Diawhoness? I'll have to look that one up. I have no experience experimenting when baffled. But I recently acquired a 3d printer that's going to help. I have 8 inch mids so thinking of going 12 inches wide. I want to load the 12" sub sideways so I can keep a 12 inch width from the front and have a shelf style vent also exiting the very bottom front. I envision the top having that multiple angled chiseled look but ultimately provides about 30 degrees of directional inducing cant. Hopefully I can at least make it look sophisticated. 😁
Lynn,
I want to thank you for sharing so much knowledge. I wasn't aware of the over/underhung suitability for vented/sealed.
What I'm reading about modern GPA alnico-magnet 416 sounds very appealing. I was wondering if you had the chance to listen to Acoustic Elegance LO12 or 15" in OB or TD12M or 15 in a sealed box and your take on their sound vs the 416? I would be using them above 60-70hz (subs below), so midbass is what I'm after, and articulation/vivid tone colors sounds very much down my alley.
Thank you!
Sorry, I have not auditioned the AE LO12 or LO15, even though they were designed at my suggestion. Well, other folks like them, so it's all good. Gary Dahl ended up with Alnico 416's, but I should mention that he and I bought them back when the price was $450 each. Now they are $1250 each, quite a lot more. But still built the same from what I can tell, and GPA has a steady market of Altec nuts to keep them going.
But ... how many drivers on the market combine underhung voice coils, a long, deep gap, Alnico magnets, and lightweight cones (about 70 grams) with very smooth response through 1~3 kHz? The pro drivers have heavy cones, very heavy duty voice coils that are overhung, and often horrendous breakups above 1 kHz.
And most of the other drivers with Alnico magnets are for guitar amps ... these have unity-hung voice coils (efficient but tons of distortion) and peaked-up midrange response. Guitar amp drivers are musical instruments, and the dynamic, level-dependent colorations become part of the sound of the instrument and part of its expressiveness, what the player experiences as "responsiveness". Not good for hifi, with the possible exception of the Tone Tubby I wrote about a few years back.
So there's a handful of old-school drivers that are different than modern PA, movie theater, and guitar amp drivers. These are sometimes called professional monitor midbass drivers and have lighter cones and moderate power ratings (only 300 watts!). But they are kind of scarce, since it's a much, much smaller market than the zillions of heavy-duty drivers sold for PA and sound reinforcement applications. But they do exist. I look for smooth response in the rolloff region and light cones in the 65 to 75 gram range. Other folks mention low mechanical losses, which seems reasonable for retention of low-level detail.
But ... how many drivers on the market combine underhung voice coils, a long, deep gap, Alnico magnets, and lightweight cones (about 70 grams) with very smooth response through 1~3 kHz? The pro drivers have heavy cones, very heavy duty voice coils that are overhung, and often horrendous breakups above 1 kHz.
And most of the other drivers with Alnico magnets are for guitar amps ... these have unity-hung voice coils (efficient but tons of distortion) and peaked-up midrange response. Guitar amp drivers are musical instruments, and the dynamic, level-dependent colorations become part of the sound of the instrument and part of its expressiveness, what the player experiences as "responsiveness". Not good for hifi, with the possible exception of the Tone Tubby I wrote about a few years back.
So there's a handful of old-school drivers that are different than modern PA, movie theater, and guitar amp drivers. These are sometimes called professional monitor midbass drivers and have lighter cones and moderate power ratings (only 300 watts!). But they are kind of scarce, since it's a much, much smaller market than the zillions of heavy-duty drivers sold for PA and sound reinforcement applications. But they do exist. I look for smooth response in the rolloff region and light cones in the 65 to 75 gram range. Other folks mention low mechanical losses, which seems reasonable for retention of low-level detail.
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Thank you Lynn.
Did some searching and didn’t find much for underhung voice coil midbasses. An 8" Tang Band (small), and noticed the AE LO15 is underhung and meant for open baffle while the AE TD15S is overhung and meant for sealed/vented. They are around 74 gram Mms. I guess AE focuses on PA for their TD line.
Do you recall any other manufacturers making underhung voice coil midbass drivers?
Did some searching and didn’t find much for underhung voice coil midbasses. An 8" Tang Band (small), and noticed the AE LO15 is underhung and meant for open baffle while the AE TD15S is overhung and meant for sealed/vented. They are around 74 gram Mms. I guess AE focuses on PA for their TD line.
Do you recall any other manufacturers making underhung voice coil midbass drivers?
I was looking at this design trying to find a less expensive suitable tweeter/waveguide. I'm not a speaker designer, but like to build. Here are the three combinations I've found that may work, but I would appreciate anyone's opinion on them. All of them will save me an easy $100 in the total cost of the drivers from the stock Audax.
SB26ADC in a 6.5" round AugerPro waveguide
Seas 27TDFC in a Visiton WG148R
Scanspeak D2604/83300 with an adapter plate and the WG148R
SB26ADC in a 6.5" round AugerPro waveguide
Seas 27TDFC in a Visiton WG148R
Scanspeak D2604/83300 with an adapter plate and the WG148R
Today I posted a new item "Open Baffle Bass Boost: +4 to +7dB w/ Passive Xover. No DSP." An alternative to getting punchy bass from Dipole design.
What a terrific thread, with such open and respectful interactions!
I've been dabbling in audio to varying degrees for decades, but somehow have had very little exposure to OB. I've read a ton of material and tend to walk away with equal measures of understanding and confusion. Or to be honest, maybe more confusion--usually about the bass frequencies!
Here, why does this particular reflex implementation not sound "boxy" to you? Does the reflex bass reintroduce problems with room coupling that I (thought I'd) understood from other material as being a key advantage of OB bass? Please note that I'm not challenging anything, but rather, just earnestly trying to get a better grip on these topics so that I can decide what my next audio journey should be.
I've seriously considered building a system using the Rhythmik/GR Research servo subs since they seem to be one of the few OB options I've found with serious output capability below 35 Hz. My personal perception of room spatial cues and some of my listening genres mean I unfortunately really want very low capability... it would be much easier (and less expensive/bulky!) not to care
. I'm curious whether you've heard those servo subs, or paired them with your live edge speakers, or even tried any designs using them? Other thoughts on how best to extend the reach in a non-dedicated listening room aka living room that can't support multiple extra subwoofer placements?
I've been dabbling in audio to varying degrees for decades, but somehow have had very little exposure to OB. I've read a ton of material and tend to walk away with equal measures of understanding and confusion. Or to be honest, maybe more confusion--usually about the bass frequencies!
Here, why does this particular reflex implementation not sound "boxy" to you? Does the reflex bass reintroduce problems with room coupling that I (thought I'd) understood from other material as being a key advantage of OB bass? Please note that I'm not challenging anything, but rather, just earnestly trying to get a better grip on these topics so that I can decide what my next audio journey should be.
I've seriously considered building a system using the Rhythmik/GR Research servo subs since they seem to be one of the few OB options I've found with serious output capability below 35 Hz. My personal perception of room spatial cues and some of my listening genres mean I unfortunately really want very low capability... it would be much easier (and less expensive/bulky!) not to care
. I'm curious whether you've heard those servo subs, or paired them with your live edge speakers, or even tried any designs using them? Other thoughts on how best to extend the reach in a non-dedicated listening room aka living room that can't support multiple extra subwoofer placements?
I'm guessing that to jaded OB fanatics the flanagangsters might sound a little boxy. But since only the bottom 1.5 octaves are reflex and the rest is dipole, they sound overwhelmingly like dipoles.
Also - this is pure conjecture on my part - a possible explanation is these are high efficiency snappy woofers with 5mm xmax, and the DSP is carefully sculpted to squeeze every last drop out of the available excursion, with a steep shelf filter below 35Hz, in contrast to what is usually a heavy, rubber surround, low efficiency woofer which often have great specs but sound "thumpy" and not that musical.
I have a pair of 12" Dayton Titanic subs (heavy cones, rubber surrounds, 19mm xmax, 2nd category I just described) in the corners of my room. Small sealed boxes, heavily EQ'd. I have them fitted with accelerometers and motional feedback circuits (using hardware from https://piratelogic.nl/) so they are easily made to go down to 10-15Hz. I have used them with quite a few different OB designs (www.perrymarshall.info/speakers - you can see a whole list with descriptions).
Impressions:
In broad strokes they sound great. I cross them over between 30-60Hz depending on what the satellite speakers are. I have them crossed over to the Bitches Brews at 35Hz at the moment (no high pass on the Bitches Brews, just the stock curve) and you can't tell there are separate subs.
For the Cottonwood Dipoles, I crossed them at 60Hz. If you listen very closely the subs DO sound boxy, there is a slight mismatch between the low bass and the low-mid bass. Only an audiophile would notice. But we're all audiophiles.
My friend Tom Perazella who's written AX articles about multiple sub placement says the problem is not the monopole, he says the problem is the corner placement which he says turns out to be the worst. He says if they were positioned closer to the midpoint of one wall they would sound better.
My room is not conducive to that so I haven't tried it.
If you're a "deep deep bass head" then obviously OB isn't the ideal sub-subwoofer for you, so I think you can cross over to something like the Cottonwood Dipoles at 50-65 Hz, photo below; or the Live Edge Dipoles at 40-45 Hz, and end up pretty happy. Personally I think the trick is the crossover. I would make the acoustic high pass slope of the subs no steeper than 12dB per octave; 6dB if you can manage. (It's counterintuitive but the steeper the slope, the more audible the subwoofer is in my opinion) and I would pay very close attention, experimenting with timing and phase of the satellites relative to the subs.
Also - this is pure conjecture on my part - a possible explanation is these are high efficiency snappy woofers with 5mm xmax, and the DSP is carefully sculpted to squeeze every last drop out of the available excursion, with a steep shelf filter below 35Hz, in contrast to what is usually a heavy, rubber surround, low efficiency woofer which often have great specs but sound "thumpy" and not that musical.
I have a pair of 12" Dayton Titanic subs (heavy cones, rubber surrounds, 19mm xmax, 2nd category I just described) in the corners of my room. Small sealed boxes, heavily EQ'd. I have them fitted with accelerometers and motional feedback circuits (using hardware from https://piratelogic.nl/) so they are easily made to go down to 10-15Hz. I have used them with quite a few different OB designs (www.perrymarshall.info/speakers - you can see a whole list with descriptions).
Impressions:
In broad strokes they sound great. I cross them over between 30-60Hz depending on what the satellite speakers are. I have them crossed over to the Bitches Brews at 35Hz at the moment (no high pass on the Bitches Brews, just the stock curve) and you can't tell there are separate subs.
For the Cottonwood Dipoles, I crossed them at 60Hz. If you listen very closely the subs DO sound boxy, there is a slight mismatch between the low bass and the low-mid bass. Only an audiophile would notice. But we're all audiophiles.
My friend Tom Perazella who's written AX articles about multiple sub placement says the problem is not the monopole, he says the problem is the corner placement which he says turns out to be the worst. He says if they were positioned closer to the midpoint of one wall they would sound better.
My room is not conducive to that so I haven't tried it.
If you're a "deep deep bass head" then obviously OB isn't the ideal sub-subwoofer for you, so I think you can cross over to something like the Cottonwood Dipoles at 50-65 Hz, photo below; or the Live Edge Dipoles at 40-45 Hz, and end up pretty happy. Personally I think the trick is the crossover. I would make the acoustic high pass slope of the subs no steeper than 12dB per octave; 6dB if you can manage. (It's counterintuitive but the steeper the slope, the more audible the subwoofer is in my opinion) and I would pay very close attention, experimenting with timing and phase of the satellites relative to the subs.
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Thanks for those responses! Particularly interesting is the suggestion to cross over the subs with a very shallow slope. When monopole and dipole subs overlap on the same frequencies, do you tend to get the best of both, the worst of both, or... what happens?
I noticed that you'd done some work with an accelerometer-based servo sub. I believe the Rhythmik amps, when paired with the Rhythmik or GR Research drivers with sensing coils, are position-based and can effectively force the drivers to act differently than their passive parameters. The amps have 2 flavors, OB and monopole. I'm guessing these could mate up well with e.g. the Cottonwoods, as you suggested.
Btw, I've found your comments on the different sounds of materials quite intriguing. In case it's of interest, the GR 12" has a high excursion treated paper cone with the servo coil, and Rhythmik has an 8" paper cone model as well. (I have zero affiliation to either--just looking for deep bass pairing options that might tonally blend well). Building on your bass reflex idea, could a sealed servo sub be integrated into one of your living edge dipoles, especially for those who would have a hard time putting additional speaker/sub placements in a room?
I noticed that you'd done some work with an accelerometer-based servo sub. I believe the Rhythmik amps, when paired with the Rhythmik or GR Research drivers with sensing coils, are position-based and can effectively force the drivers to act differently than their passive parameters. The amps have 2 flavors, OB and monopole. I'm guessing these could mate up well with e.g. the Cottonwoods, as you suggested.
Btw, I've found your comments on the different sounds of materials quite intriguing. In case it's of interest, the GR 12" has a high excursion treated paper cone with the servo coil, and Rhythmik has an 8" paper cone model as well. (I have zero affiliation to either--just looking for deep bass pairing options that might tonally blend well). Building on your bass reflex idea, could a sealed servo sub be integrated into one of your living edge dipoles, especially for those who would have a hard time putting additional speaker/sub placements in a room?
Sure, if you wanted to make the Cottonwood dipoles a foot taller and put a small acoustic suspension box and 2nd woofer on the bottom, that would certainly work. Not terribly different than the Flanagangsters that you see in this thread. Also, you could run a motional feedback subwoofer in a dipole configuration.
The Flanagangsters seems like a great design. I noticed you used the SB Acoustics TN29BNWG Beryllium waveguide tweeter in the live edge beryllium dipoles. I'd like to use the new woofer configuration you invented in the Flanagangsters, but I also want to use the TN29BNWG. Since you have experience working with the drivers, is substituting the tweeter into the Flanagangsters or modifying the live edge berylliums for the new two woofer configuration using the Lavoce woofers the way to go? TIA
The TN29BNWG is far superior to the TW034X0 and I unhesitatingly recommend it. (Much more $ too). You can certainly use it on the Flanagangsters.
If I had to pick between Cottonwood Dipoles vs Flanagangsters with TN29BNWG I’d pick the latter. Much higher low end output capability.
If I were using with a subwoofer I’d go with the Cottonwood w/ LaVoces.
If I had to pick between Cottonwood Dipoles vs Flanagangsters with TN29BNWG I’d pick the latter. Much higher low end output capability.
If I were using with a subwoofer I’d go with the Cottonwood w/ LaVoces.