Hi!
Yesterday I picked up some speakers:-
Griffin 27's AKA Omega 3.
They appear to be mid-1970's units, and sport the following features:
KEF B200 Bass Unit, 25Hz ~ 2.3KHz
KEF T52 Mid/trebble unit, 1.6KHz ~ 7KHz
Coles/S.T.C 4001K hand-picked super tweeters, 6.5KHz ~ 25KHz
The speakers are in MINT condition - as in they look never used, came fully boxed, with original datasheet.
The datasheet claims a frequency response of 30Hz ~ 25KHz within 2.5dB (WOW!?!?!)
They have an infinite baffle design, and Aperiodic crossover network (What is special about this?) and real wood construction.
I paid £100.
According to the datasheet the Aperiodic crossover network somehow damps potentional resonance at 75Hz and 2.5KHz.
Looking at the datasheet, construction, condition, and the highly acclaimed nature of the drivers in use in these speakers, I would have expected mind-blowing results.
I do feel dissapointed. They come accross as phenominal in the high-end and mid range but bass seems to not exist atall. I think this may have something to do with my amp?
I am using a Mk I Rotel RA-931
Source components include a Rotel RP-830 Turntable with Ortofon OM10 cartridge, a NAD 5425 CD Player, and a NAD 4225 tuner.
Interconnects are the usual high quality fare with nice audio cables terminated at each end with 24K Gold banana plugs.
Atacama stands from the same period as the speakers.
Opinions on this setup? Should it be good?
I am especially interested in opinions on the speakers, as they are unmentioned on the interweb!
Yesterday I picked up some speakers:-
Griffin 27's AKA Omega 3.
They appear to be mid-1970's units, and sport the following features:
KEF B200 Bass Unit, 25Hz ~ 2.3KHz
KEF T52 Mid/trebble unit, 1.6KHz ~ 7KHz
Coles/S.T.C 4001K hand-picked super tweeters, 6.5KHz ~ 25KHz
The speakers are in MINT condition - as in they look never used, came fully boxed, with original datasheet.
The datasheet claims a frequency response of 30Hz ~ 25KHz within 2.5dB (WOW!?!?!)
They have an infinite baffle design, and Aperiodic crossover network (What is special about this?) and real wood construction.
I paid £100.
According to the datasheet the Aperiodic crossover network somehow damps potentional resonance at 75Hz and 2.5KHz.
Looking at the datasheet, construction, condition, and the highly acclaimed nature of the drivers in use in these speakers, I would have expected mind-blowing results.
I do feel dissapointed. They come accross as phenominal in the high-end and mid range but bass seems to not exist atall. I think this may have something to do with my amp?
I am using a Mk I Rotel RA-931
Source components include a Rotel RP-830 Turntable with Ortofon OM10 cartridge, a NAD 5425 CD Player, and a NAD 4225 tuner.
Interconnects are the usual high quality fare with nice audio cables terminated at each end with 24K Gold banana plugs.
Atacama stands from the same period as the speakers.
Opinions on this setup? Should it be good?
I am especially interested in opinions on the speakers, as they are unmentioned on the interweb!
Attachments
Cabinet looks to be the same size as the IMF "Compact"
I had a pair of those and while the mid-range was very good I was always disappointed in the bass.
Price is right, the drivers would cost what you paid, what in particular don't you like with these??
Regards
Ted
I had a pair of those and while the mid-range was very good I was always disappointed in the bass.
Price is right, the drivers would cost what you paid, what in particular don't you like with these??
Regards
Ted
Thanks for the reply.
Well to be honest I was initially dissapointed by the lack of extended bass, and expected more presence, but having sat down to Pat Metheny's "Watercolours" album I can see what these speakers are all about.
They do reproduce my source material rather faithfully and portray the bass in an astonishingly clear manner, I think possibly because I am used to "in your face" bass AKA Mission I need to sit down and listen to some music for a while to fully appreciate where these speakers are coming from.
Their agility and accuracy with Jazz, Classical, and Vocal music is astonishing, I might try some Enya in a bit, namely Boadacia, to see how they fare in the bass department now that the amp has warmed up a bit 🙂
Do you think the rest of my equiptment does them justice? I can't help thinking that the amp may be to blame for these speakers "Bright" colouration?
Well to be honest I was initially dissapointed by the lack of extended bass, and expected more presence, but having sat down to Pat Metheny's "Watercolours" album I can see what these speakers are all about.
They do reproduce my source material rather faithfully and portray the bass in an astonishingly clear manner, I think possibly because I am used to "in your face" bass AKA Mission I need to sit down and listen to some music for a while to fully appreciate where these speakers are coming from.
Their agility and accuracy with Jazz, Classical, and Vocal music is astonishing, I might try some Enya in a bit, namely Boadacia, to see how they fare in the bass department now that the amp has warmed up a bit 🙂
Do you think the rest of my equiptment does them justice? I can't help thinking that the amp may be to blame for these speakers "Bright" colouration?
Your source equipment is probably much better than anything these speakers would have had been used with when new.
You may want to listen for a while and then think abut subs, these are not in your face with the bass, the B200 just doesn't have that last bottom octave, also power handling isn't great
You may want to listen for a while and then think abut subs, these are not in your face with the bass, the B200 just doesn't have that last bottom octave, also power handling isn't great
I just found how to explain the bass - after listening to a wide variety of music - the bass is clear and present, but where it should be - at the back of the room 😉
I find these units so un-fatiguing I really don't miss the punchy undertones one bit 😀
I find these units so un-fatiguing I really don't miss the punchy undertones one bit 😀
izools said:
Aperiodic vent possibly?
Marketing babble ...essentially a resistive air leak, or a stuffed oft tuned hole/vent.
Very useful when used with higher Q woofers with small magnets (weak motors).
Ah I see it refers to the vent at the top-right (See the foam?) - it's a resistive port as you say 🙂
Thank you. I'm learning more every day 😀
Thank you. I'm learning more every day 😀
Hi,
Looks like a copy of the 60's American east coast sound. (ARs, ADS, boston Ac) I really like mid domes and big woofers with sealed infinite baffle bass.
Looks like a copy of the 60's American east coast sound. (ARs, ADS, boston Ac) I really like mid domes and big woofers with sealed infinite baffle bass.
Griffin 27
Hi
I was an apprentice at Griffin Electronics and most likely built your speakers in the mid 70`s.
Aperiodic refers to certain resonance frequencys of the driver being filtered out by the crossover.
(take a look inside - there very complex).
Paul Griffin was a genius - but was also an unstable man.
Hi
I was an apprentice at Griffin Electronics and most likely built your speakers in the mid 70`s.
Aperiodic refers to certain resonance frequencys of the driver being filtered out by the crossover.
(take a look inside - there very complex).
Paul Griffin was a genius - but was also an unstable man.
Is that a B200 SP1014?
And the question was raised, is that an aperiodic port next to the Coles?
And can you take a close up pic of the coles? What are the red bits?
dave
PS: i love the depth of this forum...thanx for dropping in the thread deaks.
And the question was raised, is that an aperiodic port next to the Coles?
And can you take a close up pic of the coles? What are the red bits?
dave
PS: i love the depth of this forum...thanx for dropping in the thread deaks.
Deaks50 - that's amazing to find someone who probably originally built these speakers just on the off chance! Good work by the way 🙂
Planet10 - yes that's a B200 SP1014
I'll take a close up pic tomorrow - the red bits are the cones themselves - you'll see (hopefully) in the close ups 🙂
It is a resistive port next to the Coles yes, but as Deaks50 sais the term aperiodic reffers to the design of the crossover which passively filters the peaks and troughs in the impedance graph; so as to create a more linear and consistent impedance of the speakers accross the frequency range.
I'll post up a copy of the original datasheet too... tomorrow 🙂
Planet10 - yes that's a B200 SP1014
I'll take a close up pic tomorrow - the red bits are the cones themselves - you'll see (hopefully) in the close ups 🙂
It is a resistive port next to the Coles yes, but as Deaks50 sais the term aperiodic reffers to the design of the crossover which passively filters the peaks and troughs in the impedance graph; so as to create a more linear and consistent impedance of the speakers accross the frequency range.
I'll post up a copy of the original datasheet too... tomorrow 🙂
Aperiodic
Hi
No Aperiodic refers to the design of crossover.
The port was a standard tuned reflex system covered with foam.
Hi
No Aperiodic refers to the design of crossover.
The port was a standard tuned reflex system covered with foam.
Aperiodic
Hi
The coles was a lower cost production option in the late 70`s, the red ring you can see was just a cosmetic feature of the cone.
The mid range driver was a Kef unit with the outer securing ring removed (it was used to secure the foam covering the reflex port)
Paul designed the speakers to be neutral in response across the range, as he disliked speakers that had a characteristic "sound".
Perhaps this explains the apparent lack of bass?
Hi
The coles was a lower cost production option in the late 70`s, the red ring you can see was just a cosmetic feature of the cone.
The mid range driver was a Kef unit with the outer securing ring removed (it was used to secure the foam covering the reflex port)
Paul designed the speakers to be neutral in response across the range, as he disliked speakers that had a characteristic "sound".
Perhaps this explains the apparent lack of bass?
Aperiodic
Hi
A high quality mike positioned directly in front of the cone/dome was used to map high spots in the frequency response of the driver, which were then filtered out passively in the crossover.
It was an idea inspired by the tri amplified Griffin 85 speakers with electronic crossovers and "tandem line" actively braked bass
system (a fantastic speaker-and very advanced for it`s time).
Hi
A high quality mike positioned directly in front of the cone/dome was used to map high spots in the frequency response of the driver, which were then filtered out passively in the crossover.
It was an idea inspired by the tri amplified Griffin 85 speakers with electronic crossovers and "tandem line" actively braked bass
system (a fantastic speaker-and very advanced for it`s time).
Re: Aperiodic
Thanks for all the info... can you tell us more about this one?
dave
deaks50 said:
Thanks for all the info... can you tell us more about this one?
dave
Griffin 85
Hi
The 85 tandem line base system (patented) was basicaly a Kef B139 unit in a sealed box, "air braked" by a reverse-phased Kef B200 unit fixed into the top of the box, with a pot used to vary the damping of the bass.
The power amps (3-total around 150 watts rms) were fitted into the back of the speaker. There were three active crossovers and three pots to vary the output levels. Pre amp was remote.
The cabinets were constructed in high density chipboard and mounted on an S shaped steel stand to isolate the speaker.
Thirty odd years later I`ve still yet to hear a better speaker (although my ears are shot compaired with the day!).
Hi
The 85 tandem line base system (patented) was basicaly a Kef B139 unit in a sealed box, "air braked" by a reverse-phased Kef B200 unit fixed into the top of the box, with a pot used to vary the damping of the bass.
The power amps (3-total around 150 watts rms) were fitted into the back of the speaker. There were three active crossovers and three pots to vary the output levels. Pre amp was remote.
The cabinets were constructed in high density chipboard and mounted on an S shaped steel stand to isolate the speaker.
Thirty odd years later I`ve still yet to hear a better speaker (although my ears are shot compaired with the day!).
Re: Griffin 85
This is very interesting. Do you have a patent number?
Somewhat similar is the idea of adding an R to a second voice coil on a woofer, and an idea i had for an isobarik with the rear driver driven by another amplifier controlled by a DSP.
What mid & top did they use? Any pictures?
dave
deaks50 said:
This is very interesting. Do you have a patent number?
Somewhat similar is the idea of adding an R to a second voice coil on a woofer, and an idea i had for an isobarik with the rear driver driven by another amplifier controlled by a DSP.
What mid & top did they use? Any pictures?
dave
Griffin 85
Hi
I`m afraid not.
However, I believe that Linn also patented a similar system in the 70`s. The bass system was unbelievably simple - genius in fact.
The 85 used twin STC super tweeters, a large single KEF mid range driver and a KEF B139 bass driver.
Hi
I`m afraid not.
However, I believe that Linn also patented a similar system in the 70`s. The bass system was unbelievably simple - genius in fact.
The 85 used twin STC super tweeters, a large single KEF mid range driver and a KEF B139 bass driver.
Hi guys! Re: pictures camera batteries dead I'm afraid.
They're on charge at the mo, just gotta do the mother's day honours (Whetherspoons... about £4 a head per course! 😛 ) and when I come back batteries should be charged & I'll post some more pics.
I'll try to get a pic or two of the crossover, too. I've not seen it yet but should be interesting from sounds of things!
They're on charge at the mo, just gotta do the mother's day honours (Whetherspoons... about £4 a head per course! 😛 ) and when I come back batteries should be charged & I'll post some more pics.
I'll try to get a pic or two of the crossover, too. I've not seen it yet but should be interesting from sounds of things!
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