sensitivity or frequency response for cabs?

[lbwdog]

I suppose there will always be two main camps in amp systems, those that want an uncolored, or "flat" response, and those who dig the sound of a given rig regardless of specs. I can go either way but lean toward a relatively uncolored cab so that I can create my sound with the upstream components. This probably comes from many years of high quality studio work with good engineering and state of the art equipment.

That said, I may want to dial in an SVT tone on certain gigs, and a super clean tone on others.

As stated before though, "flat" is very elusive when it comes to loudspeakers, which are the "speaking voice" of any system. The last time I shopped for a pair of bookshelf hi-fi speakers, I auditioned three different brands, all claiming accurate response (JBL, Infinity, & can't remember the other). I think all three used terms like "Studio Monitor" or "Reference Monitor" in their descriptions.
The sonic differences were very pronounced but in the end, I went with the one that was most pleasing to my ear, regardless if it was the "flattest" or not.

 

[Musicman20]

I have been lured in by the potential of 'flat response' cabinets, even though Im not 100% sure they are actually 'flat response'...as is stated on this thread.

Markbass AMPS for me are the amps to choose if you want a fairly uncoloured tone, and yes, they let your bass breathe and it sounds like the bass should, with little colour. But there is STILL a little colour.

Ive tried Markbass amps with various types of 'flat response' cabinets, and I found in the end, the little nuances that 'slightly coloured' cabinets offer is where I have my tonal preferences.

I have no idea if the cabs I tested are actually of the 'flat response' type, but I found them quite 'dull' and uninspiring.

Thats my preference though. I like a little colour, I like a tone ranging from Jamerson P Bass w/flats all the way to all out Stingray grind in a punk band. I like to have a range of tones to choose from, depending on what band Im playing in.

 

[mulchor]

Is it worth bothering with specs such as the Thiele-Small parameters of the drivers? Can those parameters help guide us towards a good design if we understand them and know what to do with them? Or should we simply try every driver in every possible box until we are satisfied?

Do you mean as DIY or in acoustical engineering?

I believe there is value in using models. It's almost a religion for me. But every model has assumptions and in any application the first assumption is that your model is correct. The pre-qualifying assumption is that the operator understand the model.

IME people with inadequate understanding of a model will enthusiastically apply it. Enthusiasm and understanding are often inversely related.

For DIY, the parameters are basically impossible to measure, so you'll have to rely on the manufacturer's averages which of course don't come with any indication of their precision, let alone manufacturing tolerances.

The whole point of this thread is you can't blindly trust published specs, eh.

For the professional view, I dunno, but I'm hoping they've read more recent of JAES than early 1970s.

So yes, it's worth using the parameters. It's much easier to avoid catastrophe if you do. But if making the perfect cab were only a matter of plugging in some numbers, this whole endeavor would be trivial.

 

[alexclaber]

A lot of "spec nerds" might think so, until they compared that 30 hz speaker with another that is better "voiced" to place the bass in the mix where it belongs. The latter will be louder, and will probably be generally judged to have "better tone".

Specs are no use if you don't understand them! The lower frequency response specs (whether accurate or mythical) are the most commonly misinterpreted ones.

Amps have EQ, some have DSP features, and a huge number of various "effects units" are sold every year. That rather squashes the idea that "most" or even "many" people want the raw output of the electric bass "re-produced".

I don't believe most people want the raw output of their electric bass. But I don't believe zero people want it either. As I keep saying, it's down to personal preference!

But there are enough people who like the sound of their bass when recording through a high quality clean DI to justify more accurate speaker systems. They're not for everyone but they have their place.

One nice bonus of being a member of that school of playing is that if you can get a great bass sound out of a relatively uncoloured bass rig, you'll be able to DI your bass and get an equally great sound out of a decent PA system or onto 'tape' when recording. It does make life easy!

Countless great bass sounds on record were DI'd only so one has to wonder if those players would have enjoyed low-colouration modern rigs if they'd existed at the time.

 

[tombowlus]

i get that, but what cabs out there are flat? even bill fm's cabs aren't dead flat.

While I have not measured them myself (yet, though I have seen some of Jim's measurements, which I trust), I'd have to say that the most "flat" cabs that I have played are the Bergantino IP series, which are both internally powered and also incorporate an on-board DSP which has EQ and dynamics control, and which can be programmed. Jim didn't set up each cab and each program to be entirely flat, but he got fairly close (with a reasonable low-end roll-off, of course) on several. To my ears, these really did present the information in a different manner than "regular" cabs (with bass amps/heads driving them). As you might expect, with the IP series, you can really hear what different preamps and instruments bring to the table. I like them a lot, but I realize that they are not for everybody. That being said, I like some very "colored" sounding rigs, too. But then again, I am Pollyanna, and I like everything.

Tom.

 

[rpsands]

Luckily there is a vast array of cabinets to choose from out there, so I think everyone really has the ability to find a flavor that works for them. I don't think it should be considered a fault of those of us in the amplification industry that we choose not to make a bass cabinet that sounds like a PA cabinet. iMO, there are already a number of PA cabinets out there that do a good job of that.

There's no reason you can't use a PA speaker in your rig if that's the sound your'e after.

1. I did not say that I thought all cabs should sound like PA speakers.

I said that If you want a cabinet that has a relatively flat frequency response then one way to tell whether it is is to use an accurate frequency response plot.

2. There are almost no PA speakers with sufficient low end to be used for bass guitar without subwoofers. I am not carrying a PA subwoofer and a PA main for my bass rig (minimum 60-70lbs each if I'm lucky).

 

[rpsands]

lots and lots? you grossly overestimate. if lots and lots wanted it, then more manufacturers would make it. plus your assumption that pa's are flat response is a fallacy. you've seen the graphs of current speakers. haven't seen a single one that's got truly flat response, even those reference monitors or a nice balanced pa. there's always something in there that will screw the pooch.

Almost all quality PA people start flat using DSP solutions and pink noise to autoeq the rig to flat.

Some of them even use presets for particular speakers that auto-flatten their eq curves.

Again, this argument is ridiculous because I wasn't saying all bass cabs should be flat, but that if I want flat I can recognize it using an fr chart.

 

[bobcruz]

The question of whether or not "flat response" is desirable in a bass cabinet is totally unrelated to the question of whether cabinet makers should provide accurate specifications. I have zero desire to play through a "flat" cab, but I do want to know the frequency response, sensitivity, displacement limited power handling and weight of a cab, the same as I want to know what the price is! I don't like being misled regarding any of these specs.

 

[jnewmark]

The question of whether or not "flat response" is desirable in a bass cabinet is totally unrelated to the question of whether cabinet makers should provide accurate specifications. I have zero desire to play through a "flat" cab, but I do want to know the frequency response, sensitivity, displacement limited power handling and weight of a cab, the same as I want to know what the price is! I don't like being misled regarding any of these specs.

+1. I don't think the argument was whether bass cabs should be flat like pa cabs, but whether bass cabs should be subjected to the same AES test protocalls as pa cabs. According to Agedhorse, they should not be. According to BFM, it does'nt make any difference what you are using the speaker for, it goes through the same AES procedures to find out what it's specs are. At least, that's my interpretation of what has proceeded for the last few pages. This flat vs. colored argument is sort of a sidebar. IMHO, of course !

 

[JimmyM]

The question of whether or not "flat response" is desirable in a bass cabinet is totally unrelated to the question of whether cabinet makers should provide accurate specifications. I have zero desire to play through a "flat" cab, but I do want to know the frequency response, sensitivity, displacement limited power handling and weight of a cab, the same as I want to know what the price is! I don't like being misled regarding any of these specs.

well you know how it goes on these threads that go 15 pages

 

[rpsands]

There is also the sub argument that because bass signal is colored, and speakers often pushed into breakup modes, you can't use frequency plots to tell anything of use.

The more I think about it the more I think this argument is just a copout.

 

[JimmyM]

There is also the sub argument that because bass signal is colored, and speakers often pushed into breakup modes, you can't use frequency plots to tell anything of use.

The more I think about it the more I think this argument is just a copout.

well let's face it, a frequency plot for a cab can be easily defeated by a graphic eq.

 

[R Baer]

1. I did not say that I thought all cabs should sound like PA speakers.

I said that If you want a cabinet that has a relatively flat frequency response then one way to tell whether it is is to use an accurate frequency response plot.

RP,
No offense intended. There are obviously two schools of thought here and my point was simply that there are choices for everyone.

We provide the specs we do to provide a frame of reference for comparing cabs and we tend to lean towards the conservative with our numbers. But honestly, I'm not even sure how useful that is because not every company is using the exact same methods to get their results. Basically, if your'e not comparing apples to apples, then what are you comparing? My school of thought is that, just like your bass, an amp is only one part of your signal chain and all those detailed specs are not going to tell you if that cabinet is going to work for you. Given the same bass and amplifier, a cabinets "frequency response chart" simply will not sound the same in the hands of every player that uses the cabinet. Our decision not to publish more detailed specs is in no way an attempt to deceive anyone. It's simply a marketing decision based on our opinion of the usefulness of those specs.

 

[mulchor]

There is also the sub argument that because bass signal is colored, and speakers often pushed into breakup modes, you can't use frequency plots to tell anything of use.

The more I think about it the more I think this argument is just a copout.

I think it's not a copout, because what we've learned since 1970 is that you can not simply treat a loudspeaker as a bank of filters because they are dynamic.

It's a linear systems theory applied to a dynamical system, so therefore it's only gonna work for signals close to the "unit impulse response." If the actual range of interest isn't sinusoidal 1W 1M etc. you're moving off to fantasy land.

I think an approach that tries to consider the response to useful input ranges is going to be more fruitful from a design point of view, and ultimately from the users' points of view, too.

But then meh... I've sworn off this thread a few times, but then feel compelled to click back in.

 

[bobcruz]

Sorry for shouting a few posts ago, but the thread kept veering off into the flat vs. colored signal reproduction discussion which is a straw man--my point is that you can want to know the specs for good reasons, or reasons that others don't care about, but finding a flat cab isn't one of them, at least for me. I want to see specs so I can get a general idea of how the cab stacks up against its competition in terms of compromises the designer made, and whether those line up with my general preferences. Then I can narrow down the contenders somewhat before trying them out.

 

[rpsands]

RP,
We provide the specs we do to provide a frame of reference for comparing cabs and we tend to lean towards the conservative with our numbers. But honestly, I'm not even sure how useful that is because not every company is using the exact same methods to get their results. Basically, if your'e not comparing apples to apples, then what are you comparing? My school of thought is that, just like your bass, an amp is only one part of your signal chain and all those detailed specs are not going to tell you if that cabinet is going to work for you. Have 5 different players play the same bass through the same amp and cabinet and that cabs output simply will not sound the same in the hands of each player that uses the cabinet. Our decision not to publish more detailed specs is in no way an attempt to deceive anyone. It's simply a marketing decision based on our opinion of the usefulness of those specs.

Yeah, I think you're probably right about the marketing decision. What I would like to see is it be an option for every manufacturer, personally.

Polar response and frequency plots are useful to a lot of folks and folks to whom they are not useful can learn how to interpret them easily. Yeah, it doesn't give distortion characteristics but it gives a lot of useful info. People have been interpreting FR charts for other types of sound reproduction systems for ages and the same ideas apply to the bass.

If a hard-sell customer like myself wants to see polar response and frequency plots, do you think it's worth having them available in a technical manual perhaps?

(For the record: I don't see these charts as a risk for reverse engineering; a company like Behringer is totally capable of buying one of your cabs and just copying it

 

[R Baer]

If a hard-sell customer like myself wants to see polar response and frequency plots, do you think it's worth having them available in a technical manual perhaps?

(For the record: I don't see these charts as a risk for reverse engineering; a company like Behringer is totally capable of buying one of your cabs and just copying it

Well, this thread has given us much to think about in this regard.

I don't worry about someone copying our design. As you mentioned, it is very easy to do from reverse engineering the cab, it's just part of the game. Of course, matching the driver is a bit trickier as we don't use a stock driver. Honestly, I think all us manufacturers are more than content to do our own thing and I'm not sure it does a company's reputation any good to blatantly copy another companies designs.

 

[JimmyM]

Well, this thread has given us much to think about in this regard.

I don't worry about someone copying our design. As you mentioned, it is very easy to do from reverse engineering the cab, it's just part of the game. Of course, matching the driver is a bit trickier as we don't use a stock driver. Honestly, I think all us manufacturers are more than content to do our own thing and I'm not sure it does a company's reputation any good to blatantly copy another companies designs.

certainly true with behringer. it's definitely hurt their standing in the pro community. and yet they're huge and keep getting bigger. go figure...maybe blatantly stealing other designs IS the way to go

 

[billfitzmaurice]

Genuine question Bill....is the "Law 1" dependant on the box staying the same size, e.g. if we have box 1, x cubic feet in volume, y sensitivity, would box 2, with x+n cubic feet in volume, and also y sensitivity, potentially have a greater low frequency response?

In general you'll get more low end from a larger box than a smaller one. But that doesn't affect the base sensitivity rating of the cab (Transfer Function), which is the same no matter what the box size is. What's altered by the box size and tuning is the +/-dB part of the spec.

The question of whether or not "flat response" is desirable in a bass cabinet is totally unrelated to the question of whether cabinet makers should provide accurate specifications.

+100. Those who want a highly colored response actually benefit more from an SPL chart than those who don't, as it enables them to see what the response looks like on a known cab that they like and find a similar response on a different cab that they can't try before buying.

 

[bottomzone]

This ship seems to have veered off course!

A Groove is a Terrible Thing to Waste!