smallangryboy said:
Okay, I'll bite.
Here's my take on how a folded MLTL48 might look. It would give an enclosure 7.5" wide, 12.25" deep and 25.5" high. You'd have to incorporate a stand or extend the enclosure (with a sand-filled cavity), height to suit. The horizontal divide would be 2" thick, all the rest 0.75" material.
A bit deep and not as elegant as the original but it gets close to your size requirement. I have no idea how the loading would change with the folds but at least it would be a stable box!
Attachments
Hi Dave - thanks for the comment. Yes, I wondered about the void in the back but left it off for simplicity. If open to the back, the void could incorporate a reflector to 'load' the port in the same way as GM's original 31MLTL. The height of the void would also allow some flexibility to vary one of the two 11.5" line lengths so they were dissimilar.
MLTL 31 VS 48
Hi everyone, a new member here with a quick question.
I believe I have read everything that has been written on the internet about GM's MLTL's 31 and 48 designs (and their variations) and there is something that is still not clear for me.
As a matter of fact the 31' version becomes at least a 44' tower when the extension is added, making it in practice very similar to the 48' in terms of height.
So, since the 48' reaches 35Hz vs 45Hs with the 31' and the 48 seems easier to build, what is the advantage of building the 31' version?
Do they have a different sonic character altogether? Are they suitable for different rooms, purposes , tastes, etc??
I am about to receive a pair of JX92s to build my first DIY speakers and your comments will be greatly appreciated. I have a tight budget and unfortunately I cannot build them both to compare. Actually, my plan in principle is to build Jim Griffin's 46' version in order to be able to eventually add the Aurum Cantus G2si if I feel it necessary (using his xover design), but I am still intrigued about the possible convenience of going for the 31'
Many thanks
Antonio
Hi everyone, a new member here with a quick question.
I believe I have read everything that has been written on the internet about GM's MLTL's 31 and 48 designs (and their variations) and there is something that is still not clear for me.
As a matter of fact the 31' version becomes at least a 44' tower when the extension is added, making it in practice very similar to the 48' in terms of height.
So, since the 48' reaches 35Hz vs 45Hs with the 31' and the 48 seems easier to build, what is the advantage of building the 31' version?
Do they have a different sonic character altogether? Are they suitable for different rooms, purposes , tastes, etc??
I am about to receive a pair of JX92s to build my first DIY speakers and your comments will be greatly appreciated. I have a tight budget and unfortunately I cannot build them both to compare. Actually, my plan in principle is to build Jim Griffin's 46' version in order to be able to eventually add the Aurum Cantus G2si if I feel it necessary (using his xover design), but I am still intrigued about the possible convenience of going for the 31'
Many thanks
Antonio
Hi Antonio,
Welcome to DIY!!
The biggest differences between the two are the 31" is more narrow than the 48"er (at least the way I build them). As you've already mentioned, the 48"er will go lower than the 31". But probably the most significant difference between the two is there seems to be some harmonic interaction in the 48"er that you don't get in the 31".
I enjoy this 'coloration' in the 48"er very much. The sound of the 31" is more analytic or more, I hate to say it this way, true if you will. Now please understand I am not saying one is better than the other. Believe me you will be delighted with whichever one you choose to build. They both are truly excellent speakers.
I'm sure Colin can add some light on this as well.
Hope that helps a little -
Bruce
Welcome to DIY!!
The biggest differences between the two are the 31" is more narrow than the 48"er (at least the way I build them). As you've already mentioned, the 48"er will go lower than the 31". But probably the most significant difference between the two is there seems to be some harmonic interaction in the 48"er that you don't get in the 31".
I enjoy this 'coloration' in the 48"er very much. The sound of the 31" is more analytic or more, I hate to say it this way, true if you will. Now please understand I am not saying one is better than the other. Believe me you will be delighted with whichever one you choose to build. They both are truly excellent speakers.
I'm sure Colin can add some light on this as well.
Hope that helps a little -
Bruce
abpea said:Hi Antonio,
Welcome to DIY!!
The biggest differences between the two are the 31" is more narrow than the 48"er (at least the way I build them). As you've already mentioned, the 48"er will go lower than the 31". But probably the most significant difference between the two is there seems to be some harmonic interaction in the 48"er that you don't get in the 31".
I enjoy this 'coloration' in the 48"er very much. The sound of the 31" is more analytic or more, I hate to say it this way, true if you will. Now please understand I am not saying one is better than the other.
Thanks Bruce,
I remember someone saying that the 31' has a "tight" bass response. If tight means a clear, well defined, response maybe this be a reason for its analitic character? Lets see what others say.
Antonio
Correctomundo! My audio goals from the get-go has been to as accurately reproduce the signal as practical, so design vented alignments that have the accuracy of a 0.5 Qtc sealed cab in our acute hearing BW except with more gain BW.
The 48" done at Bruce's request and by far the most popular of the two OTOH is proof positive that most folks 'talk the talk' of wanting accuracy of reproduction, but the reality is most prefer some euphonic distortion to artificially replace some of the subtle ambient information often lost in the recording process, hence the continuing popularity of tube electronics and under-damped (sub) woofer cab alignments.
I've neither built nor auditioned either, but some others who have done both note that BSC is required for the 48" Vs the 31" just needing to be toe'd in per Jordan's recommendation.
As always though, YMMV.
GM
The 48" done at Bruce's request and by far the most popular of the two OTOH is proof positive that most folks 'talk the talk' of wanting accuracy of reproduction, but the reality is most prefer some euphonic distortion to artificially replace some of the subtle ambient information often lost in the recording process, hence the continuing popularity of tube electronics and under-damped (sub) woofer cab alignments.
I've neither built nor auditioned either, but some others who have done both note that BSC is required for the 48" Vs the 31" just needing to be toe'd in per Jordan's recommendation.
As always though, YMMV.
GM
Bruce and GM beat me to it. Good summary from Bruce (who has probably built more JX92S variants than anyone on the planet). I would add that the 31 is probably the better bet if you are planning to use the speakers in corners.
Scott produced a couple of sims for me a while back, which I've added below. These may give a clue as to why the 48 needs BSC to overcome a leaness to the sound. If the 31 will do without BSC, you'll have a more efficient speaker and can always add a sub later, funds permitting.
GM's insight is fascinating. I've never been a fan of tubes but appreciate that accuracy is not the easiest aspect of sound to live with in the home. The 48s certainly draw you in and make you want to listen. They may well be more amp dependant than the 31 - the Naim amp I use has a reputation for leaness so the two balance each other to an extent.
BTW, Instead of a group buy we should instigate a group build so that GM can hear why we think his design is so good.
Scott produced a couple of sims for me a while back, which I've added below. These may give a clue as to why the 48 needs BSC to overcome a leaness to the sound. If the 31 will do without BSC, you'll have a more efficient speaker and can always add a sub later, funds permitting.
GM's insight is fascinating. I've never been a fan of tubes but appreciate that accuracy is not the easiest aspect of sound to live with in the home. The 48s certainly draw you in and make you want to listen. They may well be more amp dependant than the 31 - the Naim amp I use has a reputation for leaness so the two balance each other to an extent.
BTW, Instead of a group buy we should instigate a group build so that GM can hear why we think his design is so good.
Attachments
abpea said:
In terms of dimensions, according to Jordan's page the only difference between the two apart from the height is the driver placement from the top but the original designs are equally wide.
Colin said:
I am actually for flexibility in terms of placement. I want to have as many options as possible when negotiating with my wife the speakers position.
Colin, thanks for the sims. Now I have to do my homework to understand all the subtle differences in paper properly. That's the only way to learn.
I would have never thought that accuracy could be an issue when one is in principle looking for (high) fidelity. You and GM are really making me think. I do want something I want to listen without much fatigue even if some coloration is around.
I hope my Sonographe amp and pre amp (a 1980's Conrad Johnson entry level models) do a good job with Jordans either with the 48 or 31.
Anyway, thank you all for your replies, which make the decision more difficult but a lot more interesting!
Antonio
I think Bruce produced a wider front version of the triangle than is shown on the Jordan pages. You could do this with either of the two MLTL designs, so don't worry about that too much.
I've found the 48 a joy to listen to, pulling out bass lines and information I have not heard before. It's only once been caught out by a track which sounded overblown. But the design as shown on the Jordan site does need the BSC to avoid a thinness to male voices. Again, a wider baffle might sort that and warm up the sound at the expense of a bulkier-looking cabinet.
My previous Jordans - a JX53/JX125 design - had a sealed cabinet aligned to 0.7 which rolled off below 45Hz. So in theory more accurate than the 48s. It sounded good but upon hearing the 48 triangles, my partner's reaction was: "Sell the old ones".
My reading of Scott's sims - given that I have only heard the 48 version - is that the 31 may not sound as initially exciting as it doesn't have the lower bass kick of the 48. And that kick may come from the low bass being exposed compared to the lowered output in the 150-400Hz region. Given that you have tube amplification (I assume, I'm not familiar with the model), perhaps the 31 is the one to go for, the accuracy of the bass balancing out any warmness from the amplifier.
I've found the 48 a joy to listen to, pulling out bass lines and information I have not heard before. It's only once been caught out by a track which sounded overblown. But the design as shown on the Jordan site does need the BSC to avoid a thinness to male voices. Again, a wider baffle might sort that and warm up the sound at the expense of a bulkier-looking cabinet.
My previous Jordans - a JX53/JX125 design - had a sealed cabinet aligned to 0.7 which rolled off below 45Hz. So in theory more accurate than the 48s. It sounded good but upon hearing the 48 triangles, my partner's reaction was: "Sell the old ones".
My reading of Scott's sims - given that I have only heard the 48 version - is that the 31 may not sound as initially exciting as it doesn't have the lower bass kick of the 48. And that kick may come from the low bass being exposed compared to the lowered output in the 150-400Hz region. Given that you have tube amplification (I assume, I'm not familiar with the model), perhaps the 31 is the one to go for, the accuracy of the bass balancing out any warmness from the amplifier.
Colin said:
Antonio,
What Colin suggests in the quote above is exactly what I do. The baffle on my 48"ers are significantly wider than the plans call for. I tried a BSC on my 48"er and didn't like it so I listen to mine wired straight from the amp to the driver. Never thought the 31" version needed a BSC either.
Go for it, you'll not regret building either design.
Bruce
Bruce/Colin
Thanks for your replies/advise.
The Sonographe is a Mosfet amp and apparently Mosfet transistors produce a very tube like sound.
I like the idea of the triangular shape to avoid reflections but I am a bit afraid of the construction difficulties, mainly of having the wood angles perfectly cut and then I imagine that the clamping/gluing/bracing process is easier with rectangular shapes than with triangles. There is a CNC cutting company in London that would do any cut at a reasonable price but they do MDF only and I have not found a company that would do he same with plywood (all these things in London are particularly expensive).
My problem is that I will build the boxes in the London way: that is, in my little kitchen...
I will definitely go for it but will decide the size/shape tomorrow evening after work and a couple of drinks.
Antonio
Thanks for your replies/advise.
The Sonographe is a Mosfet amp and apparently Mosfet transistors produce a very tube like sound.
I like the idea of the triangular shape to avoid reflections but I am a bit afraid of the construction difficulties, mainly of having the wood angles perfectly cut and then I imagine that the clamping/gluing/bracing process is easier with rectangular shapes than with triangles. There is a CNC cutting company in London that would do any cut at a reasonable price but they do MDF only and I have not found a company that would do he same with plywood (all these things in London are particularly expensive).
My problem is that I will build the boxes in the London way: that is, in my little kitchen...
I will definitely go for it but will decide the size/shape tomorrow evening after work and a couple of drinks.
Antonio
Actually what will really help me decide between 31' and 48' is this:
Which one in your opinion performs better (in terms of balance between highs mids and lows) at lower volumes??
I wonder if the 48' would show its capabilities in the low range also at low volumes.
Your feedback will again be very appreciated.
Antonio
Which one in your opinion performs better (in terms of balance between highs mids and lows) at lower volumes??
I wonder if the 48' would show its capabilities in the low range also at low volumes.
Your feedback will again be very appreciated.
Antonio
Okay, Bruce is your man for the comparison.
Re the 48, I'm happy listening at low volumes - my listening levels peak at 85dB and are usually in the upper 70s dB - and the bass seems to provide enough drive to keep toes tapping at low levels.
Interesting question whether a more accurate speaker would need more volume to come alive. I wonder if GM has any information on this.
Re the 48, I'm happy listening at low volumes - my listening levels peak at 85dB and are usually in the upper 70s dB - and the bass seems to provide enough drive to keep toes tapping at low levels.
Interesting question whether a more accurate speaker would need more volume to come alive. I wonder if GM has any information on this.
Antonio
I sent you an off-board email inviting you to contact me by phone.
I'm running a pair of 48" MLTLs in Chiswick, West London. I don't know which part of London you are in, but you are welcome to come and hear them if you want. They are pentagonal and have a ribbon tweeter using a xover based on Jim's but I can easily run them without the ribbon and xover as in the original design.
I also have some suggestions about getting the wood cut.
Please check if you got the email and contact me or post a reply if you if you didn't. I don't want to put my phone number on the web.
I sent you an off-board email inviting you to contact me by phone.
I'm running a pair of 48" MLTLs in Chiswick, West London. I don't know which part of London you are in, but you are welcome to come and hear them if you want. They are pentagonal and have a ribbon tweeter using a xover based on Jim's but I can easily run them without the ribbon and xover as in the original design.
I also have some suggestions about getting the wood cut.
Please check if you got the email and contact me or post a reply if you if you didn't. I don't want to put my phone number on the web.
Nardis, Thanks very much. I got your e-mail but I could not reply earlier. Your offer is very welcome and appreciated. Nothing like listening to the speakers myself. I will e-mail you in a moment.
Thanks Colin. The issue of low volume came to my mind when I thought about the reality of home systems (at least my reality). Apart from the few times I will find to enjoy the speakers at mid- high volume, most of the time I will be listening to music while spending time with my wife and daughter and honestly we cannot cope with high volumes for a long time. However, that does not mean I like having, damped, semi-dead or indistinguishable music playing at the back. Also, it is nice to be able to play a nice music passage for others without blowing everyone ears and stopping completely the flow of a conversation because the music needs to be very loud for the speakers to come alive . I know this topic is very subjective, but anyway this is my view.
Lets see what the others say about low volume performance of these speakers.
Antonio
Thanks Colin. The issue of low volume came to my mind when I thought about the reality of home systems (at least my reality). Apart from the few times I will find to enjoy the speakers at mid- high volume, most of the time I will be listening to music while spending time with my wife and daughter and honestly we cannot cope with high volumes for a long time. However, that does not mean I like having, damped, semi-dead or indistinguishable music playing at the back. Also, it is nice to be able to play a nice music passage for others without blowing everyone ears and stopping completely the flow of a conversation because the music needs to be very loud for the speakers to come alive . I know this topic is very subjective, but anyway this is my view.
Lets see what the others say about low volume performance of these speakers.
Antonio
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