Hi all
Here in EU the price are pretty similar. But Seas seems to show their measurement for this driver, in only 21 liters(written in small, under the FR ):
http://www.seas.no/images/stories/prestige/pdfdatasheet/h1252_l22rnx_p_datasheet.pdf
Dayton recommend around 12,5 liters:
https://www.daytonaudio.com/product/104/rs225-8-8-reference-woofer-8-ohm
SB23NRX recommend somewhere between 38-75 liters:
https://www.soundimports.eu/en/sb-acoustics-sb23nrxs45-8.html
I Have 3 way mains and 4 subwoofers and have 12 channels of amplification and DSP for each. So I need midwoofers to blend nicely with subwoofers - around 50 - 500hz.
I would like to build something sleek looking like a Jamo 707i or Dali evidence 870. Everything above around 500hz is handled by an SB MW13TX and SB26ADC in 5" Augerpro waveguide.
Subwoofers are four individual boxes - 2 x 12" SS Discovery( 90 liters ) and 2 x 15" Dayton RS390HF ( 125 liters ) - all closed.
So... are different brands recommendations a bit off? Did they forget to be specific about the Q of a given volume? Because I could make the woofer part around 60 liters... just making the design deeper. But it would be nice to know how much artistic freedome I have - given the moderne possibilites from DSP and amplification. Of course keeping in mind, the goal of excelent sound quality.
I should be able to figure this out myself.... but I'm a little baffled - no pun intended 😊
Here in EU the price are pretty similar. But Seas seems to show their measurement for this driver, in only 21 liters(written in small, under the FR ):
http://www.seas.no/images/stories/prestige/pdfdatasheet/h1252_l22rnx_p_datasheet.pdf
Dayton recommend around 12,5 liters:
https://www.daytonaudio.com/product/104/rs225-8-8-reference-woofer-8-ohm
SB23NRX recommend somewhere between 38-75 liters:
https://www.soundimports.eu/en/sb-acoustics-sb23nrxs45-8.html
I Have 3 way mains and 4 subwoofers and have 12 channels of amplification and DSP for each. So I need midwoofers to blend nicely with subwoofers - around 50 - 500hz.
I would like to build something sleek looking like a Jamo 707i or Dali evidence 870. Everything above around 500hz is handled by an SB MW13TX and SB26ADC in 5" Augerpro waveguide.
Subwoofers are four individual boxes - 2 x 12" SS Discovery( 90 liters ) and 2 x 15" Dayton RS390HF ( 125 liters ) - all closed.
So... are different brands recommendations a bit off? Did they forget to be specific about the Q of a given volume? Because I could make the woofer part around 60 liters... just making the design deeper. But it would be nice to know how much artistic freedome I have - given the moderne possibilites from DSP and amplification. Of course keeping in mind, the goal of excelent sound quality.
I should be able to figure this out myself.... but I'm a little baffled - no pun intended 😊
I have 4x Seas L22RNX-P in my current stereo. They're pretty good. However, the motor is low-tech - there aren't any demodulating rings, so there's a bit more inductance and harmonic distortion than there might be with a higher-end driver.
That said, I don't have any complaints about the sound. I use an 18Sound NSD1095N for >1kHz, and use a 2.5-way passive crossover with some DSP correction. It's an excellent-sounding system*, but there's always a small part of me that wonders about using some nicer woofers. Purifi have recently released an aluminium-coned 8" that I have my eye on. They're very expensive, but probably also the best drivers in that class.
* I say that having spent lots of time with some very expensive commercial HiFi.
Chris
That said, I don't have any complaints about the sound. I use an 18Sound NSD1095N for >1kHz, and use a 2.5-way passive crossover with some DSP correction. It's an excellent-sounding system*, but there's always a small part of me that wonders about using some nicer woofers. Purifi have recently released an aluminium-coned 8" that I have my eye on. They're very expensive, but probably also the best drivers in that class.
* I say that having spent lots of time with some very expensive commercial HiFi.
Chris
Afaik the pole piece is undercut but this unit is designed to be used as a woofer, demodulating rings woudl have little effect over harmonic distortion below 500Hz and I bet on a blind test you`d not identify which driver produces higher harmonics down there.
While a lot of people seem to think that harmonic distortion in the LF region is inaudible, I'd suggest that consulting the equal-loudness contours will provide a very different story.
Profiguy, I'm using the 18Sound XT120. They just about provide enough loading for 1kHz use, especially in domestic settings where maximum output isn't hugely important. If I wanted PA-system-levels, I'd stay >2kHz with this horn.
Chris
I would feel at least a cubic foot of volume for the rs225. Most of the time 8-in woofers will not fit in a half cube.
Well... how many liters do you put the driver in? And how much does minimizing volume, "suffocate" a driver?
I think that would be a good idea too. But I was surprised that Seas mention 21 liters for their measurement.
I mean... what truly makes one woofer sonically better than others? I always found harder coned drivers, to play more detailed and "snappy" - which I like.
To me, it seems logical that the Seas had a lighter cone, therefore needed more volume and maybe was a little quicker to play "snappy" transients. But is that a false theory?
As long as the motor can keep up and move the cone, the cone mass really has little to do with it in the bass range. The harmonic distortion of the motor structure is the main producer of negative effects unless mechanical Excursion has been exceeded. Cone break up is likely the second producer of ill effects that needs to be taken care of. As long as mechanical stability maintains, drivers should be happy where they are applied.
Ok. Some refer to Dayton RS drivers, as high loss, in comparison with drivers that have higher Qms. I tried to compare WO24-P, 23NRX and Dayton RS225, right next to each other, in the same setup. I cant say for sure that it made much difference. I also tried a couple of Purifi 6,5 drivers, which I found to not like closed boxes. So those are out for woofers in my system. They might work wonders as a midrange or smaller 2-way though.
I also had the idea, that a drivers that could play in smaller volume, would be easier to make into a sub 0,7Q, so that "tighter" bass could be obtained. But maybe I'm getting myself fooled here...
Can I ask what was the issue you encountered using PTT6.5 in a sealed box?
cheers
Lars/Purifi
Think it's about 35L for each pair of drivers. Sealed, with lots of stuffing.
My room dominates the LF response. The speakers are -3dB @ 50Hz when measured nearfield. At the listening position, they're +15dB at 40Hz, and -3dB is about 9Hz. It's a very helpful room, and I gain a lot of headroom by EQing down the excess bass.
IMO, then, worrying about a couple of dB between LF alignments makes little sense, when the room has fluctuations 10x as big.
Chris
Audioexcite has a precise T&S measurement with the sb23nrx.
With DSP and 60 flexible liters why not a bigger 12" like the 12PR360, could work in 60l to 75l with DSP. At the opposite a littlier Seas U16rcy ? Could blend well with the 13 TX !
Sb23 NBAC should also work in the 38 liters and plus.
Edit , the SS woven 8 Discovery comes to mind as well.
With DSP and 60 flexible liters why not a bigger 12" like the 12PR360, could work in 60l to 75l with DSP. At the opposite a littlier Seas U16rcy ? Could blend well with the 13 TX !
Sb23 NBAC should also work in the 38 liters and plus.
Edit , the SS woven 8 Discovery comes to mind as well.
Off course 😀 I have two in parallel in around 20 liters, which seem to make them drop before 100 hz, so not much low-end extension. I thought that maybe that would be ok, since I use multiple subwoofers. But they also seem to lack surface area in comparison with two SB23NRX in around 60 liters. The SB gives me more "smack" or "kick" if you will. I hoped that I could simply turn up the Purifi at bit more( I have lots of power to do so ). But somehow it does not sound right - even though I really wished it would, since the Purifi clearly opened up for at more elegant design, and that I do not play that loud. But even at low volume, you still hear the benefit of a more dynamic system - IMO.
So around 17 liters per driver? Would that not give you a Q of 0,9 or something along those lines? But that can just be EQ'd out? Because as long as the driver and amplifier does not become stressed - we hear no difference?
Because I would end up with a very wide and bulky speaker 😉 But thank you for the link - I almost forgot that page 👍
I cant find any "12PR360" If it's the faital pro... then I think I would find it difficult to look nice, with that edge on the basket. I believe it's designed to be mounted from inside of a cabinet.
Mostly, yes. So long as you're not throwing large amounts of power at the driver via EQ (remember: +3dB = 2x power), you'll be fine.
Below the Schroeder frequency, we should really be considering the speaker+room as one system anyway, and processing them as a combination.
One of the things a lot of people get wrong, for example, is designing a ported box with a flat frequency response, and then finding that most rooms will make them sound very "boomy". That's nothing to do with the ported box, and everything to do with the speaker+room combination. In my room, a speaker that's flat in the LF would probably end up at +20dB at 40Hz - a very boomy sound indeed!
Chris
Oups...sorry. Faital 12pr320. With the idea of less volume with a linkwitz transform with the DSP. But the SS Discovery 22 size looks good.
From what I gathered online, I got the feeling that Seas has better built consistency than Dayton. Dayton does have shorting rings but that is not enough to call it a 'better' woofer, as it also matters where these are placed. Both do not publish Klippel reports which makes a fair comparison difficult.
A few years ago I faced the same dilemma, Seas or Dayton. At the end I figured they would perform very similarly and chose a Scan Speak 22W Discovery for its looks.
Something to consider is that a phase plug is a small leak and might chuff if the woofer is crammed in a small cabinet.
A few years ago I faced the same dilemma, Seas or Dayton. At the end I figured they would perform very similarly and chose a Scan Speak 22W Discovery for its looks.
Something to consider is that a phase plug is a small leak and might chuff if the woofer is crammed in a small cabinet.
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