There was recently a thread where we discussed the pros and cons of a single 12" versus a pair of 8". Many of the things discussed in that thread are relevant here.
https://www.diyaudio.com/community/...x8in-as-woofers-in-a-3way.410149/post-7623184
Quoting myself:
j.
https://www.diyaudio.com/community/...x8in-as-woofers-in-a-3way.410149/post-7623184
Quoting myself:
Comparing a 10 to a pair of 8's is a closer call, because the Vd of many 10" drivers is about twice the Vd of many 8" drivers.
But with 8 vs 10, the Fs differences will be smaller
Again, with a 10 vs 8, the difference is less.
And comparing a 10 to 2x8, the voltage sensitivity is even more in the favor of the 2x8.
This is still true. Maybe even more so.
Of course a 10 is only a little wider than a pair of stacked 8s... But this is still a consideration.
j.
Clean displaced volume is what matters (surface area * displacement). So if a 12" woofer has a larger displacement than 2 x 8" woofers then it can play louder and likely deeper but will be less capable in terms of high frequencies. This assumes the 8" and 12" drivers are designed to be broadly similar woofers rather than a mix of woofer, midwoofer and/or subwoofer.
A woofer needs to be able to accurately follow low frequency transients of percussive instruments like kickdrums. The perceived sound of a kickdrum involves a fair bit but if a woofer cannot track the fundamental transient it tends to be audible. This means a woofer needs to remain clean for a significant margin above the average level required. This is why speakers with a single 6.5-8" can sound loud enough but won't sound as clean as speakers with 2 x 8" or a 12" at standard levels (80-85 dB average) at 3-4m away in a good sized room like yours. It isn't to do with loud and deep because there isn't much transient information below 60 Hz or so. It also means all the displaced volume provided by distributed subs isn't going to help much. The mains need to have sufficient clean volume displacement.
What matters is the sound level, not the electrical power. A 12" will make better and louder sound than two 8" because fewer Watts are required. The amp is happier with less current drain and produces cleaner sound with less heat. "Do the math", and that means the big picture, beyond Ohms law. There are plenty of amps that overheat, distort, and even self-destruct if driven hard into 4 Ohms.
Multiple smaller woofers will outperform one larger woofer of same surface area in midbass punch and still have comparable low end extension, given xmax is comparable. I love 2.5 way speakers with 8" woofers, because they have the lower midrsnge agility of a larger woofer but can be crossed higher into the mids thanks to a smaller cone being able to play cleaner up higher. It depends on the quality of the smaller woofer which can greatly differ. A pair of Audax HM210CO with a Morel CAT378 can really make for a powerful combination which still has midrange finess and transparency.
But the OP wants to build a 3-Way, so the advantage of the smaller driver being able to cross higher isn't relevant.
I'm open to the possibility that you are correct about the advantage of a single large woofer. However, you seem to be in the minority so far in this thread and haven't made any very convincing arguments yet. I would love to see the "math" but asking ICG to do the math to make your point seems odd. If you are going to argue the point, shouldn't YOU do the math?
This is interesting !
my knowledge is limited, may I state that traditional and intuitive people as me will say that a bigger driver will play better. More science based guys state that we can measure small drivers doing a better job.
The WAF factor brought us to better looking speakers. WAF not being needed what is the best setup I can get in 2024?
Walter
my knowledge is limited, may I state that traditional and intuitive people as me will say that a bigger driver will play better. More science based guys state that we can measure small drivers doing a better job.
The WAF factor brought us to better looking speakers. WAF not being needed what is the best setup I can get in 2024?
Walter
Firstly, that strongly depends on the drivers. A 12" that delivers over 3dB more than a 8" usually only delivers that in the midrange. But please, show me the "over 3dB more" driver you have in mind. But since @wfr329 wants to build a 3-way, that actually doesn't really matter.
Secondly, it's not the question if a 12" can outperform 2x8" but @wfr329 wants arguments towards the decision 2x8" vs. one ten inch!
A good amp should have protection against over current, over heat and short circuit. Would you please tell which good modern amps would so easily self-destruct on 4 Ohm?
The thread starter didn't mention any required spl nor spoke about any amp problems. And while we're at 'beyond Ohms law': There are more tweeters killed by clipping amps.
I quote again:
To get clean, precise bass, a x.5 -way is the easiest to achieve that. Even passive there's an easy way to adjust the 'dosage' of the bass by changing the coil and the BR tuning (in case a vented enclosure is preferred). There's nothing wrong with a 10" or 12" bass at all but if you can't specify exactly what you want, that's the most flexible thing you can go for. If you don't need high spl, a 2x8" in a .5 configuration with sealed enclosure would likely give you the cleanest deep bass.
So, that said, what are you planning for mid and high range? What spl do you need? How big is your room? Active/passive?
Its relevant because double the LF driver count has multiple benefits. It improves dynamic range, being able to cross a little higher to the mid driver. It smooths out lower midrange FR having double lower midrange sources relative to the floor boundary, also helping break up standing waves. You can also shape the lower midrange FR by staggering the lower bass driver LP filter so that power handling also improves. A single LF driver doesn't come close in the versatility mentioned above.
Okay, the room is on the bigger side but the spl is not. It's nice to have headroom but 2x 8" will fulfill that nicely, as well as a single 10 or 12" per side will do. What are other points you feel are a 'must have' in your speakers? Top resolution, sound stage location? The SBA 2" mid dome seems to fit both and will also work nicely with 8" or 10", a 12" maybe too, depending on the xo frequency. If you like the idea of a mid dome, I'd tend to the 8", if you rather want a mid cone, I'd go for a bigger diameter.
It seems he doesn't need a high dynamic range (but I'd almost always opt for headroom). I agree in versatility of a 2 driver bass configuration. At this point I think it's more appropriate to concentrate on the whole concept and even dispersion since the spl requirement will be met by practically all possible combinations.
I can see why its not a priority to search for more of whats already better than adequate. I've however found the benefit of smoother, more refineable lower mid response from multiple LF drivers being of great benefit for the overall refinement of the speaker. That in itself makes it worth pursuing IMO.
Definitely. Especially because that not only fits to the LF driver but gives also a lot of freedom for the other drivers. At the same time, it also limits the other drivers choices, a 12" can often not be paired up with a lot of HiFi mid- and high drivers because they are too loud and you can't increase the level of the drivers above and you can't reasonably lower their spl. That weeds out a plethora of efficient 12" drivers unfortunately.
If talking about multople woofers that is true, I'm not sure it's applicable to midrange drivers over about 110mm and that depending on the faceplate size of the tweeter
It's not about the mid driver size but most HiFi dome tweeters (like @wfr329 seems to want to use preferably SBA ones) got a sensitivity of 85-90dB and that does limit the choice of bass drivers, especially larger ones.
E: You can't boost the tweeter level passive, so the bass level is essential for the selection of the tweeter. Or vice versa, depending on how you look at it.
E: You can't boost the tweeter level passive, so the bass level is essential for the selection of the tweeter. Or vice versa, depending on how you look at it.
Its kind of a shame we have to settle for sub 90dB sensitivity with most tweeters. It makes the issue even worse when the tweeter sensitivity is rated at 4 ohms, making it a deficit of 3 dB. There goes half your power handling. Sure, its not an issue crossing a tweeter much lower where you run out of excursion before reaching the thermal power limit. I prefer higher sensitivity systems, which is why I always look for drivers which can accommodate multiple LF drivers. I'm sure you can always kill a bit of woofer sensitivity via BSC, but thats counterproductive in other ways. Unfortunately, most higher sense tweeters are in a much higher price bracket than the usual 89 dB / 4 ohm ceramic nangnet tweeter. Tweeters are easy to pad, but actually not that easy to pad if you're trying to preserve the damping factor up top. There's alot of debate regarding HF driver padding using various methods ie. Resistor voltage devices, transformer, etc.