Re: Hemp FR8c ?
Greets!
Perfect? No, but still a good 'fit', though ideally you would make the vents larger/longer to get closer to a 221 cm^2 vent area. If limiting cab Vb to around 100 L is a big deal, then reduce the vent area down to ~166 cm^2.
Like CLS said, not much content below ~40 Hz in most music, but even old vinyl sounds more 'full'/'rich' played through systems tuned into the high 20s if its F3 isn't too high.
Ideally you want an F3 that matches up with the room's or at least a near boundary's (wall or corner's) rising response to keep it from sounding ''boomy', which is typically in the 30-40 Hz range/wall, 60-80 Hz/corner, so going with a N = 6.34 or higher if you want them near/at a wall or corner seems the way to go, but then the cab size increases and vent length eventually becomes too long, so you may have to tune the vents with stuffing to get the desired in-room response regardless of the alignment used.
All that said, agonizing over finding a driver that 'works' in the Onken calculator seems a waste of time to me now that free/cheap, powerful computer programs can quickly, easily calculate as good or overall better performing cabs using a wider range of drivers. I mean for HIFI/HT use, there's no advantage to having a BR with vent area = Sd (vent mach < 0.1) Vs one with a < 0.5 vent area.
GM
Greets!
Perfect? No, but still a good 'fit', though ideally you would make the vents larger/longer to get closer to a 221 cm^2 vent area. If limiting cab Vb to around 100 L is a big deal, then reduce the vent area down to ~166 cm^2.
Like CLS said, not much content below ~40 Hz in most music, but even old vinyl sounds more 'full'/'rich' played through systems tuned into the high 20s if its F3 isn't too high.
Ideally you want an F3 that matches up with the room's or at least a near boundary's (wall or corner's) rising response to keep it from sounding ''boomy', which is typically in the 30-40 Hz range/wall, 60-80 Hz/corner, so going with a N = 6.34 or higher if you want them near/at a wall or corner seems the way to go, but then the cab size increases and vent length eventually becomes too long, so you may have to tune the vents with stuffing to get the desired in-room response regardless of the alignment used.
All that said, agonizing over finding a driver that 'works' in the Onken calculator seems a waste of time to me now that free/cheap, powerful computer programs can quickly, easily calculate as good or overall better performing cabs using a wider range of drivers. I mean for HIFI/HT use, there's no advantage to having a BR with vent area = Sd (vent mach < 0.1) Vs one with a < 0.5 vent area.
GM
Onken Loudspeaker
I had been thinking about building a horn design using my existing speaker units, they need to be in a better cabinet than they are already. My problem is space so full horn system would just be too big for my living space.
Having heard of the Onken design and then coming across it by accident a few days back, I have been doing some research on it, it seems a feasible design to me.
My speaker units are something of a rarity, they are Dynastatics came out in the UK late 60's uses a 12" Richard Allen bass mid unit in conjunction with shackman electrostatic unit, they sound rather good are easy to drive, my amp at the minute is a single ended Mr Liang 845 Triode amp zero feedback. Stops starts and turns on a dime has highs lows and everything in between what it lacks is the boxiness from the speakers, at the minute they are in a sealed box which is not good for the sound.
I think the only Onken could be a solution as it is roughly the same size as the current speaker cabinets but a little bit deeper but has the advantage of being a reflex design, which should even things out a bit.
I have no data for drive units, it is not available, I can tell you that the Richard Allens are CP12 (12") but can not remember off the top of my head if they are 8R or 16R either way I have driven them off a single ended EL84 amp from my Vortexion CBL6H reel to reel and they still go loud, so they are an easy load.
I am currently reworking other aspects of my system the power amp is a new addition in the last 12 months but the rest of the system has stayed as it is for the last 10 years or so, it is time for it to be updated. I am working on building some Peter Millet designs looking at a new phono amp and the low mu line amp which uses 6080's as line drivers and EL34 as CCS, on top of which I am going to build the HA2 headphone amp as well. My thinkiing being that if we get a hot summer here in the UK, which we did a few years back or even a moderate one then the 845 amp just puts out too much heat to use, hence the desire for a headphone amp.
Needless to say the system sounds good right now, other projects include a Ladergaard parallel tracking tone arm which will be mounted on my Garrard 401 which needs a reworking plinthwise, cartridge wise I was going to go for a Denon DL103 which should fit in nicely with the rest of the system.
Any thoughts or input greatly appreciated, my main problem with the speakers is trying to locate a source which will cut the plywood or mdf if I go that route with iron on veneer. So that is my problem really someone to cut the wood to requirements and do I use plywood or mdf which could be veneered on the outer cabinet, I was thining of using blackboard paint for the vents and inner surfaces. oh and I was thinking of adding a supertweeter as well, which should fill in those upper registers.
Cheers Steve
I had been thinking about building a horn design using my existing speaker units, they need to be in a better cabinet than they are already. My problem is space so full horn system would just be too big for my living space.
Having heard of the Onken design and then coming across it by accident a few days back, I have been doing some research on it, it seems a feasible design to me.
My speaker units are something of a rarity, they are Dynastatics came out in the UK late 60's uses a 12" Richard Allen bass mid unit in conjunction with shackman electrostatic unit, they sound rather good are easy to drive, my amp at the minute is a single ended Mr Liang 845 Triode amp zero feedback. Stops starts and turns on a dime has highs lows and everything in between what it lacks is the boxiness from the speakers, at the minute they are in a sealed box which is not good for the sound.
I think the only Onken could be a solution as it is roughly the same size as the current speaker cabinets but a little bit deeper but has the advantage of being a reflex design, which should even things out a bit.
I have no data for drive units, it is not available, I can tell you that the Richard Allens are CP12 (12") but can not remember off the top of my head if they are 8R or 16R either way I have driven them off a single ended EL84 amp from my Vortexion CBL6H reel to reel and they still go loud, so they are an easy load.
I am currently reworking other aspects of my system the power amp is a new addition in the last 12 months but the rest of the system has stayed as it is for the last 10 years or so, it is time for it to be updated. I am working on building some Peter Millet designs looking at a new phono amp and the low mu line amp which uses 6080's as line drivers and EL34 as CCS, on top of which I am going to build the HA2 headphone amp as well. My thinkiing being that if we get a hot summer here in the UK, which we did a few years back or even a moderate one then the 845 amp just puts out too much heat to use, hence the desire for a headphone amp.
Needless to say the system sounds good right now, other projects include a Ladergaard parallel tracking tone arm which will be mounted on my Garrard 401 which needs a reworking plinthwise, cartridge wise I was going to go for a Denon DL103 which should fit in nicely with the rest of the system.
Any thoughts or input greatly appreciated, my main problem with the speakers is trying to locate a source which will cut the plywood or mdf if I go that route with iron on veneer. So that is my problem really someone to cut the wood to requirements and do I use plywood or mdf which could be veneered on the outer cabinet, I was thining of using blackboard paint for the vents and inner surfaces. oh and I was thinking of adding a supertweeter as well, which should fill in those upper registers.
Cheers Steve
Onken / Altec 817
It is interesting given the history of asian interest in older design of speaker / pa cabinents....which came first, the onken or the Altec 817...? They seem to be related...
http://www.altecpro.com/pdfs/vintage/SpeakerAndMics/cabinets/817A LF Speaker Cabinet.pdf
http://www.altecpro.com/pdfs/vintage/SpeakerAndMics/cabinets/817 LF Speaker Cabinet Plan.pdf
It is interesting given the history of asian interest in older design of speaker / pa cabinents....which came first, the onken or the Altec 817...? They seem to be related...
http://www.altecpro.com/pdfs/vintage/SpeakerAndMics/cabinets/817A LF Speaker Cabinet.pdf
http://www.altecpro.com/pdfs/vintage/SpeakerAndMics/cabinets/817 LF Speaker Cabinet Plan.pdf
AFAIK, the Onken dates from '73 and the 817 was originally a Stanley Screamer cab that came along shortly afterward and added to the Altec line around '77, though not sure if Altec designed it or not. Regardless, they were offshoots of the 'early '50s Jensen Ultraflex cabs which in turn were just a variation of Thuras's original BR patent cab. I have a pic of an early '50s Altec duplex cab with Ultraflex vents, so plagiarism among the manufacturers was a live and well back then.
An interesting footnote is that in Thuras's BR patent he states that Sd = Av was used strictly to simplify his electrical equivalent ckt. equations, but somewhere along the line it became 'gospel' as the ideal.
GM
An interesting footnote is that in Thuras's BR patent he states that Sd = Av was used strictly to simplify his electrical equivalent ckt. equations, but somewhere along the line it became 'gospel' as the ideal.
GM
Stanal Sound / Stanley Screamers
Thanks GM, you just help me solve the mystery of some cabs I just picked up in a garage buy. They had the exterior dimensions of 817's with twin 15" drivers but were fiberglassed and the internal baffling and vent structure did not jive to the Altec / Onken 817 specs....
http://www.lansingheritage.org/html/altec/catalogs/1979-screamer.htm
It appears they are the Stanley Screamer SS-1120R with the "road case finish" and flush handles. Thanks for the info...Now onto bringing them back to life and loading them up with the optimum drivers...for my large open living room!
Any suggestions?
How about 4x GPA 416's with a horn on top... or maybe 1pr GPA 604's up with 1pr JBL 2235's down...or what ever you would optimize them with?
Thanks in advance
Thanks GM, you just help me solve the mystery of some cabs I just picked up in a garage buy. They had the exterior dimensions of 817's with twin 15" drivers but were fiberglassed and the internal baffling and vent structure did not jive to the Altec / Onken 817 specs....
http://www.lansingheritage.org/html/altec/catalogs/1979-screamer.htm
It appears they are the Stanley Screamer SS-1120R with the "road case finish" and flush handles. Thanks for the info...Now onto bringing them back to life and loading them up with the optimum drivers...for my large open living room!
Any suggestions?
How about 4x GPA 416's with a horn on top... or maybe 1pr GPA 604's up with 1pr JBL 2235's down...or what ever you would optimize them with?
Thanks in advance
Fellas,
I hope that I am not driving this thread off course but does this qualify as an Onken enclosure? http://www.bcspeakers.com/SGG/PDF/208.pdf
Or is it simply a bass reflex on steroids??
I hope that I am not driving this thread off course but does this qualify as an Onken enclosure? http://www.bcspeakers.com/SGG/PDF/208.pdf
Or is it simply a bass reflex on steroids??
Re: Stanal Sound / Stanley Screamers
You're welcome!
Well, these came along at the tail end of my active involvement with Altec, so have very limited experience, but I see no reason why the 416s can't be a good choice with a 604 on an OB or sealed cab perched on top. The 2235's don't have the 'snap' I prefer, so while I like them for many multi-ways, not with Altec tops.
My preference is 515B, though C, or E should work well also, with experience in 816, 825, 210 and DIY customs, though some folks claim the best performing overall is the G, another one that came along after my time, so have only auditioned them in an 816 AFAIK with nothing to compare them with. Up top, a MR94A with a digitally delayed super tweeter suspended in its mouth seems a good choice for a large, open room, leaving only the need for some type of band-pass subs to fill in the bottom 2+ octaves:
GM
JoMoCo said:
You're welcome!
Well, these came along at the tail end of my active involvement with Altec, so have very limited experience, but I see no reason why the 416s can't be a good choice with a 604 on an OB or sealed cab perched on top. The 2235's don't have the 'snap' I prefer, so while I like them for many multi-ways, not with Altec tops.
My preference is 515B, though C, or E should work well also, with experience in 816, 825, 210 and DIY customs, though some folks claim the best performing overall is the G, another one that came along after my time, so have only auditioned them in an 816 AFAIK with nothing to compare them with. Up top, a MR94A with a digitally delayed super tweeter suspended in its mouth seems a good choice for a large, open room, leaving only the need for some type of band-pass subs to fill in the bottom 2+ octaves:
GM
Attachments
FYI, it can be DLed from here now: http://www.esnips.com/nsdoc/b6631ebb-6bcd-44f0-8f6b-2e4ac9492c4b/?action=forceDL
GM
GM
Hi, I hope its ok to use this thread
I had been asking here about those fine Altecs used, got nice response, and took the advice to put my money on new...and I believe I dont have enough experience to handle such a deal...man, alone shipping back and forth in case of renovating, those are heavy things
I have been watching 2 pairs on Ebay
A 288G went fore a little less than 700 EUR
A 288C just above 700 EUR
But I do think they were absolute mint condition
Maybe they didnt need repair, I dont know...but who knows what may have been done to them along the way, could be anything
But its kind of exciting, this vintage stuff and I almost got drawn in
Maybe I missed a good deal, an awfull thought
But had I wanted them badly, price may have gone even higher
I decided to stay away
Just thought I would tell
I had been asking here about those fine Altecs used, got nice response, and took the advice to put my money on new...and I believe I dont have enough experience to handle such a deal...man, alone shipping back and forth in case of renovating, those are heavy things
I have been watching 2 pairs on Ebay
A 288G went fore a little less than 700 EUR
A 288C just above 700 EUR
But I do think they were absolute mint condition
Maybe they didnt need repair, I dont know...but who knows what may have been done to them along the way, could be anything
But its kind of exciting, this vintage stuff and I almost got drawn in
Maybe I missed a good deal, an awfull thought
But had I wanted them badly, price may have gone even higher
I decided to stay away
Just thought I would tell
Onken calculation with new GPA416-8C
Hi guys, I need your help . I am planning to buid big Onken for my new GPA416-8C. Problem I have is that when I put TS parameters fot these units (which are different from old Altec models) in calc I get some bad values specially regarding vent size. I suppose I am making mistake somwhere. Can you help?
Fs 22.900 Hz
Re 6.550 ohms
Qms 6.700
Qes 0.222
Qts 0.215
Mms/d 77.251 gr
Sd 8.900E-02 m^2
Rg 0.500 ohms
Cms 6.25E-04
Vas 693.596 litres
Vas*Qts2 36.921
n = 6.340 (best 5.7)
________________________________
Box and system response
F-3 39.419 Hz
Fb 38.710 Hz
Cab 16.720
Map 10.110
S vent 849.000 cm^2
nO 0.036
dB 1w/1m 96.944 dB
_________________________________
Vent lenght
L vent 66.387 cm
L’ vent 50.113 cm
_________________________________
Vent dimension (habitually an Onken speaker have a S vent equal or -15 % smaller to the driver Sd)
Width 5.000 cm
Height 28.300 cm
Quantity 6.000
S vent 849.000 cm^2
Vent volume 42.546 litres
__________________________________
Total Box Volume
Vb 234.078 litres
Vb Total 276.623 litres
Regards,
Zeljko
Hi guys, I need your help . I am planning to buid big Onken for my new GPA416-8C. Problem I have is that when I put TS parameters fot these units (which are different from old Altec models) in calc I get some bad values specially regarding vent size. I suppose I am making mistake somwhere. Can you help?
Fs 22.900 Hz
Re 6.550 ohms
Qms 6.700
Qes 0.222
Qts 0.215
Mms/d 77.251 gr
Sd 8.900E-02 m^2
Rg 0.500 ohms
Cms 6.25E-04
Vas 693.596 litres
Vas*Qts2 36.921
n = 6.340 (best 5.7)
________________________________
Box and system response
F-3 39.419 Hz
Fb 38.710 Hz
Cab 16.720
Map 10.110
S vent 849.000 cm^2
nO 0.036
dB 1w/1m 96.944 dB
_________________________________
Vent lenght
L vent 66.387 cm
L’ vent 50.113 cm
_________________________________
Vent dimension (habitually an Onken speaker have a S vent equal or -15 % smaller to the driver Sd)
Width 5.000 cm
Height 28.300 cm
Quantity 6.000
S vent 849.000 cm^2
Vent volume 42.546 litres
__________________________________
Total Box Volume
Vb 234.078 litres
Vb Total 276.623 litres
Regards,
Zeljko
Hmmm... good question. I'm interested because I'll soon be building an Onken box for the 416-8A reconed by GPA. (don't know T/S yet)
What are the normal T/S for the original 416A? That's the driver that is supposed to work best in the big Onken box.
Your Vb seems low. Did you change it to fit your drivers?
What are the normal T/S for the original 416A? That's the driver that is supposed to work best in the big Onken box.
Your Vb seems low. Did you change it to fit your drivers?
Woofer Specs
Maybe GPA could do this when they freshen your drivers or if they can't...you may want to buy or borrow one of these for parameter input...
Dayton WT3 Woofer tester http://www.parts-express.com/pe/showdetl.cfm?Partnumber=390-804
panomaniac said:
Maybe GPA could do this when they freshen your drivers or if they can't...you may want to buy or borrow one of these for parameter input...
Dayton WT3 Woofer tester http://www.parts-express.com/pe/showdetl.cfm?Partnumber=390-804
Vb is calculated by formula - automatically. If I change Onken alingment to higher I get higher Vb and lower vent lenght. Anyway something in not good here. Any clue? Is it possible that new 416-8c is not good candidate for Onken? Maybe T/S are not good. Not all parameters are in datasheet. Effective radiation area of the driver cone - Sd and total cone assembly mass are missing so I copied data found on web. Maybe this data is not good.
zeljkor said:
I think it is. At least Hiraga's article from 1977 seems to indicate that it is. Tho he says the 416A is prefered.
Once I tried the published 416A T/S in the spreadsheet and could not get it to work - but I may have been doing it wrong. Will try again. Somebody here did it and made it work. Was it GM?
JoMoCo: I will have GPA run the numbers and I do have a WT3 (Nice gaget!) so I can run them too.
Cal: I haven't given up yet! But if I don't find a decent VOTT box, Onken it will be. My new 803B horns will look nice on top of either
panomaniac said:
I think it is. At least Hiraga's article from 1977 seems to indicate that it is. Tho he says the 416A is prefered.
Once I tried the published 416A T/S in the spreadsheet and could not get it to work - but I may have been doing it wrong. Will try again. Somebody here did it and made it work. Was it GM?
JoMoCo: I will have GPA run the numbers and I do have a WT3 (Nice gaget!) so I can run them too.
Cal: I haven't given up yet! But if I don't find a decent VOTT box, Onken it will be. My new 803B horns will look nice on top of either
Getting the spreadsheet to work is a matter of carefully juggling some parameters.
Try reducing S vent to no less that 85% of Sd..
Tinkering with RG - try increasing the value which is realistic if you are using a tube amplifier to drive it.
n can be increased or decreased by 10% or so in order to help get vent lengths down, this affects overall flatness. I'm using very close to the flat tuning in mine. (5.6)
Very low values of FS and high values of Mms are not conducive to convergence either.
Choose drivers with moderate fs (30Hz and up) and low Mms 60gms or even less with a 15 inch driver. You will quickly find that a fair number of drivers with low qts do not work as well as you would think due to cone mass, etc.
I am using Iconic 165-8G in my Onkens which are ~ 11.4 cu ft internal volume including the vents. I believe the GPA 515-8G is similar if not identical, but I have not checked.
I checked several 416 variants in the spreadsheet and they all worked, but I was unwilling to put the kind of money I ultimately spent on the Iconics into a used pair of vintage Altecs sight unseen.
Next time I am running windoz I will post a spreadsheet of mine.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.