After two years of building different First Watt and Pass Labs amps (F1J, F2J, F4, F4 with SS100, F5, Aleph P, Pumpkin, UGS v3, BA-1, BA-1 with SS100, BA-2, Aleph3,Aleph 30, Aleph60 and Babelfish J2) I had much pleasure, but could not fix the problem that my speakers Thiel SCS4 (3,9 Ohm, 87 db) did not match in the right way with the First Watt line and the Alephs giving more power had not the effortless sound of the Semisouth solutions.
So I sold my beloved Thiel and looked for some Lowthers. I found an offer, two Acousta 115 with PM6A for half the price... I asked my wife.... she agreed and drove me to the merchant and back with the precious speakers on board.
Fine sound, very detailed and lively, but the bass was small and clumsy.
I was a bit disappointed......
searching for a solution I found Jon Ver Halens TOA (Tiny Open Baffle Alnico) and it solved the rest of the problem.
Tone Tubby 12´´ for the bass and PM6A .... what a wonderful combination! I do not understand why this solution can reproduce effortless Stanley Clarks bass lines, going down to the same point to about 70 Hz and Acoustas could not.
I have only small rooms and I doubted if the baffles would work.
Big surprise, no problem at all... best sound ever, huge stage and wonderfull voices, fast details.
The recommended ASC oil caps are good for shouty Lowther, I first used Obbligato, not bad too... a bit more stressing in long time hearing.
In the background you see my Pumpkin Pre and Babelfish J2....
Please excuse this a bit off topic writing, but I had to place it in the Pass forum, giving me the help I needed to go along this way...
special thanks to Mr. Pass, Zen Mod, tea-bag, flg, Bill Fuss, Melon Head and some guys from the diyaudio.rs forum (especially spavlesky)for good advices on the way.
So I sold my beloved Thiel and looked for some Lowthers. I found an offer, two Acousta 115 with PM6A for half the price... I asked my wife.... she agreed and drove me to the merchant and back with the precious speakers on board.
Fine sound, very detailed and lively, but the bass was small and clumsy.
I was a bit disappointed......
searching for a solution I found Jon Ver Halens TOA (Tiny Open Baffle Alnico) and it solved the rest of the problem.
Tone Tubby 12´´ for the bass and PM6A .... what a wonderful combination! I do not understand why this solution can reproduce effortless Stanley Clarks bass lines, going down to the same point to about 70 Hz and Acoustas could not.
I have only small rooms and I doubted if the baffles would work.
Big surprise, no problem at all... best sound ever, huge stage and wonderfull voices, fast details.
The recommended ASC oil caps are good for shouty Lowther, I first used Obbligato, not bad too... a bit more stressing in long time hearing.
In the background you see my Pumpkin Pre and Babelfish J2....
Please excuse this a bit off topic writing, but I had to place it in the Pass forum, giving me the help I needed to go along this way...
special thanks to Mr. Pass, Zen Mod, tea-bag, flg, Bill Fuss, Melon Head and some guys from the diyaudio.rs forum (especially spavlesky)for good advices on the way.
Attachments
After two years of building different First Watt and Pass Labs amps (F1J, F2J, F4, F4 with SS100, F5, Aleph P, Pumpkin, UGS v3, BA-1, BA-1 with SS100, BA-2, Aleph3,Aleph 30, Aleph60 and Babelfish J2) I had much pleasure, but could not fix the problem that my speakers Thiel SCS4 (3,9 Ohm, 87 db) did not match in the right way with the First Watt line and the Alephs giving more power had not the effortless sound of the Semisouth solutions.
So I sold my beloved Thiel and looked for some Lowthers. I found an offer, two Acousta 115 with PM6A for half the price... I asked my wife.... she agreed and drove me to the merchant and back with the precious speakers on board.
Fine sound, very detailed and lively, but the bass was small and clumsy.
I was a bit disappointed......
searching for a solution I found Jon Ver Halens TOA (Tiny Open Baffle Alnico) and it solved the rest of the problem.
Tone Tubby 12´´ for the bass and PM6A .... what a wonderful combination! I do not understand why this solution can reproduce effortless Stanley Clarks bass lines, going down to the same point to about 70 Hz and Acoustas could not.
I have only small rooms and I doubted if the baffles would work.
Big surprise, no problem at all... best sound ever, huge stage and wonderfull voices, fast details.
The recommended ASC oil caps are good for shouty Lowther, I first used Obbligato, not bad too... a bit more stressing in long time hearing.
In the background you see my Pumpkin Pre and Babelfish J2....
Please excuse this a bit off topic writing, but I had to place it in the Pass forum, giving me the help I needed to go along this way...
special thanks to Mr. Pass, Zen Mod, tea-bag, flg, Bill Fuss, Melon Head and some guys from the diyaudio.rs forum (especially spavlesky)for good advices on the way.
I can see you are using a passive crossover. I am using a similar design with tone tubbys, though not with lowthers but with fostexs. Can you share the crossover design?
Cheers.
Is it still panoramic ?
Congrats !
thanks Juma,
more panoramic than ever.......! I get lost in space and time....
you know the dipole characteristic of the baffles makes more room after the speakers.....
hi anilva,
the crossover is on the Lowther America side from Jon, but the values are for Lowthers PM6A..... I do not know if they will fit to your Fostex..... on the other side they are normally calculated for 200 Hz crossover and the bafffle size.... I suppose.
Tiny Alnico Open Baffle
much luck!
I think more important is if your Fostex have the same efficiency of the tone tubby around 96/97 db.....
and to get more on topic... I tried F1J and F2J on the baffles too... there was considerably more bass with the tone tubbies, but the overall sound is the best with FET input and SemiSouth of Babelfish J2 .....
I did not try, but I think F3 and F4 would be also good candidates for this open baffle. I did not try F3 up to now ( excuse me Gyuri, he sent me two of precious Lu1014, a parcel for you is on the way).....
and to get more on topic... I tried F1J and F2J on the baffles too... there was considerably more bass with the tone tubbies, but the overall sound is the best with FET input and SemiSouth of Babelfish J2 .....
I did not try, but I think F3 and F4 would be also good candidates for this open baffle. I did not try F3 up to now ( excuse me Gyuri, he sent me two of precious Lu1014, a parcel for you is on the way).....
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the forum subject is "Amplifiers-Pass Labs"
and I write mostly about open baffles......
the forum subject is "Amplifiers-Pass Labs"
and I write mostly about open baffles......
Juz blame that on ZM - no wait - that would be incorrect - I don't think ZM is OB kinda guy (I am).
When you write a bunch of pages about 1st Watt stuff you can give credit to Papa about all of the good things - and have some fun with ZM about all the stuff that blew up - smoked - made sparks - blew fuses - etc.......
Not really of course - but we gotta keep him on his toes - just because...
Attachments
ya sure about that .......... ?
http://www.diyaudio.com/forums/multi-way/106603-all-eminence-ob.html?highlight=eminence
Thanks. Lowthers are more efficient than fostexs. Will build and check how they sound. May need to tweak attenuation of tone tubby.
no attenuation in bass range
in my book even attenuation in main range kills something
either go to biamp or
use autoformer for taming bass range or
use autoformer to up main range
resistive attenuator in bass range is good just for finding level of attenuation
Hi Zen Mod,
nice to see in the link how you helped Yunick 2007 to get a very good low cost open baffle system....
very interesting lecture for me today to read......
http://www.diyaudio.com/forums/multi-way/106603-all-eminence-ob.html
the residual problem is the deep bass, I do not miss him up to now, to much details to hear new in the midrange and in the deeeeeeeeeeepness of soundstage, but inevitably the day will come i want to hear at least 40 Hz.....
nice to see in the link how you helped Yunick 2007 to get a very good low cost open baffle system....
very interesting lecture for me today to read......
http://www.diyaudio.com/forums/multi-way/106603-all-eminence-ob.html
the residual problem is the deep bass, I do not miss him up to now, to much details to hear new in the midrange and in the deeeeeeeeeeepness of soundstage, but inevitably the day will come i want to hear at least 40 Hz.....
send me T/S for TTs
I "made" what I made then purely by experience with Eminence drivers in servicing PA gear and some bits form www ; now it's easier - with MJK sheets
usually - more bass goes either with biamp or simply doubling number of them
NB that deepness is different issue , even if with 2 per side they really go little lower
considering your residence ( small room in Vaterland ) maybe chasing mint Canton Plus B ( or similar ) is worth chasing ....
I "made" what I made then purely by experience with Eminence drivers in servicing PA gear and some bits form www ; now it's easier - with MJK sheets
usually - more bass goes either with biamp or simply doubling number of them
NB that deepness is different issue , even if with 2 per side they really go little lower
considering your residence ( small room in Vaterland ) maybe chasing mint Canton Plus B ( or similar ) is worth chasing ....
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send me T/S for TTs
I "made" what I made then purely by experience with Eminence drivers in servicing PA gear and some bits form www ; now it's easier - with MJK sheets
usually - more bass goes either with biamp or simply doubling number of them
NB that deepness is different issue , even if with 2 per side they really go little lower
considering your residence ( small room in Vaterland ) maybe chasing mint Canton Plus B ( or similar ) is worth chasing ....
Hi Zen Mod,
I went to the tone tubby side
and got these two pictures...
the values are a surprise for me not going down very far....
Attachments
saved in //Generg/OB/
considering PM6A - 8 Ohms , Al coil ?
PM6A Drive Unit
Theile Small Parameters for PM6A with 8 ohm Aluminium Voice Coil DC Resistance of Voice Coil Re 7.4 ohms
Free Air Resonance Fo 61.980 Hz
Emission Piston Area Sd 0.021M²
Equivalent Volume Suspension Vas 47.192 Ltrs
Suspension Compliance Cms 753.6 u M/N
Mass of Cone Mmd 7.0 g
Mass of Moving Parts Mms 8.75 g
Force Factor Bl 7.27 T-M
Mechanical Q Factor Qms 1.578
Electrical Q Factor Qes 0.477
Total Q Factor Qts 0.366
Voice Coil Inductance @ 1 kHz Le 148.2 uH
Reference Efficiency No 2.278%
Sound Pressure Level SPL 95.593 Db
what I also need is :
dimensions of OB and exact position of drivers
considering PM6A - 8 Ohms , Al coil ?
PM6A Drive Unit
Theile Small Parameters for PM6A with 8 ohm Aluminium Voice Coil DC Resistance of Voice Coil Re 7.4 ohms
Free Air Resonance Fo 61.980 Hz
Emission Piston Area Sd 0.021M²
Equivalent Volume Suspension Vas 47.192 Ltrs
Suspension Compliance Cms 753.6 u M/N
Mass of Cone Mmd 7.0 g
Mass of Moving Parts Mms 8.75 g
Force Factor Bl 7.27 T-M
Mechanical Q Factor Qms 1.578
Electrical Q Factor Qes 0.477
Total Q Factor Qts 0.366
Voice Coil Inductance @ 1 kHz Le 148.2 uH
Reference Efficiency No 2.278%
Sound Pressure Level SPL 95.593 Db
what I also need is :
dimensions of OB and exact position of drivers
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