I recently started a project for some slightly upscale extended range "subs" for my son's studio, originally having chosen the JBL 2268HPL in a large vented cab. We needed some extended range up into the 200 hz area with low THD and this JBL looked good. Unfortunately it looks like it won't go that low using an unassisted vented tuning, originally trying to get down into the very low 30s to upper 20s hz cutoff without greatly exceeding xmax. So now we had to regroup and look for a 15 or dual 12S with good midbass, sensitivity, low distortion and minimal time domain issues.
These new Dayton woofers look promising, although having a lower Qts. Their other specs look great. I'm weary of their build quality and distortion figures up into the lower 100s hz area. Has any had experience with these drivers?
These new Dayton woofers look promising, although having a lower Qts. Their other specs look great. I'm weary of their build quality and distortion figures up into the lower 100s hz area. Has any had experience with these drivers?
Attachments
Okay, so here we are again. I want to make damm sure that I understand your goal(s) here. Deepest bass possible for a recording studio? What are your limiting factors? You are aware of Hoffman's Iron Law?
@Scott L I knew you'd be back. First off, to be very clear, I don't like drivers with heavy floppy surrounds the size of garden hoses. They don't do the full range up to 120hz without nasty resonances and artifacts. I also don't want to waste 100s of watts on inefficient, long, high inductance VCs. The only exception to the rule in the sub $500 price range is the SB34NRXL75-8. Call it a sub, a woofer, potato, tomato...
Yes, I'm very familiar with Hoffman and his Iron Law. He's not a friend of mine. I'm not against large enclosures. They're obviously necessary to get deep bass with decent efficiency and sensitivity across the widest bandwidth. Call it subwoofer, woofer, etc... I'll call it whatever it will do and won't get hung up on descriptions. The advice I seek is to achieve the cleanest and most accurate reproduction of the lower frequency portion of music. The driver I seek is a hard to find one which ideally doesn't exist, but one with few compromises does. I'm asking alot from a cheaper driver.
Now, to my premise. These Dayton drivers I found look to be good candidates - good sensitivity, decent xmax, lack of heavy, nasty rubber surrounds, progressive spiders, etc. I appreciate any input you may have regarding the info I requested in title of this thread. If you have any creative input, please do share, but please don't lecture me on theory in a brow beating manner.
Yes, I'm very familiar with Hoffman and his Iron Law. He's not a friend of mine. I'm not against large enclosures. They're obviously necessary to get deep bass with decent efficiency and sensitivity across the widest bandwidth. Call it subwoofer, woofer, etc... I'll call it whatever it will do and won't get hung up on descriptions. The advice I seek is to achieve the cleanest and most accurate reproduction of the lower frequency portion of music. The driver I seek is a hard to find one which ideally doesn't exist, but one with few compromises does. I'm asking alot from a cheaper driver.
Now, to my premise. These Dayton drivers I found look to be good candidates - good sensitivity, decent xmax, lack of heavy, nasty rubber surrounds, progressive spiders, etc. I appreciate any input you may have regarding the info I requested in title of this thread. If you have any creative input, please do share, but please don't lecture me on theory in a brow beating manner.
The Dayton drivers are clearly for subs, early impedance rise, drop of spl above 250Hz, resonances at 300/400Hz and last but not least, the LF in the driver names. From what you've wrote it's not clear what you want to build. If you want to build subwoofers, these will both work nicely. If you're looking for a mid-woofer, neither will deliver what you want.
E: oh, before I forget, all PA drivers have a suspension which becomes progressive above the linear excursion to protect them from damage. If you don't want that (for which there's no valid reason), you have to go to HiFi drivers. But they will not have the spl you want. Like Scott L already said, there are competing factors and you have to decide what you want (you do want PA drivers)
E: oh, before I forget, all PA drivers have a suspension which becomes progressive above the linear excursion to protect them from damage. If you don't want that (for which there's no valid reason), you have to go to HiFi drivers. But they will not have the spl you want. Like Scott L already said, there are competing factors and you have to decide what you want (you do want PA drivers)
Last edited:
On paper, they have beautiful parameters, but what about the sound quality of these speakers in reality, have you found good reviews on this forum? A good speaker from well-known manufacturers costs 300 usd and more. If this speaker plays for its hundred dollars, will it suit you or do you expect the quality to be higher than the price?
There are affordable beyma 12BR70 speakers, they have a rubber suspension, but the sound is good. There is an audio recording of these dual speakers in a three-way, but the sound is bass, not subwoofer.
Their lower Qts values do tend to reduce the low-frequency extension that's available in a close-to maximally-flat low-frequency alignment. It's the natural tuning that can be obtained using their Thiele–Small parameters.
Here's a VituixCAD simulation of the 15LF in a 120-litre enclosure.
Increasing the enclosure volume to 180 litres gives us some extra bass performance, albeit with a shelved response function.
Last edited:
How large was the cabinet that you were considering?
The VituixCAD simulations for the JBL 2268HPL driver mounted in a 180-litre vented cabinet are shown below. The −3dB point is at a highish 43.0Hz, which is just barely adequate for reproducing the lowest note on a bass guitar with some fidelity. Still, it would be capable of a decent amount of SPL at that frequency. But it is not really into subwoofer territory with this particular alignment.
If we over-volume the more standard enclosure by 50% to 270 litres, the following response is obtained. The −3dB point has been reduced to 36.7Hz, but there is now a step-down in the bass response of about 0.5dB (which seems relatively minor).
Last edited:
Good input everyone. I do have high expectations from these Dayton woofers.
I suppose my ideal driver is one that can play very loud for excellent dynamics and not have a different character in sound throughout the spl range. That isnt as easy to do if you observe how people observe the bass quality of various drivers. While the accordion style surround isn't as linear as a half roll rubber surround, it doesn't behave as bad at the surround / cone junction when the cone breaks up in a bell type mode, essentially reflecting the cone's internal bending wave propagation. This isn't really in the bandwidth a typical subwoofer is being used, but it does emit a sound of its own at lower frequencies, vibrating out of phase with the cone at times. Spiders can do the same, but they're terminated by the stiff VC former and basket, so not a big problem as long as the spider is dampened properly.
Cone rocking back and forth at higher SPL is another problem with many long throw subwoofers with large rubber surrounds. This also has a sound of its own, which isnt pleasant to listen to, plus it risks the VC losing its centering in the VC gap, potentially risking the windings contacting the upper pole plate and rubbing through wire enamel. The VC windings can short out this way and ruin the amplifier.
As I said before, the SB34NRXL75-8 and its neighbor models are very good cone drivers which don't cost as much as other higher end woofers. I would need 2 of these per side, which ends up costing $1300 for both channels just in drivers alone without the enclosures. The SB34s are the only rubber surround woofer under $500 which has a dead quiet motor. That means its a very well dampened driver and it costs much less than the otherwise excellent Scanspeak 12" Revelator.
I suppose my ideal driver is one that can play very loud for excellent dynamics and not have a different character in sound throughout the spl range. That isnt as easy to do if you observe how people observe the bass quality of various drivers. While the accordion style surround isn't as linear as a half roll rubber surround, it doesn't behave as bad at the surround / cone junction when the cone breaks up in a bell type mode, essentially reflecting the cone's internal bending wave propagation. This isn't really in the bandwidth a typical subwoofer is being used, but it does emit a sound of its own at lower frequencies, vibrating out of phase with the cone at times. Spiders can do the same, but they're terminated by the stiff VC former and basket, so not a big problem as long as the spider is dampened properly.
Cone rocking back and forth at higher SPL is another problem with many long throw subwoofers with large rubber surrounds. This also has a sound of its own, which isnt pleasant to listen to, plus it risks the VC losing its centering in the VC gap, potentially risking the windings contacting the upper pole plate and rubbing through wire enamel. The VC windings can short out this way and ruin the amplifier.
As I said before, the SB34NRXL75-8 and its neighbor models are very good cone drivers which don't cost as much as other higher end woofers. I would need 2 of these per side, which ends up costing $1300 for both channels just in drivers alone without the enclosures. The SB34s are the only rubber surround woofer under $500 which has a dead quiet motor. That means its a very well dampened driver and it costs much less than the otherwise excellent Scanspeak 12" Revelator.
I've done a frequency analysis of the first portion of the audio that's in the YouTube video. Below are the results. The recorded music seems to have plenty of low-frequency energy at 35Hz, and also between about 52Hz and 85Hz. I wonder how low in frequency these 220-litre vented boxes can go? Those Sica 8 M 1,5 CS midrange drivers have a very high sensitivity of 98.7dB.
You will need four of these: https://eminence.com/products/lab_12#frequency-response
Two drivers per enclosure, mounted magnet-to-magnet bracing structure for dual opposed operation. Be careful not to block the vents on the back plate. This driver is optimal for a 4th order butterworth, vented. Theoretical operation down to 22Hz. It will be a challenge to configure a port that is sized in a practical manner, that does not chuff. You will notice how much easier it gets to fit a port as you raise Fb up to perhaps 24, 25, or 26Hz. Complete vibration cancelling; it will take the box sound out of the equation. The only remaining source of colouration would be the possible balooning of the cabinet walls due to the pressure created by said drivers. When you run the Ka (directivity) calculations, you will see omni is possible to at least 300Hz. Have fun !
Two drivers per enclosure, mounted magnet-to-magnet bracing structure for dual opposed operation. Be careful not to block the vents on the back plate. This driver is optimal for a 4th order butterworth, vented. Theoretical operation down to 22Hz. It will be a challenge to configure a port that is sized in a practical manner, that does not chuff. You will notice how much easier it gets to fit a port as you raise Fb up to perhaps 24, 25, or 26Hz. Complete vibration cancelling; it will take the box sound out of the equation. The only remaining source of colouration would be the possible balooning of the cabinet walls due to the pressure created by said drivers. When you run the Ka (directivity) calculations, you will see omni is possible to at least 300Hz. Have fun !
Eminence Lab 12
The VitiuxCAD simulation for the SB Acoustics SB34NRXL75-8 woofer in an over-volumed 80-litre vented enclosure (160 litres for two drivers) is shown below. The −3dB point is 34.1Hz, with only a 0.5-dB step-down in the bass response.
The above is still not subwoofer territory. It is only able to handle the 30.9-Hz lowest note on a 5-string bass with 6dB of attenuation. To get down to 29.5Hz at −3dB would require a 120-litre enclosure for one driver, which is shown below.
No brow beating………but I would be remiss to not point out that you don’t understand the modal region and exactly what subwoofers are meant to do……and that is pressurize the room/space to excite modal responses. The driver properties you pronounce as highly desireable have little to nothing to do or contribute to the the actual function of a sub woofer. Below 80hz, there’s simply no musicality anymore……fundamental notes are nearly purely resonances.
So all I can add is that if you’re looking for success in your project would be to address the musical regions and modal regions separately with drivers and alignments that best fit their intended region of operation.
If I could offer you any consolation it would be that you are not alone in quoting so many misconceptions as to how to derive low frequency extension into a closed space…..the hifi/stereo sector has gotten this wrong for so long that all they can do is double down on their theory. If you want to break the chain of marketing obsessions and misconception, my first recommendation to you would be to calculator the Schroeder frequency of your son’s space. From that, derive the drivers and alignments that will work best below that frequency down to 80hz. From below 80hz your concentrations will be much different.…..but there is still a choice……you can either extensively treat the space to eliminate the resonant or modal behavior ( possible, but terribly expensive and both time and space consuming) OR you can work with the modal behavior. I’ll stop here for the simple fact that to explain the last statement is going to require that you accept the reality I’ve placed before you above…..if that’s not an option, there’s not much common ground for this conversation to produce anything useful to either of us.
Last edited:
Those are nice drivers. Below is the VituixCAD simulation for a pair of Eminence LAB 12 drivers connected in series mounted in a 180-litre vented enclosure tuned to 23.9Hz. The −3dB low-frequency cut-off point is 25.9Hz. The −6dB low-frequency cut-off point is 22.1Hz. To reduce chuffing, there are 4 ports that are each 7.5cm in diameter, which keeps the vent air velocity below 17m/s at 200W (re 8 ohms) input.
For comparison, below is the VituixCAD simulation for a pair of Eminence LAB 12C drivers in a 160-litre vented enclosure tuned to 28.1Hz. The −3dB low-frequency cut-off point is 28.7Hz, while the −6dB low-frequency cut-off point is 25.2Hz. To reduce chuffing, 4 ports each 7.5cm in diameter are used.
@Scott L The Eminence Lab12 is admittedly a great driver. I’ve used them before in home theater settings where they do well. They're definitely the picture perfect example of a dedicated subwoofer. Their only drawback is a serious cavity resonance behind the dustcap, but that won't affect their performance in a VLF / strictly subwoofer application. With this resonance, I find they cant be crossed higher than 80 hz to stay away from exciting that resonance in the slightest way. At least they use a paper cone and not so thick surround. They're not cheap though for needing 2 of them per side. The other issue is they only come in 4 or 6 ohms (as far as Eminence says).
@mayhem13 I understand all of the specifics of your argument and the definition of terms you talk about. My main issue with the advice I've been given is the sense of being told what I should want instead of what I actually prefer, despite my decision to embrace other less orthodox solutions which may be on the fringe of functionality. Stating there's no musical content below 30 Hz isn't true if you listen to music that has a large spread of harmonics centered around the lowest frequencies. While only fundamental notes occur under 30 hz, they can have harmonics higher up. Some instruments like this are large contra-bass in orchestras, pipe organs and grand pianos.
In the area my son is needing to work in, synthesizers can and do reach down very low way past 20hz (again, rarely in some genres of music, but it does happen). He uses a Moog Taurus pedal synth, which emulates the lowest register of organ notes, some reaching past 16 hz low C. If you're a fan of prog rock ie. Genesis, you'll know what I mean, as this synth is commonly used throughout their older albums. We also record most instruments without an external HP filter, which is only limited by the DC input transformer in the channel strip and A-D conversion. That's about -3dB @ 6 hz which most people would claim to be pointless. I dont agree, as when you stack up all the HP filters in the signsl path, it can wreak havoc on the upper bass above when you've pushed everything through the individual input and output stages of the recording gear.
The final important aspect i need to mention in regards to low end extension is the relative phase relationship between all of the lower harmonics, which is also important. This is why I don't use filters steeper than 2nd order on subs or mains. Group delay is an ugly animal and it can ruin your day if you need cohesive low end reproduction. In the past we used open driver headphones with corrected low end for monitoring with clean low end phase. Both my son and I can actually hear the simulated fundamental low C on an organ (without harmonics and noise). Its said people can't hear this, only feel it. This isnt true at all. We definitely know the neighbors dog can hear it, as he starts barking the instant we play the intro to Also Sprach Zarathustra by J.S. Bach using our 8 x SVI12 subs in sealed, assisted Q=0.6 enclosures. This setup managed to crack the corner of the bay window in our living room. You can definitely hear the 16.3 hz low C before you notice clothing starting to flap around.
It may sound as if I'm stubborn and unrealistic in my goals or have prejudices against specific suggestions, but I'm really just trying to achieve my own goals. I don’t need people telling me I don’t need extension below 30 hz because I can't hear it or its not present in music. I do appreciate the advice I've been given, but the whole premise of this thread for me was to seek feedback on the Dayton drivers in question.
@mayhem13 I understand all of the specifics of your argument and the definition of terms you talk about. My main issue with the advice I've been given is the sense of being told what I should want instead of what I actually prefer, despite my decision to embrace other less orthodox solutions which may be on the fringe of functionality. Stating there's no musical content below 30 Hz isn't true if you listen to music that has a large spread of harmonics centered around the lowest frequencies. While only fundamental notes occur under 30 hz, they can have harmonics higher up. Some instruments like this are large contra-bass in orchestras, pipe organs and grand pianos.
In the area my son is needing to work in, synthesizers can and do reach down very low way past 20hz (again, rarely in some genres of music, but it does happen). He uses a Moog Taurus pedal synth, which emulates the lowest register of organ notes, some reaching past 16 hz low C. If you're a fan of prog rock ie. Genesis, you'll know what I mean, as this synth is commonly used throughout their older albums. We also record most instruments without an external HP filter, which is only limited by the DC input transformer in the channel strip and A-D conversion. That's about -3dB @ 6 hz which most people would claim to be pointless. I dont agree, as when you stack up all the HP filters in the signsl path, it can wreak havoc on the upper bass above when you've pushed everything through the individual input and output stages of the recording gear.
The final important aspect i need to mention in regards to low end extension is the relative phase relationship between all of the lower harmonics, which is also important. This is why I don't use filters steeper than 2nd order on subs or mains. Group delay is an ugly animal and it can ruin your day if you need cohesive low end reproduction. In the past we used open driver headphones with corrected low end for monitoring with clean low end phase. Both my son and I can actually hear the simulated fundamental low C on an organ (without harmonics and noise). Its said people can't hear this, only feel it. This isnt true at all. We definitely know the neighbors dog can hear it, as he starts barking the instant we play the intro to Also Sprach Zarathustra by J.S. Bach using our 8 x SVI12 subs in sealed, assisted Q=0.6 enclosures. This setup managed to crack the corner of the bay window in our living room. You can definitely hear the 16.3 hz low C before you notice clothing starting to flap around.
It may sound as if I'm stubborn and unrealistic in my goals or have prejudices against specific suggestions, but I'm really just trying to achieve my own goals. I don’t need people telling me I don’t need extension below 30 hz because I can't hear it or its not present in music. I do appreciate the advice I've been given, but the whole premise of this thread for me was to seek feedback on the Dayton drivers in question.
If you want a woofer that can go real low and relative high (lack of cone resonances until about 800Hz), have a not so bad efficiency:
https://audioxpress.com/article/test-bench-the-sb42fhcl75-6-15-subwoofer-from-sb-acoustics
https://audioxpress.com/article/test-bench-the-sb42fhcl75-6-15-subwoofer-from-sb-acoustics
@YSDR I saw that one when it came out and talked to Brian @ Madisound about it. Problem is its on backorder for a while now without an ETA. I wanted to use those in the large 4 way I was working on and had to "settle" for double the amount of SB34NRXLs.
The F6 on the SB34s is nothing to sneeze at and I even tried a slot loaded push-push design. The extra air load pushed Fc down 4 hz but then I was left with the cavity resonance of the slot. I was able to reduce it with a diagonal brace across the slot.
The F6 on the SB34s is nothing to sneeze at and I even tried a slot loaded push-push design. The extra air load pushed Fc down 4 hz but then I was left with the cavity resonance of the slot. I was able to reduce it with a diagonal brace across the slot.