Martin Logan Serial Number Decoder - Collaborative Update Project

[Lite]

Some additions from my personal collection:

MA = Matinee
Format MAym nnn

BI (i not L)= Grotti I
Format GIym nnn

I'll try to get the format for my Sources soon.

 

[TheSequel]

My ML Sequels are of the format 8803173. Surely the "88" is 1988. If done as we do here at work, 8803 would be 3rd week of 1988.

My replacement panels for said Sequels (I tipped one over in 1998) are format SS1JA705.

The notes about the "1" designation and "7" being a replacement panel are missing from the updated decoder sheet.

 

[geeji]

Thanks for your inputs Lite, could you please clarify the following points :

MA = Matinee
Format MAym nnn

"ym" = 2 capital letters
The 2 Matinee examples pictures I found on Internet were MAUC030 and MATC 019.
Which by itself is curious, since supposedly same models have the same first 3 capital letters (the 4th letter is the year)

BI (i not L)= Grotti I
Format GIym nnn

Based on pictures I saw on Internet, I assume your "Grotti I" is actually "Grotto I"; please confirm.
Also I need the 3rd capital letter "y", which is part of the model designation.

 

[geeji]

My ML Sequels are of the format 8803173. Surely the "88" is 1988. If done as we do here at work, 8803 would be 3rd week of 1988.
My replacement panels for said Sequels (I tipped one over in 1998) are format SS1JA705.

Thanks for your input TheSequel.
The Decoder is only for loudspeakers up to now, so it explains replacement panels S/N do not fit into it.
But I am extremely surprised by your "8803173" S/N for your SEQUELs : the SEQUEL was part of the decoder sheet initially provided by Martin Logan, and their S/N should start with "SS".
Could you please provide a picture ? ; you can blur the last 4 digits.

 

[TheSequel]

Thanks for your input TheSequel.
The Decoder is only for loudspeakers up to now, so it explains replacement panels S/N do not fit into it.
But I am extremely surprised by your "8803173" S/N for your SEQUELs : the SEQUEL was part of the decoder sheet initially provided by Martin Logan, and their S/N should start with "SS".
Could you please provide a picture ? ; you can blur the last 4 digits.

Here ya go...

 

[ttocs]

^^^^ Maybe the "88" is instead of "SS"?

 

[geeji]

Here ya go...

View attachment 22483

Thanks for the picture TheSequel, extremely curious. I found an other Sequel on Internet with the same numbering scheme (8812023).
But Sequel II seems to follow the general (later ?) numbering scheme such as this S/N : SEDE411.
At this point I am not too sure what I should do : introduce an exception, with a single example ???

 

[Lite]

Thanks for your inputs Lite, could you please clarify the following points :

"ym" = 2 capital letters
The 2 Matinee examples pictures I found on Internet were MAUC030 and MATC 019.
Which by itself is curious, since supposedly same models have the same first 3 capital letters (the 4th letter is the year)

ym = Year/Month 2 letter product code with year/month. EG my Matinee was manufactured in December of 2010.

Based on pictures I saw on Internet, I assume your "Grotti I" is actually "Grotto I"; please confirm.
Also I need the 3rd capital letter "y", which is part of the model designation.

Correct, "Grotto I" typo on my part.

Same applies for my Grotto. 2 letter product code, then Year/Month letter designators.

All of my ML speakers were purchased within a 4 month timeframe, so it makes sense they would all follow the same SN convention.

 

[TheSequel]

Thanks for the picture TheSequel, extremely curious. I found an other Sequel on Internet with the same numbering scheme (8812023).
But Sequel II seems to follow the general (later ?) numbering scheme such as this S/N : SEDE411.
At this point I am not too sure what I should do : introduce an exception, with a single example ???

Search this forum - there are at least 2 other original Sequel owners who have posted the same style serial number. Sequel was only made for like 1 year before it was updated to Sequel II and serial number scheme was changed. If I had to guess, as they started producing several series of product, higher volume and different revisions/replacement panels etc, they had to update their serial number scheme to change date code from 4 digits to 2 to make room.

 

[geeji]

Thanks to Lite, an updated version of the S/N Decoder

 

[TheSequel]

The Sequel may have also used the "1", "2" etc. to identify replacement panels. This panel is a replacement for the original Sequel, or Sequel "1". Haven't seen a replacement panel for a Sequel II to confirm, however.

 

[Stereonerd]

Lordy, I'm hopeless at understanding graphs/charts. So, my Summits' serial number is: SUSF 414. Can anyone tell me what year they were built?

 

[Robert D]

Lordy, I'm hopeless at understanding graphs/charts. So, my Summits' serial number is: SUSF 414. Can anyone tell me what year they were built?

June 2007 I think. The panels themselves should have a number too, and then you can see if those are the original panels. Probably are.

 

[Stereonerd]

June 2007 I think. The panels themselves should have a number too, and then you can see if those are the original panels. Probably are.

Thanks for that. I believe that they are the original panels. The original owner bought the Summits as "new" from a store in Brisbane, Australia in 2012 (a long time to be sitting in the store if the manufacture date is right), shipped them to NZ and put them in storage until 2021 when he sold them to me. They sound incredible.

 

[Robert D]

Thanks for that. I believe that they are the original panels. The original owner bought the Summits as "new" from a store in Brisbane, Australia in 2012 (a long time to be sitting in the store if the manufacture date is right), shipped them to NZ and put them in storage until 2021 when he sold them to me. They sound incredible.

Take a good look at the inside of the panels for the serial number. I think mine are on the bottom of the panel.

I hope I decoded that right! Maybe someone else will verify that.

 

[geeji]

I hope I decoded that right! Maybe someone else will verify that.

You decoded perfectly Robert, according to the Decoder SUSF 414 is SUMMIT 2007 June, 414th unit manufactured this month.

Search this forum - there are at least 2 other original Sequel owners who have posted the same style serial number. Sequel was only made for like 1 year before it was updated to Sequel II and serial number scheme was changed. If I had to guess, as they started producing several series of product, higher volume and different revisions/replacement panels etc, they had to update their serial number scheme to change date code from 4 digits to 2 to make room.

Thanks TheSequel, I added a note for pre-1989 models (like Sequel 1) whose S/N seems to be only a 7 digits manufacturing date yymm###, with no built-in model identification.

 

[geeji]

The Sequel may have also used the "1", "2" etc. to identify replacement panels. This panel is a replacement for the original Sequel, or Sequel "1". Haven't seen a replacement panel for a Sequel II to confirm, however.

According to the original Decoder provided by Martin Logan, there is also some ambiguity related to the first 2 characters of the S/N : "S" could as well mean "Sequel" as "SL3".
Obviously, "SS" means "Sequel" ("Sequel" as well as "Sequel II" ?).
If anybody with a SL3 could provide the first 2 characters of his S/N, we could correct this ambiguity.
Note that "X2" for "Statement "also seems to violate the general S/N coding logic.

 

[JonFo]

If anybody with a SL3 could provide the first 2 characters of his S/N, we could correct this ambiguity.

Sure, I happen to have a 'spare' SL3 as decor at the entrance to my XStatic Theater.

The serial number on that one is SEJBnnn

Haven't seen a replacement panel for a Sequel II to confirm

When I ordered the replacement panels for the Monoliths and the SL3, I was told the SL3 panels are the same for the Sequel II. But I've yet to order replacements for my '1993-vintage Sequel IIb's as the panels work fine in their application (rear channels) as of now.

 

[geeji]

Sure, I happen to have a 'spare' SL3 as decor at the entrance to my XStatic Theater.
The serial number on that one is SEJBnnn

Thanks JonFo, very interesting "doorway"

 

[TheSequel]

When I ordered the replacement panels for the Monoliths and the SL3, I was told the SL3 panels are the same for the Sequel II. But I've yet to order replacements for my '1993-vintage Sequel IIb's as the panels work fine in their application (rear channels) as of now.

Interesting - I see that the solo SL3 in the doorway has the same spar arrangement that my replacement Sequel (manuf in 1998) panels had. I'll call it the 3-4-3 pattern for the (3 small, 4 large, 3 small). That's not counting the leftover even smaller strips at the top and bottom of panel. The original sequel and most of the Sequel II's I've seen have other patterns. I did see some Sequel's for sale with the same pattern, but luckily they showed the panel S/N and they also had replacement panels made in 1998. Seems I have SL3 replacement panels. No issues for past 24 years, I just measured the frequency response and they are +/-4dB in-room from 200-20kHz @ 90dB SPL. As for the spar locations, currently their modern line has settled on a big-small alternating pattern, but it's fascinating looking at pictures of the "tweaking" of spar locations that has occurred over the years!

I added a note for pre-1989 models (like Sequel 1) whose S/N seems to be only a 7 digits manufacturing date yymm###, with no built-in model identification.

Thanks for adding that note Minor quibble, the PDF says "pre-1988" whereas it should say "pre-1989" as you correctly noted in the quote.