I am a Civil Engineer and know absolutely nothing whatsoever about electrical engineering or speaker building. I appreciate there are hundreds of threads on this website on the subject but to be honest, it is difficult to find definite information and as time has gone on, advice seems to have changed.
Firstly, the reason for the project. I have a Cyrus system including a Streamline 2, DAC XP+ and two Stereo 200 amplifiers. I had Dali Ikon 6 speakers for years which I always enjoyed as they were detailed and entertaining, but were too bright for my room, which is unsuitable for a hifi, being a large conservatory with hard glazed and wooden walls/ ceiling with a high apex and a stone floor to top it all off! I bought some PMC 20/24’s and although it solved the bass problem, they just weren’t powerful enough to fill the room and I always felt that the midrange was too quiet when compared to the Dali’s. Therefore, as you do, I came to the very obvious and sensible conclusion to build my own speakers…
So to cut a long story short, I’ve been in the process of building my own version of Thors over the last 10 months and due to the time that it has taken, I have taken bits of information from this forum, knitting it together and ended up with the speakers that I have. Now I look back at the notes I made, mostly on scrap bits of paper, it’s not always immediately apparent why I made certain decisions and finding my way back to the original posts has proved impossible, partially as my research was often undertaken whilst travelling on trains on the way to work etc etc.
Anyway, in summary, I have built the following:
• Thor cabinets to the dimensions shown on the attached ‘Cabinet dims’ pdf although I’m still to fix the angled bits at the bottom. As you can see from the photo, I've created a separate compartment at the top of the speaker which contains the crossover for ease of access!
• Seas W18EX001 midrange drivers (note the ‘X’ i.e. not the W18E001 and I’ve attached the datasheets for both versions)
• Seas Millennium T25CF002 tweeters
For the crossover, I looked at various versions of jimangie1973’s as follows:
• I have built the crossover shown on the attached ‘Thor XO’ pdf (I think this was taken from the thread ‘Clarity on Seas Thor kit’, post 998
• I note that there were earlier version(s), which I assumed were superseded by the above
• I have subsequently found an even later version from 2015ish, thread title ‘Curved Small Thor Redux’ post 1 (attached 'Thor XO circa 2015' pdf)
They have been up and running now for about 3 days and I am fairly pleased with the sound, they are definitely improving with use and I’m not doing a comparison against the PMC’s until they have run in properly. However, it feels that I’m not getting the full spectrum of music if I can put it that way, there are parts of the music that are too quiet. And there isn’t the soundstage that I was really hoping for.
Also, having initially stuffed them with the metric equivalent of 0.75lb/ft3 of sheeps wool following advice from the forum, the bass completely disappeared, which seems similar to other people’s experience. I played around with this and currently have only 150g (0.33lbs) of insulation in the first half length and nothing in the last half, the result being plenty of bass, particularly as both speakers are close to a solid wall, one of which being tight into a corner.
My queries are as follows:
1. Which is the correct version of the crossover, or perhaps a better question;
2. Do the crossovers needs adjusting to the incorrect midrange drivers that I purchased
3. Does the reduced quantity of stuffing cause problems with the transmission line effective length and am I best not touching this until I have everything else sorted out
4. I’m sure that the only way to analyse this is to take measurements but
I have no idea what equipment (hardware and software) that I need to purchase. Obviously I don’t want to spend a fortune
I would be very grateful for some advice.
Thanks
Alex
Attachments
Looks like you have built the Thor box as designed by Joe. This has been clearly shown to be a very poor TL design exacerbated by a critical measurement mistake when he was vetting performance.
Clarity on Seas Thor Kit
The box as has been built will do better bass with a single woofer.
I hate to say this, but time to burn those boxes and start over.
dave
Clarity on Seas Thor Kit
The box as has been built will do better bass with a single woofer.
I hate to say this, but time to burn those boxes and start over.
dave
Seas W18EX001 are great drivers for "Thor the God of Thunder"
-magnesium cone
-copper phase plug
-natural rubber surround
circa 2015 crossover.....
On the tweeter... Is it REALLY EASY to move the 2.5-ohm resistor to in front of the 12.47uF capacitor and experiment with lower values from 1-2.5 ohms? This will increase tweeter efficiency PB2 discusses, produce a higher Q on the RLC filter, and use the increasing impedance of the tweeter to compensate for the RLC tail.
You have built beautiful cabinets. I hope the diy-group finds modest internal bracing and stuffing changes which improve measurements and soundstage in your room. Maybe.... wall treatment?
-magnesium cone
-copper phase plug
-natural rubber surround
circa 2015 crossover.....
On the tweeter... Is it REALLY EASY to move the 2.5-ohm resistor to in front of the 12.47uF capacitor and experiment with lower values from 1-2.5 ohms? This will increase tweeter efficiency PB2 discusses, produce a higher Q on the RLC filter, and use the increasing impedance of the tweeter to compensate for the RLC tail.
You have built beautiful cabinets. I hope the diy-group finds modest internal bracing and stuffing changes which improve measurements and soundstage in your room. Maybe.... wall treatment?
I'd start with REW, which is free. You'll need a way of connecting a laptop (or desktop, if you can be bothered to drag it out) to the HiFi system, and you'll need a measurement mic.
A Behringer ECM8000 is cheap, and usually good enough to get you started. Combine that with a UMC202HD soundcard. Add an XLR cable, and you're set.
I must admit that if I was to choose a set of HiFi speakers for an acoustically reflective room, I would have seriously considered compression drivers with horns, or at the very least a waveguide for the tweeter. By focusing the sound on a narrower area, you gain efficiency (or give the HF driver an easier life) and avoid throwing excess sound at the side walls.
If you're near Sheffield, give me a shout. I have the measurement gear around. We'll have to work something out WRT the virus.
Chris
For the box, pull some of the damping out of the last 10in. When I did some further modelling work on the Thor, I noted results under those conditions that came somewhat closer to the original intent. I'll try to have a gander at the rest, FWIW. However, you will certainly need to raise Qt back to that of the design driver or the enclosure load will not work as intended, period. Using series inductors with greater DCR should help there, as has been noted.
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Thanks all for your replies and suggestions. I note the comments about the design not being suitable for TL, but I'm going to stick with what I've built and learn as I go along. The bass is currently probably the best I've heard from speakers and is certainly better than the PMC's, which were already good.
I have a few questions:
1. Firstly, should I stick with the current XO to make the suggested modifications i.e. not change everything to the circa 2015 version, but continue with the other older version (from about 2010/11 I believe)?
2. What is the 'tweeter pad'? Is this related to changing the resistor value?
3. By moving the '2.5-ohm resistor to in front of the 12.47uF capacitor' (or 8.7uF in my case with the older XO), does this mean to the incoming side of the capacitor, or between the 12.47uF and 22uF capacitor?
4. Should I change both 14 ga resistors to 16 or 18 ga inductors on the woofer and what effects will this have on the sound?
5. For the damping, I've only currently got 150g (0.33lbs) in the first half length and nothing at all in the last half, which is probably why I have got such good bass, but should I add more wool apart from the last 10inches and if so, is the density important?
Once I've managed to sort these bits out as best possible, I will look into the hardware/software details provided.
Thanks again,
Alex
I have a few questions:
1. Firstly, should I stick with the current XO to make the suggested modifications i.e. not change everything to the circa 2015 version, but continue with the other older version (from about 2010/11 I believe)?
2. What is the 'tweeter pad'? Is this related to changing the resistor value?
3. By moving the '2.5-ohm resistor to in front of the 12.47uF capacitor' (or 8.7uF in my case with the older XO), does this mean to the incoming side of the capacitor, or between the 12.47uF and 22uF capacitor?
4. Should I change both 14 ga resistors to 16 or 18 ga inductors on the woofer and what effects will this have on the sound?
5. For the damping, I've only currently got 150g (0.33lbs) in the first half length and nothing at all in the last half, which is probably why I have got such good bass, but should I add more wool apart from the last 10inches and if so, is the density important?
Once I've managed to sort these bits out as best possible, I will look into the hardware/software details provided.
Thanks again,
Alex
Is the .pdf for the original article available online, or anyone have it?
I posted here years ago that something was not quite right with the crossover but I'd have to
refresh my memory.
Here's a very old post, see also the ones following:
https://www.diyaudio.com/forums/multi-way/64799-clarity-seas-thor-kit-28.html#post879684
I posted here years ago that something was not quite right with the crossover but I'd have to
refresh my memory.
Here's a very old post, see also the ones following:
https://www.diyaudio.com/forums/multi-way/64799-clarity-seas-thor-kit-28.html#post879684
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Phew. This is hard work! 
THOR
I'm not convinced at all by that crossover you have posted as an awkward PDF. 45uF and 0.025mH breakup notch just looks like an outlier on what is needed around 5kHz. And an LCR on the tweeter Fs won't do much with a third-order.
For sure Troels Gravesen uses something wildly different:
TJL-2W
And Madisound did too:
SEAS Brand Archives - Madisound Speaker PDF Library
I can't think the exact driver makes a huge difference to the filter, but affects the bass loading:
E0017-08S W18EX001
E0018-08S W18E001
http://www.seas.no/index.php?option=com_content&view=article&id=367:e0011-06-t25cf002&catid=50:excel-tweeters&Itemid=360
Well, that's where I am so far. Possibly Troels has done the best job with this combo. But it's quite complex. But the MTM conversion isn't rocket science. One to sleep on.
THOR
I'm not convinced at all by that crossover you have posted as an awkward PDF. 45uF and 0.025mH breakup notch just looks like an outlier on what is needed around 5kHz. And an LCR on the tweeter Fs won't do much with a third-order.
For sure Troels Gravesen uses something wildly different:
TJL-2W
And Madisound did too:
SEAS Brand Archives - Madisound Speaker PDF Library
I can't think the exact driver makes a huge difference to the filter, but affects the bass loading:
E0017-08S W18EX001
E0018-08S W18E001
http://www.seas.no/index.php?option=com_content&view=article&id=367:e0011-06-t25cf002&catid=50:excel-tweeters&Itemid=360
Well, that's where I am so far. Possibly Troels has done the best job with this combo. But it's quite complex. But the MTM conversion isn't rocket science. One to sleep on.
Ah. Here it is:
https://www.diyaudio.com/forums/multi-way/64799-clarity-seas-thor-kit-100.html#post2240904
Your driver is going to be 2dB louder. If that is a good tonal balance, you just need to reduce a series resistor in the crossover by a couple of ohms.
https://www.diyaudio.com/forums/multi-way/64799-clarity-seas-thor-kit-100.html#post2240904
Your driver is going to be 2dB louder. If that is a good tonal balance, you just need to reduce a series resistor in the crossover by a couple of ohms.
Thanks. I've just changed for a 2.2R which made a big difference. I might try a slightly larger value as it feels a bit 'bright' for my listening room.
I'm also going to try biamping, as I have two Cyrus Stereo 200 power amps, so want to make best use of them. Not sure if there will be any difference but I'll give it a go.
I'm also going to try biamping, as I have two Cyrus Stereo 200 power amps, so want to make best use of them. Not sure if there will be any difference but I'll give it a go.
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