Jensen MOD speakers

xander8280 · #1 05-22-2012, 09:51 PM

Anybody use these? Good for bass? I like vintage Jensen speakers, will these MOD speakers work good for bass? Sound good?

JimmyM · #2 05-22-2012, 10:05 PM

It's possible. I know some folks who use the 32 ohm Jensen Mod 50's to brighten up the 810e's that have unusually dark speakers (2000-2006). But it cuts down on power handling, so that's the tradeoff. They don't have a lot of power handling, and in some cases, the cab design will actually cut down on their power handling and overall usefulness for bass. It's definitely a case by case basis if they'll work for you.

billfitzmaurice · #3 05-23-2012, 06:16 AM

Quote:

Originally Posted by xander8280

will these MOD speakers work good for bass? Sound good?

Not by themselves, except at bedroom volume levels. They're guitar drivers.

xander8280 · #4 05-23-2012, 06:26 AM

Quote:

Originally Posted by billfitzmaurice

Not by themselves, except at bedroom volume levels. They're guitar drivers.

If I got four of them that are rated at 110 watts a piece do you think I could achieve better results?

billfitzmaurice · #5 05-23-2012, 06:38 AM

Quote:

Originally Posted by xander8280

If I got four of them that are rated at 110 watts a piece do you think I could achieve better results?

Wattage ratings are meaningless. Output is limited by driver displacement. The displacement of the Mod 10-50 is 50cc. That's one-third that of a good bass ten. To get the low end output of a good 410 you'll need twelve Mod 10-50s.

BurningSkies · #6 05-23-2012, 06:59 AM

Quote:

Originally Posted by billfitzmaurice

Wattage ratings are meaningless. Output is limited by driver displacement. The displacement of the Mod 10-50 is 50cc. That's one-third that of a good bass ten. To get the low end output of a good 410 you'll need twelve Mod 10-50s.

Now you go and say that, all the TB kids will be cobbling together their 8x12 cabinets.

christw · #7 05-23-2012, 08:40 AM

Quote:

Originally Posted by BurningSkies

Now you go and say that, all the TB kids will be cobbling together their 8x12 cabinets.

I'm going to go build a 10x12 Mod bad cab for my highs and a 6x15 cab for lows.

xander8280 · #8 05-23-2012, 01:34 PM

By the power handling being weak are we talking that they fart on yah when you turn it up too high? Or just don't get any louder

BurningSkies · #9 05-23-2012, 01:38 PM

Quote:

Originally Posted by xander8280

By the power handling being weak are we talking that they fart on yah when you turn it up too high? Or just don't get any louder

Distortion will set in fairly quickly, especially if lows are applied...and if the xmax is low, the xlim will also be fairly low, meaning mechanical harm to the drivers.

Mr. Foxen · #10 05-23-2012, 01:45 PM

Bear in mind that lows aren't essential to a good bass sound, depending on context, but it will be a pretty guitary bass sound. Or if you have lots, it will be like using the old SVT cabs, squareback type.

xander8280 · #11 05-23-2012, 01:50 PM

Wouldn't porting a cab/tuning it help with the displaced volume? I mean, I wouldn't stick a bunch or holes in the cabinet; but a vent hole in the center of the 4 drivers might help. I'll experiment. I need the cab to be able to handle 250 watts from my head and the volume won't be dimed. Most likely around one or two volume. I never need to go louder.

billfitzmaurice · #12 05-23-2012, 01:51 PM

Quote:

Originally Posted by BurningSkies

if the xmax is low, the xlim will also be fairly low.

Not necessarily. Bass drivers tend to have around a 2:1 xlim to xmax ratio, because they have high xmax. Guitar drivers tend to have 4:1 or higher xlim to xmax ratios, because the xmax is so small. This means that guitar drivers can withstand a lot more overshoot, because they're intended to be driven into heavy clipping, bass drivers are not.

Quote:

By the power handling being weak are we talking that they fart on yah when you turn it up too high? Or just don't get any louder

Both.

xander8280 · #13 05-23-2012, 01:52 PM

What's a good bass drivers Xmax?

Mr. Foxen · #14 05-23-2012, 01:52 PM

Quote:

Originally Posted by xander8280

Wouldn't porting a cab/tuning it help with the displaced volume? I mean, I wouldn't stick a bunch or holes in the cabinet; but a vent hole in the center of the 4 drivers might help. I'll experiment. I need the cab to be able to handle 250 watts from my head and the volume won't be dimed. Most likely around one or two volume. I never need to go louder.

Speakers aren't really suited to a vented enclosure, just make it a bunch easier to tear them up. The air pressure of a sealed cab will make their survival much easier.

billfitzmaurice · #15 05-23-2012, 01:55 PM

Quote:

Originally Posted by xander8280

What's a good bass drivers Xmax?

4.5mm

Quote:

I need the cab to be able to handle 250 watts from my head and the volume won't be dimed

Forget about watts. They do not define output. Speaker frequency response, sensitivity and displacement do.

BbbyBld · #16 05-23-2012, 01:56 PM

Quote:

Bear in mind that lows aren't essential to a good bass sound, depending on context, but it will be a pretty guitary bass sound. Or if you have lots, it will be like using the old SVT cabs, squareback type.

I agree with you, except that specs-wise, they are nothing like the square magnet SVT speakers I had. I bought a vintage SVT 810 with some blown speakers and I ran specs on the remaining good ones. I then looked at the MOD speakers because they were supposed to be good replacements, but I did not use them because they did not seem to be on paper. They may work just fine, but I wanted a more authentic sound.

In case anyone is interested, here are the specs. I measured from a 1978 SVT square magnet Eminence speaker for comparison purposes:

Qts=0.919
Qms=3.775
Qes=1.215
Vas=1.568 cu. ft.
Fs=59.37Hz
SPL=90.87(funny...I figured this would be higher)
Z=40 ohms
DCR=26.1 ohms

Mr. Foxen · #17 05-23-2012, 02:02 PM

Were you comparing 30 year old used speakers with new MOD ones?

xander8280 · #18 05-23-2012, 02:09 PM

Quote:

Originally Posted by Mr. Foxen

Were you comparing 30 year old used speakers with new MOD ones?

Yes, I like the power handling of old jensens with bass. I was thinking maybe these new MOD's are like the classic tuck n roll jensens that could do guitar AND BASS. LOL, thanks for all the replies guys. Much thanks. I need to get back into my physics studying and learn my stuff.

billfitzmaurice · #19 05-23-2012, 02:09 PM

Quote:

Originally Posted by BbbyBld

In case anyone is interested, here are the specs. I measured from a 1978 SVT square magnet Eminence speaker for comparison purposes:

Fs=59.37Hz

Mod 10-50 fs is 109Hz, so right there you've got an octave lost with them. Even the C12Ns used by Fender and others (as in my '65 Bassman) have a 112Hz fs and 1mm xmax. Today we wouldn't consider them for a moment for electric bass.

BbbyBld · #20 05-23-2012, 02:26 PM

Quote:

Were you comparing 30 year old used speakers with new MOD ones?

Again, I went by specs alone. I never listened to the MODs. Obviously, mine were broken in, but I would hope that Jensen breaks in speakers before THEY list specs.

At any rate, I was able to obtain a 32 ohm 70's Eminence spec. of unknown vintage. Speakers can vary a lot. For comparison purposes:

Qts=0.449
Qms=7.361
Qes=0.478
SPL=93.30
Vas=2.017 cu. ft.

...and that's all I have.

I'm not telling anyone not to buy the MODs. I'm saying that I don't think they are an authentic replacement going by specs alone. On the other hand, I believe that Electro-Harmonix makes a replacement speaker, and I remember the specs. on that one looking A LOT closer.