It be b/c audiophiles cannot think out of the box. I got fed up with 'what u cannot do' in HiFi that I've almost exclusively designed and built instrument amps the last 10years. With electric guitar and bass (and actually every instrument - even vocals) u can experiment and go completely nuts b/c amplified instruments are not singular instruments but rather a music system where the whole chain together determines tone. Adding sweetnes or dirt or whatever can be very much the purpose in music production, but absolutely horrendous even to think of in HiFi.
Without people willing to try things out of the ordinary we'd never have musicians like Hendrix, Zappa, and just about anyone in amplified sound.
I think there are two applicable explanations. At high frequencies the efficiency gain comes from directivity, the sound is beamed on-axis at the expense of cancellation elsewhere.
At low frequencies it comes from coupling, each speaker is firing into air that is already being compressed by the speakers around it, and this gives the cone more back pressure to work against, resulting in a better acoustic impedance match.
At low frequencies it comes from coupling, each speaker is firing into air that is already being compressed by the speakers around it, and this gives the cone more back pressure to work against, resulting in a better acoustic impedance match.
The cabinet is probably used for other uses as well, and could even have a switched tweeter fitted if required.
I also don't quite see why they would sound 'truly horrible', when it's fed through the PA with tweeters anyway?.
But I'd certainly recommend a switch, if a guitar cab did have a tweeter I can see it would be nice to be optional.
It's VERY uncommon in guitar speaker cabs, as there's no need for it 😀
Many are even open-backed, which rather proves there's no bass content worth bothering about
When you send guitar sounds through a PA, you either mic a guitar cab (hence imposing the frequency response of the guitar speaker), or use some kind of cab simulation circuit or modelling device. I actually do have switchable tweeters on the cab I built, and I use them for acoustic, where they sound quite nice. But that is way more uncommon on a guitar cab, than are the use of ports.
I can easily find several more commercially built ported 1x12 guitar cabs. I agree it is not common on the larger cabs such as 4x12.
Anyway, it doesn't really matter, it works. I've given up hope on getting any feedback from this forum on the questions I first asked, but the discussion is still interesting.
I can easily find several more commercially built ported 1x12 guitar cabs. I agree it is not common on the larger cabs such as 4x12.
Anyway, it doesn't really matter, it works. I've given up hope on getting any feedback from this forum on the questions I first asked, but the discussion is still interesting.
If PA mikes a guitar cabinet, guitar speakers have "brickwall" around 24 dB/oct lowpass response above typically 3000 to 4500Hz which remove all Tweeter program for all practical purposes.
Compensated Line out meant to directly drive a mixer channel incorporate such filters .
As of providing a nice 3 to 6dB hump around 100Hz is cool for some Heavy styles, obviously not so for, say, Country Music.
That's why Metalheads use almost exclusively 4x12" closed back cabinets (ever saw anyone with a Twin Reverb?) and worry about chest thump while chickenpickin' guys worry about twang and shimmer and use killer (for that use) Super Reverbs and such.
A lot of good sound coming from very light 10" speakers in open back cabinets.
Different needs.
FWIW a friend of mine got a gig (had to replace an ill friend) at a Country show, and he showed up with his everyday gear, a Marshall head, a 4 x 12" and a Warlock type guitar.
And although he dressed properly for the occasion, with a plain shirt and faded jeans, he could not hide the tatoos and piercings or the half shaved head.
They were terrified 😉
But he set the pickups to parallel coils, which gave him some sparkle, used the clean channel, at some 20 to 30W level and everything went along very well 🙂
Looks to me like you're just seeing the effects of a very high Qts driver in a ported box. You'll see a huge increase in cone excursion at 50Hz, which would account for the extra output.
I'd recommend the latest version of WinISD Pro - you can get a lot more information there.
Chris
Oh yes, killer guitar player, plays Classic nylon string, Flamenco, our own Folkloric music, *anything* .
But he just loves the very heavy Metal "attitude" 😉 ) .
But he just loves the very heavy Metal "attitude" 😉 ) .
Hi,
Its nothing new. It has be known for a long time. It is not common.
Wrong driver in the wrong cabinet with wrong port tuning is hardly
adding anything to the font of wisdom regarding guitar cabinets.
rgds, sreten.
FWIW there is nothing sensible about adding Vas to Vbox at all.
It doesn't work, provide an example, I'll show that it is wrong.
Modelling short (panel width) ports is far more complicated than
the end corrections applied to tubular ports, and most software
gets very dodgy when the length is lower than the diameter.
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Yes, if you want to get gigs and play with ported cabinets, get a bass 😀
Also https://www.youtube.com/watch?v=jWK0sa7tlfI
Also https://www.youtube.com/watch?v=jWK0sa7tlfI
Well, there is people needing (and getting) bone crushing (literally) bass frequencies out of their guitars 😉
Enter Ken Gilbert's BAGA (Big A.S.S. Guitar Amp): 600W RMS with 12 x KT90 driving 2 cabinets, loaded with 4 Eminence Delta Pro each:
Does not look *that* large, until you notice the "small" tubes are EL84 cathode driving the output KT90 .
Yes, it has two fans, one was not enough.
Enter Ken Gilbert's BAGA (Big A.S.S. Guitar Amp): 600W RMS with 12 x KT90 driving 2 cabinets, loaded with 4 Eminence Delta Pro each:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Does not look *that* large, until you notice the "small" tubes are EL84 cathode driving the output KT90 .
Yes, it has two fans, one was not enough.
I think a 700VDC supply amp such as this one must be bedroom or headphone stuff for you 😉
How's the 250kV, guitar driven generator doing? 😀
How's the 250kV, guitar driven generator doing? 😀
franken cabs rule
I have my own custom cab.
Its a reused Hartke H410 basscab 🙂
I replaced the bass drivers with 10" "greenbacks".
I have never done a ported guitar cab. I have yo say that i never felt the need, even tuning CGADBE...with a valve head (or at least mine) i find that bass has never been an issue.
Seriously. I would be concerned that the driver may become seriously unloaded by all that downtuned chugging ;-)
But...as i have not tried it, its not really a criticism, but a reason that i would never port a guitar cab.
I have my own custom cab.
Its a reused Hartke H410 basscab 🙂
I replaced the bass drivers with 10" "greenbacks".
I have never done a ported guitar cab. I have yo say that i never felt the need, even tuning CGADBE...with a valve head (or at least mine) i find that bass has never been an issue.
Seriously. I would be concerned that the driver may become seriously unloaded by all that downtuned chugging ;-)
But...as i have not tried it, its not really a criticism, but a reason that i would never port a guitar cab.
Thanks for your comments. That's all good, most cabs are just fine as they are. My discussion is about, if, a given cab is judged to want just a bit more bass based on testing it, how to think about achieving that by the use of ports, without causing problems. It works for me, and I think this is more likely to be a feature of smaller cabs such as 1x12 than larger 4x cabs.
My keeping of the resonant frequency lower than the used frequencies I believe, will mitigate against the unloading issue.
To others: Please, please, no more posts telling me my cab is 'wrong' in some way, when I know that it sounds good, works well, people who listen to it agree, and its entirely functional.
Hi JohnDH,
you are right in saying there are quite a number of 1x12 cabs that are ported. I could name at least 3 or 4 right of the top of my head. 1x10 and 1x8, are good candidates. I think although less common, 2x8 or 2x10 are relevent too. Not many players are lugging 4x12 cabs that I know. Sure they are out there but the vast majority of them play smaller venues and mic up with PA. So getting a bit more bottom end out of a 2x10 cab sounds like a good idea, less weight , smaller volume cab etc..FYI The original marshall 4x cabs were sealed backs simply because the speakers would survive longer run full out at 100w. Unloaded, they would blow out real fast as they were not rated to that power level.
you are right in saying there are quite a number of 1x12 cabs that are ported. I could name at least 3 or 4 right of the top of my head. 1x10 and 1x8, are good candidates. I think although less common, 2x8 or 2x10 are relevent too. Not many players are lugging 4x12 cabs that I know. Sure they are out there but the vast majority of them play smaller venues and mic up with PA. So getting a bit more bottom end out of a 2x10 cab sounds like a good idea, less weight , smaller volume cab etc..FYI The original marshall 4x cabs were sealed backs simply because the speakers would survive longer run full out at 100w. Unloaded, they would blow out real fast as they were not rated to that power level.
Hi,
We know that, trouble is it is simply not optimum in any way.
And that is why its different to most commercial stuff.
Like boutique amplifers there are boutique cabinets that
extract the maximum out of rare drivers, and that may
be your maxims, but just as likely some other maxims.
So what your cabinets work, loads of others do, better
or worse depends on a lot of things your not considering
though that does not prevent your approach being viable.
That it is viable does mean it is sensible in any strict sense.
Its just approach that seems to work, and there are lots of them.
However its simply not an approach that is commercially common,
because it is not optimum in any real optimum sense for design.
rgds, sreten.
Its simply like saying to people I can make your speakers better
by making them twice as big. They say twice as good ? I say
no, not possible, just better, most say well, no thanks.
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What is sensible or optimal regarding the performance of musical instrument speakers? The fact that when driven by a high impedance output amp, creating resonant peaks and dips all over the bandwith, is exactly the opposite of optimal from an audio reference standpoint.
Ok, I'm interested. My full time job is carrying out and teaching design, (in a different field, building structures and structural engineering).
So what, philosophically, is an 'optimum' design in the case of a guitar cab, and is it not a matter for personal preference? What in general, would take a working design that is 'viable', and does everything that its owner wants it to, and make it also 'sensible'?
My main point on this thread is ideas about how to add a bit of extra bass to a given cab/speaker set up, given that it has been determined that this is something that is wanted. How would you do it?
On the idea of adding Vb to Vas, if you would look at it I would be happy to post several sets of results. Im certainly not saying this corresponds to any fundamental theory, but it seems to work very well within the range that I use it, and if so, it gives a bit of insight. On the other hand, you will say that what I am using it for is nonsense anyway?
And if I can make something better by 'doubling' it, I might often do that, even iif it is not twice as good - diminishing returns are still returns.
So what, philosophically, is an 'optimum' design in the case of a guitar cab, and is it not a matter for personal preference? What in general, would take a working design that is 'viable', and does everything that its owner wants it to, and make it also 'sensible'?
My main point on this thread is ideas about how to add a bit of extra bass to a given cab/speaker set up, given that it has been determined that this is something that is wanted. How would you do it?
On the idea of adding Vb to Vas, if you would look at it I would be happy to post several sets of results. Im certainly not saying this corresponds to any fundamental theory, but it seems to work very well within the range that I use it, and if so, it gives a bit of insight. On the other hand, you will say that what I am using it for is nonsense anyway?
And if I can make something better by 'doubling' it, I might often do that, even iif it is not twice as good - diminishing returns are still returns.
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