#1
So I heard a half stack can easily achieve around the 120dB range. The problem is my Randall RG1003 only can get to 101dB before distorting the speakers. I can't have any mids because it distorts the speakers. Do I need a new cabinet, amp, are my blackouts too hot, is it not meant for 120dB, like what's going on here? I've tried turning the gain down, volume in my guitar and the speakers distort after 101dB. And why am I getting radio signal through my amp?
Last edited by AOD3 at Nov 29, 2014,
#2
Quote by AOD3
The problem is my Randall RG1003 only can get to 101dB before distorting the speakers.
Why do you care to reach 120dB?
How can you tell distortion starts at 101dB(SPL, I'm assuming)?
How can you tell it's the speaker(s) distorting the signal?
Quote by AOD3
Do I need a new cabinet, amp, are my blackouts too hot, is it not meant for 120dB, like what's going on here?
The right cab would get you to 120dB, yeah.
A new amp with the same cab will likely not, whatever the power.
No p/ups don't matter shit here, this is a matter of power.
Amps aren't "meant" for reaching a certain volume level, they are meant to put out a certain amount of power that gets sent to speakers, and the speakers are what "transforms power in volume", to say it in a simplistic way.
Quote by AOD3
I've tried turning the gain down, volume in my guitar and the speakers distort after 101dB.
If the speakers distort there, they are the problem.
Though again, how can you be sure it's them distorting your signal?
Quote by AOD3
And why am I getting radio signal through my amp?
You are using the wrong cable somewhere, likely from your guitar to your amp.
Get a proper instrument cable.

Also are you using a proper power cable to go from the amp to the cab?
Name's Luca.

Quote by OliOsbourne
I don't know anything about this topic, but I just clicked on this thread because of your username :O
Quote by Cajundaddy
Clue: amplifiers amplify so don't turn it on if you need quiet.
Quote by chrismendiola
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#3
Quote by AOD3
So I heard a half stack can easily achieve around the 120dB range. The problem is my Randall RG1003 only can get to 101dB before distorting the speakers.


A 100W tube half stack can sometimes crank out 120dB. And it will definitely be distorted when it's doing that. And it will not be producing bottom end at that volume; all the power will be used to get 1000Hz (or so) coming out of the amp.

One of the main factors involves your speaker cabinet -- if you have Celestion Rocket 50's in your cabinet, you will produce about 6 dB less than a cabinet with Vintage 30's due to the difference in efficiency. Generally, the more efficient the speaker, the louder it will be for a single watt of power.

Another involves the impedance of your speaker cabinet. In particular with solild state amps, a 16 ohm speaker cabinet might only allow your amplifier to generate 1/4 of the power that a 4 ohm load will allow. Your Randall is designed to put out 100W at 4 ohms. If you're running a 16 ohm cabinet, your Randall may only be putting out 25 watts. If your speakers are inefficient (like the difference between the Vintage30's and the Rocket 50's, your system will be putting out the equivalent of 6 watts at its rated "clean" settings.

Meanwhile, a tube amp run well into distortion might actually be putting out half again or as much as double its rated power (a lot of this depends on the efficiency of the transformers, the gain levels generated by the preamp, and the kind of tubes being run) when run at maximum. And so you may be looking at 150-200W.

There's also directionality. A 4x12 beams treble. Anything above about 500Hz, actually. That's due to the form factor of the 4x12. Off axis you'll hear noticeably less treble. On axis, the highs will split your skull. Since the highs require considerably less power to produce (a speaker is required to move four times as much air to produce a note one octave down at the same volume), the position of your dB meter and the frequencies of the notes being put out will be important if you're actually measuring this stuff.
#4
It's just a 200 watt rg412. It's certainly no mesa but it matched so I assumed it could do that. And all of my cables are correct.
#5
Quote by dspellman
A 100W tube half stack can sometimes crank out 120dB. And it will definitely be distorted when it's doing that. And it will not be producing bottom end at that volume; all the power will be used to get 1000Hz (or so) coming out of the amp.
With a pair of v30's you'd be able to put out 121 to 124dB @ 1m using 64w.

Now, power ratings in guitar amps are made up and speakers sensitivity specs may well be generous, but if ya ask me it's exaggerated to say you couldn't produce that volume keeping the power amp clean.
Quote by AOD3
It's just a 200 watt rg412. It's certainly no mesa but it matched so I assumed it could do that. And all of my cables are correct.
That cab has no name speakers which probably have a fairly low sensitivity, plus it has an 8ohm mono input, and IIRC the amp puts out 100w @ 4ohm, so you'd theoretically be getting 50w from your amp with that cab.

Though, again, how can you be sure it's the speakers distorting the sound?
Name's Luca.

Quote by OliOsbourne
I don't know anything about this topic, but I just clicked on this thread because of your username :O
Quote by Cajundaddy
Clue: amplifiers amplify so don't turn it on if you need quiet.
Quote by chrismendiola
I guess spambots are now capable of reading minds.
#6
Because they move like crazy and it does this for all 3 channels. Maybe I'm wrong but that's just what I think. I mean I'm using distortion anyway but this only happens at high volumes. Nothing in the loop. I was going to get another cabinet to kind of ease the pressure on the speakers but that obviously would increase the amount to drag around.
Last edited by AOD3 at Nov 29, 2014,
#7
I don't get:

1. Why in gods name would you every want/have to run your amp that hard?
2. What kind of noise meter are you using to take your measurements? Part of my jobs is taking noise measurements around our mine, so I'm pretty familiar with these device's, and I know they're not cheap. They also easily go out of calibration, which is why its recommend that you check its calibration before each use. The calibrating device isn't cheap either.
Guitars:
PRS Custom 24
Gibson Les Paul 60's Tribute
85' MIJ Strat
97' Snakepit Les Paul
LP Traditional 1960 Zebra
MIJ Tele
MIA Strat

Amps:
Silver Jubilee 2525
Peavey Ultra 112
Jet City JCA50H
66' Bassman
Pink Paisley Princeton RV
74' Vibro Champ
#8
Quote by red.guitar
I don't get:


2. What kind of noise meter are you using to take your measurements? Part of my jobs is taking noise measurements around our mine, so I'm pretty familiar with these device's, and I know they're not cheap.


If you're working at a mine, you're probably using hardened industrial stuff. Expensive.

For studio and live work, you can do a surprisingly good job with an iPhone and a free app. No, seriously. If you were going to step things up to a pro level, you'd end up spending more for the mike system for it, but that's mostly for wide-band frequency reading (like an RTF setup). Check out some of the products at Studio Six Digital http://www.studiosixdigital.com/.

An iTestMic is around $229, the iPrecisionMic more like $1100.
#9
Cool! I'll DL the app, and try it against my meter for shits and giggles tomorrow.

I still don't know why you would want/need an amp to go that loud. I've stood next to a main 66" vent fan that puts out a steady 107dBa, and I'll tell you, that Fu@ker is loud! I wouldn't be able to comfortable stand there for more then 10mins or so. And that's with my custom fit hearing protection in. You're going to start getting hearing loss above 85dBa, and you'll really start to feel it at 90ish. You'll need double hearing protection (plugs and muffs) @105dBa.
Guitars:
PRS Custom 24
Gibson Les Paul 60's Tribute
85' MIJ Strat
97' Snakepit Les Paul
LP Traditional 1960 Zebra
MIJ Tele
MIA Strat

Amps:
Silver Jubilee 2525
Peavey Ultra 112
Jet City JCA50H
66' Bassman
Pink Paisley Princeton RV
74' Vibro Champ
Last edited by red.guitar at Nov 29, 2014,
#10
That's what I've been using. And I've got really good hearing protection.
Last edited by AOD3 at Nov 29, 2014,