And the SB26ADC works great in a 3D printed waveguide!!! Which I know you are thrilled about! š
First you simulate the woofer+box in the enclosure tool. This is a 2-pi response. Then you export that response as a *.frd or *.txt file using the "SPL" button at the top.
Next you open the diffraction tool, and import that same response file. In the lower right corner there is a button called "half space response". click this button and you will be prompted to enter the path to the response file. After you enter it, be sure to click the "full space button". Now you can use the diffraction tool as normal.
I thought I said that 4 ohm woofers or at least system impedance should be 4 ohm optionable. More power, greater sensitivity, and possibly multiples.
@andy19191
Any design requires a balance of trade-offs. In a group project, different people have different priorities (or uncertain of their priorities) thus different tradeoffs they are willing to accept.
I believe the OSMC swa successful because the group leader made it clear what HE wanted. And one of those things that was stated from the start, that made it through to the end, was that he wanted was to use the Volt VM752 midrange.
"I have some experience with the ATC SM75-150 dome, which is VERY good, expensive, and not available to DIYers anymore. When ATC stopped selling to the DIY market, Volt released the VM752 dome, which is a very good clone of the ATC driver. I really want to use the Volt VM752 dome"
I think there needs to be something that leads spark curiosity or interest to get people to get up and build something, rather than just type away endless about it...
Also, the project wasn't particularly price sensitive. Here we are trying to cut costs, without knowing our target it.
If you want to do an active, do an ACTIVE! There are plenty of people who can convert the crossover to passive version later, as long as good measurements are provided eg. impedance, minimum 0-90 degrees hor/vert.
I'm sure @mbrennwa has some insights into the challenges of the group project
Your thoughts?
Any design requires a balance of trade-offs. In a group project, different people have different priorities (or uncertain of their priorities) thus different tradeoffs they are willing to accept.
I believe the OSMC swa successful because the group leader made it clear what HE wanted. And one of those things that was stated from the start, that made it through to the end, was that he wanted was to use the Volt VM752 midrange.
"I have some experience with the ATC SM75-150 dome, which is VERY good, expensive, and not available to DIYers anymore. When ATC stopped selling to the DIY market, Volt released the VM752 dome, which is a very good clone of the ATC driver. I really want to use the Volt VM752 dome"
I think there needs to be something that leads spark curiosity or interest to get people to get up and build something, rather than just type away endless about it...
Also, the project wasn't particularly price sensitive. Here we are trying to cut costs, without knowing our target it.
If you want to do an active, do an ACTIVE! There are plenty of people who can convert the crossover to passive version later, as long as good measurements are provided eg. impedance, minimum 0-90 degrees hor/vert.
I'm sure @mbrennwa has some insights into the challenges of the group project
Your thoughts?
I'm not agree. In active speakers you just don't care about sensitivity matching of your drivers, you may even don't care about bass extension as long as you have headroom and comfy xmax and you put a boost.
Going passive to active is always possible. Not the contrary (or you may go into unacceptable comprises)
The only contraint was BUDGET, that's why cost is looked...
Going passive to active is always possible. Not the contrary (or you may go into unacceptable comprises)
The only contraint was BUDGET, that's why cost is looked...
Yes, then you need clear constraints like what @mbrennwa had. Like cabinet size, sensitivity and F6 for example.
Otherwise we go around in circles discussing different cost woofers as options...
Last edited:
I do have 830845 woofers, but don't have time to build any new cabinets for them-
I can only offer measurements in a 1 cu ft sealed box with fibreglass fill.
Or a pair in 100L sealed box with fibreglass fill.
Let me know what kind of measurements you'd like to see.
I can only offer measurements in a 1 cu ft sealed box with fibreglass fill.
Or a pair in 100L sealed box with fibreglass fill.
Let me know what kind of measurements you'd like to see.
All the more reason to nail down a woofer or 3. Its sensitivity will drive the mid choice. (Less so the tweeter as it's normal enough to pad it down).
The SLS12 appears to check a lot of boxes & might become widely available so perhaps it is #1. SB34NRX75-6 does similar with higher SPLmax & deep bass extension at higher cost & already widely available. Maybe it is #2? Is the sensitivity close enough for them to be nearly interchangeable for sealed box & crossover?
The latter, I believe. Will take a close look tomorrow.
Last edited:
seems to me the sb34rnx has lower sensivity then the sls-12. Hence the lower Fs of the SB. 1 to 2 db ? to be checked...
For box, yes certainly but not at iso Qtc.
For box, yes certainly but not at iso Qtc.
You are correct, you actually said that on the very first page. I think after we discussed some more drivers I asked again, to which no one answered. I'm going with "yes, 4-ohm is okay" unless someone speaks up and says they strongly disagree.
I don't see 4 ohm drivers being a barrier. Most amplifiers should be able to drive a 4-ohm load, so "yes, 4-ohm is okay" with me.
Humm I looked at loudspeakers database site, and I understand why I was wrong with the sensivity numbers ! It is given for 1W... lol !
SLS12 (830669)
8R impedance
89.8dB at 2.83V/1m
100W max
8.3mm Xmax
31Hz Fs
0.54 Qts
132L Vas
SB34NRX75-6
6R impedance
Sensitivity (2.83V/1m) 90 dB
200W max
11mm Xmax
19Hz Fs
0.4 Qts
260L Vas
Just looking at the numbers, SLS looks maybe better suited for sealed, but won't play as loud or as deep. It's also not a cast frame, not as hefty a driver (3.2 vs 6 kg, 38mm vs 75mm VC diameter). The SB34 is closer to a sub driver.
8R impedance
89.8dB at 2.83V/1m
100W max
8.3mm Xmax
31Hz Fs
0.54 Qts
132L Vas
SB34NRX75-6
6R impedance
Sensitivity (2.83V/1m) 90 dB
200W max
11mm Xmax
19Hz Fs
0.4 Qts
260L Vas
Just looking at the numbers, SLS looks maybe better suited for sealed, but won't play as loud or as deep. It's also not a cast frame, not as hefty a driver (3.2 vs 6 kg, 38mm vs 75mm VC diameter). The SB34 is closer to a sub driver.
The SB is also fit for sealed, it's not that fit for ported i think.
This is a basic sim of the SB34NRX75-6 sealed with filling (half filled with damping material) in a 70L F3 is arround 40hz, F6 arround 30hz.
you can make this a bit smaller without much change, 50L looks very similar on response but with a Q of 0.867. the only disadvantage is the price that is maybe a bit to much for a budget build.
This is a basic sim of the SB34NRX75-6 sealed with filling (half filled with damping material) in a 70L F3 is arround 40hz, F6 arround 30hz.
you can make this a bit smaller without much change, 50L looks very similar on response but with a Q of 0.867. the only disadvantage is the price that is maybe a bit to much for a budget build.