JRKO, I can't thank you enough for those phase plugs! Popping them into place smoothed the sound even more than just having the dustcaps removed. To be honest, at first i thought they smoothed things out too much (there was an audible difference i'm glad shows in the measurements in the link you provided above). The resonance inherent in the stock 12lta pretty much completely goes away once the dustcap is removed taming the driver for home use (it's even pretty good leaving it stock but has a PA quality). Check the link comparing the stock driver vs having the dustcap removed. It really shows how the frequency response smooths out.
Thanks for posting the measurements of the phase plug. I don't see it as mandatory since the sound is good with or without it but it does complete the look and the tweaking of the driver. I listen to this speaker all the time with very little fatigue (maybe it's a bit forward but not as forward as the Fostex i've got and they are all pretty good too).
The 12lta is a fantastic driver if you like a big dynamic sound that doesn't have the crossover induced fatigue.
Thanks for posting the measurements of the phase plug. I don't see it as mandatory since the sound is good with or without it but it does complete the look and the tweaking of the driver. I listen to this speaker all the time with very little fatigue (maybe it's a bit forward but not as forward as the Fostex i've got and they are all pretty good too).
The 12lta is a fantastic driver if you like a big dynamic sound that doesn't have the crossover induced fatigue.
glad you like 'em!
the points you sent are doing sterling work in various places - speakers, amps, turntable support (turntable on mdf then 3x half hardest squash balls then thick ply then your spikes) etc etc
keep your eyes peeled - my 12LTA's are coming back without Beta15's (neighbour issues) but I don't care! I love the immediacy and reality of the 12LTA
James
the points you sent are doing sterling work in various places - speakers, amps, turntable support (turntable on mdf then 3x half hardest squash balls then thick ply then your spikes) etc etc
keep your eyes peeled - my 12LTA's are coming back without Beta15's (neighbour issues) but I don't care! I love the immediacy and reality of the 12LTA
James
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Glad you put the spikes to use. It was fun trading them for the plugs with you! I am wondering how your new speakers will be setup... large ported box... small sealed with a powered sub hidden away so the neighbor can't find it... back horn? I look forward to seeing your new speakers when you are ready to present them.
Zilla
Zilla
I was looking into OB but due to room placement, I'll have room boundary issues I think. What are your OB dims and placement specifics?
My current sim puts it around -3dB at about 60z - not the best but about the same as a bookshelf monitor but with way better dynamics, speed and realism. 'specs are subject to change without prior notice'
My current sim puts it around -3dB at about 60z - not the best but about the same as a bookshelf monitor but with way better dynamics, speed and realism. 'specs are subject to change without prior notice'
HIP HIP HORAAAAAAAYYYYYYY!!!
Came out to the car this morning and the stinkin' upstairs neighbours are moving out! They never opened their curtains/drapes once in the 6 months they lived above me. They put wooden flooring down which is in violation of the lease (very poor sound deadening) so could 'hear' my music - not as much as we could hear every footstep they took!!
I've been here for just over 10 years and not had a single complaint until they turned up. I'll be glad to see the back of them...
...that and I may be able to bring the beta15's out to play
Came out to the car this morning and the stinkin' upstairs neighbours are moving out! They never opened their curtains/drapes once in the 6 months they lived above me. They put wooden flooring down which is in violation of the lease (very poor sound deadening) so could 'hear' my music - not as much as we could hear every footstep they took!!
I've been here for just over 10 years and not had a single complaint until they turned up. I'll be glad to see the back of them...
...that and I may be able to bring the beta15's out to play
Ribbons/OB mids/sealed Altec 416 midbass + subs
Lowther Open Bafflesfor sharing your knowledge, experience and encouragement-enabling me to begin my journey into the OB world. Of course, all DIYing involves risks of time and money, such as buying expensive drivers for the wrong enclosures and/or room size, or attempting to passively cross a three way speaker system when truly cost effective results might only be achieved by at least bi-amping the mids and midbass drivers.
But here’s what I’ve got to work with and what my goals are. I just hope that I won’t get laughed out of court:
OBs, I’m told, should have at least have 4 ft of space behind them, and ?? ft to either side of them. In any case, while this won’t be a problem in my 18’ x 14 living room, I have another speaker system planned for that room. And though that room is uncluttered enough to accommodate both speaker systems, my crazy idea is to build a pair of OBs for one of two fairly cluttered bedrooms. One room is 12 ft x 11; the other is 17 ft x 9.
I’ve read that putting speakers (most or all types of?) along the longer wall is not advisable. If yes, why is this so? In any case, at least I can get rid of stuff along one of the longer walls in the bigger room to allow placement of speakers there.
Regarding placement and listening position in the 12 ft x 11 bedroom, I’d be sitting in my small easy chair in front of the north wall, with my single twin bed to the right of me. The bed is 24” high and my ears are 35” above the floor. For listening sessions, I could slide the right OB away from the west wall where I’d normally keep it to then be in front of the doorway. However, the place for the left OB would be impossibly cluttered, leaving no more than 3 ft behind it-before encountering my left floor standing TV speaker behind my 32” TV, none of which I want to part with. And there would be only a few inches between the left OB and the East wall and the 32” TV to its right.
While I’m no one’s kind of speaker designer, presumably the need to maximize the OB’s distance from boundaries allows fuller wavelength excursions for low frequency response from, say, what those Eminence Alpha 12” LTA drivers, can generate-though I lack the first year college physics to understand the entire event. Sadly, unless I’m wrong it would seem that neither of my bedrooms have adequate space to draw decent LF response from those Eminence Alpha 12” LTA in OBs-at least down to 70Hz, to where my sub can take over. Yes or No?
Likewise, note the amount of space needed even for Jon Ver Halen’s Tiny OBs. Open Baffles Lowthers, which otherwise would have worked for me. As stated here, the TOBs go down to 65Hz and even in my smaller bedroom I might have room for one of my Rythmik 12" sealed servo subs. Rythmik Audio • Servo subwoofer products built by Jim Salk Salk/Rythmik - home
And so, in my crazed pursuit of using OBs in one of my small cluttered rooms, I cobbled together thissystem idea, which I hope won’t cause more problems than I think it might solve, as follows: The pair of sealed 15” midwoofers that I will be using in my three-way living room system. They are a pair of GPA Altec 416-8Bs http://www.greatplainsaudio.com/downloads/416-8B Spec Sheet.pdf . They would be in the same low diffraction, 3 cu. ft sealed cabinets designed by fellow diyaudio.com member Gary Dahl for use with another speaker project. Gary’s sealed boxes keep the 416s within their 700Hz to 70Hz comfort zone, thereby minimizing IM distortion. Gary, Lynn Olson, Jon Ver Halen among others have long known the Altec 416 to be a very unusual driver, and enjoy its almost “magical” sonic properties of this “PA” speaker in almost any kind of enclosure. http://www.diyaudio.com/forums/multi-way/100392-beyond-ariel-781.html and New Adventures In High Efficiency My Lowther Journey With a rant or two sprinkled in for good measure. Article By Scott Faller Thus, to overcome the OBs’ room boundary issues for adequate low frequency response in very small rooms, I would place an Eminence Beta 12 LTA OB atop each Altec 416 midwoofer box.
There’s only ~0.3db difference between the 416 and the Beta LTA, so activecrossovers are obviously not needed, at least for level matching. And aren’t sealed boxes the most forgiving of placement restrictions? If so, then their handling of everything from 700Hz down to 70Hz should take most room boundary problems off the Beta LTA OBs. Correct?
As for highs, while expensive it appears that the best solution by far would be a pair of 9” RAAL Lazy ribbons
https://www.madisoundspeakerstore.com/ribbon-tweeters/raal-lazy-ribbon-9-ribbon-tweeter/ Along with excellent dispersion, their > 100db sensitivity would again remove the need for active crossovers.
Question: Depending on which of my two small bedrooms I’d be installing thesehybrid OBs-and on whichwall they are placed along-I’d be sitting between 7.5 ft and 12 ft away in one bedroom and between 8 ft and 9 ft away from them in the smaller bedroom. Gary’s Altec sealed midwoofers cabinets are 26” w x 15” d x 20” h. But assuming on-axis placement is desirable, how wide and how high does the OB panel for the Beta 12 LTA need to be, with each panel sitting atop each Altec midwoofer cabinet?
Obviously, these numbers would also impact placement for the RAAL ribbon tweeter, being either to the side or atop each Beta 12 LTA OB.
Another question: Would I be compromising a lot sound quality if don’t at least partially cross this system actively?
Btw, I would drive the system with my First Watt F4 amp FIRST WATT F4 via a tube preamp like this K&K Audio | Line Stage
As for Lowthers (in OBs atop the Altec midwoofers?), I’ve heard it said that most people either love them or hate them. Whether that be due to the “shout”-though apparently due to a problem with the driver’s whizzer that was banished more than 15 years ago-or the break in period or other personal listening preferences, I wouldn’t know. However, I’ve certainly been long interested in hearing them, particularly the Alnico models. But to best of my knowledge no has ever once done a Lowther show in New York City. Nor could I find Lowther owners there-or on Long Island, where I live-who might let me hear them.
On the other hand, everyone seems to love the sound of OBs in general; ditto for Alnico drivers, such as the GPA Altec 416s-particularly in low diffraction sealed boxes that cut their low end off below 70Hz. Despite having to contend with 3 cu ft midwoofer boxes in my bedroom, I’m hoping that I might have hit upon “a best
of all worlds” system that works in at least one of my bedrooms.
But did I overlook anything?
Anything else good or bad about my bedroom speaker system idea?
How good do you think it might sound?
Thanks Godzilla and JRKO and to Scott F, Poultrygeist, Richard and BoJonJovi from
Lowther Open Bafflesfor sharing your knowledge, experience and encouragement-enabling me to begin my journey into the OB world. Of course, all DIYing involves risks of time and money, such as buying expensive drivers for the wrong enclosures and/or room size, or attempting to passively cross a three way speaker system when truly cost effective results might only be achieved by at least bi-amping the mids and midbass drivers.
But here’s what I’ve got to work with and what my goals are. I just hope that I won’t get laughed out of court:
OBs, I’m told, should have at least have 4 ft of space behind them, and ?? ft to either side of them. In any case, while this won’t be a problem in my 18’ x 14 living room, I have another speaker system planned for that room. And though that room is uncluttered enough to accommodate both speaker systems, my crazy idea is to build a pair of OBs for one of two fairly cluttered bedrooms. One room is 12 ft x 11; the other is 17 ft x 9.
I’ve read that putting speakers (most or all types of?) along the longer wall is not advisable. If yes, why is this so? In any case, at least I can get rid of stuff along one of the longer walls in the bigger room to allow placement of speakers there.
Regarding placement and listening position in the 12 ft x 11 bedroom, I’d be sitting in my small easy chair in front of the north wall, with my single twin bed to the right of me. The bed is 24” high and my ears are 35” above the floor. For listening sessions, I could slide the right OB away from the west wall where I’d normally keep it to then be in front of the doorway. However, the place for the left OB would be impossibly cluttered, leaving no more than 3 ft behind it-before encountering my left floor standing TV speaker behind my 32” TV, none of which I want to part with. And there would be only a few inches between the left OB and the East wall and the 32” TV to its right.
While I’m no one’s kind of speaker designer, presumably the need to maximize the OB’s distance from boundaries allows fuller wavelength excursions for low frequency response from, say, what those Eminence Alpha 12” LTA drivers, can generate-though I lack the first year college physics to understand the entire event. Sadly, unless I’m wrong it would seem that neither of my bedrooms have adequate space to draw decent LF response from those Eminence Alpha 12” LTA in OBs-at least down to 70Hz, to where my sub can take over. Yes or No?
Likewise, note the amount of space needed even for Jon Ver Halen’s Tiny OBs. Open Baffles Lowthers, which otherwise would have worked for me. As stated here, the TOBs go down to 65Hz and even in my smaller bedroom I might have room for one of my Rythmik 12" sealed servo subs. Rythmik Audio • Servo subwoofer products built by Jim Salk Salk/Rythmik - home
And so, in my crazed pursuit of using OBs in one of my small cluttered rooms, I cobbled together thissystem idea, which I hope won’t cause more problems than I think it might solve, as follows: The pair of sealed 15” midwoofers that I will be using in my three-way living room system. They are a pair of GPA Altec 416-8Bs http://www.greatplainsaudio.com/downloads/416-8B Spec Sheet.pdf . They would be in the same low diffraction, 3 cu. ft sealed cabinets designed by fellow diyaudio.com member Gary Dahl for use with another speaker project. Gary’s sealed boxes keep the 416s within their 700Hz to 70Hz comfort zone, thereby minimizing IM distortion. Gary, Lynn Olson, Jon Ver Halen among others have long known the Altec 416 to be a very unusual driver, and enjoy its almost “magical” sonic properties of this “PA” speaker in almost any kind of enclosure. http://www.diyaudio.com/forums/multi-way/100392-beyond-ariel-781.html and New Adventures In High Efficiency My Lowther Journey With a rant or two sprinkled in for good measure. Article By Scott Faller Thus, to overcome the OBs’ room boundary issues for adequate low frequency response in very small rooms, I would place an Eminence Beta 12 LTA OB atop each Altec 416 midwoofer box.
There’s only ~0.3db difference between the 416 and the Beta LTA, so activecrossovers are obviously not needed, at least for level matching. And aren’t sealed boxes the most forgiving of placement restrictions? If so, then their handling of everything from 700Hz down to 70Hz should take most room boundary problems off the Beta LTA OBs. Correct?
As for highs, while expensive it appears that the best solution by far would be a pair of 9” RAAL Lazy ribbons
https://www.madisoundspeakerstore.com/ribbon-tweeters/raal-lazy-ribbon-9-ribbon-tweeter/ Along with excellent dispersion, their > 100db sensitivity would again remove the need for active crossovers.
Question: Depending on which of my two small bedrooms I’d be installing thesehybrid OBs-and on whichwall they are placed along-I’d be sitting between 7.5 ft and 12 ft away in one bedroom and between 8 ft and 9 ft away from them in the smaller bedroom. Gary’s Altec sealed midwoofers cabinets are 26” w x 15” d x 20” h. But assuming on-axis placement is desirable, how wide and how high does the OB panel for the Beta 12 LTA need to be, with each panel sitting atop each Altec midwoofer cabinet?
Obviously, these numbers would also impact placement for the RAAL ribbon tweeter, being either to the side or atop each Beta 12 LTA OB.
Another question: Would I be compromising a lot sound quality if don’t at least partially cross this system actively?
Btw, I would drive the system with my First Watt F4 amp FIRST WATT F4 via a tube preamp like this K&K Audio | Line Stage
As for Lowthers (in OBs atop the Altec midwoofers?), I’ve heard it said that most people either love them or hate them. Whether that be due to the “shout”-though apparently due to a problem with the driver’s whizzer that was banished more than 15 years ago-or the break in period or other personal listening preferences, I wouldn’t know. However, I’ve certainly been long interested in hearing them, particularly the Alnico models. But to best of my knowledge no has ever once done a Lowther show in New York City. Nor could I find Lowther owners there-or on Long Island, where I live-who might let me hear them.
On the other hand, everyone seems to love the sound of OBs in general; ditto for Alnico drivers, such as the GPA Altec 416s-particularly in low diffraction sealed boxes that cut their low end off below 70Hz. Despite having to contend with 3 cu ft midwoofer boxes in my bedroom, I’m hoping that I might have hit upon “a best
of all worlds” system that works in at least one of my bedrooms.
But did I overlook anything?
Anything else good or bad about my bedroom speaker system idea?
How good do you think it might sound?
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>>> Thus, to overcome the OBs’ room boundary issues for adequate low frequency response in very small rooms, I would place an Eminence Beta 12 LTA OB atop each Altec 416 midwoofer box.
This might work.
This might work.
Oltos, I got your PM. I live on Long Island in Great Neck. You are welcome to visit and listen to my system. I don't have Lowthers but I have 12LTA on OB about 12" from the walls in the corner. They are sitting on top of an H-frame so not quite the same as your Altecs. We could pull the 12LTA away from the walls and listen for the difference in sound. I have a few other drivers on OB we can listen to as well (TB 1808, TB 1320, Dayton PS95, Vifa DC9, Betsy, Fostex 168z and a few oddball drivers I've picked up along the way).
Wow so cool, I'm in Syosset! Would you have a DAC? I've been putting off selecting one ($$$$) until my speakers are done. I could copy my uncompressed WAV files of CD tracks to a flash drive. I use Samplitude on my laptop as a player and fxs. Or might your CD player have a USB or other digital input? But I can bring CDs too. 🙂
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