Still trying to understand.

[Dustin Teel]

Why there are different speaker sizes. I know this is beaten to death, and I've read the stickies, but I'm puzzled as to why there are still so many (apparent) disagreements. I've come to understand the following, and please correct me if I'm wrong:

1. Driver size does not determine tone. (10s are NOT generally punchier, 15s are NOT generally lower/boomier, etc.)
2. Many factors other than driver size determine how a cab will sound, most important being the efficiency of the speaker and how the cabinet itself is constructed.
3. Mixing driver sizes is generally a bad idea. (Which still kind of confuses me, since fEarfuls mix 15s and 6s and they have such an outstanding reputation).
4. Speaker size alone only affects midrange dispersion. 15s are "generally" better in this area, based on the opinions I have read. I'm sure many would disagree... I would really enjoy reading more educated debate on this.
5. More speakers generally means more volume unless a single speaker is much more effecient than aforementioned multiple speakers. (A really nice, well built 1x12 cab can be louder than a budget 4x10).
6. Cabinet design can have dramatic effects on frequency response and tone. (Such as ported cabs being able to reach lower frequences [30hz] and sealed cabs being "punchy").
7. Vertically stacking similar cabinets with like driver sizes is infinitely superior than trying to run "stereo" low end. (Since bass is omnidirectional, having a cabinet closer to your ears will help you hear your mids, etc.)


Things I am still trying to understand:

1. Acoustic dispersion based on the architecture of a given room and how certain frequencies react to stage height, ceiling height, room shape, etc.
2. Driver sensitivity, such as "104 dB @ 1W1M". (This is the area I am fuzziest on, any information in lamens terms would be appreciated.)
3. What specs make driver A superior to driver B.
4. What specs make cabinet A superior to cabinet B.

Unfortunately, I am in my early twenties and haven't had the chance to use a plethora of different cabinets. Every bassist I know and every cabinet I have owned up until recently had 10" drivers.

I'm simply trying to increase my knowledge and ask some questions that other, newer TBers may be afraid to ask for fear of getting flamed.

Any, friendly, educated contributions are welcome! And thanks ahead for any input.

[335guy]

I'll give my opinions and limited understanding, but I'm not a speaker builder, so FWIW.

The multiple driver cabs have built in crossovers and in the case of the Fearfuls you mentioned, the mid driver is isolated in it's own enclosure within the cabinet. This is different than mixing a 4 x 10 cab and a single 15. With those designs, all the freq. are going through all the speakers, which MAY cause phasing issues. Single cabs with multiple, crossed over drivers take into acct. the different drivers and phase issues.

I'm not sure a single 12 would sound "louder" than a 4 x 10, even if it was better built. It maybe clearer, punchier, etc but speaker area plays a large factor in overall volume output, given the same wattage. What you maybe having a hard time grasping is speaker efficiency. Yes, there are speakers that are not as efficient as others. So, if one had a speaker rated at 103 db at one watt, and another speaker at 100 db at one watt, the first speaker will get louder with less wattage. It takes double the wattage to increase 3 db, so speaker A will sound as loud with 100 watts as speaker B with 200 watts. This is driver efficiency and has little to do with cab design, although cabs are designed around the speakers parameters.

As far as why one speaker or cabinet is "superior", that is very subjective. Generally, it is the quality of the components. Better cabs will have been better designed and use higher quality materials. But superior can mean lower weight, better components, greater freq. response, and a whole plethora of other factors. Cost alone doesn't mean better or worse, as some manufacturers charge for their brand name and others have found ways to lower their manufacturing costs.

What I look for in a cabinet is quality components, good construction practices, size/weight and the sound/tone/response that I want. That may be very different from what another player wants or needs. That's why there are so many choices. It's like cars. One has to define their needs and wants first, then look to see what the market has that fits it.

There is no better way to tell what you need than auditioning the gear in person. Take it for a test drive in the store, if you like it then, buy it with the option of returning it. Then take the gear to gigs and see how it works out. Different gigs will have different needs. Only you can decide which piece of gear meets your needs.

[will33]

The fEARful, or any other good "multi-way" speaker uses a crossover to split the frequency band and send portions of it to the appropriate drivers. Example: low frequencies to the woofer, middle frequencies to the mid driver and high frequencies to the tweeter. That way, each speaker is playing it's "strong suit", what it's best at. This is better than making one speaker type "play it all". This is vastly different than mixing different speakers, like a 10, a 12 and a 15 and having all of them playing all the frequencies....no crossover, no separating the sound and sending it to the appropariate speaker. They're all trying to do all the work.

Any speaker has tradeoff's in it's design. One that's really good at playing lows won't be good at playing highs and vice versa. In a "one kind of speaker plays it all" kind of bass cab, you have to make more tradeoffs. In the fearful, each speaker only has to play that part of the sound that's it's designed to play well.....less tradeoffs.

That's about as simple as I can explain that one........more later.

[bassteban]

There are different size speakers because people will buy them. There are other reasons- real & imagined- but this is the most powerful.

[xed]

^ what 335guy said ^

Another choice that may be available to you instead of "buy with the option of returning" would be to see if anyone in your area "rents". You could rent something for a weekend so that you could use it at practice and possibly a gig to see how it went and you wouldn't have to deal with any potential hassles. Just a thought.

[will33]

Originally Posted by bassteban

There are different size speakers because people will buy them. There are other reasons- real & imagined- but this is the most powerful.

There's a lot of truth in this too.^^

[billfitzmaurice]

Larger drivers are capable of higher low frequency output per dollar spent, but at the cost of shrinking dispersion with increasing frequency. Smaller drivers have better dispersion but it's more expensive using lots of small drivers to get adequate low frequency output. Therefore for the best cost to performance ratio for lows you use the largest driver that will fit into the cabinet size that you want to deal with. When dispersion narrows to the point of unusable you cross over to a smaller driver that's designed to operate in that higher bandwidth. Repeat again as required.

The problem with traditional electric bass cabs is that no attention is paid to either dispersion or using drivers designed to operate in higher frequency bandwidths. For that matter very little attention is paid to anything other than how the cabs look. That's not entirely the fault of the manufacturers. What sells is looks, so that's what they base their production decisions on. Unfortunately those looks reflect the latest and greatest of loudspeaker design knowledge circa 1949.
Some recent introductions, like Avatar's 153, Duke's Thunderchild and the Barefaced line, and some old favorites like Acme, get the engineering right. But they're the proverbial exceptions to the rule.

[tstone]

Originally Posted by Dustin Teel

1. Driver sensitivity, such as "104 dB @ 1W1M". (This is the area I am fuzziest on, any information in lamens terms would be appreciated.)

It's a measure of output divided by input. The output is sound pressure level in decibels (dB), the input is electric power (Watts). In other words, when I give this speaker one Watt of electric power, how loud a sound, measured in decibels, do I get at a given distance from the cone?

To test sensitivity, a sound level meter is placed one meter (39.37 inches) in front of the speaker. A signal is fed into the speaker and the signal level is adjusted so that the speaker is consuming one Watt of electric power. Then the resultant sound pressure level in decibels is measured by the sound level meter. That should explain what the "@1W1M" means. Ideally, the test is done in an anechoic test chamber and the signal is some form of broadband noise, such as pink noise.

To the working musician, the importance of speaker sensitivity is that a speaker with higher sensitivity will be louder than one with lower sensitivity when hooked up to the same amp.

[will33]

The best example I can think of for you to hear what poor dispersion sounds like is to listen to a typical 412 guitar cabinet being played at good volume outdoors. Have a friend setup outside and play. You start way off to one side, slowly walk across way to the other side. You'll hear the sound as more woofy way off to the side. As you walk across, the closer you get to being on center with the speaker, the more you'll hear the mids and highs come in and start to sound more like it should. When you get directly on center with the cabinet, it'll be pinning your ears back. As you get past that point, further to the other side, you'll hear the mids and highs go away again and the woofy sound come back.

The guitar 412 has some of the worst dispersion of anything commonly used and is the most obvious example. Pay close attention when you're centered on the cabinet....you don't have to move very far in either direction to notice a change, that's how narrow the "beam" is, hence the term beaming. The full sound only being directed in a very narrow beam on center with the speaker.

That's where speaker size and layout matter. The bigger the sound source, the lower in frequency it starts to beam. Four 12" speakers positioned in a square have dispersion similair to playing a single 24" speaker. Worse even because all those 12's aren't scrunched together as tight as possible. Maybe more like one giant, square 28" cone.

[billfitzmaurice]

Originally Posted by tstone

To the working musician, the importance of speaker sensitivity is that a speaker with higher sensitivity will be louder than one with lower sensitivity when hooked up to the same amp.

Unfortunately truthful sensitivity specs are as rare as honest politicians. And the fact of the matter is that the sensitivity range of most musical instrument drivers covers a very narrow range, plus or minus about 2dB, which is barely audible.

[335guy]

Unfortunately truthful sensitivity specs are as rare as honest politicians

Ain't that the truth Bill. Power handling as well, seems to be overly exaggerated.

[rad bassman]

what a great thread, straight to the point in simple terms and no flames.... yet

[billfitzmaurice]

Originally Posted by rad bassman

what a great thread, straight to the point in simple terms and no flames.... yet

Wait for it....

[Bassmec]

Originally Posted by Dustin Teel

Why there are different speaker sizes. I know this is beaten to death, and I've read the stickies, but I'm puzzled as to why there are still so many (apparent) disagreements. I've come to understand the following, and please correct me if I'm wrong:

1. Driver size does not determine tone. (10s are NOT generally punchier, 15s are NOT generally lower/boomier, etc.)
2. Many factors other than driver size determine how a cab will sound, most important being the efficiency of the speaker and how the cabinet itself is constructed.
3. Mixing driver sizes is generally a bad idea. (Which still kind of confuses me, since fEarfuls mix 15s and 6s and they have such an outstanding reputation).
4. Speaker size alone only affects midrange dispersion. 15s are "generally" better in this area, based on the opinions I have read. I'm sure many would disagree... I would really enjoy reading more educated debate on this.
5. More speakers generally means more volume unless a single speaker is much more effecient than aforementioned multiple speakers. (A really nice, well built 1x12 cab can be louder than a budget 4x10).
6. Cabinet design can have dramatic effects on frequency response and tone. (Such as ported cabs being able to reach lower frequences [30hz] and sealed cabs being "punchy").
7. Vertically stacking similar cabinets with like driver sizes is infinitely superior than trying to run "stereo" low end. (Since bass is omnidirectional, having a cabinet closer to your ears will help you hear your mids, etc.)


Things I am still trying to understand:

1. Acoustic dispersion based on the architecture of a given room and how certain frequencies react to stage height, ceiling height, room shape, etc.
2. Driver sensitivity, such as "104 dB @ 1W1M". (This is the area I am fuzziest on, any information in lamens terms would be appreciated.)
3. What specs make driver A superior to driver B.
4. What specs make cabinet A superior to cabinet B.

Unfortunately, I am in my early twenties and haven't had the chance to use a plethora of different cabinets. Every bassist I know and every cabinet I have owned up until recently had 10" drivers.

I'm simply trying to increase my knowledge and ask some questions that other, newer TBers may be afraid to ask for fear of getting flamed.

Any, friendly, educated contributions are welcome! And thanks ahead for any input.

Well my take on this is as follows:
The reason people say that speaker size does not describe
typical 10" and 15" BASS GUITAR loudspeakers frequency response and tonality is because they are not old enough not to have their heads cluttered with a load of superflous crap about in car audio subwoofers cluttering up the issue.
Efficient speakers are generally brighter and more forward in the midrange and have a higher fundamental resonance.
Of course mixing speaker sizes is wrong (so is smoking dope) as is passive crossovers with long overlaps and no real attempt at proper time alignment between the drivers.
But hey thats the imperfect world of bass guitar amplification for yer!.
Assuming correct polarity or phase mixing speaker sizes can be awesome specially if you can eq the different sizes individually.
Good cabinet port tuning makes a bit of difference in the very low end. But then if the cabinet was anything like big enough for the drivers it would probably sound better any way without any ports.
Acoustic environments? too many variables in different situations to get into here.
To the thing you are fuzziest on, Efficiency! the ability to produce a volume level measured in dB from a fixed output level measured in watts at a distance measured in meters.
sorted!
The answer to 3 and 4 is basically NONE its all subjective, listening is the only way to define what's better for you.
Anyway most specs in the bass industry are heavily massaged by sales teams.

[will33]

Originally Posted by 335guy

Ain't that the truth Bill. Power handling as well, seems to be overly exaggerated.

Power handling/"wattage" ratings are arrived at by adding up all the watt ratings of every voice coil in the box. It's generally accepted that that's a thermal rating, ie: how much heat the coils can take before they melt. Most common bass cabs will be farting like mad at about half that input, some a little better, some as low as 1/3.

That does mean consistent power over time. Luckily, our megawatt amps aren't putting out mega power all the time. Only to handle transient peaks here and there, the majority of the time cruising along at much less power than most of us think we're using.

[will33]

Actually, "mega" is a technical term that means 10,000 or 1,000,000 or something so don't take that literally. Let's just call it "uber" or "mucho" and butcher somebody elses language instead.

[will33]

A couple terms that may be confusing you are "efficiency" and "sensitivity". They are often interchanged but don't mean the same thing at all.

Efficiency-- This refers to how much of the energy put into the speaker actually comes out as sound. It is measured in % and will almost always be between 1% and 5%. The speaker as we know it, as good as it can be, is still a 100 year old, horribly inefficient machine.

Sensitivity-- This is the spec explained in previous posts. The decibel level resulting from 1 watt of input measured 1 meter away.

[billfitzmaurice]

Originally Posted by will33

Actually, "mega" is a technical term that means 10,000 or 1,000,000 or something

It means 'million', and is the second most mis-used term today. The first, also derived from Latin, is 'anniversary', which TV's talking heads always combine with 'year', as in "This is the ten year anniversary". Of course those of us who paid attention in 5th grade know that 'Tenth anniversary' means ten years after the event.
And yet Matt Lauer gets paid millions.

[will33]

Originally Posted by billfitzmaurice

It means 'million', and is the second most mis-used term today. The first, also derived from Latin, is 'anniversary', which TV's talking heads always combine with 'year', as in "This is the ten year anniversary". Of course those of us who paid attention in 5th grade know that 'Tenth anniversary' means ten years after the event.
And yet Matt Lauer gets paid millions.

The 5th grade ain't what it used to be. My parents always refer to anniversary's as tenth, fortieth, etc., never ten year or forty year, but then again, they don't get paid millions.

Any coincidence as to why "anniversary" and "adversary" look so similair?

[Dustin Teel]

Great input so far. I understand the fEarful design now.

Excellent information on sensitivity, thank you.

@Bill,

So if one can afford it, it's generally smarter to use several small drivers than a few large ones?

@Will33,

Perhaps the example you gave about the 412s is proprietary to guitar cabinets, sense that is what you mentioned. I am currently using a Peavey TVX 412 cabinet, and I really like it, and it seems (to my understanding) to be a good design. We have focused on 10" and 15" discussion, so more opinions/input on 12s would be greatly appreciated.

Also, I'm still a little fuzzy on dispersion...

But great replies thus far, thank you. I learned more with the first dozen or so posts than I have in ages.