The full stuffing raise the Vb around something 15%. If the mid cut off is around 300 hz acoustical, the baffle step willl not be 8 to 10 dB as I readed in the other thread but more likely around 3/4 dB loss. So with 91 dB efficienty free air at 100 hz you are more likely in the 86 dB sensivity going progessivly 4 Pi when goind to the lows. With 36 cm the baffle step middle point is around 400 Hz (3 Pi, in my ubnderstading).
On some drivers, difference between 06 & 0.7 can be low at F3... 1 hz or two, but not the Vb which can be for instance 15L between both. So when simmming the Vb if sealed if chosen, take into account the 15% raise of the full stuffing - bracinf and colume of the magnet (around 2 L for a 12" just for the magnet and body inside the box). It is really about the T&S of the drivers, some surprises good or bad might account between two drivers different models about the size between for instance 0.5 and 0.7 Qtc... A fast modelling in Vituix, Dome acoustique website, etc, give fast approximation. Very useful for the project target to stay close to 70L max for the 3-Way classic look and nice proportions. The less high the internal volume the higher the resonance frequency as well, so also easier to reject the first mod resonance above the cut off, but if you target to let them there at lowish frequency for whatever reason... but here it is more the territory of a tower size cabinet.
If vented, stuffing changes, it is too less to care.
85 dB efficienty at the end in box if not a PA driver but a hifi efficienty for Hifi driver 90 tp 92 dB/2.83V is where to go imho. With acoustical cut off not higher than 300/350 Hz; You have indeed to model with thhe DC added by thelow filter as inputed by Mikesi.
Speacialists will rectify if infos not correct.
On some drivers, difference between 06 & 0.7 can be low at F3... 1 hz or two, but not the Vb which can be for instance 15L between both. So when simmming the Vb if sealed if chosen, take into account the 15% raise of the full stuffing - bracinf and colume of the magnet (around 2 L for a 12" just for the magnet and body inside the box). It is really about the T&S of the drivers, some surprises good or bad might account between two drivers different models about the size between for instance 0.5 and 0.7 Qtc... A fast modelling in Vituix, Dome acoustique website, etc, give fast approximation. Very useful for the project target to stay close to 70L max for the 3-Way classic look and nice proportions. The less high the internal volume the higher the resonance frequency as well, so also easier to reject the first mod resonance above the cut off, but if you target to let them there at lowish frequency for whatever reason... but here it is more the territory of a tower size cabinet.
If vented, stuffing changes, it is too less to care.
85 dB efficienty at the end in box if not a PA driver but a hifi efficienty for Hifi driver 90 tp 92 dB/2.83V is where to go imho. With acoustical cut off not higher than 300/350 Hz; You have indeed to model with thhe DC added by thelow filter as inputed by Mikesi.
Speacialists will rectify if infos not correct.
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Yes, for my 60L sim, I would assume that's after allowing for braces, and such. The whole speaker would likely be 90L after also allowing some room for a mid chamber.
I like the 12 for its low cost, but we've not really determined how big of a box we want to design for.
I have no place in my room for this but I already had the simulation files of the OSMC, so I adjusted everything.
12" version: circa 450€ for the drivers at TLHP
Measurements in mm (depth is about 380mm with 19mm panels)
LaVoce SSF122.50L-8 in 70L BR cabinet tuned @40hz (stuffing on the wall) / F3 circa 37Hz
SBA SB15NBAC30-4 in 5L closed cabinet (fully stuffed)
SBA SB26ADC
10" version: circa 330€ for the drivers at TLHP / measurements (position of the drivers) are the same as in the above image (no vent ofc).
SBA SB26SFCL38-8 in 70L closed box (fully stuffed) Qtc 0.69 / F3 circa 52Hz
SBA SB15NBAC30-4 in 5L closed cabinet (fully stuffed)
SBA SB26ADC
12" version: circa 450€ for the drivers at TLHP
Measurements in mm (depth is about 380mm with 19mm panels)
LaVoce SSF122.50L-8 in 70L BR cabinet tuned @40hz (stuffing on the wall) / F3 circa 37Hz
SBA SB15NBAC30-4 in 5L closed cabinet (fully stuffed)
SBA SB26ADC
10" version: circa 330€ for the drivers at TLHP / measurements (position of the drivers) are the same as in the above image (no vent ofc).
SBA SB26SFCL38-8 in 70L closed box (fully stuffed) Qtc 0.69 / F3 circa 52Hz
SBA SB15NBAC30-4 in 5L closed cabinet (fully stuffed)
SBA SB26ADC
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Tymphany XXLS-P830845 12" Nomex Cone Subwoofer 8 Ohm
I ran a sim, and it needs essentially the same box as the other 12" Peerless, so it's not a good choice after all due to higher cost.
I ran a sim, and it needs essentially the same box as the other 12" Peerless, so it's not a good choice after all due to higher cost.
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The XXLS has a larger voice coil, handles 75% more power, has lower Le, 50% more xmax, etc. It is a higher quality driver, but I agree, that while it isn't "expensive" it doesn't fit the "budget" theme when you can get 80% of the performance for 40% of the cost.
The PE website stated 1.25 cu-ft sealed. I got excited and posted here. I ran a sim today, and 1.25 cu-ft is not even close..
I used it because it was suggested in this and in the other thread.
Cabinet is bigger, 120L in closed box and 155L in BR. The same is for the Peerless above: 118 and 142L.
This is
Parts Express shows Qms of 3.22 which isn't meaningfully different from 2.9 but I wondered why the difference. I checked the official LaVoce data sheet at Parts Express and it also said 3.22.
So, I went to toutlehautparleur.com and checked, and sure enough they show 2.9 and have an official LaVoce data sheet that says 2.9.
So I went to LaVoce's home page. And they show on their product page as well as an official LaVoce data sheet Qms = 5.36.
I won't translate for those non-English speakers, but WTF?
How about the GRS 12SW-4HE, PE recommends a 1.2 ft3 sealed box for an f3 of 40.6, since i have never heard a vented box system I really liked. On sale now at $49.99 but back ordered. If that won't get loud enough or efficient enough use 2. Got 2 in the basement to play with. An SB17CAC354 ($105.60) coming in about 300 hz out again at 1500 to 2k. Have listened to this on my Bromos and really like it. Wavecor TW030WA12 ($86) for the hi end. I haven't heard it but Micheal Chua seems to think very highly of it, and it has a wave guide built in. $242 per side, $484 per speaker. Put the money where our ears are most sensitive, and a box size that I can still lift.
Comments 2 and 3 in the thread below suggest the GRS 12SW isn't going to work as the anchor of a 3-way speaker. JR has used the driver, so he is not just speculating based on mfg spec sheet.
https://diy.midwestaudio.club/discussion/2039/als-compact-monkey-box-3-way-design-build-thread
https://diy.midwestaudio.club/discussion/2039/als-compact-monkey-box-3-way-design-build-thread
I have the strong suspicion GRS woofers aren't for anyone serious about good sound.
The SBA 12" and my Peerless SDS 10s are looking better all the time. 😀
Possibly. I bought them for subs under the Bromos with an 80 hz sub output from the preamp. OTOH, Note that later in that same thread RJJ45 gets 2 good usable response curves from the. GRS. I might even prefer the 6 db rise centered about 70 hz. My space seems to absorb some of the low notes.
I relooked at the response curve, at MWA, it's only a 2 db rise at 70 hz. Probably sound great.
That's part of the "budget" game. Different measurements of different samples of a product with poor manufacturing tolerances.
How did you choose the woofer for the OSMC?
Also, did you buy/test a few alternatives?
Without doing so I find it difficult to make a good decision. Sometimes it’s luck
Also, did you buy/test a few alternatives?
Without doing so I find it difficult to make a good decision. Sometimes it’s luck
The OSMC woofer choice was guided by the targets re. efficiency, low-frequency extension, and box volume. Searching for suitable drivers that would come close in simulations resulted in two good candidates (Faital, D.A.S). I ordered the Faital and the D.A.S. for hands-on testing. The D.A.S. driver was different from the description in the datasheet, so it went back to where it came from. There were also some concerns related to the long-term and global availability of the D.A.S. The Faital driver was good (and also measured low harmonic distortion), so we stuck to the Faital driver. The details are in the OSMC thread.