Hello. I'm new to the his forum and have very little diy audio experience other than car audio in my younger days. I'm currently working on a project that involves building the bass section of an almost full range 3 way tower. I'll be using a pair of Emotiva B1+ bookshelf speakers on top of the new bass section. Also using a Mini Dsp 2X4 hd for crossover and eq. Each side will house a Denovo Magnum 12 woofer in a 2 cubic ft vented enclosure tuned to 36 hz. My crossover point will be somewhere between 200 and 300 hz. Has anyone on this site experimented with tuning these particular woofers? Any suggestions on what damping material works well for this type of enclosure. A little more extension wouldn't bother me but my priority is to have tight articulate bass for 2 channel critical listening.
I have not played with that driver.
I find articulate bass has more to do with integration (mid highs crossover), but i do prefer 27hz tuning over 40hz (thunk smoothes out to boom) with sub or deep woofers.
That denovo is not a cheap woof, but high power, 3" coil, i like what i see.
Not the deepest bass ( .34 qts and 42hz fs), but with eq at 50hz (many receivers have bass tone control at 50hz nowadays), i enjoy my 12" 2-way that has ported f9 near 50hz (fs 52hz and qts .32).
A friend said my 2x12" 27hz ported was quicker than his 10's sealed.
Tight bass can also be a lack of low bass.
I sealed my deep 2x15" 2-way for sealed f3 60hz vs ported at / f3 of 27hz.
Sealed wasn't faster, just an octave less bass..............sad face
So, don't expect rumble with that 12, but deep punch if eq'd, sure.
I can crunch numbers sunday, but f3 may be 60+ hz.
Since you are crossing 2-300hz, i wouldnt mess with dampening.
For me, if i was going 3 way, i would aim for less sensitivity and a deeper f3 so i wouldnt desire a sub.
But get back to us and good luck with your projects !!!
I find articulate bass has more to do with integration (mid highs crossover), but i do prefer 27hz tuning over 40hz (thunk smoothes out to boom) with sub or deep woofers.
That denovo is not a cheap woof, but high power, 3" coil, i like what i see.
Not the deepest bass ( .34 qts and 42hz fs), but with eq at 50hz (many receivers have bass tone control at 50hz nowadays), i enjoy my 12" 2-way that has ported f9 near 50hz (fs 52hz and qts .32).
A friend said my 2x12" 27hz ported was quicker than his 10's sealed.
Tight bass can also be a lack of low bass.
I sealed my deep 2x15" 2-way for sealed f3 60hz vs ported at / f3 of 27hz.
Sealed wasn't faster, just an octave less bass..............sad face
So, don't expect rumble with that 12, but deep punch if eq'd, sure.
I can crunch numbers sunday, but f3 may be 60+ hz.
Since you are crossing 2-300hz, i wouldnt mess with dampening.
For me, if i was going 3 way, i would aim for less sensitivity and a deeper f3 so i wouldnt desire a sub.
But get back to us and good luck with your projects !!!
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Using (which is a little off vs classic 4th ported)
Speaker Box Enclosure Designer / Calculator
I get 1.4ft3
Tune = 49.9hz
F3 = 53.7hz
4" port 6.62" long
I've had 6th order (unboosted).
Basically an ebs (extended bass shelf).
I ported to the f9 of 27hz (speaker's fs).
It was lean to say the least, but a bump of eq at 40hz (max excursion point though), it worked well.
Actually worked well watching Dune last night.
Speaker Box Enclosure Designer / Calculator
I get 1.4ft3
Tune = 49.9hz
F3 = 53.7hz
4" port 6.62" long
I've had 6th order (unboosted).
Basically an ebs (extended bass shelf).
I ported to the f9 of 27hz (speaker's fs).
It was lean to say the least, but a bump of eq at 40hz (max excursion point though), it worked well.
Actually worked well watching Dune last night.
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This is a really odd pairing to me, especially the 7dB or so sensitivity difference.
How do you plan on implementing the xover? If passive it could be difficult to implement well, especially once you factor in baffle step etc into the overall design. And if passive, losing 7dB on the Magnum will be a challenge.
How do you plan on implementing the xover? If passive it could be difficult to implement well, especially once you factor in baffle step etc into the overall design. And if passive, losing 7dB on the Magnum will be a challenge.
yeah the sensitivity wasn't a consideration as I'll be using a Mini Dsp 2X4hd for the x over so easy level matching.
I selected the drivers based on what they were supposedly designed for which is the woofer in a large tower. Maybe there are better drivers for this and I'm definitely open to suggestions. I was originally going to use two Sb Acoustics sb23nrxs45-4 per side and changed to a single Magnum 12 per side to save a few bucks and gain a bit of cone area and excursion. Maybe it wasn't a good choice. What's the downside or trade off if I tune lower than what the box calculators say is optimum?
Thanks
I selected the drivers based on what they were supposedly designed for which is the woofer in a large tower. Maybe there are better drivers for this and I'm definitely open to suggestions. I was originally going to use two Sb Acoustics sb23nrxs45-4 per side and changed to a single Magnum 12 per side to save a few bucks and gain a bit of cone area and excursion. Maybe it wasn't a good choice. What's the downside or trade off if I tune lower than what the box calculators say is optimum?
Thanks
As far as I know , diysoundgroup does not make a magnum 15.
Eminence made a “magnum” line.
My buddy said they got sued by pyramid over the magnum wording on their subs.
So they stopped making/selling them, changed them a squeak, and they became the kilo max line (I think).
I had the eminence magnum 15lf’s, absolutely amazing.
If I could see a freq response of that driver, it could be an amazing option for a 1.2khz crossed 2-way (or 2.5 way, I need slamming bass).
Eminence made a “magnum” line.
My buddy said they got sued by pyramid over the magnum wording on their subs.
So they stopped making/selling them, changed them a squeak, and they became the kilo max line (I think).
I had the eminence magnum 15lf’s, absolutely amazing.
If I could see a freq response of that driver, it could be an amazing option for a 1.2khz crossed 2-way (or 2.5 way, I need slamming bass).
I'm very sorry, I completely missed it.
I still think this approach is very half-burro-ed. If you're going active, just design it from scratch, buy a kit or build someone else's design. I've never heard systems like this integrate properly, or sound 'correct' nor matter how well they measure. Sort of like putting a Powerglide 2 speed auto on a rotary, it might run on paper, put will never be quite as much fun as the correct trans for the motor.
If you go active, design a 3 way with all high, or low, efficiency components, do a basic design, get it critiqued, tweak, build, measure, measure again, adjust and sit back and listen.
I'm just getting my feet wet here and already have the system up and running with the 2x4 hd and the Emotiva's with a pair of bass modules on loan from a friend. Don't get me wrong. I appreciate the advice but at this point I'm committed. Given the fact that i already have the equipment is there a woofer that would be a better match for my plan? I can always build a different tweeter/mid module at a later date and ad a third amplifier for a fully active 3 way system.
1'st rule of speaker design is, what are your performance goals? Then factor enclosure size and budget, ported, sealed, LF/SPL aspirations (how low and loud you want it to play) and you can start to narrow it down. I probably have 20 different drivers here that I could use 'as bass in a large tower'; that's a pretty useless definition. Also how much power do you have on hand for the LF section?
There is very little information below 40Hz with real instruments, so that's a useful place to aim in that regard.
If you look at many manufacturer's datasheets and site, they will often have enclosure recommendations. Experience says take them with a grain of salt.
There is very little information below 40Hz with real instruments, so that's a useful place to aim in that regard.
If you look at many manufacturer's datasheets and site, they will often have enclosure recommendations. Experience says take them with a grain of salt.
Performance goals would be clean bass with an f3 in the mid 30s or so. Spl aspirations? That's a tough one but I'll take a stab at it. In the neighborhood of 110 db consistent with the mic three feet away from the speaker.I will often listen for an entire day at moderate listening levels. Ihave around 3 cubic ft per side to work with and am open to either ported or sealed although there appears to be quite a few more ported options. The measured sensetivity of the Emotiva's is 85 at 1 meter with 2.83 volts. I'll likely be using an 200 wpc Adcom gfa 555 for the bass drivers but originally considered using the 100wpc Schiit Vidar when i thought about going with a single magnum 12 per side. For a sealed option i am considering the Sb acoustics SB34NRX75-6 which is at the top of my budget for two woofers. I also considered the Sb23NRXS45-4 and using two per side in ported enclosures.
There was two iterations of these custom Eminence drivers for DIYSG; the 12” as used as a floor-standing midbass module for the Maximus-12 and the 15” version used as a floor-standing midbass module for the Titan-615. When Erich decided to put up the 12” woofer as a stand-alone midbass module (with baffle) the kit was called the MBM-12LX. I asked about purchasing the 15” version and that was also made available with baffle as the MBM-15LX. The individual drivers alone were referred to as the “magnum-12” and “magnum-15,” respectively. I purchased my pair of magnum-15 woofers as b-stock, without the baffle.
Nope. The plan is to use them as self-powered midbass modules crossed over circa 200-250hz. Not many analog plate amps (if any at all) allow a crossover that high. DSP plate amps can do this of course, I’m just not there yet. At any rate, they would work well as active speaker stands to mitigate floor bounce.
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