Ah, the "crux of the biscuit"... In short, I'd say "no". Let's take just the Q parameters for example. If you've ever done a sine sweep on a driver using a function generator - while measuring and recording the driver impedance at as many frequency points in the sweep as practical - you'll see that all drivers have an impedance peak corresponding to something called their free air resonance. Now the "peaky-ness" of this resonance - the ratio of how tall the impedance peak is to the width (at some conventional two points sufficient to describe the "base" of such peak) determines this Q. A higher Q speaker has a sharper shape to its resonant behavior. This is further broken down into electrical and mechanical components, to aid in your comprehensional continuity.
Now that you have that abstract comprehended, we can move on to what that does to the sound a speaker makes. XRK971 said a bigger more expensive magnet is needed for lower Q. Why? It's about control, with more magnetic field for the voice coil to push and pull against, it'll have a better "grip" on the cone motion and not allow it to "flop about" so much when the cone mass is interacting with the suspension "spring" so fiercely at resonance. So generally one would think lower Q is better, as the sound resulting will be more controlled as well, as in uniform - the opposite of "one note bass".
Got it? But even it's not as simple as that, because some engineers can take the higher Q exhibiting speakers and use the "flop" to advantage - provided it's in the right place frequency wise. It of course interacts with the box part of the speaker so in all cases where there's a box involved, it's the two together that you listen to. There's all manner of box designs that attempt to dance with just the speaker Q. A friend told me so many years ago that a Karlson enclosure was capable of making a cheaper speaker sound good. Cheaper speaker, less magnet, worse Q behavior - but tamed by the clever enclosure design when connected together into something listenable.
I remember an EV ad where they said by making the VC winding better, they could reduce the amount of "expensive magnet" - and make a better sounding driver less expensively - with the implication of the advert that they were passing the savings on to the consumer. You see? It's all engineering and though you may not have a degree, you'll need the levels of understanding required to get such a degree in order to be most successful with this hobby.
The other parameters I have no idea how they effect the sound. Other way more experienced folks here than I, do. These are the folks that could take a dumpster driver, measure it and build an enclosure that would be a perfect dance partner. But if you have that level of skill, you'd probably pay for drivers with known, most ideal parameters in the first place. Not that finding some junked drivers, unraveling their secrets and successfully designing (or modifying) an enclosure for them wouldnt be fun to impress your friends.
I was the automated test engineer for power supply designers for many years. One switch-mode controller vendor made a poster for the power supply engineers office wall. It was like one of those yoga posters, showing all the different poses - but circuit topologies - that were common designs and of course implying their controller product line could handle any one of them. I wonder what such a "poster" would look like, for all the known speaker cabinet designs, along with the speaker parameters necessary to utilize each?
Last edited:
Oh, wow. Well... Though I guess it is *possible* to fit any kind of driver into any kind of enclosure, but the results and sizes would vary significantly.
The cheat-sheet is to get the most important parameters from the end-user:
Frequency extension, price and size.
THEN you can start looking for drivers.
OTOH, if you don't care about size and have the drivers with proper parameters just make whatever's optimal.
If you don't have a clue and don't really care, but somehow suspect that the driver has a bit of xmax (IE it can move back and forth a fair bit) just chuck it in a somewhat suitable closed box, measure it with a cheap mic of some kind and adjust with EQ until happy.
The cheat-sheet is to get the most important parameters from the end-user:
Frequency extension, price and size.
THEN you can start looking for drivers.
OTOH, if you don't care about size and have the drivers with proper parameters just make whatever's optimal.
If you don't have a clue and don't really care, but somehow suspect that the driver has a bit of xmax (IE it can move back and forth a fair bit) just chuck it in a somewhat suitable closed box, measure it with a cheap mic of some kind and adjust with EQ until happy.
Oh man, thanks so much Joe for that excellent explanation!
Something along the lines of what you just did, but for each parameter that affects driver performance, is exactly what I would need in order to be able to get at least a tentative grasp on the concepts involved in driver characterization, and the related art (and science) of enclosure design.
I really appreciate you taking the time to type that out, it helped a lot.
As I said, I'm only looking to learn enough to be able to not go instantly cross-eyed when I look at all the various charts and tables that get tossed about here on the forums in reference to the performance of a particular driver, or speaker system.
Thanks!
"As I said, I'm only looking to learn enough to be able to not go instantly cross-eyed when I look at all the various charts and tables that get tossed about here on the forums in reference to the performance of a particular driver, or speaker system."
That hypothetical poster would be a lot of help. The first "pose" would be the sealed box enclosure type. Underneath it would be a set of speaker parameters, stating things like "Qts between 0.5 and 0.71" or some such that many folks here know by heart.
The next pose would be adding a reflex port and below, a set of driver parameters most appropriate to that type of design.
The next one might be a MLTL - and so on through Karlson couplers and all the beautiful cabinet designs people have conceived and executed successfully over the years. I can only imagine what a help such a "cheat sheet" would be to folks like "us". At least we could ask more intelligent questions about speaker paramaters - perhaps those falling just outside recommendation - here.
"As I said, I'm only looking to learn enough to be able to not go instantly cross-eyed when I look at all the various charts and tables that get tossed about here on the forums in reference to the performance of a particular driver, or speaker system."
That hypothetical poster would be a lot of help. The first "pose" would be the sealed box enclosure type. Underneath it would be a set of speaker parameters, stating things like "Qts between 0.5 and 0.71" or some such that many folks here know by heart.
The next pose would be adding a reflex port and below, a set of driver parameters most appropriate to that type of design.
The next one might be a MLTL - and so on through Karlson couplers and all the beautiful cabinet designs people have conceived and executed successfully over the years. I can only imagine what a help such a "cheat sheet" would be to folks like "us". At least we could ask more intelligent questions about speaker paramaters - perhaps those falling just outside recommendation - here.
Last edited:
A bit hard to give absolute rules, but in general:
The qts value says something about the bass roll off, the fs defines where in the frequency spectrum, and vas gives some indication towards if it's better suited for a small or bigger box.
But you really can make any kind of box for any kind of driver, it depends on what sacrifices you're willing to make. IE a driver of qts 0.71 and fs of 90hz may well be useable in a BLH or large MLTL to lower frequencies, just don't expect it to perform at nightclub levels.
Edit:
I guess the closest comparison for a SMPS engineer would be something like this: You can take any kind of smps, use a dc-dc converter, and power any kind of circuit. Just don't expect it to function optimally.
The qts value says something about the bass roll off, the fs defines where in the frequency spectrum, and vas gives some indication towards if it's better suited for a small or bigger box.
But you really can make any kind of box for any kind of driver, it depends on what sacrifices you're willing to make. IE a driver of qts 0.71 and fs of 90hz may well be useable in a BLH or large MLTL to lower frequencies, just don't expect it to perform at nightclub levels.
Edit:
I guess the closest comparison for a SMPS engineer would be something like this: You can take any kind of smps, use a dc-dc converter, and power any kind of circuit. Just don't expect it to function optimally.
Last edited:
Check out Dumpster Diving, Yard Sale and Thrift Store Speaker Quick Assessor as a way to have a first look at such things you may come across in the future -