cab problem

[Jacko]

well the amp itself is 6 years older than me, but i do not like modern music, im a van halen, dokken, lynch mob, basicly anything with lynch fan. I love the sound of this amp, i can get a close to early van halen sound out of it at low levels, and a very lead sound with it around 5. my only complaint is the damn low end from the speakers, its not tight and its not smooth, its saggy and over powers everything at the low levels, though everything smoothes out around 5 i cant practice that loud.

 

[Outlaws]

well i dont know if this really helps but my amp is a 120 watt peavey vtm, all tube, running into the hartke amp with 4 30 watt "celestion designed" speakers. even though on the back of the amp over the outlet cord it says 400 watts.

i had band practice today, and when i had the post gain on about 5 the low end thud went away but the amp sounded very bitey and high, not warm like it is at lower volumes.

could the fact that you said when i palm mute the amp goes over 120 watts have something to do with it? should i find something with 70 watt speakers?

Well, Celestion V30's are actually 60 watts. So four of them can handle 240 watts. But the thing is, tube amps do not output at what they say. Marshall's SLP 100watt amp is NOT to be used with one 100watt Greenback cab because it can, and will, peak out at 180watts when cranked.

You should have enough there for that amo though. Do you have the ohms matched?

 

[Outlaws]

wait....whats this Fender cab you linked to and this Hartke?

 

[Jacko]

yes i have the ohms matched, and i have 4x10s not 12s, i played with my band today, it sounded pretty good, then i noticed it was on 4 ohms, so i guess its only at 16 ohms that i have the problem.

the hartke cab i have in the link is my current cab, the ashdown was the one i was asking about, i didnt put up a link to any fender cab.

 

[Outlaws]

yes i have the ohms matched, and i have 4x10s not 12s, i played with my band today, it sounded pretty good, then i noticed it was on 4 ohms, so i guess its only at 16 ohms that i have the problem.

the hartke cab i have in the link is my current cab, the ashdown was the one i was asking about, i didnt put up a link to any fender cab.

Ya, bass cab speakers generally sound difference and more woofy than gutiar speakers becuase they are voiced differently...ie not for guitar.

What was at 4 ohms and what was at 16?

 

[Outlaws]

nope it was a guitar cab, this is what i got
http://samash.com/catalog/showitem.asp?ItemPos=3&TempID=4&STRID=163225&Method=3&CategoryID=134&BrandID=0&PriceRangeID=0&PageNum=0&DepartmentID=1&pagesize=10&SortMethod=3&SearchPhrase=&Contains=&Search_Type=SEARCH&GroupCode=

That looks like a Fender to me.

 

[easychair]

They are spec'd differently, that is the problem for someone who doesn't know this. This is the same reason that a 100 watt tube guitar amp will be louder than a 100 watt solid state guitar amp. The printed specs on the two
are not analogus to each other, your comparing apples and oranges.

Yoiks, another old chestnut. Power is power, tube amps seem louder due to being more dynamic and having more harmonic content and different tone, but they aren't, if they are putting out the same power to the same speaker. 50W is 50W is 50W. Check it on your DVM, and decibel meter, if you want. I know I have. A diesel car going 50mph is just as fast as a gas car going 50mph. The gas car might accelerate faster, and have a higher top speed, but they are both going 50mph when they are both going 50mph. An amp putting out 50W is as loud as any other putting out 50W.

The specs also may be inaccurate regarding peak power, but there isn't one set of specs for tube and one for solid state, nor is there one set for PA speakers and one set for guitar speakers.

If everything were spec'd to the same standard, this wouldn't be an issue. Everything isn't, so it is.

That is the issue, not the differences in the speakers. Two speakers that spec the same using the same standards will perform the same, be they PA or guitar speakers. There aren't special specs for guitar speakers, just inaccurate and incomplete ones.

Some makers follow AES (like Eminence and JBL) some don't, like Celestion and Fender. They give power ratings with no mention as to whether they are peak, RMS, or program. Looking at the specs for an Eminence or JBL guitar speaker gives you the exact limits of the speaker.

The bottom line is, if you plug a 120 watt guitar head into a cabinet that is supposed to handle 120 watts of clean power, you will roach the speakers. If you plug it into a cabinet with 120 watts of celestions (like he has), the speakers will be fine.

Again, it comes down to specs, not construction or type of signal you throw at the thing. 120W peak? 120W program? With no reference point, you just can't tell. I can only assume Celestions are either rated conservatively, or with program not peak specs.

But you are right, his Celestion cab will probably be fine.

 

[Outlaws]

Yoiks, another old chestnut. Power is power, tube amps seem louder due to being more dynamic and having more harmonic content and different tone, but they aren't, if they are putting out the same power to the same speaker. 50W is 50W is 50W. Check it on your DVM, and decibel meter, if you want. I know I have. A diesel car going 50mph is just as fast as a gas car going 50mph. The gas car might accelerate faster, and have a higher top speed, but they are both going 50mph when they are both going 50mph. An amp putting out 50W is as loud as any other putting out 50W.

The specs also may be inaccurate regarding peak power, but there isn't one set of specs for tube and one for solid state, nor is there one set for PA speakers and one set for guitar speakers.



That is the issue, not the differences in the speakers. Two speakers that spec the same using the same standards will perform the same, be they PA or guitar speakers. There aren't special specs for guitar speakers, just inaccurate and incomplete ones.

Some makers follow AES (like Eminence and JBL) some don't, like Celestion and Fender. They give power ratings with no mention as to whether they are peak, RMS, or program. Looking at the specs for an Eminence or JBL guitar speaker gives you the exact limits of the speaker.



Again, it comes down to specs, not construction or type of signal you throw at the thing. 120W peak? 120W program? With no reference point, you just can't tell. I can only assume Celestions are either rated conservatively, or with program not peak specs.

But you are right, his Celestion cab will probably be fine.

50 watts is not 50 watts.

This is measured until they start to distort. There is a lot of extra volume that can be achieve when the amp starts to clip because the overal average volume is still increasing as the clipping gets harder.

Solid state does not do that because it would sound like complete dogshit.

 

[easychair]

Well, Celestion V30's are actually 60 watts. So four of them can handle 240 watts.

There ya go. A 120W cab, but 120W program. It's peak rating is 240W. No special distortion-handling power rating, just accurate specs.

 

[Outlaws]

There ya go. A 120W cab, but 120W program. It's peak rating is 240W. No special distortion-handling power rating, just accurate specs.

But I highly doubt a 120 watt tube amp can peak at 240 watts.

They call them Vintage 30's because they were updated designs of th G12H 30 watt speaker, but everyting has gotten more powerful since those were originally designed so they upped the power handling.

 

[easychair]

You are a fine fucking idiot.

50 watts is not 50 watts.

Tube amps are measured until they start to distort. There is a lot of extra volume that can be achieve when the amp starts to clip because the overal average volume is still increasing as the clipping gets harder.

Solid state does not do that because it would sound like complete dogshit.

No, really?

If both amps are putting out 50W without clipping, there won't be a volume difference, but the tube amp will sound louder anyway, due to the harmonic distortion content of the signal, among other things. Tube amps generally run pretty high distortion levels, even when "clean". That was my point, that there isn't one set of watts for tubes and one for solid state.

 

[easychair]

But I highly doubt a 120 watt tube amp can peak at 240 watts.

Exactly. That is why the cab is safe, not because the guitar speakers have special distortion handling features.

 

[Outlaws]

No, really?

If both amps are putting out 50W without clipping, there won't be a volume difference, but the tube amp will sound louder anyway, due to the harmonic distortion

Harmonic distortion is a byproduct of clipping.


Its not an imaginary thing, amps can exceed their listed RMS...thus producing more real volume.

 

[easychair]

Harmonic distortion is clipping.

No, it isn't. Harmonic distortion from clipping is it's own thing, and is an inherent component of clipped or square waves. It is separate from the harmonic distortion developed in a device.

All electronics develop some amount of harmonic distortion. Mixers, amps, preamps, whatever. It is marked as %THD, total harmonic distortion.

Distortion is any deformation of the waveform from the inputs of a device to it's outputs. Harmonic distortion is generated by the simple act of a signal passing through any circuit.

THD rises as signal level rises. That's the reason the ratings are given for a certain level, such as .001% THD@0db any input to any output, all channels unmuted, pretty common for a mixer.

The maker is telling you that the device will give a gauranteed level of clean signal at a certain level, beyond that level THD rises.

 

[Outlaws]

You just don't get that tubes amps clip themselves into sounding louder. ANd they start clipping well before we can hear it. Like Fender amps....ever heard them described as "shimmering"? You get where I am going....

A 100 watt SLP Marshall that can peak at 180 watts will probably be outputting consistantly at 120-150watts. I don't know of any 100 watt solid state amps that can lay claim to that. Feel free to google some up though.

(You left out even and odd order harmonics in that rant.)

 

[easychair]

Harmonic distortion is a byproduct of clipping.


Its not an imaginary thing, amps can exceed their listed RMS...thus producing more real volume.

Jeez, you keep editing all the mean parts out.

Yes, HD is a byproduct of clipping, it's also inherent in electronics.

Yes, you are right. Amps can exceed their RMS ratings, both tube and solid state. In solid state, they are measured with regard to a certain %THD, and can exceed that before clipping, just with more distortion. I've got a Crown PB2 rated for 325W@8ohms, that will kick out 460W before it clips. Is it louder than any other amp with the same rating? Not at the same power output, but it may have a higher max output.

Tube amps are rated at a certain point before clip as well, and also, older tube amps are individuals, not all the same, and were often pretty conservatively rated. I have seen many a tube amp that puts out way more than it's rated for, and way less, too. That's just manufacturing drift, not some mysterious thing. Newer tube stuff is much more consistent, if still not properly rated all the time.

And you are right, a clipping tube amp has a much higher apparent volume than a non-clipped amp, because of the compression.

I don't disagree with that. Farview just seemed to be saying that tube amps and guitar speakers have some different kind of ways they are measured, when it's no mystery, just inaccurate and misunderstood specs, and that damned myth that distortion destroys speakers.

 

[easychair]

You just don't get that tubes amps clip themselves into sounding louder. ANd they start clipping well before we can hear it. Like Fender amps....ever heard them described as "shimmering"? You get where I am going....
)

Of course I do. Not all harmonic distortion is from clipping, though. As far as Fenders, you do realize Leo Fender spent much of his time trying to ensure that his amps wouldn't distort or clip, right?

 

[easychair]

A 100 watt SLP Marshall that can peak at 180 watts will probably be outputting consistantly at 120-150watts. I don't know of any 100 watt solid state amps that can lay claim to that. Feel free to google some up though.
)

You realize it's less than 2db from 120W to 180W. I'd be more impressed if you could find a guitar player who only has 2db dynamic range.

No matter how much an amp actually puts out, versus it's rating, is beside the point. There are reasons for discrepancies between ratings and actual output, none of which have anything to do with whether an amp is tube or solid state.

Two amps, putting out 5W each, will be the same actual volume, tube or solid state.

 

[ggunn]

The idea that distortion kills speakers is a busted myth. It was the prevailing view for thirty years, it is not anymore, as someone finally did the research to find out what was really happening.

Can you site a source and lead me to that research? I'd like to read more about it than just what some guy says (no offense) on an internet forum.

Thanks,

 

[Farview]

You are all making my point. Your just busting my balls for the way I said it. If everything were measured the same way, you could mix and match equipment without problem. It's not, so you can't.

No, guitar speakers don't have any special distortion handling capability, they are just spec'd way below what they will take. Like the vintage 30 being 60 watts, most people run around thinking that they are 30 watt speakers.

And no, tube guitar amps do not have any supernatural reserve power that will magically kill flimsy PA speakers with a single power chord, but they do put out way more power than they say they have. That is what kills the speakers, the fact that in the guitar world you think you have a 100 watt amp feeding 4 30 watt speakers. If you take out the celestions and put in 4 30 watt (pick your accurately spec'd speaker brand) you will blow them up.

Now in answering a question from a guy who can't figure out why his cheesy 4 10 cabinet can't handle low end, I decided not to go into all this technical stuff and give him an answer that is easy to grasp and, taken in the spirit with which it was posted, accurate enough to keep him out of trouble.

Most guitar players don't have an EE degree and don't understand the finer points of why any of this is the way that it is. Hell, I keep running into guys who are using shielded cable for speaker cable and have the impedance selector set wrong. Look back at Jackos post after we started getting into this, all he grasped was that the amp is putting out more power on the palm mutes and he thinks he only has 30 watt speakers. Now we have confused him. Nice.