I know there are 1000000000000 threads about mixing different cabs, but what do the purists think about single cabs with mixed drivers? The Mesa Powerhouse with four 10" speakers and a 15" comes to mind.
That cab gets loads of press. Most of it bad to horrible. Unsurprising since it's possibly the worst way to *not* design a cab.
Ampeg used to make the SVT1540HE (a 1X15 + 4X10). They don't anymore - arguably one of the worst cabs they made.
With enough math and design there probably is. I assume you mean full range drivers and not a crossed over cab with a low frequency driver and separate mid driver. As people are fond of pointing out here, a speakers size isn't indicative of bass response or tone. There are 10s and 12s with more bass response than some 15s. If you're looking for a specific response you might just design a driver and cab combination with the response you are looking for. Differing sensitivity and impedance and tone at different frequencies and power probably add enough variables to make it impossible to know what the cab would sound like. With enough time and money you could find a combination of drivers and cabinet that would work. But to save time and money using multiple identical speakers in a well modeled cabinet would be orders of magnitude easier and much cheaper to design. At least based on posts Ive read. That's been my takeaway.
Sure, Peavey made a cab with 2 10" and 1 18". Still not a great cab but at least they used a crossover for the 10s.
Crossed over is not mixing, as the crossover separates them. There are ways of making mixed drivers work, one of the designers posted here about the basics of how he did it. It was for a very specific tone goal and was really fiddly to get right, so you wind up with a lot of cost for a cab that suits not many people. Possible, but not worth it. Doing it wrong anyway is way cheap though, so you can generally assume its that.
Imo the right way to do it would be to make sure the excursion-limited power handling is equal or very nearly so, and that the thermal power handling is pretty close. The reason is, if one driver becomes the limiting factor well before the other, that's an inefficient use of resources - you're leaving much of the more capable driver's potential "on the table". Or even worse, the more capable driver is also enough louder that you don't notice the distortion from the over-driven driver until it's too late. This is easier to do if each driver has its own separate airspace, as there are few off-the-shelf dissimilar driver combinations that don't involve some compromise if they share the same airspace. But it is theoretically possible to have two drivers share the same airspace and interact in such a way as to raise the fartout threshold of the less capable driver. I have designed and tested three such systems, and so far have not felt that any of them were a worthwhile improvement over their dollar equivalence in a more conventional system. But I'm keeping what I learned in my bag of tricks, just in case. Accugroove has done quite well with high-end mixed-driver cabs.
Of course it's entirely possible if you fully understand the engineering behind it. This means using an appropriate choice of drivers that exploit NONCONFLICTING performance aspects of each. Just sticking drivers in a box... Not so likely. At the bottom end of the market... Not so likely. In a common airspace... Not so likely. My favorite combination is either a JBL 2240/1/2 or 2225/6 with something like a 2220a, 2206, or even an EVM-12. These combinations all work quite well and allow for some options not possible with a single driver platform.
I have cabs with mixed drivers, and the reason I have them is because they sounded the best to me of everything I tested. They are 2x12 and 1x6 in each cabinet (W2126) by TKS Engineering in Sweden. http://tks.se TKS is very popular among bassists in Sweden and have started selling in the UK too now. Here are some discussions about them on BassChat http://basschat.co.uk/topic/246338-hello-from-tks-engineering So it can be done and work well.
No arguing about it. The TKS's look like they're crossing over the 6" mid driver, which is a whole different ballgame from throwing two different size full range speakers in a box.
Of course. Fearful cabs have mixed drivers. PA cabs and stereo cabs have mixed drivers. But it is more than just slapping together a box and speakers.
"The Mesa Powerhouse with four 10" speakers and a 15" comes to mind." 5 full range speakers, no crossover.
Still in production & catalog. ......2x12,2x12 & 4x10. Given the quality of their products, I have no reason that this would be any different . http://www.tecamp.cc/en/products/cabinets/41-bad-cab.html#specifications