This thread grew out of several threads that I've been following of late, namely Lynn Olson's "Beyond the Ariel" and "Western Electric 15A Small SATO Horn".
I had just posted on the SATO thread when I noticed that an old friend, Greg Monfort (GM or Altec on various forums) had also posted. Anyway, afterwards Greg suggested that I start a new thread rather than muddle up someone else's thread...and here we are! I intend to copy and paste the parts of the other thread that lead up to this thread.
Whereas I would like to finalize my design with a SATO horn, I will be building this speaker in a number of stages toward some (yet unrealized, nor totally planned) final design.
To protect myself from future criticism, I'll mention right now that this project may turn out to be more about the journey itself than the final destination (Yes, I do like sailboats more than powerboats!). Hopefully, we may get into some interesting approaches (or even solutions) to problems that are encountered from time to time.
Best Regards,
Terry Olson
I had just posted on the SATO thread when I noticed that an old friend, Greg Monfort (GM or Altec on various forums) had also posted. Anyway, afterwards Greg suggested that I start a new thread rather than muddle up someone else's thread...and here we are! I intend to copy and paste the parts of the other thread that lead up to this thread.
Whereas I would like to finalize my design with a SATO horn, I will be building this speaker in a number of stages toward some (yet unrealized, nor totally planned) final design.
To protect myself from future criticism, I'll mention right now that this project may turn out to be more about the journey itself than the final destination (Yes, I do like sailboats more than powerboats!). Hopefully, we may get into some interesting approaches (or even solutions) to problems that are encountered from time to time.
Best Regards,
Terry Olson
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I might mention right now that I have a pair of Eminance (Beta 8) drivers already, that I'll probably use. I believe that they're the same model drivers as the pair that Bud Purvine uses to supplement the Lowther drivers on his latest open baffle/no baffle speakers. ( BTW: They are absolutely excellent sounding speakers!)
Best Regards,
TerryO
Best Regards,
TerryO
I'm on the same trip as you Terry......different path though.
So I picked up a pair of Dayton 10" round waveguides and loaded them with Celestion 1746 CDs and paired that with an open baffle mounted Celestion TF1020 10" woofer. Let me say that this budget woofer is amazingly smooth and controlled with a tone that screams 1970's vinyl.....a real bargain IMO. No access to a DSP right now so in the process of modeling and plugging in some components to work out a network but so far I'm extremely impressed.
Not completely settled on the bottom end but seriously considering Nelson Pass' slot loaded OB approach with a sealed 18 for 30hz on down.
Look fwd to your progress.
So I picked up a pair of Dayton 10" round waveguides and loaded them with Celestion 1746 CDs and paired that with an open baffle mounted Celestion TF1020 10" woofer. Let me say that this budget woofer is amazingly smooth and controlled with a tone that screams 1970's vinyl.....a real bargain IMO. No access to a DSP right now so in the process of modeling and plugging in some components to work out a network but so far I'm extremely impressed.
Not completely settled on the bottom end but seriously considering Nelson Pass' slot loaded OB approach with a sealed 18 for 30hz on down.
Look fwd to your progress.
Celestion cone drivers: Agree on the TF1020, sleeper midrange, great sound for the $$ - try the 1530 woofer for bass they are equally as good of value. The mids are excellent with the 15 too. Maybe roll them in around 150 Hz below the 10 they will only go to 45 though in the bass. The sealed back mids aren't so great but the compression drivers seem to be as good as you can get. my 2 cents
Beta-8A? If so, looks like an inductor around 1 kHz and use one or more of those tiny 'FR' drivers for a super tweeter, so that you can just cap it off.
If the 8A sounds too rough up high, then a proper XO with an econo horn is a currently popular choice.
Details of Bud's setup?
GM
Hi Greg,
Bud crosses over the Beta 8A's a lot lower than I'm thinking of, but if its too rough then I'll probably need to look at a Delta Pro 8A, like your initial suggestion. Right now nothing is completely off the table that's within reason.
Greg, about Bud's speakers, I'll call him tomorrow and just relay the information, rather than trusting my less than perfect memory!
😀
Best Regards,
TerryO
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Because I alluded to this during an exchange with Greg Monfort in my previous post, I should mention that I just finished talking to Bud Purvine on the phone.
His Open Baffle/No Baffle speakers consist of a pair of Dual Transmission Line Sub/Bass Units from Planet10 using two CSS SD-7 Woofers per side. These hand off to a pair of Eminance "Delta 8" (16 ohm, 8" drivers) which, in turn cross over to Lowther PM-6A drivers (Silver Voice Coil, 16 ohm) for the high end. Bud mentioned that this Lowther configuration also sports a 3 mm X-max, instead of 1 mm. I forgot to get the specs on the crossover which Bud originally did by ear. He later called in our local Crossover Wizard, Dave Rosgaard to measure and correct any problems. Dave measured them and ended up lowering the treble by approximately one dB to get it right on the money. As you may suspect, all the drivers have received Bud's "enABLE" treatment.
While talking to Bud, he mentioned that he's added a "Super Tweeter" since I last heard the speaker about a month ago.
Best Regards,
TerryO
PS: I mentioned previously that Bud had Eminance "Beta-8" sprakers , when it turns out that his are actually "Delta 8" woofers, although mine remain Beta-8's...my sincere apologies for the error.
His Open Baffle/No Baffle speakers consist of a pair of Dual Transmission Line Sub/Bass Units from Planet10 using two CSS SD-7 Woofers per side. These hand off to a pair of Eminance "Delta 8" (16 ohm, 8" drivers) which, in turn cross over to Lowther PM-6A drivers (Silver Voice Coil, 16 ohm) for the high end. Bud mentioned that this Lowther configuration also sports a 3 mm X-max, instead of 1 mm. I forgot to get the specs on the crossover which Bud originally did by ear. He later called in our local Crossover Wizard, Dave Rosgaard to measure and correct any problems. Dave measured them and ended up lowering the treble by approximately one dB to get it right on the money. As you may suspect, all the drivers have received Bud's "enABLE" treatment.
While talking to Bud, he mentioned that he's added a "Super Tweeter" since I last heard the speaker about a month ago.
Best Regards,
TerryO
PS: I mentioned previously that Bud had Eminance "Beta-8" sprakers , when it turns out that his are actually "Delta 8" woofers, although mine remain Beta-8's...my sincere apologies for the error.
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I'll echo mayhem's post above, same goal, different path, one step at a time. I'm starting with Beta 8a's in small MLTL's, with the small Faital horns and cheapest Faital CD's on top, xover by MiniDSP. Still tuning them (may never be really done), but they aren't half bad from 60 Hz up.
Next step, upgrade to the MiniDSP 4 x 10 to get another channel to play with. I have four 10" NHT subs for the bottom end, thinking Linkwitz transform with a hefty class D amp to keep the enclosures small and the heat in the room down. With the Beta's relieved of bass duties I think I'll try them as cardioids. If that works, then the top end will go to... something. The SATO looks very cool but is probably overkill in an 11 x 14 den, and a bit taxing on my fabrication skills. The Iwata 600 might be nice. Gotta save up some pennies.
I'll be interested to see where you wind up.
Bill
Next step, upgrade to the MiniDSP 4 x 10 to get another channel to play with. I have four 10" NHT subs for the bottom end, thinking Linkwitz transform with a hefty class D amp to keep the enclosures small and the heat in the room down. With the Beta's relieved of bass duties I think I'll try them as cardioids. If that works, then the top end will go to... something. The SATO looks very cool but is probably overkill in an 11 x 14 den, and a bit taxing on my fabrication skills. The Iwata 600 might be nice. Gotta save up some pennies.
I'll be interested to see where you wind up.
Bill
Expo horns have a rising-on-axis polar response, so the perception is the horn extends behind its physical location however much its [unfolded] acoustic path-length is, i.e. tends to make the room ‘sound’ longer than it physically is while projecting the image much further forward than a cone/dome point source speaker. I liken it to sitting ‘front row center’ with horns and somewhere further back with point source speakers.
Due to this, until the horn's mouth becomes the sound wall [or half of it if stereo], then it's not too large for the room.
Some folks don’t care for this ‘in your face’ presentation though, so for them and/or those that need a wide ‘sweet spot’, a proper WG is a better choice with the trade-off being either a much lower efficiency system or a much narrower usable BW.
Yeah, I did one ‘proof of concept’ [POC] WE 15A BLH variant early on and said never again, preferring easier to make, less critical to fold, shorter horns whether front or back loaded and accept its narrower usable BW.
These require either larger drivers or more of them plus they ideally need to be designed for such apps, so is a much more expensive way to go for the woodworking and/or patience challenged DIYer, though probably much cheaper than having an artisan fabricate a WE concept folded compression horn.
GM
Due to this, until the horn's mouth becomes the sound wall [or half of it if stereo], then it's not too large for the room.
Some folks don’t care for this ‘in your face’ presentation though, so for them and/or those that need a wide ‘sweet spot’, a proper WG is a better choice with the trade-off being either a much lower efficiency system or a much narrower usable BW.
Yeah, I did one ‘proof of concept’ [POC] WE 15A BLH variant early on and said never again, preferring easier to make, less critical to fold, shorter horns whether front or back loaded and accept its narrower usable BW.
These require either larger drivers or more of them plus they ideally need to be designed for such apps, so is a much more expensive way to go for the woodworking and/or patience challenged DIYer, though probably much cheaper than having an artisan fabricate a WE concept folded compression horn.
GM
I got off track for a bit, but Greg sobered me up and has me working out again! Ok, I made that up, but I'm ready to proceed.
First of all, my Audio Buddy Dave Rosgaard (The 200% Norsky) spent some time braking in one of the Woofers for a number of hours to loosen it up before measuring the T/S Parameters.
I have a set of 18 inch Pro-Audio style woofers that I'll be using for the speakers. They are a gift so I really don't know much about them other than they haven't seen much use...if any!
Physical
Eff. Cone Dia: (in inches) 15.94 inches measured at middle of surround.
Sd: (in inches) 199.56 Square Inches (0.1287 Sq. Meters)
Mms: (moving mass) 7.94 ounces (225.00 grams)
Electrical
Re (dc resist.) 3.46 Ohms
Res (Zpk-Re) 12.83 Ohms
Le (VC Inductance @1000 Hz usin curvefit) 1.74 mH
BL (Force Factor) 20.43 T-m
Qes (Elect. Q factor) 0.60 (dimensionless)
Mechanical
Fs (Resonance Freq.) 50.5 Hz
Cms (Mech. compliance) 0.008 Inch / Lbs. (44.2 uM/N)
kms (mechanical stiffness) 129.21 lbs/inch (22624.4 N/m)
Xmax (1/2 peak to peak excursion) 0.14 inches (3.50 mm)
Qms (Mechanical Q factor) 2.19 (dimensionless)
Acoustic
Vas (acoustic compliance) 3.64 cubic ft. (103.00 liters)
SPL (effeciency) 95.4dB
Qts (Total Q factor) 0.47 (dimensionless)
~~~~~~~~~~~~~~~~~~~~
Deltamass= 193.4 grams fs'= 36.4 Hz
So this is what the Bass will be coming from. I wish the numbers on the specs were a bit different, but they are what I have to work with...and the price was just right!
Best Regards,
TerryO
First of all, my Audio Buddy Dave Rosgaard (The 200% Norsky) spent some time braking in one of the Woofers for a number of hours to loosen it up before measuring the T/S Parameters.
I have a set of 18 inch Pro-Audio style woofers that I'll be using for the speakers. They are a gift so I really don't know much about them other than they haven't seen much use...if any!
Physical
Eff. Cone Dia: (in inches) 15.94 inches measured at middle of surround.
Sd: (in inches) 199.56 Square Inches (0.1287 Sq. Meters)
Mms: (moving mass) 7.94 ounces (225.00 grams)
Electrical
Re (dc resist.) 3.46 Ohms
Res (Zpk-Re) 12.83 Ohms
Le (VC Inductance @1000 Hz usin curvefit) 1.74 mH
BL (Force Factor) 20.43 T-m
Qes (Elect. Q factor) 0.60 (dimensionless)
Mechanical
Fs (Resonance Freq.) 50.5 Hz
Cms (Mech. compliance) 0.008 Inch / Lbs. (44.2 uM/N)
kms (mechanical stiffness) 129.21 lbs/inch (22624.4 N/m)
Xmax (1/2 peak to peak excursion) 0.14 inches (3.50 mm)
Qms (Mechanical Q factor) 2.19 (dimensionless)
Acoustic
Vas (acoustic compliance) 3.64 cubic ft. (103.00 liters)
SPL (effeciency) 95.4dB
Qts (Total Q factor) 0.47 (dimensionless)
~~~~~~~~~~~~~~~~~~~~
Deltamass= 193.4 grams fs'= 36.4 Hz
So this is what the Bass will be coming from. I wish the numbers on the specs were a bit different, but they are what I have to work with...and the price was just right!
Best Regards,
TerryO
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I just got word yesterday that the other Woofers are not the same as the one that we tested for specs. It had been assumed that they were all the same woofers....and yes, I do remember what "assume" means!
Too bad, so at this point we will shift gears and investigate the possibility of taking another path towards the goal. There may actually be another opportunity available, but I'll need to check it out.
Best Regards,
TerryO
Too bad, so at this point we will shift gears and investigate the possibility of taking another path towards the goal. There may actually be another opportunity available, but I'll need to check it out.
Best Regards,
TerryO
I had planned on looking over some more Bass drivers, but a change of plans came up and it will have to be rescheduled accordingly. I'll be looking into some other issues concerning the project as well.
This is a minor setback and I'm hopeful that this project will start rolling ahead once more.
🙂
Best Regards,
TerryO
This is a minor setback and I'm hopeful that this project will start rolling ahead once more.
🙂
Best Regards,
TerryO
Bummer, you seem to have inherited my so-called life [style]. Hopefully, it won't last near as long though.
GM
GM
Greg,
If I didn't have bum luck, I believe I'd have absolutely no luck at all! If that seems to coincide with your life-style, then I'd say our lives seemingly follow much the same path!
OTOH, It never seems to get boring. It's quite often exciting or even hair-raising!
Best Regards,
Terry
Yeah, pretty much since 1997. Definitely increasingly hair raising as my body makes doing certain chores downright dangerous, but with no budget for paid labor and friends that have overall become worse off than me, it's become a 'do or die' situation. That, or let the local scum, er city code enforcers condemn/seize my house for not being up to spec.
OTOH, mine is incredibly boring, in recent years it's become an ongoing litany of repairing either the same [or similar type] storm damage over n' over, keeping me from making any real progress.
GM
OTOH, mine is incredibly boring, in recent years it's become an ongoing litany of repairing either the same [or similar type] storm damage over n' over, keeping me from making any real progress.
GM
I don't have any FR data for the Delta Pro 8a, but Eminance has a reputation for having fairly trustworthy datasheet information. Maybe someone else has measured them.
OK, I found the Eminance Data Sheets
Here's the Delta Pro 8B: http://www.eminence.com/pdf/Delta_Pro_8B.pdf
I'll assume that the Delta Pro 8A would probably be:
http://www.eminence.com/pdf/Delta_Pro_8A.pdf
Best Regards,
TerryO
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