Tell me about rated frequency response vs actual Hz

[ra1der2]

It seems like all of the 2 x 12 cabs or combo amps I look at are rated around 60 Hz - 80 Hz on their low end, yet the F# is 46.25 Hz for example.

So my question is, are these 212 cabs or combo's incapable of producing the low notes as they should be heard?

 

[bostjan]

Not incapable, they are just not rated for it. So, in other words, the manufacturer does not stand behind the use of the product to reproduce those frequencies.

It generally just means that the speaker will distort or sound weaker below the rated frequency.

I used to hear my fellow salesmen at the music store tell kids that their guitar amps would explode if they tuned down below drop D or whatever. There is a miniscule shred of truth to that- inasmuch as the speakers can be slowly damaged if they are called upon to produce tones for which they are not designed.

For example, a Celestion Blue 12" is rated for 75-5k Hz. Below 75 Hz, the efficiency drops rapidy as shown in this graph from Celestion's site:

 

[gtrbmart]

It's not that the speakers are "less efficient" or that they'll blow up - it's that they will be markedly quieter at the frequencies below the rated ones. The further below the low frequency, the quieter. Same thing for the high frequencies too.

 

[Scarpie]

So what is the best remedy for such inadequacies? a full range speaker? I am particularly interested in something to go with my 6505, that can handle C1 at 32.7 hz

 

[rectifryer]

You are hearing mostly overtones. The fundamental is important but the cab will be more than good enough.

Thats not to say that there arent better cabs.

I had a similiar question before.

 

[bostjan]

So what is the best remedy for such inadequacies? a full range speaker? I am particularly interested in something to go with my 6505, that can handle C1 at 32.7 hz

If the speakers you have sound good, then I'd say stick with them. Full range speakers can drastically change the tone you are getting, and you may very likely be displeased with the result.

Frequency response of speaker cabs for guitar & bass are not very flat, and that tends to lend a lot to the tone. If you want a bassier tone, you can get that with a bassier cabinet.

The frequency limits manufacturers publish is like the "best by date" on foods. The food doesn't suddenly get maggotty on the exact date marked on the package, but it just communicates what the manufacturer suggests based on some statistical study.

In fact, I would bet that if you bought a speaker and did your own white noise spectrum, you wouldn't see the exact same frequency response as what is marked on the package, since every speaker is a little bit different anyway.

It's not that the speakers are "less efficient" or that they'll blow up - it's that they will be markedly quieter at the frequencies below the rated ones. The further below the low frequency, the quieter. Same thing for the high frequencies too.

Except that they are "less efficient" by definition of efficiency, and that's why the frequency response falls off so rapidly. Also, driving the speakers at frequencies outside of the normal range may cause them to wear more quickly.

 

[gtrbmart]

Except that they are "less efficient" by definition of efficiency, and that's why the frequency response falls off so rapidly. Also, driving the speakers at frequencies outside of the normal range may cause them to wear more quickly.

Well if you're talking about a fixed frequency response, then you could also argue that it is more efficient in that its rolloff after its 3dB point is a 2nd or 3rd order high pass (on the low end). Irregardless, as someone above pointed out, guitar is all about the overtones (all instruments are). Sure the fundamental is great but the reason people like tube amps is that they amplify the overtones (2nd order harmonics to be specific) more than solid state devices (if you're talking about overall THD strictly). The point is that it's not that big of a deal. You might have to increase your mids a bit but at least you won't suffer from Cannibal Corpse-itis. Or even worse: Defeated (in)Sanity.

 

[Scarpie]

If the speakers you have sound good, then I'd say stick with them. Also, driving the speakers at frequencies outside of the normal range may cause them to wear more quickly.

um

But won't sticking with what i have, ruin what i've got?

 

[bostjan]

um

But won't sticking with what i have, ruin what i've got?

Yes, but very slowly.

If you use this as a reason to avoid using it you might as well avoid playing any nice guitar you own for fear of wearing the frets out.

But you can refret guitars and you can recone speakers, so you shouldn't worry about it, just something to keep in a light perspective.

 

[Scarpie]

Yes, but very slowly.

If you use this as a reason to avoid using it you might as well avoid playing any nice guitar you own for fear of wearing the frets out.

But you can refret guitars and you can recone speakers, so you shouldn't worry about it, just something to keep in a light perspective.

Hahahahaha. Cool beans Bostjan!! I like your logic. I'll just enjoy my rig then cause truthfully I've never been happier.

 

[ra1der2]

So technically, having a speaker that is rated for the frequency is the best approach to having the sound of a note such as F# or lower reproduced as it should be.

My next question would be given that the majority of 15's out there have that low ability but fall short at the high end, what effect would that have if any.

If the 15's high end is around 3k and the 12's high end is around 5k.

Where do harmonics fall within the spectrum?

 

[bostjan]

So technically, having a speaker that is rated for the frequency is the best approach to having the sound of a note such as F# or lower reproduced as it should be.

My next question would be given that the majority of 15's out there have that low ability but fall short at the high end, what effect would that have if any.

If the 15's high end is around 3k and the 12's high end is around 5k.

Where do harmonics fall within the spectrum?

Harmonics fall all over the frequency spectrum.

The highest strong harmonic on a 24-fret guitar is typically around 5kHz, but there are tons and tons of weaker harmonics even above 10kHz. The low F# on an 8-string guitar is about 46 Hz with it's highest strong harmonic being about 92 Hz.

If you run a 2x15 cab and a 4x12 cab, you should be able to push a little more low end without giving up too much high end, but the tone of the guitar might sound just a little less defined with these speakers.

 

[MF_Kitten]

simple solution: get a combo 2X10 bass amp. nothing fancy, but one that hass a high wattage rating, and maybe even has a graphic EQ. if you have any pedals in the effects loop, get a pedal with two ouputs (some tuner pedals, for example, have two different outputs). plug one output into your regular guitar chain, and then one into the bass amp. if you don´t have anything in the loop, you just plug the effects send to the bass amp and keep the wet/dry to the dry side.

now, dial a normal guitar tone that sounds good, disregarding the low end. when you have a good tone, you add in the bass combo. use the EQ settings on the combo to remove highs and mids while only playing the low end. if you only have low-mid-high settings, then don´t turn the mids ALL the way down right away, as the "lows" part might be too low. see what works. you want the whole lows-low mids spectrum coming from the combo. if you have a graphic EQ, you can just turn all faders above 300 hz all the way down and turn the "treble" knob or whatever down.

congrats, you just got yourself a subwoofer for your guitar amp, and can reproduce tight and clear low end in your guitar tone without having to rely on your guitar cab to do it. guitar cabs sound great for everything else, so it just needs some help beyond that. if you get that uncomfortable "rumble" effect, or just undiscernable deep sounds coming from the combo, you use the graphic EQ to adjust it. there IS a chance, though, that you won´t want the super-low frequencies (below 70 hz) in your tone. it depends on how you use them, and what role the guitar has in your music.

good luck!

 

[paintkilz]

in all the mayhem, nobody has really recommended a speaker that COULD do well with that frequency response. no of any decent celestions that will handle the low F# freq?

 

[bostjan]

in all the mayhem, nobody has really recommended a speaker that COULD do well with that frequency response. no of any decent celestions that will handle the low F# freq?

The 15" Orange label 400W Celestions will handle it just fine, as will almost all high-wattage 15" speakers.

http://professional.celestion.com/bass/pdf/BN15-400S8.pdf

You'll want to use this as a woofer in conjunction with a couple 12" guitar speakers if you still want to sound like a guitar.

 

[Soopahmahn]

You will have to add a ton of power and some serious subwoofing ability to your rig in order to tightly, accurately reproduce those frequencies in a musical environment. As the human ear simply hears the overtones and fills in the fundamental, it is more or less a pointless endeavor unless you have very specific sonic objectives and a deep pocket.

 

[G_3_3_k_]

This is why I'm designing an amp right now that has two power sections. The guitar will go through the preamp and loop to a crossover. The crossover will separate the lows from the highs and mids and send the two signals to different power sections. A pair of KT66's for mids and highs, and a pair of KT88's for the lows. Then two speaker outs from the head to a "stereo" cab. The cab will be a rewired Budda cab since they're split into the two top twelves and the two bottom twelves by a divider. I'll be using Fane Medusas on the top and two of the speakers Bostjan was just speaking of for the bottom.

 

[bostjan]

This is why I'm designing an amp right now that has two power sections. The guitar will go through the preamp and loop to a crossover. The crossover will separate the lows from the highs and mids and send the two signals to different power sections. A pair of KT66's for mids and highs, and a pair of KT88's for the lows. Then two speaker outs from the head to a "stereo" cab. The cab will be a rewired Budda cab since they're split into the two top twelves and the two bottom twelves by a divider. I'll be using Fane Medusas on the top and two of the speakers Bostjan was just speaking of for the bottom.

Cool!

The speakers I mentioned were 15"s. It might be a good idea to drive those 15"s at 400-600 W, though, and you won't get that from 2 KT88's?

 

[CynicEidolon]

People... I'm going to get neg repped for this I am sure but... I need to allow people to hear somethings...

A GUITAR is NOT a bass freq. instrument. There is NO reason for this instrument to even be considered for the 50 or so hz mentioned here. Even at the F whatever tuning... It doesn't matter. The guitar is a mid range instrument! That's where it's DOMINANT freq. Not strong ones or fundamental... If you are wanting to manipulate that area of air movement... Play a bass.

Another way to look at it is, almost any audio tech (studio or not) will high pass a guitar up to 80 or even as much as 120hz... So, there is NO reason to have an extended range of this instrument this far. It just makes for mud and jumbled shit that destroys mixes...

Now, hear this... There is only one rule in Audio... Whatever sounds good. If that's what you are going for, do it. Heh.

 

[G_3_3_k_]

Russ, you know I know that as well as you do... And you're the only person here who knows my tone. And it's brite. Not really bassy at all. But lets be honest... We've had trouble keeping bass players, so let's you and I crank up the bass and negate the bass all together.

Sound guys...