Epi. Vol. Jr 5watt amp

[stealthdkm]

Hi ..Any ideas on what would be the best speaker in watts for the 5 watt epi, jr amp??? Dont i need to match the watts as close as i can ??? It takes 4-8 or 16 ohms. Lets debate this.

[olddawg]

My VJ is the head version. It is unmodified and even has the stock tubes still in it. I run mine through a Marshall 1965A 4X10 cabinet. I have played clubs with it. It looks sharp on stage and absolutely screams with a Rat and an OD. Having a lot of cone area makes a big difference. People cannot believe I am just using a 5 watt amp. My suggestion is to look around for a used 4X10 cab. If you just want to load the combo box at a reasonable price I would check out Eminence speakers. They're the best bang for the buck IMHO. If you want to go cheap there are some cheap Celestian clones that aren't to bad on eBay. You might want to search for a VJ forum and get their opinions. It's a very popular amp to mod and use.

[stealthdkm]

ok well i just figerd you pose to match the watts as close as pos. Closest ive found is a 15 watt weber .

[OC75]

IMO, Speaker sensitivity is especially critical in a small wattage amp. I use my Vj head with a vertical 2x12 loaded w 2-120w eminence,w a sensitivity of 102db. Sounds very loud. My combo is nowhere near as loud or assertive.

[stealthdkm]

Yeah the sensitivity is imp. But the watts got to be thats why they put the watts on there. Dont they make a 15 watt speaker with like 100 db sensitivity ?? ALSO your amp may be running hot becouse of the large amount of load it has to push.

[stealthdkm]

By the way what does Imo mean?? dont be calling me stuped.

[OC75]

IN MY OPINION, because I'm not an expert, just an enthusiastic student.

My amp does not run hot, and believe me, It gets pushed at max volume 100% of the time, as I also use an attenuator to control volume. I may be wrong, but I think power handling ratings on a speaker have nothing to do with how much load it puts on your amp. Could be wrong though.

[wyomingrocks]

I had a blues custom 30 epiphone for about 6 months. I also bought a 4x12 cab with Lady Luck 12" Eminence speakers in it. If you can find that cab, the prices are right on it. It is a solid cab and the speakers sound really good.

[olddawg]

Originally Posted by OC75

IN MY OPINION, because I'm not an expert, just an enthusiastic student.

My amp does not run hot, and believe me, It gets pushed at max volume 100% of the time, as I also use an attenuator to control volume. I may be wrong, but I think power handling ratings on a speaker have nothing to do with how much load it puts on your amp. Could be wrong though.

Mine is dimed and ODed for hours at a time through that Marshall 1965A cabinet. It does not run hot at all. It is a 16 ohm load on the 16 ohm output tap. It is loud enough to play with a live drummer and another guitarist most of the time within reason.

[stealthdkm]

Well im no expert nether. But it just makes since to me to match up the watts .. I know the ohms has to be right. Yeah can used 120 watt speakers but why ? If theres a 15 watt 98-100 db 12 inch . Anyway i hooked a 200 watt speaker to a 20 watt amp didnt help it a bit .The 20 watt speakers were very loud and clean. I just think your going to get more vibration out of a matched up amp and speaker . ok sorry for the bad spelling.

[olddawg]

Originally Posted by stealthdkm

Well im no expert nether. But it just makes since to me to match up the watts .. I know the ohms has to be right. Yeah can used 120 watt speakers but why ? If theres a 15 watt 98-100 db 12 inch . Anyway i hooked a 200 watt speaker to a 20 watt amp didnt help it a bit .The 20 watt speakers were very loud and clean. I just think your going to get more vibration out of a matched up amp and speaker . ok sorry for the bad spelling.

Better speaker efficiency + more cone area = more air movement = more apparent volume.

It takes 10 times the wattage to double the volume with everything else the same.

[OC75]

Originally Posted by stealthdkm

Yeah can used 120 watt speakers but why ? If theres a 15 watt 98-100 db 12 inch .

That could be. I use those speakers because that cab was initially put together to work with a 100w Laney. But my Valve Jr sounded so good through it, I made a set out of them. Not to be argumentative here, my original reply was not referring to watts, but to sensitivity.

[wyomingrocks]

My new favorite speaker I have been using for about a year are g12h heritage speakers, 30 watts I believe. I have not played them through an amp that they did not help at least for my ears. They are expensive but well worth it in my opinion.

[OC75]

REPRINTED FROM AN EXCELLENT THREAD ON HARMONY CENTRAL


Power rating: how many watts of amplified power can the speaker handle
Resonant Frequecy(fs): The frequency at which the driver resonates or naturally vibrates in free air
Frequency Range: The effective range the speaker is capable of producing
Sensitivity: SPL sound presure level measured in decibels. Higher number= more output/volume with less power needed
DC Resistance(Re): The DC resistance of the voice coil
Coil Inductance(Le): The inductance of the voice coil. Lower = better
Mechanical Q (Qms): characterizes the mechanical damping of the driver
Electrical Q (Qes): characterizes the electrical damping of the driver
Total Q (Qts): characterizes the combined electrical and mechanical damping. A speaker with a high QTS will have a very stiff suspension.
Vas: The stiffness of the suspension. Larger number= less stiff
Vd: The peak displacement volume of the cone
Cms: The compliance of the drivers suspension (its stiffness)
BL: The magnetic field strength. How much "oomph" the motor has
Mms: The mass or weight of the diaghram (cone)
Xmax: The maximum linear peak excursion of the cone
Sd: The area of the diaghram (cone)


So what can we tell by looking at some of these numbers? Well, we know that this driver has a strong motor since the BL force factor is quite high. The resonant frequency is 89hz and the xmax is 0.8mm which would lead me to believe that this will not be a driver suited for subwoofer duties (surprise). It should have a decent bottom end but it wont extend too far. IE- I wouldn't use it for a bass cabinet. We also know that it will be very efficient since the sensitivity is very high at 103db's. The power rating is spec'd at 75 watts.

Okay, here is where I think some people get hung up a bit too much on the numbers. Of the two numbers, power handling (watts) and sensitivity, which would you think is more important?

The answer is sensitivity. Consider this- to get a 3db increase in volume, it requires doubling the power supplied. Sensitivity is usually measured with 1 watt at a 1 meter distance. So, lets look at an example:

Speaker "A" has Power Handling of 256 watts and a sensitivity of 90db.
Speaker "B" has Power Handling of 128 watts and a sensitivity of 99db.

Which will produce more output at the rated wattage?

Speaker A-
1 watt = 90db
2 watts = 93db
4 watts = 96db
8 watts = 99db
16 watts = 102db
32 watts = 105db
64 watts = 108db
128 watts = 111db
256 watts = 114db

Speaker B-
1 watt = 99db
2 watts = 102db
4 watts = 105db
8 watts = 108db
16 watts = 111db
32 watts = 114db
64 watts = 117db
128 watts = 120db

In this case, speaker "A" would need to have 1024 watts of power supplied to it to match the output of speaker "B". But of course we know that the rating on speaker "A" was only 256watts and 1000+ watts applied to it would probably blow the cone right off of the spider ! Not to mention that even IF speaker "A" had a power handling of 1000 watts...how much more money would you have to spend for a more powerful amplifier just to match the same output of the far more efficient speaker "B" ?

So, what have we learned about SPL ratings ? The higher the sensitivity (SPL) of a given speaker, the more output it will produce with a lower amount of power needed. Using very efficient speakers allows you to save money on amplification and electricity and can save space by needing a much smaller footprint amplifier. This is a very important factor when building compact enclosures where space is a consideration. Its also good to know when building your own speaker cabinets to mate up to a head.

[olddawg]

You will still get more apparent volume with more cone area, ie more speakers. Yeah, it is better if they are efficient speakers. You simply move more air and have more projection.

[Bruce / Mission Amps]

Where is it written that doubling the power to a speaker is a +3dB increase in SPL?
And even with that, how much louder do we hear something that has an increase of 3dB sensitivity per watt?
I can never find this stuff when having a conversation with anyone.

[Enzo]

Why use a 50 watt speaker for a 10 watt amp?

If you had a shelf to hang on your wall, and it weighed 10 pounds, would you look for a shelf bracket to hold it up with a 10 pound rating, or would you look for something stronger?

Personally I wouldn;t look for a speaker that was just barely able to handle the power of my amp.

[Enzo]

A quick look in my Sound Systems for Worship book put out by Yamaha has on page 28:

"When you double the power of a signal, you increase the level by 3dB. When you double the voltage, you increase the power four times, which (is) a 6dB increase."

3dB louder is 3dB louder. ALL ELSE BEING EQUAL the difference in loudness of a 3dB more efficient speaker is the same difference made by doubling the power to the original speaker. 3dB is not much.

SO many people have the idea that a 60 watt amp is twice as loud as a 30 watt amp. it isn't. And that amazing 5 watt amp that sounds louder than expected through a larger cab? 5 watts would be half as loud as 50 watts.

[olddawg]

Originally Posted by Enzo

Why use a 50 watt speaker for a 10 watt amp?

If you had a shelf to hang on your wall, and it weighed 10 pounds, would you look for a shelf bracket to hold it up with a 10 pound rating, or would you look for something stronger?

Personally I wouldn;t look for a speaker that was just barely able to handle the power of my amp.

That would be a great analogy if a speaker was a shelf bracket. The 4X10 cabinet that I use is rated at 150 watts. I run this little 5 watt amp head through it and it sounds great. It pushes more air, has better projection, and has much more low end response. I doubt if I could use the amp in a club situation with a live drummer without it. It would be too wimpy through a tiny, tiny speaker no matter how efficient or what the power rating was. If I had to load it as a combo I would put the biggest cone speaker that I could fit into it.

[olddawg]

Originally Posted by Enzo

A quick look in my Sound Systems for Worship book put out by Yamaha has on page 28:

"When you double the power of a signal, you increase the level by 3dB. When you double the voltage, you increase the power four times, which (is) a 6dB increase."

3dB louder is 3dB louder. ALL ELSE BEING EQUAL the difference in loudness of a 3dB more efficient speaker is the same difference made by doubling the power to the original speaker. 3dB is not much.

SO many people have the idea that a 60 watt amp is twice as loud as a 30 watt amp. it isn't. And that amazing 5 watt amp that sounds louder than expected through a larger cab? 5 watts would be half as loud as 50 watts.

That was exactly my point. A 100 watt amp in theory is only twice as loud as a 10 watt amp. I know the math. I have been an ET for 30 years. However, as a head a VJ sounds great through a 4X10 cab to me. Much better and much more usable than through a single small speaker. That said a dimed Twin Reverb or a dimed JCM 800 always seems much more than two times louder than any 10 watt amp to me also.

[Enzo]

dawg, I was responding to the original poster, who was all concerned he needed to find a 5 watt speaker for his 5 watt amp - or whatever. My shelf bracket analogy was in support - pun intended - of using a speaker that could handle larger amounts being a good idea.

Forgive me if I am wrong, olddawg, but you seem to be reacting to my post in defense mode. I was actually agreeing with your points and supporting them. We have no disagreement I know of. Though I admit I had no idea you were an Extra Terrestrial.

[olddawg]

Originally Posted by Enzo

I had no idea you were an Extra Terrestrial.

That's funny. We might as well be from another planet anymore. No worries. An unfortunate reality of the internet is that people sometimes sound more serious in their post than they want to appear. I am in no way offended and have great respect for your vast experience, knowledge, and willingness to spend your valuable time to help and advice. This wattage, speaker, apparent volume conundrum has always baffled me because my personal experience does not always jibe with the math. The caveat, I guess, is the all other things being equal clause.

Cheers

[Enzo]

That is a very large clause.

[Carlsoti]

I've got a slightly modded EVJ that I use with my MIM strat. I recently picked up a Orange PPC12 for less than half off the original price. The speaker is rated at 60w. I think the three together sound great.

[OC75]

Without doubt....
My hotrodded ValveJr. amp plugged into it's combo speaker, is a 2/3....Same amp plugged into the 2x12 is a a solid 8. I suppose we could try to split hairs, but the facts are, these small amps respond well to having more/larger speakers to push. It really opens up a nice tone.

[Rick Erickson]

I'll throw down my $.02 worth here:
An amplifier doesn't care how many speakers it drives or how many watts they can handle. All it sees is an impedance at it's output terminals. If the impedance is correct it delivers it's maximum amount of power to the load. If the impedance is incorrect than the amp delivers less power than it is capable of and other bad things can happen due to the mismatch of the power tubes impedance to the reflected output transformer primary impedance. If the speaker(s) can't handle the amount of power the amp delivers to them they will likely fail. A speaker that can handle 200W is not necessarily a louder speaker than one that can handle only 15W. Every speaker has it's own unique tone - just like different amps, guitars and pickups each sound unique. A speaker that is very efficient won't necessarily sound "better" than a less efficient one, just louder. The only way to find the "right" speaker for your combination of amp, guitar, cabinet and playing style is to try various ones until you hit on a good one - just like trying out pickups in your guitar...

RE