Polytone 15“ Speakers

[maxiim]

i also found the spec sheet of the recommended standard

Eminence Beta 15




compared to the EVM15L

and the dimensions look pretty much identical so im guessing it will fit?

[maxiim]

also kinda curious now- about the Peavey 1504 Black Widow (PA reinforcment) Speaker, was talking to the phone with the dude thats selling those 2 speakers for about an hour, told me some interesting stuff

[maxiim]

I got my MBIII very early 90s to use with my Double Bass. I bought it knowing it did not produce any sound. Back then, a (recently late) good friend changed some parts and replaced the speaker. It has been very reliable for almost 30 years. I have gigged with it for most of that time. Only recently have I been playing my archtop guitars through it - I've mostly done rock, pop and country with Musicman or Fender amps and the appropriate guitars!
At long last,for the first time, I have just taken the back off to look inside! especially to see the speaker. I hadn't specified any particular speaker when I had the repairs done. Anyway, it's definitely Eminence and has ME15 2008 on the label. I believe that's 15" 200w 8ohm.
I'd appreciate opinions on that speaker and it's suitability (for guitar or bass). I think it might be the wrong impedance.
TIA
Attachment 83937Attachment 83938Attachment 83939

aint that a beauty then

if its tight its tight

4ohms are rather rare and people go for the 8ohm bc their more common, looks like its been working for years for most

[nevershouldhavesoldit]

yes i love the deep bass

You said a few posts ago that you wanted to “…cut some of that thumping bass”, but now you say that you love it. It’s not clear to me that you know what you want, which makes it very hard to help you. The basic character of your amp includes a full, deep low end with decent control. It will sound this way with almost any of the speakers you’ve mentioned.

Another part of its sonic character is a hint of boxiness, about which many reviewers have remarked. Part of this is probably from a lack of highs, but some have reported “improvement” by removing part or all of the acoustic stuffing inside. So you might try that.

Until you know specifically what you want to change and can describe it clearly, you’ll have difficulty getting advice about how you might do it. Buying things blindly in the hope that they’ll sound better to you than what you have is not likely to succeed. Trusting your luck is not a plan.

[maxiim]

You said a few posts ago that you wanted to “…cut some of that thumping bass”, but now you say that you love it. It’s not clear to me that you know what you want, which makes it very hard to help you. The basic character of your amp includes a full, deep low end with decent control. It will sound this way with almost any of the speakers you’ve mentioned.

i knew that you would say that
and i like both but

if you look at the beginning of this post you'll see why i posted it and what i was looking for - something different aka something cleaner than that thick juicy low end i already have here -

most of the 15" speaker go to 3000khz or 4000khz ofc they all sound similar

listen to the comparison video of the stock one and with the eminence one with the eminence going to 3700khz

ill doubt that the stock speaker ends there - according to my ears

its a night & day difference

but yes! i see why you'd say that and i agree most of the people that replace the speaker with the average 15" guitar speaker more or less sound really similair probably
then again i read about people saying changing the speaker totally changed their amp sooooooooooooooooooo .. theres also that

though why would you say the last part of ur reply? i assume literally everyone has to trust their luck and buy blind in order to see the results, its not like i can hear the speaker through paper

i appreciate ur input on this and hoped that i could clear some confusion

[Greentone]

FWIW, 8 ohm speakers work well in the Mini Brute. 4 ohms is better, but you will have no problem with 8.

[nevershouldhavesoldit]

i assume literally everyone has to trust their luck and buy blind in order to see the results, its not like i can hear the speaker through paper

That's true. But you're not buying blind - you're buying in the dark. The more knowledge you have, the more accurate your guesses will be because knowledge is the light that will help you see your way to more intelligent choices. And better choices have a higher probability of being successful.

The more you learn about how all this works, the more clearly you'll see your goals and ways of reaching them. You need to understand a bit more about the relationship between frequency and pitch, for example. Simply bumping up the output between 4500 and 6500 Hz by a few dB will not change much in isolation. You have to double the frequency to go up a full octave (8 notes). So the note span from 3000 to 4000 Hz includes only the 4 keys from the highest G on the piano to the highest note, which is a C. From 4500 to 6500 is only about three notes. That amount of change will not have much effect on the sound of most guitars through most amplifiers. Then there's the simple fact that the speaker "response" in post #26 is truly useless because it doesn't tell us what it means, e.g. is there any output at all below 60 and above 6,000? If so, how much? A useful response curve tells you the relative levels at its extremes, e.g. 60-6000 Hz +/- 3 dB - and even with that kind of spec, you don't know how linear it is between those extremes.

If you look at the true response curve in your own post #17, you'll see that the Jensen C15N varies by 25 dB between 70 and 2500 Hz and is down by 30 dB at 4K. At 400 Hz, it's 7 dB below its response at 120 Hz and 17 dB below its response at 1800 Hz. This is far from linear, and if it were the actual response cuve of the amplifier/speaker combo, it would probably sound pretty lousy. But there's simply no way to predict how this response curve will interact with an amplifier without knowing its response curve as well. Further, the cabinet in which that speaker is housed will alter its response curve. The response curve on the chart in your post (like most you'll get from speaker manufacturers) was measured with the speaker mounted in a large, flat board (the IEC 45575 standard baffle). Here's a link to Jensen's explanation page and here's a picture of how most speaker response curves are measured:



Other things we don't know but that will affect the sonic changes achieved with a simple speaker swap start with the distortion levels or characteristics of the amplifier outside of the range of parameters in which it was designed and sold to operate, the impedance and reactance curves of the speaker, the behavior of the amplifier if the new speaker adds a reactive load that goes beyond the acceptable limits of amplifier performance, etc etc. There's never just one effect to a change like this - and unless you have at least some information to help sort these things out, you're truly in the dark. If you're a gambler, this may be acceptable to you - but I worked too hard for my money to put it out with absolutely no knowledge at all of whether I'll get any return on it.

From your latest description of what you want ("something different aka something cleaner than that thick juicy low end i already have"), I suspect you'd be much happier with a really good 8" or 2x8" cab and a basic class D amplifier like one of the Quilter pedal amps. Everything about your 15" Polytone was designed to make it sound like it does. More than a minor change in the basic nature of its sound is probably not possible without radical surgery at great expense.

[Herbie]

Well, at least my MB IV has a bass eq, which is VERY efficient. It takes away all the bass if I want so. Same with treble eq, it can be piercing if I want so.

I have had worse bass than this MB IV with 10” Princetons. I have started to believe that a 15” speaker can really handle the lows so it won’t get boomy, while smaller speakers have to ”pretend” that they handle the bass and then they have to exaggerate it and that why they sound boomy. I am not sure if this theory is scientific…

In my experience the ”floor bass” system is highly untrustworthy because floors in different rooms, stages and studios are always different. Same goes with the chairs so an amp stand is the easiest way to control the sound of the amp.

I had once a 15” tweed amp with a Eminence Legend 1518. It was very good sounding speaker but I never tried it with my Mini Brute. Maybe I should have.

I believe that the giant magnet of the EVM speaker would have made Your MB to a hum machine so maybe it is only a good thing that it didn’t fit.

[Herbie]

And one more: some of the 15” speakers might be too big to the MB cab but You can always make an extra baffle to the hole and make it an adapter to a 12” or even a 10” speaker!

[BigDaddyLoveHandles]

thanks for the amazon tip!

yes i love the deep bass, however i am just very curious about putting a speaker in it with an extended range to 6000khz rather than -4000khz!

that would be really interesting to hear since you cant add more to something thats not already there, but you can always reduce it when you have more

im def going to put it on something, i had it before on something but since i moved i just had it on the floor

the speakers with aluminium material have the extended range of frequencies bc of the vibrations it produces - Roland Speakers are of the same material & they also sound very flat and trebly

I wonder how much above 4000hz is sent to the speaker by the amp.

[nevershouldhavesoldit]

I wonder how much above 4000hz is sent to the speaker by the amp.

The bigger question is how much above 4k is going to the amp from the guitar? Here's a fascinating (if somewhat self-serving) webpage "calculator" that simulates the effects of cable capacitance on the frequency response of many popular pickups. The large frequency response curve at the bottom is typical of guitar outputs - it's only flat to somewhere between 500 and 600 Hz, about 3 dB down at 3 kHz, and dropping like a rock below 5 kHz. Add the speaker response curve in post #17 to the pickup response curve on the "zero capacitance cable" web page and you get an output from that combination that has virtually no audible content above 4 kHz. [I call this page "self serving" only because it's on the website of a manufacturer of "zero capacitance cables" that they sell at what I consider to be a very high price. But their sonic demonstration of the effects of capacitance on signal composition is educational, fun and interesting even if it doesn't motivate me to run out and buy their $100+ cables.]

Most guitarists mix and match their guitars, picks, strings, pickups, cables, effects, amps, and speakers with little or no knowledge of how they all interact and the effect each has on how the player sounds. As the OP says, they’re buying blind and trusting luck that they’ll like what they hear. If they don’t, they buy something else again and again until they do.

Whether or not the difference in tone between a 10' cable and a 15' cable of identical construction is audible remains controversial. Some (like Eddie Van Halen and Eric Johnson) claim they can hear differences like these, but most of us are not that sensitive. Johnson once claimed in an interview that he could hear differences in tone when using different brands of 9 volt battery in his effects. HERE's an interesting analysis of this with actual spectral measurements - it seems that it's the actual voltage that affects the sound of some pedals, rather than the brand of battery. And it only happens in effects that do not have internal voltage regulation of any kind.

[Greentone]

FWIW, I have 4 Mini Brute amps with 15s. A 70s MBIII, a 80s diamond Tolex MBIV, a 70s fuzzy covered MBIV, and a 90s blue Tolex MB III.

All have original speakers and all are spectacular jazz guitar amps. The blue amp is gigged weekly and has been for 25 years. It's foolproof.

[nevershouldhavesoldit]

FWIW, I have 4 Mini Brute amps with 15s. A 70s MBIII, a 80s diamond Tolex MBIV, a 70s fuzzy covered MBIV, and a 90s blue Tolex MB III.

All have original speakers and all are spectacular jazz guitar amps. The blue amp is gigged weekly and has been for 25 years. It's foolproof.

I agree. That’s why my advice to the OP was to find a new amp that was more to his liking. My only amp for years was an Ampeg B15-N, which had many characteristics in common with the 15” Polytone - closed cab, 15” speaker, great jazz guitar tone, bulletproof, and simple. I loved it, and I’m sure I would have been happy with a Polytone too.

This thread has been interesting, but I still don’t understand exactly what prompted it.

[maxiim]

heres all kinds of different speakers including few Eminence‘s and an EV 12L

my theory was right and it wasnt hard to tell from the beginning with all that information on the internet

[maxiim]

i dont see whats wrong with experimenting by just changing the gah damn speaker lol

[maxiim]

with the EV cutting that much bass you could probable leave it on the floor,

if i want that thick juicy baby mama bass i can still swap it out again

i might do an comparison vid

recording a DI Track and playing it thru both speakers hooked up with a mic or some shit

[maxiim]

or to get an cabinet to hook up the polytone to a 2x 12“ that would probably sound pretty smooth

that way the poly can still be the thick boi as he is

[GNAPPI]

This is a fortuitous thread... my polytone has a bad speaker. I've been thinking about bringing it to a nearby lab to have it re-coned.

[timjgbeun]

The best 15" replacement for Polytone 15 mini brutes, etc is the Eminence DeltaLite 2515 neo speaker. Super smooth, huge low end, takes tons more power and headroom at 300W RMS (600W peak) fits most brutes perfect AND is super light being neo, about 5 lbs.

It is 8 ohm so slight power loss BUT since super efficient at 99.2 which I'm sure is way higher the originals, will be as loud or louder. And being an 8 will allow proper use of the EXT speaker jacks for the brute amps that have them, as adding another ext 8 ohm spk in parallel will be 4 ohm total that the brute amps can handle. Just perfect all around for jazz guitar and jazz bass, I have used it for both. Smooth full tone very similar to the original...better actually. Cost about $200 usd.