Vintage P12N sound? or damaged?

[Natstrat79]

This post is in reference to the vintage Jensen P12N NOT the Italian Jensen "reissue". Recently I bought a 1960 ampeg rocket and when I got it the speaker had a large tear in it so I replaced the speaker with a 1960 P12N that I found that seemed to be in good condition overall but had some small radial cracks around the edges. This amp sounded good cranked but at low volumes it sounded extremly thin nasally and lacking any bass response. I always assumed it was the amp but never tried another speaker untill now. Recently I tried the P12N in a 1960 Ampeg mercury I just bought and ended up with the same results great cranked but extremely thin at any other volume. So I stuck a vintage P12r I had laying around in the rocket and amazingly it sounded great at any volume. I'm thinking that the P12N was the problem. Is this the typical sound of a P12N with a lower wattage amp? Or, is there something wrong with this speaker. I don't want to bother having it reconed if I'm going to end up with the same results.

[JohnnyCrash]

A typical P12N likes a loud amp or high volumes.

I'd try a P12Q as a happy medium between the P12R and the P12N, unless you're sticking with the P12R... how many watts is the amp?

[Natstrat79]

It's pretty similar to a tweed deluxe so around 12 watts and correct me if I'm wrong but I thought the vintage P12N was only rated for around 18 watts. At least thats what the old Jensen flyer I found on the internet from 1955 says. Is it really that hard for a 12watt amp to push this speaker?

[Natstrat79]

I guess I should be more specific. It's not that I'm expecting this speaker to get any breakup. Ive tried fairly high wattage speakers in deluxe sized amps before and while they sounded clean they still produced a full sound at low volumes. With the P12N its like the bass and low mids are being removed and all thats left is a thin sterile sound.

[JohnnyCrash]

Originally Posted by Natstrat79

It's pretty similar to a tweed deluxe so around 12 watts and correct me if I'm wrong but I thought the vintage P12N was only rated for around 18 watts. At least thats what the old Jensen flyer I found on the internet from 1955 says. Is it really that hard for a 12watt amp to push this speaker?

If it were truly an 18 watt speaker - YES. Amp power was in wattages BEFORE the onset of distortion/clipping. So, you can expect a 12 watt amp to push a 15-18 watt speaker pretty hard when cranked up and distorting.


Perhaps they changed power ratings after the '55 flyer. The P12N is the higher wattage version of their AlNiCo 12" so I am not sure why the old catalog shows it as 18 watt.

For instance, the current reissues are P12R (25 watts), P12Q (35 watts), and P12N (50 watts)...

When you put in a P12R it sounded much better... how many watts does that old flyer say a P12R is? The numbering scheme still seems to indicate the P12N is higher wattage and probably really 50 watts.

This still leads me to recommend a P12R or a P12Q.

Originally Posted by Natstrat79

I guess I should be more specific. It's not that I'm expecting this speaker to get any breakup. Ive tried fairly high wattage speakers in deluxe sized amps before and while they sounded clean they still produced a full sound at low volumes. With the P12N its like the bass and low mids are being removed and all thats left is a thin sterile sound.

Have you tried these particular P12N's in a "Deluxe sized amp"?

Sometimes its not just the wattage. In this case I actually do think the power handling between the P12R and the P12N combined with the amp you're running them with is the issue, but generally most circuits can sound good at lower volumes with any speaker (although there are some speakers and/or amps that just plain like to be cranked).

[Natstrat79]

Originally Posted by JohnnyCrash

If it were truly an 18 watt speaker - YES. Amp power was in wattages BEFORE the onset of distortion/clipping. So, you can expect a 12 watt amp to push a 15-18 watt speaker pretty hard when cranked up and distorting.

Exactly, I knew this, thats why I was thinking that if it were truly rated at 18 watts that a tweed deluxe on edge is going to be pushing this speaker pretty well.

Originally Posted by JohnnyCrash

Perhaps they changed power ratings after the '55 flyer. The P12N is the higher wattage version of their AlNiCo 12" so I am not sure why the old catalog shows it as 18 watt.

For instance, the current reissues are P12R (25 watts), P12Q (35 watts), and P12N (50 watts)...

I was kind of thinking the same thing but I couldn't dig up any other information as to the actual power handling capabilities of the vintage jensens . The flyer says that the P12R is 12watts. It's hard to make a comparison to the new "reissues" though since the only thing they have in common with the old jensens is the name. It does seem as though the P12N should be more than that though since fender did use them in the high powered tweed twin. Even though fender had problems with this speaker blowing in that amp they were able to handle 80watts of clean power for some amount of time. Even if this speaker is a 50watt speaker it just doesn't seem right that I should have to have nearly 18watts into it before its sound starts to fill out. The sound I'm getting is like if a tweed deluxe were to have a bass control and you turned it to zero. And this isn't just happening at 2 or three on the volume control but at 6 or 7 where this amp is just at the edge of breakup.

Originally Posted by JohnnyCrash

Have you tried these particular P12N's in a "Deluxe sized amp"?

See thats the problem I've never had any experience with other P12N's before but I have used higher power ceramic speakers such as the eminence cannabis rex and some weber ceramics with both champs and deluxe sized amps and they've always sounded "full" even at low volumes with a champ. Maybe it is just the fact that this speaker doesn't get along well my amps who knows. I'm still not completely convinced its a speaker wattage issue, though you may be right. I just keep thinking that if I had a P12R and a P12N in identical amps that while the P12r should in theory sound "warmer" at lower volumes than the P12N since its being pushed closer to its max power handling shouldn't the P12N still have better bass response than the P12R? It just seems weird that at the same on the edge of breakup volume that I can feel the vibration of the P12r's bass in the soles of my feet but the P12N doesn't even come close to producing the same amount of bass and low mids at the same volume untill the amp is cranked. Thats why I was wondering if anyone else had experience with the P12N in smaller amps before I went ahead and had it repaired thinking there was something wrong with it when there wasn't.

[JohnnyCrash]

Originally Posted by Natstrat79

See thats the problem I've never had any experience with other P12N's before but I have used higher power ceramic speakers such as the eminence cannabis rex and some weber ceramics with both champs and deluxe sized amps and they've always sounded "full" even at low volumes with a champ. Maybe it is just the fact that this speaker doesn't get along well my amps who knows. I'm still not completely convinced its a speaker wattage issue, though you may be right. I just keep thinking that if I had a P12R and a P12N in identical amps that while the P12r should in theory sound "warmer" at lower volumes than the P12N since its being pushed closer to its max power handling shouldn't the P12N still have better bass response than the P12R? It just seems weird that at the same on the edge of breakup volume that I can feel the vibration of the P12r's bass in the soles of my feet but the P12N doesn't even come close to producing the same amount of bass and low mids at the same volume untill the amp is cranked. Thats why I was wondering if anyone else had experience with the P12N in smaller amps before I went ahead and had it repaired thinking there was something wrong with it when there wasn't.

1. The new Jensen Reissues are great speakers... don't be too shy to try them. I absolutely love them.

2. AlNiCo speakers compress and become less efficient when pushed hard... ceramics do NOT do this. This may also be part of the wattage issue.

Simply saying it is a wattage issue isn't that simple. The voice coil, magnet, and other things are involved in the differences in wattage... then combine the voice coil reducing the AlNiCo driver's efficiency when really cranking (VC sorta creates its own magnetic field), and you've got a recipe for wattage becoming a little more important in AlNiCo speakers.


ALNICO
As the voice coil moves in response to the signal, the VC generates a magnetic field of its own that slightly demagnetizes the AlNiCo magnet, the speaker then becomes less efficient, the VC moves less, and compression kicks in.

[Natstrat79]

Originally Posted by JohnnyCrash

1. The new Jensen Reissues are great speakers... don't be too shy to try them. I absolutely love them.

2. AlNiCo speakers compress and become less efficient when pushed hard... ceramics do NOT do this. This may also be part of the wattage issue.

Simply saying it is a wattage issue isn't that simple. The voice coil, magnet, and other things are involved in the differences in wattage... then combine the voice coil reducing the AlNiCo driver's efficiency when really cranking (VC sorta creates its own magnetic field), and you've got a recipe for wattage becoming a little more important in AlNiCo speakers.


ALNICO
As the voice coil moves in response to the signal, the VC generates a magnetic field of its own that slightly demagnetizes the AlNiCo magnet, the speaker then becomes less efficient, the VC moves less, and compression kicks in.

1. I didn't mean to discount the newer jensen reissues Ive never actually tried them. I only meant that they weren't really accurate comparisons specification wise to their vintage counterparts.

2. I think we're kind of thinking the same things I'm just not expressing them that well. I realize it's not just a wattage issue and thats what makes this so hard. The P12N still has a larger voice coil 1.5" verus the P12R's 1" and a larger magnet, differences in efficiency, frequency response, etc. The problem I'm having wrapping my mind around this problem is that I'm talking about lower volumes before theres much compression or the wattage would be as much of an issue as it could be. At the volumes I'm talking about I guess maybe I wrongly figured that voice coil size, strength of the magnet, and the energy it takes to get the voice coil moving would be more important than alnico versus ceramic. I'm not talking about driving the P12N anywhere near compression. The sound of this P12N at any volume but cranked is really like you took all the bass and low mids and severely attenuated them then once you reach a certain volume level theres a sudden onset of bass and low mids. I've never experienced this before even in speakers with larger voice coils and more robust magnets that I figured would take more energy to move than the P12N.

I'm here to learn so anyone feel free to correct any errors in my thinking please. I would also really love to hear any first hand experiences with this speaker in deluxe sized amps.