Why a 15 inch speaker?

Craig A Davidson · Post by **Craig A Davidson** » 8 Apr 2007 1:23 pm

Three of us were talking last night and the subject of speaker size came up. One of the guys was talking about how efficient a ten inch speaker is and how the frequencies in a steel guitar don't begin to go down as far as a 15 inch speaker will go. So what started the trend to a 15 inch speaker instead of a 10 inch speaker?

Richard Sinkler · Post by **Richard Sinkler** » 8 Apr 2007 3:50 pm

Do you play C6th? I tried an old deluxe reverb recently at a practice, and when I hit my bottom 2 or 3 strings on C6th, I thought the speaker was going to fly across the room. I imagine that playing just E9th would work through a 10" but I would still go to at least a 12".

Of course we're going to hear the argument that bass players are using 10" speakers. I guess if you used 4 or 8 10' speakers like bass players use, it would probably work out OK.

Craig A Davidson · Post by **Craig A Davidson** » 8 Apr 2007 4:23 pm

I do play C6 and that is why I was asking. I have heard bass amps with 1 ten and they are killer rigs. By the way I do play thru a 15 or two 12's. My question was what caused the trend to a 15 years ago.

Michael Cutsforth · Post by **Michael Cutsforth** » 8 Apr 2007 5:24 pm

Craig;

Just a reminder per our conversation.

The CABINET is crucial. You'll never get an open back Fender to punch like a ported closed back. Frankly, if you're getting that much low end to send a speaker across the room anyway maybe you should look at how much lows are being used. The final analysis (in my humble opinion) is drop a Neumann U-87 on your cabinet and you'll find out how much low end you are literally throwing away.

That's all I'm saying for now, but hopefully this will start the debate. This whole thought process is why I joined the forum in the first place and I'm hoping this becomes a hot topic for debate. I can just see a million steel players going "Baloney!" right now, but I'll hold fast to this belief. After fifteen years of studio engineering and 35 years of playing and live-engineering I'm anxious to hear all comers.

I'll leave here for now with a question: What are the frequency points ( or crossover points) of the low, mid & highs on a Fender amp? We spin these dials all the time but what are we adjusting in terms of Hertz? Anyone?

By the way, happy Easter to all who partake and to any others have a great weekend.

Craig A Davidson · Post by **Craig A Davidson** » 8 Apr 2007 5:28 pm

Thank you Michael. I was having trouble getting the topic across I wanted to discuss in the right terms.

David Doggett · Post by **David Doggett** » 8 Apr 2007 6:37 pm

In the '50s, amps had less power, and a 15" speaker and the larger cabinet helped give them some low end boost. The Tweed Pro with it's 15 was the top pro amp for both guitar and steel. Chimey, twangy solid-body electric guitar was not the model for tone that it is today. People played hollow-body electrics, and they liked the fuller sound of a large speaker and cabinet. Then Standel with it's 15 came along and for awhile beat out Fender for the high end pro amp market. Eventually Fender and everyone else beefed up their amps so that 12s and 10s had all the low end needed for guitar.

Steelers too could make do with 12s in a clean powerful amp like the Twin. But the Vibrosonic (basically a Twin with 1x15) had a deep organ-like sound that some steelers preferred. It tamed the shrill highs (steels are solid-body with only a neck pickup), gave warm mids, and lush lows. When Peavey started making its line of powerful clean playing solid state amps dedicated to steel in the '70s, they took a lesson from the old Pro, Standels, and the Vibrasonic, and they put a single 15 in their steel amps. These amps with powerful organ-like tone and miles of clean headroom set the style for pedal steel.

The real story for me regarding different sized speakers is all about the voice of the speaker. It is not about how much air is moved. Four 10s sound like a single 10, only louder. They do not sound like a 15. It is also not about low end power these days. You can take a heavy duty 12" speaker and put it in a powerful amp, and it wont break up on bottom, even with C6 or uni, but it wont sound like a 15. My 180 watt Super Twin Reverb with 2x12 could not be made to break up with any 12- or 14-string steel. Low end breakup was simply not a problem. But it still sounded like 12" speakers. When I put it in a head cabinet and played it through one or two 15" speakers, it sounded completely different. The larger speakers simply have a different voice, that shifts the whole EQ spectrum of the amp. Some people might argue that one could change the amp EQ circuits and get that 15" sound from 12" speakers, but I am skeptical.

The fact is, guitar amps and speakers are not meant to have a flat EQ across the full spectrum. If you ever plug a full spectrum home stereo speaker or PA speaker into your amp's speaker jack, you will understand why. If you want to run a guitar amp directly into a full spectrum system, they make adaptor direct boxes to model the EQ of a guitar amp and speaker. Guitar amps and speakers have evolved the peculiar kind of EQ that sounds good for guitar, and the same is true of steel amps. The woofer size speakers (10, 12 or 15), with no tweeter, help tame the shrill highs of electric guitars and steel guitars, and give a more pleasing tone.

The bass amp analogy is not a good one. Believe it or not, bass sounds better when lots of the high overtones (that make guitars and steels sound shrill) are captured. You can then get pick noise, slapping, and good string definition. A single 15 tends to sound muddy with the very low frequencies of a bass guitar. You get more of those desirable highs with a 10 (and multiple 10s handle the power), or when you add the crossover network and tweeter that most bass 15 cabinets now have. But a guitar or steel might not sound so good through such a full spectrum bass system.

10", 12" and 15" guitar speakers just have different voices. The 10s in Supers and Vibroluxes have bell-like, chimey voices to me. I love their sound for clean blues guitar like Robert Cray plays. They really sing for him. The guitar player in my blues band plays a Vibrolux (2x10) with his tele and sounds great. But I have tried playing pedal steel through his Vibrolux, and it sounds too shrill and piercing. Then I unplugged his 10s, and plugged one of my 15s into his speaker jack, and it had that full organ-like pedal steel sound we all love. There is a sweetness in the highs, and a kind of lower midrange moan that a pedal steel gets from a 15 that is just not there with 10s or 12s. For country and jazz, or any genre that needs sweetness, 15s are the ones. On the other hand I have come to think that when I play blues and rock on pedal steel, my 15s sound too throaty and deep. I am beginning to think 12s work best for blues and rock, especially when you add some distortion from a tube amp or stomp box.

So that's the bottom line for me. Different size speakers have different voices. Maybe theoretically you could mod the amp EQ circuit and compensate for that. But why go to that trouble when you can just plug in a different size speaker. I like amp heads for that versatility.

Kevin Ruddell · Post by **Kevin Ruddell** » 9 Apr 2007 2:07 am

" The larger speakers simply have a different voice, that shifts the whole EQ spectrum of the amp ".

I agree with this for sure . I recently got a Tube Works ProValve 60 . A really great sounding solid state preamp with 2 6L6 power output tubes.... but it's fairly bright sounding .Plugged in into a tweed cabinet with a 15" Eminence Delta LF driver really is a good combination though . Playing through the cab with a 12 sounds good .... but it's not the match the amp has going with the 15 inch larger driver

T. C. Furlong · Post by **T. C. Furlong** » 9 Apr 2007 4:24 am

I think that the David D's statement about larger speakers simply having a different voice is partially true. I have done a ridiculous amount of testing, measuring, listening and even fabricating different combinations of cones, motors (magnet and voice coil), cabinets, power amplifiers and EQ's to determine what the deal is about where tone and responsiveness comes from. It's obviously the combination of all of it. The interesting thing is that if you work at it, you can make a 12" to sound pretty much like a 15". In fact recently I was challenged to make a single 12" in a closed back cabinet sound like a single 15" in an open back cabinet. I got pretty darn close.

It is true that a 12" in a Deluxe Reverb cabinet will sound different than a 15" in a Vibrosonic cabinet. However, I have a 12" that sounds more like a 15" than a lot of 15" speakers. The point is that the extra mass in a 15" cone does mellow out the highs and the additional cone area supports a lower extension in the bass response. If you put a heavier cone in a 12" it will mellow out the highs and if you put either an "assisted allignment" (low frequency EQ boost to compliment the naturally occurring missing lows in a speaker) or a closed back cabinet that is carefully designed to support the low frequency response, you can get a "15 inch sound". I played a variety of 15" speakers in a variety of amps for many years. I now much prefer one or two 12" speakers for steel and I play more C6th than E9th. It is very important with 12" speakers that you pay attention to all of the above elements and you need to make sure that you have enough power. A tube Fender Vibrolux or Deluxe probably doesn't have enough power for most stage situations. Miss one thing and a 12" can sound thin for sure.

TC

Donny Hinson · Post by **Donny Hinson** » 9 Apr 2007 5:17 pm

Craig A Davidson wrote:Three of us were talking last night and the subject of speaker size came up. One of the guys was talking about how efficient a ten inch speaker is and how the frequencies in a steel guitar don't begin to go down as far as a 15 inch speaker will go. So what started the trend to a 15 inch speaker instead of a 10 inch speaker?

Craig A Davidson · Post by **Craig A Davidson** » 9 Apr 2007 5:29 pm

And then what happened?

Donny Hinson · Post by **Donny Hinson** » 9 Apr 2007 5:34 pm

Craig A Davidson wrote: One of the guys was talking about how efficient a ten inch speaker is and how the frequencies in a steel guitar don't begin to go down as far as a 15 inch speaker will go. So what started the trend to a 15 inch speaker instead of a 10 inch speaker?

Hmm. "One of the guys" seems to know very little about pedal steel.

Simply tell him that no 10" speaker on the face of the earth will do what a good 15" speaker will do. Oh sure, if you put a bunch of 10" speakers in a cabinet, they can sound great.

But who wants to buy and carry around a bunch of speakers when just one will do?

A 15" speaker is the hands-down choice for pedal steelers. Why? Because it works. It's compact, full-sounding, and cheap. In a word, practical.

ebb · Post by **ebb** » 9 Apr 2007 7:11 pm

i will trade my 2 peavy tweed cabinets with 15" celestions for any 10"speaker configuration

Michael Strauss · Post by **Michael Strauss** » 9 Apr 2007 9:03 pm

Phil Jones Bass uses 5" speakers and are supposed to sound great. It would be interesting if the suitcase would work (2-5") with a pedal steel.

Donny Hinson · Post by **Donny Hinson** » 12 Apr 2007 8:44 am

Yes, and if you look real closely, you will see that the Phil Jones amp is advertised as a practice amp!

Personally, I take that to mean it's not meant to replace a big amp in a large (un-miked) situation.

William Matthews · Post by **William Matthews** » 12 Apr 2007 9:41 am

If I may give my $.02, I think that the discussion going on between which is better, a 15, a 12, or a 10 must be taken in context. In chosing a speaker, one must know the frequency range they are trying to replicate, and choose a manufacturer whose specs best suits their needs. It is also VERY important to remember, in constructing a cabinet, to utilize the small Thiele parameters to emphasize the frequencies they most need. The steel is inherently treble heavy instrument, and geting the lows out of an amp/speaker combo is usually difficult, therefore people have gone to different size speakers to help. I firmly believe, a properly constructed cabinet, with 1-10 and 1-12 or 1-12 and 1-15 could petty much handle any live gig in a club. This is just my opinion, please don't beat me

Chris LeDrew · Post by **Chris LeDrew** » 12 Apr 2007 11:14 am

I like "standards" in pedal steel playing:

15" speaker
7/8 bar
Unwound 6th string
3+4
Regular height volume pedal
Pac-a-seat w/ no back or sidecar
A thumb and 2 fingerpicks
Amp reverb

I have deviated briefly from all these "standards" only to return a short time later upon realizing that the standard version of all these aspects of steel playing suited me best.

The 15" speaker has a big sound that is very conducive to the broad range of frequencies on a steel guitar. It's standard for a reason: it's tried, tested and true. A 12" is okay, but to my ear it does not have the sweet and open sound of the 15". Two 12's is of course a different story, but still a different beast than the one 15". Why fight a good thing?

Besides, I like that "thump" when a 15" speaker amp is turned on.....PPHHFF!!

Susan Alcorn · Post by **Susan Alcorn** » 14 Apr 2007 1:08 pm

interesting discussion

Ernest Cawby · Post by **Ernest Cawby** » 16 Apr 2007 10:09 am

Hey guys try a Peavey NV 112 you may change your minds about 15's and 12's, after I learned how to set the amp the NV 112 is a monster that works.

ernie

Boo Bernstein · Post by **Boo Bernstein** » 16 Apr 2007 10:44 am

Just to point out, I bought a brand new Peavey Session 400 in 1976 and it came with 2 x 12-inch speakers. I don't really remember if I was even given a choice between the 12's and a 15. When I was living in Texas in 1979, Tommy Roots had one with a 15-inch speaker and I was impressed with the low end and switched over. The point is simply that as Peavey was making major in-roads into the steel world with this amp, they saw fit to offer 2 12's -- which most of us had been using in Twin Reverbs for years.

Craig A Davidson · Post by **Craig A Davidson** » 16 Apr 2007 2:20 pm

Actually the original question was more like, what caused the trend toward a 15" speaker, and not what is the better thing to do? The notes on a pedal steel, even with the back neck do not go down to the low frequencies that a 15 will/or would need to handle. Your lowest note on most is an "A" in the same range as on an electric bass. A 10" speaker in the right enclosure with the right porting could handle it.

David Doggett · Post by **David Doggett** » 16 Apr 2007 3:06 pm

Craig, it's not about hitting the notes. A bookshelf home stereo speaker with a 6" woofer will hit the lowest note we can hear. What it's about is the tone of the notes we hit (and to some extent about the efficiency). Because of the way the overtones are reproduced, the same note (same fundamental) will sound different with a 15", 12" and 10" speaker in the typical open back guitar speaker cabinet. With a 15" speaker the high notes will sound thicker, the mids will have a throatier moan, and the lows will sound lush (but with less definition).

The very low notes a bass hits will sound muddy if there is not enough definition - so bass cabs use multiple 10s, or use a 15 but add a tweeter. Steel and guitar don't have notes that low, and don't need that much definition added. And adding too much "definition" can make the high strings of steel sound thin and shrill.

Guitar and steel are not helped with a flat full-range frequency spectrum (such as a home stereo or PA speaker system). Instead, the speaker is used to shape the frequency spectrum to sound good with the instrument. Guitar and steel amps do not have flat full-spectrum tone stacks. Instead, the tone stacks are intentionally shaped away from flat in order to give what is perceived by most as better tone. The speaker size plays a part in that and helps the amp "voice" the tone. You can take an identical Fender amp and tone stack, and use 10" speakers for a bell-like chimey tone like Robert Cray, or take the same amp with a 15" speaker and get the throaty sound of Stevie Ray Vaughn and the organ-like tone steelers love. Take your pick.

Now having said that, it may be technically possible to shape the amp tone stacks differently, and use appropriately designed speaker cabs (especially if they are closed-back and ported) to get a very similar tone from different size speakers. But the manufacturers have usually found it cheaper to make similar tone stacks, and use similar cheap open back cabs, and get different tone by using different speaker sizes in different amp models. There are exceptions like SRV and his 15", and there are steelers who like playing through a Fender Super with 4x10. But in general, given similar guitar amps, guitar players mostly prefer 10s or 12s, and steelers mostly prefer 15s. Manufacturers go along with that and mostly offer 10s or 12s in guitar amps, and 15s in steel amps.

[Disclaimer: I ain't no expert. I just play the durn things, and have tried a bunch of different amps with a bunch of different speakers. I'm just sort of thinking out loud to try to explain what I hear. Sometimes it almost sounds like I know what I'm talking about. But it's really just a bunch of half-baked opinions.

]

The Steel Guitar Forum

Why a 15 inch speaker?

Why a 15 inch speaker?

I concur

Re: Why a 15 inch speaker?

Re: Why a 15 inch speaker?

Amps