What do you look for when you look at specs?

[terribilino]

I've started lurking in the amps forum recently - there's going to be new amp for me under the Christmas tree next year, I can feel it in my bones... My Peavy Micro Bass is a great little practise amp, but I've yet to test it against a drummer, and I'm thinking just maybe the 50 watts wouldn't exactly cut it at a gig.

I'm in no rush, and I keep browsing around on various websites, reading up on things, and falling in love with a different amp each week. Ashdown, Ampeg, Markbass, and lately this Genz Benz 6.2 which has been getting a lot of attention these last few days.

The thing that gets me is that the more I read, the more I realize how little I actually understand about what I'm reading. My first assumption was simply that more was better - 500 amps are louder than 300 amps, 15" cabs are better than 10" cabs because they provide more low end, etc. The consensus from people who actually have used various amps and cabs and know what they're talking about, however, seems to be that you simply have to use and hear each amp - you can't generalize. If this is the case, why do they even bother publishing specs? Or better: do the specs tell you anything at all about the sound of the amp? If so, what do you look for, and why?

Thanks!

[MuzikMan]

Unfortunately, most published specs are useless. They are marketing jargon with no real meaning.

[Ukiah Bass]

Specifications are the foundation of comparisons between different technology. Some vendors are accused of stretching the meaning of specs, and while that's probably true, specifications are a crucial start to understanding what's what. Practical feedback from actual users (not readers) of the technology such as commentary here on TalkBass is extremely valuable. But the ultimate measure will be when you use the gear. Rarely will you even know what's a keeper until you use something for a while in actual gig situations. So to answer the OP: specifications are the start of the journey and can save you a lot of time in making decisions -- at least pointing you in the general direction of where you want to go.

If you're new at this, start by reading the stickies at the top of each thread.

[BassmanPaul]

Sadly your understanding is in error. If by amps you are actually meaning watts then yes a 500W amp will be louder than a 300W amp through the same speaker system. However the difference will not be all that noticeable. In order to get twice as loud you'd need to increase power ten fold.

The size of the cone is immaterial to the lows it can produce. Look at PJB and his use of 5" drivers. If the driver is designed to go low then it will.

Specs, as musicMan correctly posted, are usually wrong. For instance most people would expect that if a cabinet is rated at say 400W that they could input that power into the cabinet safely. Problem is that most cabinet power specs are thermal. That's the point where the voice coils begin to melt. In the real world a cabinet will run out of excursion, the amount the cone can safely travel, at about half that thermal rating.

[Staccato]

Many of the current production practice amps for bass have a headphone jack, and it's important to realize that mfg.'s often measure output differently. I'll give you an example: One 15 watt amp may seem louder than another 15 watt amp played in the same location with the same instrument.

Note: Speaker size is important on a practice amp, and can make/break a sale in terms of being too small. (10 inch speaker is okay, 12 inch or larger is better).

[will33]

Yep, the stickies are a great place to start.

Sadly, the specs, or rather lack of them, you see in advertisements don't give much if any real useful info at all. Obviously a 500 watt amp is more powerful than a 100 watt one but there are so many more things that affect your final sound.

If you can't go try out everything out there with your own ears...and most of us can't...you're left with weighing the opinions of others trying to describe tone and taking advantage of return policies.

[icecycle66]

Dimensions, in inches, and weight, in pounds.

[Tim1]

Resistance (ohms), weight, power handling (as a rough guideline), speker size and number of speakers.

[agedhorse]

Speaker sensitivity is probably one of the most important regarding real world volume.

Another spec that I find particularly helpful in analyzing the potential for speaker performance it it's non-linearity curves... an indicator in what's going on within the operating components of the speaker and enclosure... BUT (that's a big but) there are so many different parameters all lumped together that the graph would be utterly meaningless unless you were to invenst considerable time learning the theory (and inter-related equations) of electromagnetic transducer behavour. Things like slopes, plateaus, discontinuities, derivitives, differential equations all play into the theory of understanding what happens when a speaker transitions from a (reasonably) linear to non-linear set of functions. There are multiple causes for non-linearity and some are desireable (for some applications), some are not. This is a very complicated subject, but responsable for much of the speaker's contribution to tone and operating SPL when driven hard.

[bobcruz]

Originally Posted by terribilino

...My Peavy Micro Bass is a great little practise amp, but I've yet to test it against a drummer, and I'm thinking just maybe the 50 watts wouldn't exactly cut it at a gig....

One thing to learn is the difference between how many watts an amplifier might draw from the wall, and how many watts it puts into the speaker. The Microbass puts 20 watts into the speaker. So keep reading, reading, reading, before you lay out any cash. Peace,

[will33]

Originally Posted by agedhorse

Speaker sensitivity is probably one of the most important regarding real world volume.

Another spec that I find particularly helpful in analyzing the potential for speaker performance it it's non-linearity curves... an indicator in what's going on within the operating components of the speaker and enclosure... BUT (that's a big but) there are so many different parameters all lumped together that the graph would be utterly meaningless unless you were to invenst considerable time learning the theory (and inter-related equations) of electromagnetic transducer behavour. Things like slopes, plateaus, discontinuities, derivitives, differential equations all play into the theory of understanding what happens when a speaker transitions from a (reasonably) linear to non-linear set of functions. There are multiple causes for non-linearity and some are desireable (for some applications), some are not. This is a very complicated subject, but responsable for much of the speaker's contribution to tone and operating SPL when driven hard.

This, is valuable info...you also won't find it in any ads either. I think what the OP means by "specs" is just comparing advertisement info you see online. With the current state of things...people thinking "I have a 300 watt speaker and a 300 watt amp, I can do whatever I want and it'll be ok", these guys have to design speakers that will not only survive, but sound good, when constantly being pushed to levels that under ideal circumstances, they maybe wouldn't have to design for....at least not as much. Then throw in the fact that some things, to some people, just plain sound better when pushed and I would imagine you become a pretty good juggler.


BTW, agedhorse, I played a guys neoX112 the other day and yes, we pushed it a little farther than we maybe should've just because. It didn't start to sound ratty like some...it sounded sweet...nicely done.

[Steve]

There's not a single spec from a single "bass gear" manufacturer that I would trust to be truthful and accurate.

I'm not saying that all lie. I'll say that enough of them do that it spoils the well and that of the ones I hope are honest, I know of no independent source of
confirmation.

Except for bass gear mag. which seems to try really, really hard to provide that in their review process

[impactwrench]

Pick a head / amp combo that will be loud enough to practice with only one cab, and loud enough to gig with 1 or 2 cabs.

[Nev375]

Size and weight. Beyond that, you better trust your ears.

[agedhorse]

Originally Posted by will33

TW, agedhorse, I played a guys neoX112 the other day and yes, we pushed it a little farther than we maybe should've just because. It didn't start to sound ratty like some...it sounded sweet...nicely done.

This is specifically the result of what I posted above. It's easy to design products that hold up well lin the linear region, it's a lot more difficult and subjective to make that transition to non-linearity in a forgiving and non-destructive way while maintaining high sensitivity.

[grendle]

Tube or SS preamp. Wattage (300+ for live) . Other than that its all in the ears.

[JTE]

Originally Posted by Nev375

Size and weight. Beyond that, you better trust your ears.

These are the only specs I pay attention to any more.

Jogn

[Sartori]

You can look at the power ratings for cabs and divide the number in half to get a real world, ballpark figure.

Different manufacturers rate their equipment with varying methods. Many are misleading, and the info they do provide leaves much to be desired.

Depending on your tone goals, looking at the frequency range they list for cabs can be somewhat useful as well. It doesn't matter as much to me, as I don't use a whole lot of extreme low end or really high end in my sound.

As for wattage ratings of heads... more is not always better. Different heads have a wide variety of voicings. Amps and cabs that are more mid prominent will sound louder, even if the amp is putting out less power than another, more low end voiced head.

As well, 300 watts for a solid state head is not very much at all. 300 watts for an all tube head (by which, I mean an amplifier head that has a tube power section) is quite substantial.

Even between two of the same type of amplifier, more power does not always equate to a better head. While one head might have more power, another might have less power but sound more pleasing to your ears. Old school GK heads aren't rated as putting out a tremendous amount of power, for a solid state, but they are loud considering such, and have a tone that many many people love.

In short, the best way to judge amplification gear is to use your ears.

[JimmyM]

Originally Posted by Steve

There's not a single spec from a single "bass gear" manufacturer that I would trust to be truthful and accurate.

I'm not saying that all lie. I'll say that enough of them do that it spoils the well and that of the ones I hope are honest, I know of no independent source of
confirmation.

Except for bass gear mag. which seems to try really, really hard to provide that in their review process

Bass Gear has proved that a lot of companies are pretty truthful about wattage ratings. They've also proved one that lied about it to an insane level. Won't mention the company's name but their initials are TCE. But they've proven that Ampeg's honest and that's all I care

[JxBass]

Ohms, watts, size, weight.