I have been using the stock xo's from Madisound -- not quite happy with these -- my testing of the xo's does not quite comport with the graphs in the AudioXpress article -- and there is some nastiness arising from the compensation network -- more work to follow.
I forgot that I took this pic of the shop-vac after finishing the speakers -- from routing the speaker cutouts:
I forgot that I took this pic of the shop-vac after finishing the speakers -- from routing the speaker cutouts:
An externally hosted image should be here but it was not working when we last tested it.
well, they sound awfully, awfully good -- they do take quite a while to get excercised -- note that my design is hardly the one which was published in AX in 2003 -- I used Martin's Mathcad worksheets and advice from fellow forum members. I will have to work on the baffle step correction a bit more -- all in all it's a very nice project and I am not disappointed.
Thanks for that feedback. Good to know the high investment in drivers is worth it if they sound very good. I was just concerned that if the cabinet design was suspect - the xo might be too.
I can't remember the xo topology... was the compensation a notch filter? or zobel (woofer or tweeter section)? Are you saying the issue with the xo is in the frequency range where BSC is required (ie. the speakers sound a bit thin) - or are you getting harshness / brightness higher up the freq. range?
Have you done any phase tracking measurements through the xo region? I'm interested not only in their freq response but phase tracking (something I can't recall whether published in AX).
Also - are you doing your measurements in room? (or open space?).
Cheers,
DAvid.
I can't remember the xo topology... was the compensation a notch filter? or zobel (woofer or tweeter section)? Are you saying the issue with the xo is in the frequency range where BSC is required (ie. the speakers sound a bit thin) - or are you getting harshness / brightness higher up the freq. range?
Have you done any phase tracking measurements through the xo region? I'm interested not only in their freq response but phase tracking (something I can't recall whether published in AX).
Also - are you doing your measurements in room? (or open space?).
Cheers,
DAvid.
WOW, it's been a year since I made these for Repute and he has not complained to me about them once.
http://www.diyaudio.com/forums/showthread.php?postid=773590#post773590
That is incredible if you know Repute. Great guy, but can find the flaw in ANY diamond....
His father is a looonnng time audiophile who rutinely visits his son, listens and he still like this design / new cabinet.
I personally think I could live with them and this new box did let the woofers shine as the marvelous drivers they are.
http://www.diyaudio.com/forums/showthread.php?postid=773590#post773590
That is incredible if you know Repute. Great guy, but can find the flaw in ANY diamond....
His father is a looonnng time audiophile who rutinely visits his son, listens and he still like this design / new cabinet.
I personally think I could live with them and this new box did let the woofers shine as the marvelous drivers they are.
Dave Bullet said:
I first measured them out-doors on a stool so that the drivers were about 6 feet above ground. Have measured them in-doors -- the problem here is that they "load" the chimney! Most recently , I measured them out-of-doors again, this time with the drivers close to earth -- but it got to cold to finish up the measurements.
fwiw -- here's a sim of the stock xo -- and i get the same results when i do the analysis on the workbench -- L4/RL2 are the electrical parameters of the tweeter, L5/RL1 those of the 2 woofers.
the "effective" baffle width of the beveled design is about 16 inches.
the "effective" baffle width of the beveled design is about 16 inches.
An externally hosted image should be here but it was not working when we last tested it.
Hi,
First my compliments go to all contributors in this very interesting (and ultimately very constructive) thread.
In the AxP article the designer points out the importance of using the specified gage for L3. I can confirm that he is right about that. Here's a sim of the xover: the green trace shows the high pass section with 0 dc resistance for L3 (same as in jackinnj schematic); the red trace includes a 0.35ohm resistor in series with L3. Not much... but audible. There is 1dB difference between the two traces over a good part of the xover region. I'm not very familiar with loudspeaker design so I can't tell into what spl an 'electrical' dB translates to. In my case L3 has 0.2ohm and I added a 0.15ohm resistor (in an effort to tame some brightness)... mission accomplished.
For those who'd like to try it please pay attention to what maximal value you choose. Too high and some low frequencies may enter the tweeter.
Anyone tried something similar?
cheers
First my compliments go to all contributors in this very interesting (and ultimately very constructive) thread.
In the AxP article the designer points out the importance of using the specified gage for L3. I can confirm that he is right about that. Here's a sim of the xover: the green trace shows the high pass section with 0 dc resistance for L3 (same as in jackinnj schematic); the red trace includes a 0.35ohm resistor in series with L3. Not much... but audible. There is 1dB difference between the two traces over a good part of the xover region. I'm not very familiar with loudspeaker design so I can't tell into what spl an 'electrical' dB translates to. In my case L3 has 0.2ohm and I added a 0.15ohm resistor (in an effort to tame some brightness)... mission accomplished.
For those who'd like to try it please pay attention to what maximal value you choose. Too high and some low frequencies may enter the tweeter.
Anyone tried something similar?
cheers
Attachments
jackinnj said:
Sorry didn't see your reply, yes exactly, measured on axis. It's been a while since I looked at the design but I believe that it is an in-phase design as it should be with LR-2 or 4 designs and therefore the reverse wiring should produce a deep null.
I see that your using a SPICE type of simulation to obtain the crossover response, it would be better to use a simulator designed for speaker design. I use CALSOD which is now rather dated, but does work well. These programs simplify the impedance model of the drivers and provide for simulation of the acoustic response of the driver.
Pete B.
jackinnj said:
It is unfortunate that Madisound is not maintaining their archives, as we had a good discussion about the Thor crossover. I had linked it in this post some time ago, but the link is dead now:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=41123
I also mentioned it here:
http://www.diyaudio.com/forums/showthread.php?s=&postid=879684#post879684
and here:
http://www.diyaudio.com/forums/showthread.php?postid=883583#post883583
Pete B.
PB2 said:
There aren't enough hours in the day.
I've been talking to myself of late -- http://www.diyaudio.com/forums/showthread.php?postid=1088394#post1088394
the Heybrooks have been sitting in a guest bedroom for about 8 years without benefit of music -- i purchased them circa 1986 -- decided to see what they looked like inside -- more foam rubber than a Hollywood starlet -- talk about overdamping!.
Fat Thor
So as one of those that has the original Madisound cabinet Thor, standard xover, I've perused this thread with some degree of sadness lamenting the apparent arbitrary box shrinking of the original design--and not having the space nor tools to engage in a box rebuild--I was wondering if anybody has contemplated constructing fat Thor boxes for those of us determined to get the best out of their upscale drivers yet lack the wherewithal to do it themselves.
Give me a price?
Thanks!
So as one of those that has the original Madisound cabinet Thor, standard xover, I've perused this thread with some degree of sadness lamenting the apparent arbitrary box shrinking of the original design--and not having the space nor tools to engage in a box rebuild--I was wondering if anybody has contemplated constructing fat Thor boxes for those of us determined to get the best out of their upscale drivers yet lack the wherewithal to do it themselves.
Give me a price?
Thanks!
Fat Thor modifications?
What a wonderful thread this has been Thanks to those who have devoted much time and energy to this build. (Fat Thor)
Being as this is my first speaker build, I have a few questions.
If the box is built and then a solid cherry wood front baffle is added (speakers flushed in face of cherry) would this effect the acoustical dynamics?
If I wished to exit the port in front (Speakers will be close to rear wall in living room) how would / could I build this?
I was advised by a local speaker designer that I should opt to add a lower compartment to fill with lead shot or sand to make it heavier. Is this really needed?
Last question....for now , Has anyone in the Sacramento San Francisco built the Fat Thors? Perhaps I could listen to them???
Worth a cold beer or two for someone....
Thank you for the superb community and education provided.
Ron
What a wonderful thread this has been
Thanks to those who have devoted much time and energy to this build. (Fat Thor)Being as this is my first speaker build, I have a few questions.
If the box is built and then a solid cherry wood front baffle is added (speakers flushed in face of cherry) would this effect the acoustical dynamics?
If I wished to exit the port in front (Speakers will be close to rear wall in living room) how would / could I build this?
I was advised by a local speaker designer that I should opt to add a lower compartment to fill with lead shot or sand to make it heavier. Is this really needed?
Last question....for now
, Has anyone in the Sacramento San Francisco built the Fat Thors? Perhaps I could listen to them???Worth a cold beer or two for someone....
Thank you for the superb community and education provided.
Ron