Having purchased Magnepan LRS's, which I'm completely blown away by, I thought I'd try adding two subwoofers. Although the smallest Maggies, they were quite confronting (I've got used to them now and don't even notice!) so my preference for open baffle subs to best integrate meant putting up with equally imposing stacked H frames till I discovered Mr Linkwitz.
https://www.linkwitzlab.com/woofer.htm
I built a pair of Dipole Woofer 3's slightly modified (not in dimensions) for ease of construction and practical shape/finish/use. Cutting sheet for 18mm MDF 2400x1200 and construction photos available by email.
They are yet to have top veneer and grill cloth frames but photo shows neat size (KEFs in background are retired). They use a pair of 12" OB woofers (BIANCO-120B150) per channel. Very inexpensive approximately $500US all up including materials.
line.com.au/sb-audience-bianco-12-open-baffle-woofer-150w/sb-audience-range/sb-acoustics/speaker-drivers/audio-speakers-pa/bianco-120b150-89896/1002166/pd/
I used this inexpensive low pass filter leaving the LRS's full range on their own monoblocks.
ps://www.wagneronline.com.au/subwoofer-low-pass-filter-active/crossovers-assembled/speaker-components/audio-speakers-pa/ax100-6812/962104/pd
I've not got any measuring equipment but they integrate very unobtrusively and smoothly into the LRS's. I've used a test CD running c/s 100 down to 20 and there is a smooth transition from LRS's to subs. Musically they match, only reinforce and do not dominate. I'm a retired classical musician so I have good ears!
https://www.linkwitzlab.com/woofer.htm
I built a pair of Dipole Woofer 3's slightly modified (not in dimensions) for ease of construction and practical shape/finish/use. Cutting sheet for 18mm MDF 2400x1200 and construction photos available by email.
They are yet to have top veneer and grill cloth frames but photo shows neat size (KEFs in background are retired). They use a pair of 12" OB woofers (BIANCO-120B150) per channel. Very inexpensive approximately $500US all up including materials.
line.com.au/sb-audience-bianco-12-open-baffle-woofer-150w/sb-audience-range/sb-acoustics/speaker-drivers/audio-speakers-pa/bianco-120b150-89896/1002166/pd/
I used this inexpensive low pass filter leaving the LRS's full range on their own monoblocks.
ps://www.wagneronline.com.au/subwoofer-low-pass-filter-active/crossovers-assembled/speaker-components/audio-speakers-pa/ax100-6812/962104/pd
I've not got any measuring equipment but they integrate very unobtrusively and smoothly into the LRS's. I've used a test CD running c/s 100 down to 20 and there is a smooth transition from LRS's to subs. Musically they match, only reinforce and do not dominate. I'm a retired classical musician so I have good ears!
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I think I'd flip those woofers 90 degrees so the cones aren't sagging. And, ultimately, you'd want to high-pass the main speakers to reduce their workload and improve distortion.
I'd shoot for a 80Hz symmetrical crossover between the two. I've had my MMG/Linkwitz setup like this for many years.
Also, that wagner filter doesn't have the proper equalization for those Linkwitz woofers.
Dave.
I'd shoot for a 80Hz symmetrical crossover between the two. I've had my MMG/Linkwitz setup like this for many years.
Also, that wagner filter doesn't have the proper equalization for those Linkwitz woofers.
Dave.
Thanks for your feedback.
Yes I'd like to highpass the Maggies but had to can the decision. I'm using a Schiit Freya+ and a pair of Vidars with balanced connections. To get an active filter using balanced connections to go in between would cost thousands. I'm not capable of designing my own but could build it. I suppose I could do two pairs of passive filters in front of the LRS's and subwoofers.
The boxes were rotated so I could have the base plate rather than side removable for driver installation and it is a more room friendly shape (occasional coffee tables or seats!) I ran the design past the SB Audience Marketing Manager and he didn't have any concerns, and as many (KEF) brands have floor firing subs thought it wouldn't be an issue.
You may be interested in a very generous email I received from him concerning a remark I made about the OB drivers having a fairly high Fs.
"Well we can make the Fs anything we want. But it comes at great expense in terms of sound and integration. Low Fs dedicated subwoofer drivers are a big compromise. Very heavy moving mass and a suspension that will keep everything in check for long travel unfortunately means non linearity and high loss - transients will suffer greatly. So looks good on paper, but in reality is highly compromised. There is lots of distortion and in reality most of what we perceive as stong low end output is 2nd order harmonics masking the real signal at the very low end. True undistributed bass below 30-35Hz is not heard as much as it is felt, but in most cases the room shaking along with the physical experience on the body is much more perceivable than the sound. But in most cases we hears systems with great distortion (even big expensive ones) and that's when we "learn" that a 20Hz becomes a physical experience with the addition of 40Hz harmonic that we can easily hear.
Most live sound rigs and professional cinemas don't go below 30-35Hz and that is plenty deep enough. The key is how it integrates with the room and even more importantly for music is how it integrates with the rest of the system.
Your lively speakers will not integrate well with a traditional subwoofer and a traditional subwoofer driver in OB application would also be a poor choice in my opinion.
A large light weight surface area with good transient performance capable of reaching into the midrange is what will work for your application, so you are on the right track. Forget about the Fs or the theoretical goal of achieving infra bass, it will only detract from the sound quality and integration.
You may start with two woofers and add more if you need it. There is no shame in building some crude mockup and improving from there. In my opinion the modest cost of 4 x 15" drivers to take the Magnepan setup to a whole other level is a real bargain. You won't be able to make improvements to your system of that magnitude dollar for dollar. If done well I think you will struggle to find a better sounding system unless we are talking really large big dollar systems. OB bass is wonderful and addictive."
Even the crossovers like X-Kitz wills suit you and not cost thousands. But yea, active crossovers are hard to come by. Don't even think about passive. Yo need enough coils to sink a ship. They even have balanced IO options.
I am not sure your perceptions for dipole extend to subs. Have you done just a simple low Q sealed? Look up "critical Q". Low Q sealed subs blend with room gain a lot easier. A pair of 12's next to your Maggie's would do just fine.
Subs are basically omnidirectional to start with. No disrespect to Siegfried, but he did get a bit carried away. There are a lot of very good 10 and 12's that are not too big in a .5Q. Please ignore any of the "fast" stuff. That's not engineering. No such thing as a "fast speaker". Your sub is not integrating with your midrange. ( or it had better not be!)
I am not sure your perceptions for dipole extend to subs. Have you done just a simple low Q sealed? Look up "critical Q". Low Q sealed subs blend with room gain a lot easier. A pair of 12's next to your Maggie's would do just fine.
Subs are basically omnidirectional to start with. No disrespect to Siegfried, but he did get a bit carried away. There are a lot of very good 10 and 12's that are not too big in a .5Q. Please ignore any of the "fast" stuff. That's not engineering. No such thing as a "fast speaker". Your sub is not integrating with your midrange. ( or it had better not be!)
For a 2-chan, 2-way Linkwitz-Riley 4th-order, 24dB/oct op-amp based xover check out Marchand Electronics here:
https://www.marchandelec.com/electronic-crossovers.html
Take a look at the Model XM9L-AA for example. $750 + $250 for the XLR balanced I/O option. You change the crossover freq with a simple and cheap 8-pin DIP "frequency module" with four resistors but need to tell them what range of x-over freqs you my try so they can populate the boards with appropriately-valued capacitors. The four op-amps/chan are in sockets so you can roll your own.
https://www.marchandelec.com/electronic-crossovers.html
Take a look at the Model XM9L-AA for example. $750 + $250 for the XLR balanced I/O option. You change the crossover freq with a simple and cheap 8-pin DIP "frequency module" with four resistors but need to tell them what range of x-over freqs you my try so they can populate the boards with appropriately-valued capacitors. The four op-amps/chan are in sockets so you can roll your own.
I'm using this crossover with my system and I'm quite pleased. Balanced in/out and everything, and didn't cost a fortune.
https://www.sweetwater.com/store/detail/CX2310v2--behringer-super-by-pro-cx2310-v2
https://www.sweetwater.com/store/detail/CX2310v2--behringer-super-by-pro-cx2310-v2
Nice. Linkwitz-Riley filters with 24 dB/octave:
$109 on sale. 😵
It’s been a nice piece of kit. It does pop when you turn it on, so best to turn on the line level gear before the amp. But functionally it works great and has a lot of flexibility.
Have you considered DIY Ripole subs?
I have drawings of the version shown below, and also an easier to build version, if you're interested.
I have drawings of the version shown below, and also an easier to build version, if you're interested.
That Behringer is a good choice vs. some others I checked out before going with the Marchand XM9. I looked at the Behringer's schematic and it also uses the state-variable 24dB/oct filter topology as the Marchand. And it's just an L-R, 4th-order 24dB/oct. Period. No 12 or 18dB so there's no phase shift happening at the xover freq. They kept it simple. It uses 1% resistors which is very good. It has a +/- 15V split supply for the op amps - also smart. It does use old op-amps having high DC residual output voltage up to 6mV so unfortunately there are five electrolytic caps in each Hi and Lo signal path leg there for inter-stage DC blocking. The Marchand is nice b/c the standard op amps used have low DC offset so no coupling caps at all, plus they are faster and much lower noise. They are all mounted in 8-pin DIP sockets so you can roll other op amps - which I did, several times over the years whenever I learned of a new favorite type. I had Phil not include the standard XM9 switching supply and installed an Acopian +/-15V linear. I had a few other changes to his original design for which I sent him parts. IOW, my XM9 is customized and pricey but the goal was transparency = the rest of the chain, if possible.
All in all the Behringer looks decent. Hard to believe the price!
All in all the Behringer looks decent. Hard to believe the price!
Hi Charlie, would you mind sending me the drawings of the above and any info you have?
Yes, of course. PM me your email address and I will send the drawings/parts lists for two versions in DXF format.
The Magneplanar Bass Panel (DWM) would seem an ideal fuss free installation, could be worth a listen https://magnepan.com/products/dwm-bass-panel?variant=42607830696172
An alternative to the ripole - Papa’s slot loaded open baffle version #2 https://www.diyaudio.com/community/threads/papas-slot-loaded-open-baffle-version-2.362482/
Unfortunately the First Watt B4 active crossover is out of production, but the diyAudio store does sell the DIY BIAMP 6-24 CROSSOVER https://diyaudiostore.com/products/diy-biamp-6-24-crossover?variant=31765939322953
An alternative to the ripole - Papa’s slot loaded open baffle version #2 https://www.diyaudio.com/community/threads/papas-slot-loaded-open-baffle-version-2.362482/
Unfortunately the First Watt B4 active crossover is out of production, but the diyAudio store does sell the DIY BIAMP 6-24 CROSSOVER https://diyaudiostore.com/products/diy-biamp-6-24-crossover?variant=31765939322953
Not sure how to add an update to my original post at the beginning of this post so I'll do it as a reply but that may not be relevant.
I finally found a low cost active crossover. The Dayton LF-DSP (you have to buy 2 for stereo subs). I actually got an iPhone 7 for the iWoofer Pro app, but found the room correction facility useless for my purposes (I only wanted low frequency and the room correction forced you to extend the range to 500Hz). So free iWoofer app (android or iOS) with crossover is sufficient.
I dragged the high pass down to 20Hz 48bB/8ve and high pass from 40Hz 24db/8ve. I don't have measuring equipment but in my listening environment a test track Freq from 25Hz (some output!) to 100Hz shows gradual build to about 40Hz then fairly even integration to the LRSs. I wanted to run the LRSs full range and to apply crossover to the subs to integrate with them. From my tests the LRSs alone start to diminish at about 85Hz and fade completely by about 45Hz so I got the result I wanted with more or less 'flattish' down to 35 Hz. For a few hundred dollars and not having to DSP the LRSs, which was my objective.
You can hear the different quality of the paper cone subs compared with the LRS panels but it's not objectionable.
I finally found a low cost active crossover. The Dayton LF-DSP (you have to buy 2 for stereo subs). I actually got an iPhone 7 for the iWoofer Pro app, but found the room correction facility useless for my purposes (I only wanted low frequency and the room correction forced you to extend the range to 500Hz). So free iWoofer app (android or iOS) with crossover is sufficient.
I dragged the high pass down to 20Hz 48bB/8ve and high pass from 40Hz 24db/8ve. I don't have measuring equipment but in my listening environment a test track Freq from 25Hz (some output!) to 100Hz shows gradual build to about 40Hz then fairly even integration to the LRSs. I wanted to run the LRSs full range and to apply crossover to the subs to integrate with them. From my tests the LRSs alone start to diminish at about 85Hz and fade completely by about 45Hz so I got the result I wanted with more or less 'flattish' down to 35 Hz. For a few hundred dollars and not having to DSP the LRSs, which was my objective.
You can hear the different quality of the paper cone subs compared with the LRS panels but it's not objectionable.
I'm just curious why you don't want DSP? There's not a single speaker on this planet that won't benefit from it, and the LRS is certainly one.
When a friend measured the LRSs here they were surprisingly flat in my listening environment. The only DSP that can be applied in this case is room correction which would require purchasing at least another $1000 worth of DSP, probably a lot more for quality to DSP both subs AND mid/high. The LRSs are superb to their lower limit, short sheeted as it is, so why interfere with it. The Dayton LF-DSP is only designed to put between preamp and sub amp where, as originally pointed out, the DSP is only really useful as a LP crossover and not ideal as I couldn't figure out how to stop it automatically extending the subs range up to 500+. There it is ADDITIONAL to the LRS and is very boomy and coloured. Kept as an 'add on' to the LRS to extend it's bottom end it works well.
I could of course wait in the queue to buy the new Magnepan OB DSP subwoofer system which gets rave reviews and will probably cost thousands. I think my solution extremely cost effective for the DIY builder with limited funds like myself. Any quality can be purchased if you have deep pockets.
I could of course wait in the queue to buy the new Magnepan OB DSP subwoofer system which gets rave reviews and will probably cost thousands. I think my solution extremely cost effective for the DIY builder with limited funds like myself. Any quality can be purchased if you have deep pockets.
In my opinion, any Magnepan should be hi-passed no lower than 100 Hz, because the distortion really goes crazy at lower frequencies.
A MiniDSP Flex is only 495$, and is as good as it gets. 2 inputs and 4 outputs, exactly what you need here. It can also do FIR to flatten out the phase response, which is a very good idea I think. There's a Dirac option as well, if you buy a 199$ license for it.
I use the MiniDSP Flex on my active 3.7's, and it's simply wonderful.
A MiniDSP Flex is only 495$, and is as good as it gets. 2 inputs and 4 outputs, exactly what you need here. It can also do FIR to flatten out the phase response, which is a very good idea I think. There's a Dirac option as well, if you buy a 199$ license for it.
I use the MiniDSP Flex on my active 3.7's, and it's simply wonderful.
Thanks. Do you use subwoofers? I listen to all classical which really exaggerates the mismatch in sound quality between the planars and cones. Non classical audiophiles have it easy because the typical bass listened to doesn't have to blend to anything like the same degree. Classical piano solo or orchestral lower strings are so much better without subwoofers! Thinking of selling my subwoofers if I can afford (obtain!) bigger Maggies. Looking for some 3.7is.
Yes, I have a large subwoofer array (twenty-four 10") with my 3.7's. I have also added two 1.6's as extra midbass panels for each 3.7. Simply can't live without proper bass, and I also like to listen to a wide range of classical music from Monteverdi to Xenakis.
I do agree with you that subwoofer integration with planars like Magnepan is complicated. However, automated room correction like Dirac will make that a lot easier.
In my opinion, none of the maggies offer good low bass. I have not heard the 30.7, but the laws of physics apply even there.
I do agree with you that subwoofer integration with planars like Magnepan is complicated. However, automated room correction like Dirac will make that a lot easier.
In my opinion, none of the maggies offer good low bass. I have not heard the 30.7, but the laws of physics apply even there.
Noodlum - You are on the path to getting bigger Maggies. 😉
I have MG1.6s. The bass response peaks at 47Hz in my room. That is enough to give the impression of deep bass through harmonics even though the fundamental is missing (the sound is present but not the feeling).
Maggies don't have deep bass, but they are quite coherent. You seem to be valuing coherency more than the bottom octave.
Ed
I have MG1.6s. The bass response peaks at 47Hz in my room. That is enough to give the impression of deep bass through harmonics even though the fundamental is missing (the sound is present but not the feeling).
Maggies don't have deep bass, but they are quite coherent. You seem to be valuing coherency more than the bottom octave.
Ed