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]

blues custom

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]

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]

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]

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]

another thought

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.