I have started a new thread on an evening in melbourne to hear some speakers, although unfortunately we don't have a Thor at the moment.
I m starting to believe that the crossover topology is wrong. From what you are saying, I can only assume that a 24db/oct low pass filter would work better instead of a 6db/oct ( combined with the notch). Putting a 1st order low pass, starting to roll off early, is a good trick to eliminate the 1.5Khz spl bump without a notch filter, and really cheap too. ( a notch around 1.5khz would need approx a 33ìF capacitor which costs €10 having polypropylene dielectric ). Besides if they used a higher order low pass, they would eliminate the 4.4Khz spl bump more effectively combined with the 4.4khz notch filter, but this means "complexed crossover" as they say in the article, which is translated to my ears as less profit when selling a kit. Of course I m not a pro, and i m nobody to question joe d'appolito, but thats my personal opinion on this, since you folks say that there is strong energy around the higher mid region... And our ears are the final and ultimate judge, arent they ?
there is hope for the mighty Thor
Thanks for the words of encouragement Jomor. I have no intentions of giving up; not after $1700 worth of investment
. You are right about our ears being the final judge too. I don't think having a flat frequency response necessarily means a speaker is going to sound good. A flat response doesn't take into effect the colourations of the speakers themselves. Besides, how many P.A. speakers used at live concerts are flat?
I have went over the construction and components of my x-overs several times and they setup exactly as posted by Dr.Joe. These speakers are simply too bright in the midrange. kjv hit it on the nose - there is too much energy in the 3 - 5khz range. I think these speakers have a lot more potential than what Joe has offered the DIY community.
These speakers definitely deserve a new crossover. Check this article out:
http://www.speakerbuilding.com/content/1009/page_7.php
Although this designer is using a w17 woofer instead of the w18 in the case of the Thors, his comments on his first crossover design describes the problem with the Thors beautifully! Unfortunately I don't have the software nor the skill to transpose his crossover to the Thors. I'm assuming his circuit is designed for an 8ohm woofer whereas the dual woofers in the Thors present a 4ohm load. I also don't know how to redo the HPF of the Thors to account for the lower crossover point. I don't think the Joe's crossover for the Excel tweeter is a problem with the Thors as there are a couple of similar designs on the net for this tweeter. It would just need to be adjusted to the 1800khz crossover.
Does anyone have any suggestions on how to adapt this new crossover for the Thors?
Thanks for the words of encouragement Jomor. I have no intentions of giving up; not after $1700 worth of investment
. You are right about our ears being the final judge too. I don't think having a flat frequency response necessarily means a speaker is going to sound good. A flat response doesn't take into effect the colourations of the speakers themselves. Besides, how many P.A. speakers used at live concerts are flat? I have went over the construction and components of my x-overs several times and they setup exactly as posted by Dr.Joe. These speakers are simply too bright in the midrange. kjv hit it on the nose - there is too much energy in the 3 - 5khz range. I think these speakers have a lot more potential than what Joe has offered the DIY community.
These speakers definitely deserve a new crossover. Check this article out:
http://www.speakerbuilding.com/content/1009/page_7.php
Although this designer is using a w17 woofer instead of the w18 in the case of the Thors, his comments on his first crossover design describes the problem with the Thors beautifully! Unfortunately I don't have the software nor the skill to transpose his crossover to the Thors. I'm assuming his circuit is designed for an 8ohm woofer whereas the dual woofers in the Thors present a 4ohm load. I also don't know how to redo the HPF of the Thors to account for the lower crossover point. I don't think the Joe's crossover for the Excel tweeter is a problem with the Thors as there are a couple of similar designs on the net for this tweeter. It would just need to be adjusted to the 1800khz crossover.
Does anyone have any suggestions on how to adapt this new crossover for the Thors?
This page shows an interesting circuit for anyone wanting to modify the Thor lowpass section.
http://www.speakerbuilding.com/content/1039/page_2.php
I guess existing thor owners would appreciate it if a new crossover only involved changes to the lowpass section. If that would be possible.
http://www.speakerbuilding.com/content/1039/page_2.php
I guess existing thor owners would appreciate it if a new crossover only involved changes to the lowpass section. If that would be possible.
Have you considered going active? Seems to me it is simpler for the DIYer to achieve. Then you could have a class A amp for the tweeter. Not that this will solve your midrange problem.
Some comments on the 2nd link that you might find encouraging
(Interview with Joachim Gerhard of Audio Physic)
"you have to be very precise, the values are very critical for it to work. It is difficult, but I can assure you that it is possible to tune this driver to a level where the resonances are not audible. We also found good correlation in the waterfall diagram when we used one-third octave measurements. When the time delay in the peak is less than 0.5 milliseconds, it has disappeared in the audible sense. But don't be satisfied until it is totally gone. If it is not, it will superimpose, so be extremely careful and honest when tuning it."
Some comments on the 2nd link that you might find encouraging
(Interview with Joachim Gerhard of Audio Physic)
"you have to be very precise, the values are very critical for it to work. It is difficult, but I can assure you that it is possible to tune this driver to a level where the resonances are not audible. We also found good correlation in the waterfall diagram when we used one-third octave measurements. When the time delay in the peak is less than 0.5 milliseconds, it has disappeared in the audible sense. But don't be satisfied until it is totally gone. If it is not, it will superimpose, so be extremely careful and honest when tuning it."
Re: there is hope for the mighty Thor
Its never too late, check these links
http://www.trueaudio.com/
http://www.speakerworkshop.com
http://www.behringer.com/ECM8000/index.cfm?lang=ENG
http://www.geocities.com/f4ier/newxoversim.htm
If you decide to experiment with the crossover, you can do it without having to get an electrical engineer's degree, there are many web pages on the net that explain the principles, and in combination with some basic testing eqcuipment, you can do miracles.
I simulated the low pass filter of thor, and it seems that the notch is narrow tuned around 4+ Khz. A notch's depth also depends on the inductors' internal resistance and the capacitor's ESR, 0.5ohm make great difference on the notch's behaviour. This seems to suck frequencies from 3 to 5Khz while the woofer's spl bump due to cone resonace seems to be up to 6khz.
Boom Boom said:
Its never too late, check these links
http://www.trueaudio.com/
http://www.speakerworkshop.com
http://www.behringer.com/ECM8000/index.cfm?lang=ENG
http://www.geocities.com/f4ier/newxoversim.htm
If you decide to experiment with the crossover, you can do it without having to get an electrical engineer's degree, there are many web pages on the net that explain the principles, and in combination with some basic testing eqcuipment, you can do miracles.
I simulated the low pass filter of thor, and it seems that the notch is narrow tuned around 4+ Khz. A notch's depth also depends on the inductors' internal resistance and the capacitor's ESR, 0.5ohm make great difference on the notch's behaviour. This seems to suck frequencies from 3 to 5Khz while the woofer's spl bump due to cone resonace seems to be up to 6khz.
Taming the Thor
For those of you who are interested....
I have finally managed to tame the Thor a little and get it to stop 'shouting'. Here is what I've done so far (all changes were done to the HPF):
- removed the 2.2uf cap
- added a 1ohm resistor in front of the inductor
- changed the l-pad values to 2.4ohm in series and an 8.2 ohm in parallel
So far I am fairly happy with these changes although I plan on more experimentation once I get more x-over components to play with. The upper midrange / lower treble ringing that I was hearing on many recordings has been reduced and these speakers have become quite a bit more listenable now.
I have also purchased trueaudio and I am waiting for my mic to arrive so I can start to verify some of my results.
Has anyone else experimented with the x-over of the Thor? I would be interested to hear about what you may have done.
Cheers, Boom Boom
For those of you who are interested....
I have finally managed to tame the Thor a little and get it to stop 'shouting'. Here is what I've done so far (all changes were done to the HPF):
- removed the 2.2uf cap
- added a 1ohm resistor in front of the inductor
- changed the l-pad values to 2.4ohm in series and an 8.2 ohm in parallel
So far I am fairly happy with these changes although I plan on more experimentation once I get more x-over components to play with. The upper midrange / lower treble ringing that I was hearing on many recordings has been reduced and these speakers have become quite a bit more listenable now.
I have also purchased trueaudio and I am waiting for my mic to arrive so I can start to verify some of my results.
Has anyone else experimented with the x-over of the Thor? I would be interested to hear about what you may have done.
Cheers, Boom Boom
Hi guys,
My wifes uncle bought the Thor kit to replace the drivers in his old concrete
Rauna TLs. He bought the sheaper version with the T25CF001 tweeter.
I believe it crosses at 2.2kHz (The milleniem T25 was 2.5KHz, right?).
The woofers are put under the tweeter (No appolito config). That was
the only way to fit it into the cabinets.
The bass is very tight and deep, just as you guys mentioned.
However I don't recognize the midrange you are mentioning. To me it is
almost a little laid back in the mids. And saying that, we even listened
to Celine D.
The filters came with the kit and is of good quality.
/ Mattias
My wifes uncle bought the Thor kit to replace the drivers in his old concrete
Rauna TLs. He bought the sheaper version with the T25CF001 tweeter.
I believe it crosses at 2.2kHz (The milleniem T25 was 2.5KHz, right?).
The woofers are put under the tweeter (No appolito config). That was
the only way to fit it into the cabinets.
The bass is very tight and deep, just as you guys mentioned.
However I don't recognize the midrange you are mentioning. To me it is
almost a little laid back in the mids. And saying that, we even listened
to Celine D.
The filters came with the kit and is of good quality.
/ Mattias
I thought the purpose of a kit (rather than pure DIY) was that tricky issues like a sharp midrange and finer crossover adjustments had been dealt with. At the beginning of this thread I was very excited about building the Thors, now I'm not so sure, too many comments about issues with these speakers.
I'm now thinking that maybe the Linkwitz Orions are closer to the 'ultimate' kitspeaker, although from my calculations they're more expensive.
I'm now thinking that maybe the Linkwitz Orions are closer to the 'ultimate' kitspeaker, although from my calculations they're more expensive.
rnoble said:
I'd be inclined to agree, although with a speaker like the Orion, I think I'd want to at least try out or hear a good OB dipole before embarking on such an expensive one. Cost wise take out the passive xo and replace it with active, replace a midbass with two XLS woofers and add four channels of amplification. The driver cost alone is about $1860.
Related Thor discussion at Madisound forum!
I hope this will help.
Norris
http://www.madisound.com/cgi-bin/discuss.cgi?read=314778
I hope this will help.
Norris
http://www.madisound.com/cgi-bin/discuss.cgi?read=314778
Madisound discussion / Solen kit
Thanks for the link Norris. There are some interesting discussions there and I will be monitoring it to see if one of the participants comes up with an alternate x-over. Having said that, I did manage to get a copy of the alternate x-over from the German magazine, HiFi Hobby. Have yet to try it out as I don't have the components yet.
Slightly different topic; has anyone used the Solen kit to build their thors? If you have, get rid of the damping material they supply. I picked up some acousta stuff and put in 13oz in the front and 8oz in the back and it made a huge difference! There is considerably less midrange ring and a couple of bass resonances I was hearing earlier have also cleared up. I was not expecting such a dramatic difference, but it was very audible.
Thanks for the link Norris. There are some interesting discussions there and I will be monitoring it to see if one of the participants comes up with an alternate x-over. Having said that, I did manage to get a copy of the alternate x-over from the German magazine, HiFi Hobby. Have yet to try it out as I don't have the components yet.
Slightly different topic; has anyone used the Solen kit to build their thors? If you have, get rid of the damping material they supply. I picked up some acousta stuff and put in 13oz in the front and 8oz in the back and it made a huge difference! There is considerably less midrange ring and a couple of bass resonances I was hearing earlier have also cleared up. I was not expecting such a dramatic difference, but it was very audible.
Re: Re: Madisound discussion / Solen kit
(JPK) I'll assume that was addresses to me. The NaO is a MTM design. No left over midranges. The original NaO used SS8545 mids. The AEP uses the W18. The AEP version was designed because there were a number of requests for a system like the original NaO that used the Thor drivers.
rnoble said:
(JPK) I'll assume that was addresses to me. The NaO is a MTM design. No left over midranges. The original NaO used SS8545 mids. The AEP uses the W18. The AEP version was designed because there were a number of requests for a system like the original NaO that used the Thor drivers.
I'v had the pleasure of hearing the thor in action at ELTEK here in norway, and i cant really comprehend what yoiu are saying about the midrange.. my personal opinion was that they sounded beautiful! but somehow i wonder: what crossover quality was your kits? ELTEK delivers the THOR's with copper foile coil's..
generally i suspect the quality of the kit parts some of you buy aren't really equivalent to what should reside inside the THOR...
my thoughts..
the amp i heard it play with was an electrocompaniet eci-3 if remember correct. wonderfull combo i must say!
generally i suspect the quality of the kit parts some of you buy aren't really equivalent to what should reside inside the THOR...
my thoughts..
the amp i heard it play with was an electrocompaniet eci-3 if remember correct. wonderfull combo i must say!
demogorgon said:
Perhaps; in terms of the Solen kit available in Canada, they supply a 12guage hepalitz wound inductor for the woofers and Solen fast caps. I've heard the Solen's aren't the best around but they should be adequate. Has anyone upgraded from Solen's to something better?
I firt joined this thread cause of a highly resonant sounding upper midrange / lower treble. I figured it was a problem with the x-over. After experimenting with the x-over, I discovered that the biggest problem with my Thor's was the stuffing. I replaced the Solen supplied stuffing with Acousta Stuff - what a difference. The resonances I was hearing have cleared right up! I've reverted back to the original x-over minus the parallel cap in the tweeter network and they sound pretty darn good now!
Given the problems that the backwaves from the woofers were apparently causing me, I'd be curious to find out what an Odin mk3 sounds like. Has anyone heard these?
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