RS225-8 works really well if you need a smooth response up to high mids for low order crossover. In 24L sealed it reaches 50Hz, in a large TL it really opens up and can reach 30Hz. It’s a unique driver that I can’t find an equivalent in other brands. More on my use cases here.
First time i made my Dali Evidence 870 active, by adding a 3 way amplifier and powerful DSP, I never forgot how they had a specific "snap" in the mid-bass when listening to - lets say - the live version of Hotel california. The Eagles have a bass sequence in the beginning, where you easily - if the system is able - to hear that the bass shift between a short lasting drum kick and a longer lasting drum kick. As I remember, the Dali used a Vifa driver, which might be very close in construction as the SS Disco. So maybe I do not need an Alu driver, but just something resembling the driver in that speaker. An SS 22W Disco also has lighter cone, higher Qms and is pretty neutral to look at, making it nicer to implement in a design. Also not expensive or unnecessary exotic with neo magnets and the like.
Maybe the Dayton RS serise mostly sell on being able to deliver good deep bass, whereas I mostly need "crisp" neutral mid-woofer sound.
Maybe the Dayton RS serise mostly sell on being able to deliver good deep bass, whereas I mostly need "crisp" neutral mid-woofer sound.
Thank you. I intend to cross around 4-500hz, to avoid pushing the little MW13TX, when not really needed, if the mid woofer plays cleanly up there. I do sense that the SB23NRX is not that clean, when crossed above 400 hz - all done with 24LR.
I also always measure drivers alone first, so that I can clearly see which driver contribute to a maybe ragged response, then finding the culprit and work around it.
Isn't the midrange/woofer in the seriously acclaimed speaker Dutch & Dutch 8C the Seas L22RNX/P ??
If they use a SEAS driver then it is certainly a custom model. Black cones, for a start, but SEAS will make up a driver to your specifications. If D&D wanted shorting rings in there they can have them, if they want to alter the T/S parameters, to better suit their cardioid, open cabinet, then they can do. Without asking D&D themselves everything is just guess work.
I'm surprised you didn't like the sound of the PTT 6.5. If they had an early bass roll off, that you weren't happy with, then use a Linkwitz Transform to EQ the response to give you the bass extension/alignment you're after. Simply turning them up wouldn't fix the issue.
An absolutely fair assessment about the Seas driver - heard about this before 👍
I tried to read about the Linkwitz Transform... seems to just be an EQ thing... I can do that 👍 I know that just turning them up, wasn't the trick, but I was curious about all the rave, that the driver was so much more capable than almost all over drivers 😎
I'll measure and post my findings 👍
Yes it is an EQ thing. Obviously just turning up a driver won't shape it's frequency response to change its presentation.
Both drivers are similarly good ( enough ) , it just depends on your engineering skills and implementation goals…
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This... or you, seem to indicate, that 1 graph shows all there is to fidelity in a given driver? Does detail or dynamics translate into something else?
Yes
Though I am not sure whether the driver is given a chance to have a sound of its own. The frequency response has been hammered into shape, directivity is given by its size and I only listen at lowish levels, which makes harmonic distortion mostly irrelevant. I see I could have picked a cheaper woofer. 😀
What I don't like is how easily the cone gets scratched.
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There should be subtles differences between a metal, woden polypro, paper, plain polypro, sandwich with foam core, etc .... At least in the medium area.
Been a busy summer. But it seems to be a compromise between:
Mechanical loses - Qms and RMS - with respect to suspension, when it's stiffer you get nicer curves, but lose details of sound.
Vas - coils are wound double and Le goes up, cabinets gets smaller
Instead of me trying. Is there a matrix, with the most important parameters for speaker drivers, where you can draw a line or chose which parameters you are willing to compromise on - and then build from there?
And what about the Scan speak 22W 8534G00 ?
When I put the Scan 22W against the Seas L22 - I get 15 liters less for a pair of them, but half the Qms and I lose around 1 dB of SPL. Anyone else see any catch? We're still talking about a driver that is going to be crossed max at 500Hz with LR24 filters. The Seas also play a bit deeper - but with more excursion.
Put in the SB23NRX too.... just more group delay and even bigger box - nothing that seems better - except the even higher Qms... which I can't find any good reason to "hunt".
I was told that Dayton drivers looks very nice on paper, because - among other things - they have very high mechanical loses. But I have no clue what that really translate to. I tried them directly against SB23NRX and WO24P-8 - quite difficult to hear any difference in sound when used as midwoofers.
So - are all the bells and whistles all about the frequencies above 700-800 Hz, where we become more sensitive to all the details?
Mechanical loses - Qms and RMS - with respect to suspension, when it's stiffer you get nicer curves, but lose details of sound.
Vas - coils are wound double and Le goes up, cabinets gets smaller
Instead of me trying. Is there a matrix, with the most important parameters for speaker drivers, where you can draw a line or chose which parameters you are willing to compromise on - and then build from there?
And what about the Scan speak 22W 8534G00 ?
When I put the Scan 22W against the Seas L22 - I get 15 liters less for a pair of them, but half the Qms and I lose around 1 dB of SPL. Anyone else see any catch? We're still talking about a driver that is going to be crossed max at 500Hz with LR24 filters. The Seas also play a bit deeper - but with more excursion.
Put in the SB23NRX too.... just more group delay and even bigger box - nothing that seems better - except the even higher Qms... which I can't find any good reason to "hunt".
I was told that Dayton drivers looks very nice on paper, because - among other things - they have very high mechanical loses. But I have no clue what that really translate to. I tried them directly against SB23NRX and WO24P-8 - quite difficult to hear any difference in sound when used as midwoofers.
So - are all the bells and whistles all about the frequencies above 700-800 Hz, where we become more sensitive to all the details?
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T/s theory peters out at its upper mass corner (Fhm = 2*Fs/Qts), so the lower the Qts the wider its acceleration BW and the smaller its Vc the wider its pistonic BW, so guess this is what you want to figure trade-offs for the intended app.
Apparently... The 'snap' that I liked in my old Dali Evidence 870, should best be replicated with a SB20PFC.... We will see 🤓
You're welcome!
Hmm, just now seen this! 🙁
Responded to (So - are all the bells and whistles all about the frequencies above 700-800 Hz, where we become more sensitive to all the details?) in that all T/S box designers only account for the ramping up of the low end (acceleration BW) and where its mass is increasingly slowing its acceleration down (flattens out at (Fhm)) with increasing frequency since its acoustic power is rolling off at 6 dB octave, so ignoring any added series resistance that would lower it, your box design only accounts for up to ~2*(30/0.39) = 153 Hz and if wanting it to be higher for a given Fs, then you need to use a lower Qts and vice versa.
The VC diameter sets the driver's theoretical pistonic BW upper limit, so ~34400/pi/3.8 = ~2882 Hz for the SS 22W, ergo the smaller the VC, the wider its usable pistonic BW and vice versa, which is close enough for XO design WRT polar response, though in reality drivers start losing pattern control (much) lower due to cone design, etc., as is shown in its frequency response beginning around 210 Hz, implying the specs might be off a little as its effective Fhm is the norm.
Anyway, was just responding to box design in general, which yours appears fine and assumed 'bells and whistles' were higher up in the BW, hence the mini tutorial about how to choose a driver for a wider box loading BW.
As for 'snap', this historically implies a tonally flat, time/phase correct, critically damped alignment (AKA transient perfect); in short 'PRaT' (pace, rhythm & timing).
Hmm, just now seen this! 🙁
Responded to (So - are all the bells and whistles all about the frequencies above 700-800 Hz, where we become more sensitive to all the details?) in that all T/S box designers only account for the ramping up of the low end (acceleration BW) and where its mass is increasingly slowing its acceleration down (flattens out at (Fhm)) with increasing frequency since its acoustic power is rolling off at 6 dB octave, so ignoring any added series resistance that would lower it, your box design only accounts for up to ~2*(30/0.39) = 153 Hz and if wanting it to be higher for a given Fs, then you need to use a lower Qts and vice versa.
The VC diameter sets the driver's theoretical pistonic BW upper limit, so ~34400/pi/3.8 = ~2882 Hz for the SS 22W, ergo the smaller the VC, the wider its usable pistonic BW and vice versa, which is close enough for XO design WRT polar response, though in reality drivers start losing pattern control (much) lower due to cone design, etc., as is shown in its frequency response beginning around 210 Hz, implying the specs might be off a little as its effective Fhm is the norm.
Anyway, was just responding to box design in general, which yours appears fine and assumed 'bells and whistles' were higher up in the BW, hence the mini tutorial about how to choose a driver for a wider box loading BW.
As for 'snap', this historically implies a tonally flat, time/phase correct, critically damped alignment (AKA transient perfect); in short 'PRaT' (pace, rhythm & timing).
True 😆
By the way - thank you GM for your response about the deeper details of drivers 👍
It seem then, that the RS225 is definitely a good candidate. It looks good, easy to work with and affordable. The Purifi's should maybe go to someone aiming for a 2 way instead. Then I could maybe look at the dedicated Purifi Midrange instead - if I don't find my current MW13TX sufficient somehow... or just got the "itch" 😊
By the way - thank you GM for your response about the deeper details of drivers 👍
It seem then, that the RS225 is definitely a good candidate. It looks good, easy to work with and affordable. The Purifi's should maybe go to someone aiming for a 2 way instead. Then I could maybe look at the dedicated Purifi Midrange instead - if I don't find my current MW13TX sufficient somehow... or just got the "itch" 😊