Thanks for your reply Colin, I got the idea of the sloping baffle from a pair of Audio Physic speakers that I owned - they imaged well and projected at just the right height.
If no anomalies are expected in the sound with the MLTL, I think I'll give it a go.
Will report back upon completion, although this could take a little time - I'm not allowed to build anything until I sell my unused equipment - 3 pairs of speakers, 4 amplifiers, 3 turntables etc. They don't warn you about these things when you marry them and if I was to wear ear protectors - well I couldn't hear me music.
If no anomalies are expected in the sound with the MLTL, I think I'll give it a go.
Will report back upon completion, although this could take a little time - I'm not allowed to build anything until I sell my unused equipment - 3 pairs of speakers, 4 amplifiers, 3 turntables etc. They don't warn you about these things when you marry them and if I was to wear ear protectors - well I couldn't hear me music.
Many thanks for your reply Colin, I must apologise for the delay in my thanks to you.
I have decided to use Jim Griffins Baffle width in the 31" MLTL compensating for csa in speaker depth, this is with a view to using a ribbon tweeter (Aurum Cantus) at a later date if the top end of the jx92s proves to be o.t.t. for my ears.
As regards BSC a 4ohm resistor appears to be pretty much the standard but the inductor preferences advised have been 1.5mh and 2.mh - which is the one to use ?.
Lastly, cabinet stuffing, do I line the cabinet walls to just below the speaker position ( 1/2" felt ) or do I use BAF wadding up to the value of 0.54lb, or just suck it and see ?.
I'm afraid that I have read so much ( gratefully ) on this forum my head is whizzing with all the information, advice to others and preferences that I'm disappearing up my own existence.
It looks like I'll only get one shot at this as 'the light of my life' is rapidly losing patience with 'this will be my last speaker project'. She has been good over the past 35 years but after so many boxes (about 18 in total ) I think she is calling time and negotiation is not an available option.
Thanks once again.
John
I have decided to use Jim Griffins Baffle width in the 31" MLTL compensating for csa in speaker depth, this is with a view to using a ribbon tweeter (Aurum Cantus) at a later date if the top end of the jx92s proves to be o.t.t. for my ears.
As regards BSC a 4ohm resistor appears to be pretty much the standard but the inductor preferences advised have been 1.5mh and 2.mh - which is the one to use ?.
Lastly, cabinet stuffing, do I line the cabinet walls to just below the speaker position ( 1/2" felt ) or do I use BAF wadding up to the value of 0.54lb, or just suck it and see ?.
I'm afraid that I have read so much ( gratefully ) on this forum my head is whizzing with all the information, advice to others and preferences that I'm disappearing up my own existence.
It looks like I'll only get one shot at this as 'the light of my life' is rapidly losing patience with 'this will be my last speaker project'. She has been good over the past 35 years but after so many boxes (about 18 in total ) I think she is calling time and negotiation is not an available option.
Thanks once again.
John
jfs,
Glad to hear about your decision on the MLTL. Your room may guide you in choosing the optimum amount of BSC and stuffing to use in your speakers.
On the BSC what I suggest is 4 ohms and 1.5 mH as I have used those values and they work very well for my situation. The 4 ohms resistor provides about 3 dB compensation which is generally adequate if you have your speakers away from room walls 2-3 feet or more. If yours are closer to the walls, experiment with a lower resistor (2-3 ohms or so). If you place the speakers a greater distance from the room walls, experiment with raising the resistor value upward to about 6 ohms. In all cases limit yourself to a maximum amount of 8 ohms (6 dB compensation). Keep the inductor the same value.
On the stuffing I have found that your listening room may influence how much you use. Normal amount of damping is to fill the volume of the speaker from just below the driver and upward with stuffing. I use AcoustaStuf brand material but equivalent stuffing should be available under other product names. However, listening rooms vary between being 'live' or 'dead' vs. how much sound they absorb. Bottom line is that you should start with the normal amount of damping but reduce that amount if you have a 'dead' sounding room. GM (Greg Monfort) usually is in the camp of minimal stuffing as stuffing tends to impact how dynamic these speakers sound. Too much stuffing can dull the bass dynamics while too little can yield sound that is too lively. Thus your room may impact the balance between too lively or too dull bass. Your ears can help adapt your speakers to the room.
I hope that helps you in your building and perfection of your speakers. Building your own speakers gives you latitude that you normally would not have for store purchased models.
Jim Griffin
Glad to hear about your decision on the MLTL. Your room may guide you in choosing the optimum amount of BSC and stuffing to use in your speakers.
On the BSC what I suggest is 4 ohms and 1.5 mH as I have used those values and they work very well for my situation. The 4 ohms resistor provides about 3 dB compensation which is generally adequate if you have your speakers away from room walls 2-3 feet or more. If yours are closer to the walls, experiment with a lower resistor (2-3 ohms or so). If you place the speakers a greater distance from the room walls, experiment with raising the resistor value upward to about 6 ohms. In all cases limit yourself to a maximum amount of 8 ohms (6 dB compensation). Keep the inductor the same value.
On the stuffing I have found that your listening room may influence how much you use. Normal amount of damping is to fill the volume of the speaker from just below the driver and upward with stuffing. I use AcoustaStuf brand material but equivalent stuffing should be available under other product names. However, listening rooms vary between being 'live' or 'dead' vs. how much sound they absorb. Bottom line is that you should start with the normal amount of damping but reduce that amount if you have a 'dead' sounding room. GM (Greg Monfort) usually is in the camp of minimal stuffing as stuffing tends to impact how dynamic these speakers sound. Too much stuffing can dull the bass dynamics while too little can yield sound that is too lively. Thus your room may impact the balance between too lively or too dull bass. Your ears can help adapt your speakers to the room.
I hope that helps you in your building and perfection of your speakers. Building your own speakers gives you latitude that you normally would not have for store purchased models.
Jim Griffin
Mr. Griffin, thank you so much for your comprehensive reply to my query.
This is my first encounter with a single driver loudspeaker following years of building 2 and 3 way systems - all of which have been reasonable but not quite right.
However, in the face of such glowing testamonials regarding the jx92s and the MLTL design with the ribbon tweeter - well, it would be rude not to try it !.
Nothing else has worked for me with the exception of the Quad els57, of which a pair would be too large for my room.
On reflection in the past, I think that the integration of the multiple drivers have been the let down, never seamless and always delivering seemingly less - and I have had some quite esoteric ( for my pocket depth ) units both diy and commercial.
So now thanks to you and GM I am looking forward to a new experience, which at my age is something quite novel.
Also a big thank you to the forum contributors whose discussions, queries, suggestions and differences in opinions stimulated me to deviate from the 'norm'.
I'm really getting quite excited about the prospect of building this design.
Thank you so much once again.
Kind Regards
John
This is my first encounter with a single driver loudspeaker following years of building 2 and 3 way systems - all of which have been reasonable but not quite right.
However, in the face of such glowing testamonials regarding the jx92s and the MLTL design with the ribbon tweeter - well, it would be rude not to try it !.
Nothing else has worked for me with the exception of the Quad els57, of which a pair would be too large for my room.
On reflection in the past, I think that the integration of the multiple drivers have been the let down, never seamless and always delivering seemingly less - and I have had some quite esoteric ( for my pocket depth ) units both diy and commercial.
So now thanks to you and GM I am looking forward to a new experience, which at my age is something quite novel.
Also a big thank you to the forum contributors whose discussions, queries, suggestions and differences in opinions stimulated me to deviate from the 'norm'.
I'm really getting quite excited about the prospect of building this design.
Thank you so much once again.
Kind Regards
John
ra7,
You asked about links to the original design and I'm assuming you mean the reference to my "Jordan with a Ribbon MLTL" which adapts a GM like MLTL Jordan JX92S to a Aurum Cantus ribbon tweeter. My adaptation starts at:
http://www.diyaudio.com/forums/showthread.php?t=81634&highlight=Griffin
and continues on for now three years. My experiences with the JX92S started in 2001 with a full range JX92S mini-monitor. I continued with a version of the JX92S mini-monitor with a ribbon and finally an adaptation for the MLTL.
This GM MLTL JX92S thread is what you are reading now so between the "Jordan with a Ribbon MLTL" thread and this one you should have the full picture.
Jim
You asked about links to the original design and I'm assuming you mean the reference to my "Jordan with a Ribbon MLTL" which adapts a GM like MLTL Jordan JX92S to a Aurum Cantus ribbon tweeter. My adaptation starts at:
http://www.diyaudio.com/forums/showthread.php?t=81634&highlight=Griffin
and continues on for now three years. My experiences with the JX92S started in 2001 with a full range JX92S mini-monitor. I continued with a version of the JX92S mini-monitor with a ribbon and finally an adaptation for the MLTL.
This GM MLTL JX92S thread is what you are reading now so between the "Jordan with a Ribbon MLTL" thread and this one you should have the full picture.
Jim
Cheers Rahul
I have gone the 'Jordan' way primarily because of the write ups on this forum albeit a few years old and because many years ago I heard the Jordan Watts 2" metal dome modules ( probably mid seventies ) - they were atrocious to my ears at the time.
The reported improvement in Ted Jordans units over the years and the enthusiasm of contributors on this forum regarding suitable enclosures has sparked my interest as much as the dedication of Ted Jordan in his continuing development of his beliefs.
( I also managed to obtain a pair of boxed, unused units for half the price they sell at retail ).
Additionally, anyone who has designed enclosures/loudspeakers and have sufficient confidence in the Jordan units and enclosure to mate them with Ribbon tweeters costing almost as much again is either daft or has found a small pot of gold at the end of the rainbow. I prefer to think that GM and Jim Griffin have found a small pot of gold.
I hope they have, I'm at the last chance saloon as regards building something 'special'. I've had my orders from 'the boss'.
John
I have gone the 'Jordan' way primarily because of the write ups on this forum albeit a few years old and because many years ago I heard the Jordan Watts 2" metal dome modules ( probably mid seventies ) - they were atrocious to my ears at the time.
The reported improvement in Ted Jordans units over the years and the enthusiasm of contributors on this forum regarding suitable enclosures has sparked my interest as much as the dedication of Ted Jordan in his continuing development of his beliefs.
( I also managed to obtain a pair of boxed, unused units for half the price they sell at retail ).
Additionally, anyone who has designed enclosures/loudspeakers and have sufficient confidence in the Jordan units and enclosure to mate them with Ribbon tweeters costing almost as much again is either daft or has found a small pot of gold at the end of the rainbow. I prefer to think that GM and Jim Griffin have found a small pot of gold.
I hope they have, I'm at the last chance saloon as regards building something 'special'. I've had my orders from 'the boss'.
John
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