|
Dirty-South Blues Harp forum: wail on! >
How Loud is Your Amp?
How Loud is Your Amp?
Page:
1
2
3
Rick Davis
383 posts
May 11, 2010
11:00 AM
|
You see it all the time when this topic comes up: The chart showing the ratios of speaker surface area. It shows that a 15-inch speaker is 1.5 times larger than a 12-inch speaker, which is 1.5 times larger than a 10-inch speaker, which is 1.5 times larger than an 8-inch speaker. So, will you get 1.5 times more loudness out of your amp with the bigger speaker? In a word, NO.
Total speaker surface area has almost nothing to do with perceived loudness. That chart is meaningless, but it certainly helps perpetuate a common amp myth.
Let’s take for example a typical 4x10 Bassman-style amp. It has 312 square inches of speaker real estate, compared to 113 inches for an amp with a single 12-inch speaker. So, is the 4x10 Bassman nearly 3 times louder than the 1x12? No, not even close.
Remember, it takes ten violins to sound twice as loud as one violin. That is an immutable law of psycho-acoustics and the nature of the human ear.
With the 4x10 Bassman you have 4 speakers sharing the output of a 45-watt amp. Each speaker is “seeing” 11.25 watts. Adding a second sound source (another 10-inch speaker) that carries the same signal does not double the perceived loudness, but makes the sound seem only slightly greater. The Bassman’s four 10-inch speakers each driven by 11.25 watts will have the same total perceived loudness of a single 10-inch speaker driven by the full 45 watts.
Now we will hear owners and makers of 4x10 amps cry, “But the four tens move more air!” Perhaps, but “moving more air” has the same effect on perceived loudness as speaker area. By itself, it has almost no effect.
The proponents of “bigger is always louder” are confusing sound intensity with sound loudness. Sound intensity can be measured by instruments as a linear curve, while sound loudness is perceived by the human ear as a logarithmic curve. (Keep in mind the ten violins.) When you stand in front of your big amp and feel all that air making your pants cuffs flutter, it might impress you but it has almost nothing to do with the audience’s perceived loudness of your amp.
If speaker surface area does not affect perceived loudness, what does? Simply put, the two most important factors are 1) the power you apply to the speaker and 2) the efficiency of the speaker. When the bigger-is-better crowd insists they need a big amp for bigger rooms, they are right only to the extent the bigger amp is more powerful. But a lesser-powered amp with a more efficient single 12-inch speaker can have the same perceived loudness as a typical Bassman-style amp. Better tone, too.
Additionally, the smaller amp is likely to weigh less and cost less. It is axiomatic with vintage-style tube amps that a small amp turned up sounds better than a big amp turned down. And since your amp can be mic’ed through the PA in nearly any gig, the reasons for using a big multi-speaker amp are pretty weak.
----------
-Rick Davis
Blues Harp Amps Blog
Roadhouse Joe Blues Band
|
congaron
898 posts
May 11, 2010
11:18 AM
|
My valve junior is 112-115 db at about 10 feet with two 12 inch identical speakers.
With only one of those in a smaller cabinet, it measures 105-108. All measurements DBC with the meter and cabinets in identical positions, using an A Harp and samson vocal mic on the same musical licks.
This is why I want a couple of lady lucks for that cabinet. My 12's are only rated 94 db/1 watt@ 1m sensitivity.
As for perceived loudness, higher harps seem louder, but lower ones measure higher decibel levels, with my low F generating 117 dbc on the two speaker setup. My f harp is lucky to reach 105.
Cone excursion also plays a role as well as reinforcement from multiple speaker set-ups. Big cones on small magnets and small voice coils may not move as much air as smaller cones with big magnets and larger coils and pole pieces. It seems like lots of the old alnico speakers are more flattened out with lower excursion cones. The tone/volume game is a tough one..i like to mic my cab or line my digitech into the PA and be done with it. Multiple speaker setups have a point of diminishing returns. Eventually, you just need more power AND more speakers to get more sound pressure.
Last Edited by on May 11, 2010 11:24 AM
|
JDH
41 posts
May 11, 2010
11:22 AM
|
I thought the argument in favor of more speaker surface has been that you get more volume BEFORE feedback. Which I assumed had to do with spreading out the sound. It seems, in my experience, to be true. I can hear and be heard better with the same amp but more speakers. I've done it with my Masco's and appears to work. I get more sound before feedback from a 15 than a twelve and even more from 4-10's. I believe less speaker feeds back sooner.
Straighten me out, Rick.
|
7LimitJI
122 posts
May 11, 2010
11:23 AM
|
Erm, Rick, I think you forgot about feedback.
I agree with what you have written with regard to guitars or HiFi.
They don't have problems with feedback.
We are talking harp playing through a microphone.
Why not try this.
Set up a 4x 10 amp and play harp through increasing the volume till it feeds back.
Now get a 1 x 12 or 1x 10 and try to match that volume using the same mic.
It won't happen the single speaker will feed back much earlier.
I've tried it, using the same amp, built into a head, using different combinations of speaker.
----------
Those Dangerous Gentlemens Myspace
Due to cutbacks,the light at the end of the tunnel has been switched off.
Last Edited by on May 11, 2010 11:29 AM
|
congaron
899 posts
May 11, 2010
11:26 AM
|
The tests I mentioned above generated no feedback. They are simple maximum volume tests in a room. I'm sure a bullet mic would have fed back with levels that high. I was actually standing at the meter playing.
|
tmf714
106 posts
May 11, 2010
11:29 AM
|
The coils on the speaker effect "loudness" and tone as well.
For instance-Weber's 2" coils start at 40 watts,then 60 and 80 watt used in the alnico and ceramics,finally ending with a 100 watt coil.
If your trying to incinuate that any amp with a 12" speaker is louder than my 4x10 HarpKing,you will have to provide me with the research data and sinewave comparisons.
|
congaron
901 posts
May 11, 2010
11:31 AM
|
The only way to know is to use a meter and play them .
You can't do it by ear because of the way the ear works.
Last Edited by on May 11, 2010 11:31 AM
|
Rick Davis
384 posts
May 11, 2010
2:36 PM
|
A Bassman is louder than other amps because it is more powerful than those amps. It is not because it has more speaker area.
I've heard the claim that more speakers equals less feedback (just like I've heard the myth that more speaker area makes your amp louder) but I've not been able to prove it. Feedback has many causes along the signal chain, and the number of speakers seems to have zero impact when all other factors remain equal.
Tmf- the voice coils on a speaker will impact it's loudness to the extent they make the speaker more or less efficient. It's pretty straightforward. And, no, I'm not trying to "incinuate" that all 1x12 amps are louder than 4x10 amps. That is an absurd misreading of what I wrote.
If you are having trouble with the theory, try searching online for information about sound intensity. This document from Georgia State University is a good place to start.
----------
-Rick Davis
Blues Harp Amps Blog
Roadhouse Joe Blues Band
|
tmf714
107 posts
May 11, 2010
2:43 PM
|
What's ubsurd is your claim-"But a lesser-powered amp with a more efficient single 12-inch speaker can have the same perceived loudness as a typical Bassman-style amp. Better tone, too."
Loudness by sinewave,or meter-myabe. Tone-not even hypothetically speaking.
|
7LimitJI
124 posts
May 11, 2010
2:52 PM
|
"A Bassman is louder than other amps because it is more powerful than those amps. It is not because it has more speaker area."
Rick, my Bassman is built into a head with a multi tap output transformer.
I've tried:-
1 x 15"
1 x 12"
2 x 10"
3 x 10"
4 x 10"
9 x 8"
8 x 8"
4 x 8" + 1 x 15"
3 x 8" + 2 x 10"
I have settled on 4 x 8" + 2 x 10"
as my ultimate volume + tone.
Have a look here for some pictures
Speakers
I've proved it, as I've done it !!
----------
Those Dangerous Gentlemens Myspace
Due to cutbacks,the light at the end of the tunnel has been switched off.
Last Edited by on May 11, 2010 2:56 PM
|
9000
6 posts
May 11, 2010
2:53 PM
|
Here's an interesting quote from Bruce at Mission Amps from another forum on 2-24-10,"I have about 20 chassis and 1X12 tweed cabs I must to use up as over stock inventory and have been wanting to do another harp amp but... man!!! Some of these suckers are about as hard to work with as wanker guitar players! ha ha"
I guess we're provin' his point about how hard it is to work with harp players! LOL
|
DH
35 posts
May 11, 2010
3:43 PM
|
Came across a dead Sano 500R tube amp that's around 45 watts a while back with 1x15 and 2x8's. Took it over to Skip Simmon's place and after he got through with it, that sucker is one of the loudest amps I've heard.
----------
Too Much I..IV..V..No Such Thing
Last Edited by on May 11, 2010 3:45 PM
|
HarpNinja
456 posts
May 11, 2010
4:21 PM
|
Is there someone that can put a YoutTube together? Play an amp at the verge of feedback in a 4x10 and then smaller cabs?
There are SO many variables that a blanket statement won't totally work, but I think someone should post explicit proof of any of these claims. There is what should work "in theory" and then what really works!
----------
|
7LimitJI
126 posts
May 11, 2010
4:57 PM
|
@Harpninja
I've tried it with all the combinations listed above.
I didn't video it though !
Don't think a video would prove it unless you had a sound meter.
But I used the next best thing, my ears.
Here's what I found.
4 X 10" For max room filling volume,
I gigged with a 4 x 10" Super Reverb clone for years
2 x 10" + 4 x 8" Not as efficient as 4 x 10" but better spread of sound and a better tone.
1 x 15" For old school tone. Small gig or maybe recording, or mic it up. I do like this, but don't do many small gigs and don't like mic'ing up.
1 x 12" not for me, fed back way too soon.
2 x 10" Great tone, but struggles to fill a room. Feedsback easily using a chromatic.
I gigged a 2 x 10" Vibrolux for years.
3 x 10" To my ear, very similar to 4 x 10" A bit warmer though
The speakers were
An EV 15" guitar speaker. A good one !
Eminence legend 10" Good speakers
Fane AXA 10" Superb speakers
12" is a Marsland I think. Not a good speaker, so others will be better.
8" Are out of a Traynor 9 x 8" cabinet. Marsland I think. Good sounding speakers, way better than Celestion Super 8 and other no-name modern 8's that I've tried.
----------
Those Dangerous Gentlemens Myspace
Due to cutbacks,the light at the end of the tunnel has been switched off.
|
Greg Heumann
443 posts
May 11, 2010
5:17 PM
|
Rick, I have to disagree. I don't care what theory predicts. I have lots of on-stage time and audience time in front of a LOT of harp amps. More speakers, even with the same amount of power, move more air and fill a room better. In order to move as much air, the single speaker amp in your example (with 4x the power) would have to have cone excursion 4X the distance of the 4 speakers in the other amp. I simply don't believe this happens.
I have personally never heard a 45, or even 30W amp with a single speaker that is a great harp amp. Guitar, yes. Harp, no. Every one I've encountered was STIFF - it had a sweet spot - but if you played a little quieter it couldn't be heard and if you drove a little harder it became harsh and was a feedback monster too. I may well be proven wrong about this - I haven't heard all the high power single speaker amps in discussion here.
But in the end, I'll trust my experience over your mathematical predictions. My experience, by the way, ain't as much as many here I'm sure, but it jives completely with 7LimitJI's reported above.
I would hazard a guess that, given the tremendous complexity of speaker math in the real world, your formula just isn't taking all the factors into account.
/Greg
BlowsMeAway Productions
BlueState - my band
Bluestate on iTunes
|
Greg Heumann
444 posts
May 11, 2010
5:18 PM
|
By the way - why do you bring this up? Do you have something against 4x10 amps? What was the point of your post? And the earlier "in defense of the 1x12 harp amp" - does it need defending? And in comparing the mission amp to... no, I won't go on. Damnit, you lured me in again. I swore I wouldn't bite.
----------
/Greg
BlowsMeAway Productions
BlueState - my band
Bluestate on iTunes
Last Edited by on May 11, 2010 5:32 PM
|
6SN7
53 posts
May 11, 2010
7:15 PM
|
Rick, It seems you could have added this as a post in your last thread, but we are destine to see you continue to hawk the concept of a 1x12.
I don't care about your math or whatever, I prefer a 4x10 unmiced as opposed to a miced up 1x12. A 1x12 does not replace a 4x10, miced or otherwise.
|
walterharp
324 posts
May 11, 2010
7:18 PM
|
Our guitar player plays a mesa with a single 15 inch speaker. His tone is unbelievable. His volume right in front of the amp for a straight line out 25 feet or so is unbearable to all but him and people who love way too loud guitar. That hot cone of sound is not as much a problem with 4x10. I actually mounted my 4x10 speakers flared out to accentuate the sound spread even more and kill the hot spot where the sound waves reinforce in the center where they overlap.
I am not sure every pro harp player mic's the amp, but I am sure that if I am in a situation where a sound guy I do not trust insists on micing everything including the drums, in a room that only holds 100-200 people, things are going to get way too loud.
Playing with an amp that spreads sound enough for the room and is loud enough unmiced creates better sound separation for the audience. The problem with a bigger band with amps that are not fed back a bit through the monitors is the other players hearing all the players, and that is more of a problem with a single speaker cabinet
|
Joe_L
240 posts
May 11, 2010
7:26 PM
|
I wish someone else would buy one of the Mission Chicago's. I may have to bite the bullet.
|
htownfess
81 posts
May 11, 2010
7:28 PM
|
"You see it all the time when this topic comes up"
Yet another polemical post/thread starting with a sweeping generalization without a single direct quotation as evidence. We don't see *that* all the time, but do we see it at all often from anybody in particular?
"So, will you get 1.5 times more loudness out of your amp with the bigger speaker?"
*Nobody is claiming that. Nobody.* Referee, would you please issue a yellow warning card for another straw man violation here? For those just tuning in, "straw man" refers to the logical fallacy wherein a speaker/writer refutes *positions their opponents have never taken*, or deliberately distorts the opposing position.
"The Bassman’s four 10-inch speakers each driven by 11.25 watts will have the same total perceived loudness of a single 10-inch speaker driven by the full 45 watts."
So why doesn't the Mission harp have 45 watts and a single 10"? Others have already answered that question: extra speaker area lets the harp player utilize more power before feedback. Other people weren't claiming that it was the additional speaker area alone; anyone who's tried it knows you need to have enough power to push the extra area, reasonably harp-friendly speakers, etc.
"Now we will hear owners and makers of 4x10 amps cry, “But the four tens move more air!” Perhaps, but “moving more air” has the same effect on perceived loudness as speaker area. By itself, it has almost no effect"
Well, duh. In fact, to quote what Greg Heumann said @ 8:44 am on May 2, "VOLUME = WATTS * SPEAKER SURFACE AREA" [Greg's emphasis, not that it seems to have helped the OP remember what Greg said]. Yup, you need to apply extra power to the extra surface area. *That's* what others are saying. The OP is deliberately distorting their position. Straw man. Another yellow card.
Furthermore, "By itself it has almost no effect" implies that speaker area doesn't matter much. And that would be deliberate misinformation, just to appear to win a point.
"The proponents of 'bigger is always louder'”
No, what people say is more along the lines of "bigger may well be usably louder and is a good thing to try." Straw man again. How many yellow cards does it take?
"That chart is meaningless, but it certainly helps perpetuate a common amp myth."
There is a huge difference between a genuine gadfly nobly challenging the conventional wisdom, and a bluebottle preening on a steaming pile. Keep talking long enough, and everyone may figure it out. Rhetorical analysis is a useful way to distinguish between the two species.
"I've heard the claim that more speakers equals less feedback"
Documentation, please. Yet another straw man.
@9000: Excellent investigative reporting there, uncovering the surplus of chassis/cabs @ Mission Amps. But you need to give the precise source: Music Electronics Forum, @ http://music-electronics-forum.com/t17837/ It's post #4 in the thread @ 2:24 am. Hope it's still there when people go to look.
Starting with the clumsily inappropriate comparison of two amps from entirely diferent categories, this current string of sales pitches (both overt and veiled) is clearly awash in deliberate misrepresentation and even, arguably, deliberate misinformation.
I declare shenanigans, as they say in South Park.
Last Edited by on May 11, 2010 7:30 PM
|
Joe_L
242 posts
May 11, 2010
7:37 PM
|
Here is post one from Bruce:
"Yeah, it was a little opened ended but when I ask the locals around here, (and there are a few good ones) I get two or three different answers from each of them!!
In other words, there doesn't seem to be a solid general consensus about what makes a great harp amp except it has to be loud enough to be heard over the guitar player or drummer and needs to be feedback resistant.
I have about 20 chassis and 1X12 tweed cabs I must to use up as over stock inventory and have been wanting to do another harp amp but... man!!!
Some of these suckers are about as hard to work with as wanker guitar players! ha ha
My plan so far is; 25 watts, two 6L6s and two preamp tubes.... a mix between a Masco 18, tweed 5F4/5E5 and a GA 6 Gibson and with a variable line out."
and number two:
"I want this to be affordable and fairly simple.
Most of the players I talk to really like the cathode biasing but with respect to many of the harp amps I've made... some have both cathode and fixed bias.
I think the hard Chicago boogie players like the colder fixed bias tone.
I'm thinking of trying "cold" cathode bias with the zener diode mod talked about in the other threads.
I have tens of thousands of vintage carbon comp resistors and boxes and boxes of 200v to 630v Paper in Oil caps, from 680pF to .33uF.... I'd like to use some of them too.
The PT I'll use (that fits this smaller chassis) is 680CTvac@160ma.
The OT will be my custom wound tweed +30 watt 6L6 OT.
Any tweed Deluxe iron fits too so I can make a 10w, 18w, 30 watt version with combination's of power tubes, trannys and rectifier tubes.
I really want to use up the last of the "5F11" tweed cabinets.
These are all made with the 12" baffle board though. They are almost the same size as a 5E3 narrow panel tweed Deluxe, but the 5F11 does not use the same size chassis... 5F11 is a bigger chassis. Hence th reason I can get Vol, Treble, Bass and Line Out on the top face.
I do have a couple spare 1x10" baffles that would fit, but I don't think I want to try anything smaller then the 12" in there right now and there is no way two 10"s would fit right.
However, the next step will also be a larger tweed 2x10 Super sized cabinet (since I have more then a half dozen of those 5F4 cabs left too)... then I could make it up with the std 2x10s or a new 12" and 8" combo which I really like too.
No sure if I could get a 10 and 12 in there.
Speakers:
We've been messing with a few speakers here and found that the generic Eminence hemp coned Cannabis Rex 12" actually sounds pretty darn good... but only if the actual preamp is tuned a ways down from the 3Khz to 4Khz spikiness of that speaker and not with a tone control.
That speaker is just a bit heavy for what I'd like to do in a 3/8" baffle board though.
The other option is a custom made 12A125/P12Q from Weber with a smooth cone. I did not like the 12A100 at all.
I'm not a big fan of those nor the Signature series but others like them a lot."
These messages aren't indicative of something nefarious. It just means that Bruce had a design in mind and wanted to use up some spare inventory.
|
kudzurunner
1433 posts
May 11, 2010
7:55 PM
|
I seem to do really well with 8" speakers. I've never had a chance to play through a 4 x 8", but I think that's probably what I need for certain kinds of bigger gigs.
Can somebody, just for the record, briefly describe the 4 x 8's that are currently available: manufacturer, wattage, price, and your judgment of how good they are? I'm talking about an amp that I could, if I wanted, put in an order for tomorrow.
This forum has gone completely tech-nuts, but I'm not complaining.
|
MP
250 posts
May 11, 2010
8:50 PM
|
here is a wierd ,-almost completely off topic anectdote, but it's about an amp.
in 1988 my band opened for the MOODY BLUES in a huge arena. they had their system and JOURNEY had left their system so the sound guys used everything.
i walked in with my FENDER VIBRO-CHAMP and a GREEN BULLET. that amp had one 8" ceramic speaker and if it put out 8 watts i'd be surprised. they put one mic on it and made it huge.
i like big amps and i like small amps. sometimes i wonder at the protocol that one absolutely has to have tons of volume,headroom,and a bad back from an amp.
PS. i'm sure to get it from all sides for being so ignorant. fire away.
|
Joe_L
243 posts
May 11, 2010
9:22 PM
|
Why do you think people would hassle you for being ignorant?
|
Greg Heumann
447 posts
May 11, 2010
9:37 PM
|
You do NOT have to have a big amp if its mic'd, although hearing yourself on stage without feedback can be a problem - especially if the sound guy isn't REALLY on his game. At the level of Journey and Moody Blues, the sound guy knew his stuff.
Many, many people in this forum perform with their band, lug their PA - no sound guy - or go to jams where volumes are hard to control and again, usually no sound guy. It is there where the bigger amp is an asset as it can be heard BY ITSELF better on stage and in the audience.
----------
/Greg
BlowsMeAway Productions
BlueState - my band
Bluestate on iTunes
|
JDH
50 posts
May 11, 2010
9:39 PM
|
@MP
I don't beleive it all comes down to volume, and big is louder than small. Big amps sound different than small amps. Champ style 3 tube single ended amps have a sound and feel that to me is different than anything else. I like all good sounding tube amps, large and small, but I like them for different things and different situations. And I like some better than others. If you prefer the sound of a champ miked up then that's the sound to use. If that suits your every need then you are indeed a very lucky harp player, one $400 amp that does it all.
I like an amp that is just starting to break up and sing, so I like different sized amps for different situations. If I'm at home playing with CD's I like my 3 watt, 6" speaker wide panel champ, but for me that, and recording is the limit for that particular amp. If I'm going to play an outdoor gig, I want at least one 40 watt 4-10" speaker amp,such as a bassman. I have in the past played outdoors using two super reverbs or a super rev and a deluxe rev in a loud band with two guitars and B3/piano. There's many amps between a "champ" and a bassman that are great for some people some of the time, but there is no one amp for everyone all the time. It may be the only thing everyone would agree on, there's no one amp for all players.
Now Rick will probably say, oh contraire old timer...........
|
nacoran
1844 posts
May 11, 2010
9:46 PM
|
I made sure my amp had an 11 setting.
----------
Nate
Facebook
|
JDH
51 posts
May 11, 2010
9:49 PM
|
there's your problem, Fender tweeds go to twelve, eat your heart out spinal tap fan!
|
6SN7
54 posts
May 11, 2010
9:55 PM
|
Hey Kudz,
I know a 4x8" available. I have a Sonny Jr 1, the original, #99, with extra big magnets. interested?
|
MP
251 posts
May 11, 2010
10:33 PM
|
@JDH,
that champ was $12 or $15. i've owned three over the years. i used a silver faced PRINCETON w/blackface specs(no reverb) for many years(20?) and a twin 8 PREMIER. nowadays outdoors i use an older modified BASSMAN RI. on saturday at a festival i'll use a 50s tweed DELUXE or an ADMIRAL head powering a smooth cone alnico ROLA 12". but then again, i could use a 50s KALAMAZOO 2x12". i just think that if you can run a PA and you are indoors and you aren't competing with JEFF BECK you don't need 4x10"s.
|
7LimitJI
128 posts
May 12, 2010
1:22 AM
|
Adam, The general consensus, talked at length on the Lonewolf and other forums, is that 8" speakers don't project enough, and struggle to fill a room.
I like the sound of 8's too, but had to combine them with two 10's to get the room filling projection.
If you were going to mic it up, you'd probably be better staying with 1 or 2 x 8"
I had to get my cab custom made, but a 4 x 10" cab, or maybe a 1 x15" cab, could easily have a new baffle board cut for 8's or a combination of speakers.
These are readily available from Weber or Mojo.
Speaker wise, I'd go for a mix of types to get a full spectrum of sound. Weber speakers are good as are Kendrick, but his have limited impedance available,only 4 ohm.
----------
Those Dangerous Gentlemens Myspace
Due to cutbacks,the light at the end of the tunnel has been switched off.
|
7LimitJI
130 posts
May 12, 2010
2:03 AM
|
"These messages aren't indicative of something nefarious. It just means that Bruce had a design in mind and wanted to use up some spare inventory."
Reading Bruce's posts here, and on other forums proves he's open and honest in what he is doing.
The amp is VERY good value for money. I'd struggle to build a kit amp for that price.
Just wish I could try out the 3 x 10" in person.
----------
Those Dangerous Gentlemens Myspace
Due to cutbacks,the light at the end of the tunnel has been switched off.
|
5F6H
123 posts
May 12, 2010
2:15 AM
|
@ Rick - "A Bassman is louder than other amps because it is more powerful than those amps. It is not because it has more speaker area." - Not true. Not all bassmans area as loud as each other. On your speaker comparison you would need to have 10" & 12" speakers with the same dB rating (SPL)...that won't happen for an equivalent construction. So say your 10" is a couple of dB shy of the equivalent 12", you might eke out a little over 3dB more volume AT THE SAME VOLUME SETTING for a 4x10...which equates to twice the power, but is also typically the smallest increment humans can hear. But the 10" ability to reject feedback will have a greater effect on the final result, so you won't be playing the amp at the same volume Setting.
I have heard 1x12" amps that were louder than some 4x10" amps (that's not to say I liked the sound more, Fenders Blues Deluxe can give some 4x10" amps a run for their money), but the loudest amps that I have heard were 4x10", with power tube plate voltages in excess of 500vdc (comparatively few bassmans run that high).
Fletcher Munsen curves (your violin analagy) don't count for toffee in the real world. A 50W amp is a significantly different thing to a 5, 10, 30W amp in terms of available headroom, transformer capabilities, method of bias etc. You can have 2x 50W amps, one will be significantly apparently louder than the other due to tighter response, better dynamics & extended headroom. RMS wattage ratings are clean wattage ratings, power output under drive is what counts in the real world.
Loudness is also relative to frequency, it's possible to have a low powered amp with headroom and a cutting voice that punches well above its weight (e.g. the DT...I also have a 2x6V6 amp that only makes 5W measured into a resistive load, back to back with mid sized amps, like the mini meat, it holds its own - I honestly don't know how/why, but it does!).
This is the deal...I don't want to sound like a bombast, but years of critical testing (like for like speaker loads etc) has taught me this much...
Loudness for a given design depends on output tube plate voltage and the speaker array's efficiency...as far as the player is concerned that also normally means the spread of sound & ease of monitoring on stage. E.g. a 2x10" (horizontally arranged) at your ankles might make as much volume as a 4x10" before feedback because the speakers are not picking it up from the mic, but for the player it can be harder to hear...despite still filling the room.
A 1x12" in comparison with 3x10" or 4x10" will not make as much outright volume, assuming that the design allows the increased speaker area to be utilised without increasing sensitivity to feedback (a high current design like a single ended champ/cathode biased 50's PA style amp, might well be louder with a single speaker, or maybe 2 feedback friendly speakers, but a fixed bias amp, with moderate plate current will be more flexible with larger cabs).
Feedback is relevant to ALL amp circuit stages, not just at the speaker, not just at the preamp or power tubes. E.g. just replacing your 450v PT with a 530v PT might not instantly reveal more loudness before feedback, you might need to trim back the preamp voltage/gain to the previous level, as this will have risen as well. Whatever causes feedback first is your limiting factor, wherever it is between mic & speaker.
Joe L has hit on the nub of the matter, Bruce was looking to make something cost effective, from available parts, that was reasonably light & portable (I see guys using 5E3 Deluxes for guitar for gigs, light as a feather & with a few tweaks easily cope with a drummer...it's hard not to get jealous). At one time I was looking to do something similar, I built an amp on a 5E3 chassis, BF deluxe trannies, played with circuits, to get something light, portable, jam/taxi friendly, that would be powerful enough to cope with a drummer with sticks & an electric band...I tried every speaker in my 12" speaker mountain, some sounded good & I thought "this is a goer" until I compared to 2x10" or 3x10"...the difference was not subtle by any means. I'm not saying that you'll never get good stage volume from a 1x12", people do it all the time, but multiples of 10" are typically louder (more expensive, bigger cabs to lug about).
At the end of the day, people buy amps because they like the sound they make. If they make a nice sound, with enough volume, then that is the job done. The loudest amp is not always the sweetest sounding amp.
I don't think it is doing the Mission Chicago any favours to compare it with the loudest harp amps, it's not what it is aimed to do.
Last Edited by on May 12, 2010 2:17 AM
|
5F6H
124 posts
May 12, 2010
3:04 AM
|
Just to clarify an often (mis)quoted phrase - "More speaker area = more power"...not quite that simple.
Doubling the number of speakers, whilst retaining a matched load for the OT increases efficiency by 3dB, as long as feedback does not shut you down earlier. But you have to have a reasonably efficient & feedback resistant speaker to start with (e.g. a field proven 10")...otherwise we'd all be using 6x15" cabs, with 50oz magnets on each speaker and blowing Ted Nugent off the stage...:-)
|
kudzurunner
1435 posts
May 12, 2010
3:11 AM
|
6S: Extra-big magnets are exactly what I don't want. They've never worked for me, I'm afraid.
7Limit: I've got a 1955 Bassman and 10's just don't seem to be my thing. I like 8's. Right now I use a Premier Twin 8 with two 8's in tandem with an HG2 and its one 8. I'd like 4 x 8 in a cabinet--on the HarpGear model. I'd mic it anyway, but that would give me stage volume in band contexts that I don't have right now. (I rarely play band gigs these days.)
|
phogi
419 posts
May 12, 2010
3:14 AM
|
Mine is like all amps: too loud!
|
7LimitJI
131 posts
May 12, 2010
3:54 AM
|
Adam I meant buy an empty cab eg 4 x 10" and cut a new speaker baffle board to fit the multiple 8's
----------
Those Dangerous Gentlemens Myspace
Due to cutbacks,the light at the end of the tunnel has been switched off.
Last Edited by on May 12, 2010 3:55 AM
|
JDH
53 posts
May 12, 2010
4:32 AM
|
@MP
Great, I haven't seen many champs for $15 lately, but cool. Find me one, hell find me as many as you can and I'll buy them all.
And as I said IT IS A DIFFERENT SOUND, you may not agree, and that's fine. Even at home I prefer most times these days to play through a Masco MA808, about 8 watts, through a 12" or a 10" speaker, because to me it's a fuller sound with more character than a champ style amp with a 6" or an 8". My experience has been that I don't like those squeakey little amps with their squauky little speakers in a situation with drums and bass, they just distort way too soon AND they have a tonality that doesn't do it for me most times. I will probably play one of my 12 to 20 watt amps anytime I play with a band, even at the same volume you may like a champ or someone else may like a kalamazoo. It all depends on the style of the band you play with. We can can play whatever we like the sound of. I have no argument for you about it. The ONLY thing I'm saying is that a miked champ is a miked champ, I don't want that sound. Can it be loud enough? Sure. But it isn't just a "loud enough" issue. Years ago when guys around here started playing little guitar amps and miking them, I continued packing my super reverbs around, because that's the sound I wanted, not because I couldn't have played through a Princeton rev and been heard, I just like the sound of my amps. I prefer guitar through a SR on 2 to a princeton at any volume, just not that into distorted little amp sounds, not everyone is. Hope that made sense to you this time. JD
Last Edited by on May 12, 2010 4:45 AM
|
htownfess
83 posts
May 12, 2010
5:49 AM
|
Shenanigans on the sales pitch is what I mean. As Mark says, Bruce Collins did not set out to design the best harp amp possible and the only boutique harp amp you'll ever really need, which is how someone else has been pitching it, but a good bang-for-the-buck 1x12 that would take care of his parts surplus during the introductory price phase, yet always have the inherent limitations of a 1x12, as well as the strengths of a well-designed one. Nothing nefarious about that, but it puts the pseudo-science about 4x10 not mattering (which Mark masterfully refutes) or the alleged attacks on 1x12s in a much different light. Bruce had a good plan that would have been better if the resulting amp had been allowed to do pretty much all the talking for itself, the way Meteor and Harp Gear amps are sold. I think we've all seen how excess sales zeal can give a boutique brand a checkered reputation.
I think 7LimitJI's account of owning and gigging with various adequately powered speaker configurations is about as good a generalization as can be made, given all the other variables in the matter.
Adam, since you use 8s with single-ended amps so much, the closest thing to a 4x8 version of that would be to commission a 4x8 Model 4A from Rob at Fat Dog Amps; but IIRC Rob doesn't like 8s for harp. Test-driving an SJ1 might be more likely. 4x8 is a pretty fraught enterprise, though, not as loud as one might think or hope.
|
Ev630
407 posts
May 12, 2010
6:11 AM
|
Look... I for one think that you're all being too hard on Rick. If he hadn't started talking about single 12" amps I never would have bought that Clark Beaufort this week.
Sweet, sweet Beaufort... winging it's tweedy goodness over the sea to join my luscious amp harem... Come to pappa, baby.
|
5F6H
125 posts
May 12, 2010
6:31 AM
|
"If he hadn't started talking about single 12" amps I never would have bought that Clark Beaufort this week." Ha ha, well to be fair, you would have just waited until the urge became uncontrollable next week!
|
Ev630
412 posts
May 12, 2010
6:48 AM
|
Dude. Is it that transparent?
|
Ev630
413 posts
May 12, 2010
7:09 AM
|
Hopefully not as unwanted!
|
Kyzer Sosa
506 posts
May 12, 2010
7:15 AM
|
ever since i got my IMT, it's loud as HELL!!!! yar har har har har har!!!! dont believe me?, ask my neighbors.... 5 houses down!
----------
Kyzer's Travels
Kyzer's Artwork
|
Tuckster
519 posts
May 12, 2010
7:33 AM
|
I was wary at first,but this turned into a very informative thread. Thanks guys!
BTW- you guys have 'way too many amps. You should unload them for cheap.:>)
Seems like some knowledgeable sorts here on speakers. What works for harp? Ribbed vs. smooth, alnico vs. ceramic,big magnets vs. smaller.
|
5F6H
127 posts
May 12, 2010
7:49 AM
|
@ Tuckster "Seems like some knowledgeable sorts here on speakers. What works for harp? Ribbed vs. smooth, alnico vs. ceramic,big magnets vs. smaller."
All of the above! Really you are better off looking for specific recommendations as to particular models, rather than focussing on secondary aspects.
In 10" I like the Eminence 102, Fane AX10 (now the Medusa 75), Fane AXA 10, Eminence Alpha, Kendrick blackframe...I prefer Jensen style alnico speakers in tolex amps, with a more scooped mid sounding circuit, but many others like them just fine in tweeds. Even in 10" the suggestions there cover all the perameters that you mention, without knowing more about the amp in question & more importantly, your personal preference, it's too open ended a question to give a definitive answer to...even before we start discussing different sizes. Probably best to start a fresh thread asking for recommendations for a particular amp, but be warned, tastes are highly personalised...ask 10 different folk and you'll get 20 different answers! ;-)
|
Tuckster
521 posts
May 12, 2010
8:06 AM
|
5F6H-Thanks. I guess it's not as cut and dried as I thought. I didn't know it would be so amp specific.
|
Rick Davis
385 posts
May 12, 2010
10:06 AM
|
Yikes! I appear to have hit a raw nerve!
On the notion that an amp with 4 speakers somehow magically kills feedback: Try playing harp through a Marshall Half-Stack. Your theory will get blown to pieces along with your head.
A Bassman is louder than other amps because it is more powerful than other amps, not because it has more speaker area. Some Bassman amps feed back less than other amps because they are voiced for BASS (duh) or for harp. Any amp regardless of speaker configuration can enjoy the same advantage with the proper voicing in its circuits.
I've played many Bassman style amps, some of which fed back like crazy at 2.5, and others that fed back at 5. To suggest they all are magically feedback free is to defy the laws of physics, and is just nonsense.
Four speakers driven by a single amp has zero advantage in perceived loudness or feedback resistance. Four speakers do not "move more air" since they are driven by one fourth of the power and their cone excursions are concomitantly less. VOLUME = WATTS X SPEAKER EFFICIENCY. Speaker area has very little to do with it. In fact, large speaker mass burdens your amp.
All the anecdotal examples given so far are flawed because they disregard the other, more important element of perceived loudness in any amp: speaker efficiency.
If you guys have questions for Bruce Collins about the new Mission Chicago harp amp I suggest you give him a call. His contact info is at the Mission Harp Amps website.
And Peace Out, Guys! No need for all this anger. I know it is uncomfortable to get your biases challenged, but some of the lore that floats around harp forums is just silly. The notion that volume = watts x speaker area is a good example. That is why I wrote this article.
|
Ev630
415 posts
May 12, 2010
10:49 AM
|
LOL. Thanks Rick.
|
htownfess
85 posts
May 12, 2010
12:32 PM
|
"On the notion that an amp with 4 speakers somehow magically kills feedback"
Why there's that same old straw man again! I'd greet him by name, but there's so many of them, I can't keep their names straight.
"All the anecdotal examples given so far are flawed because they disregard the other, more important element of perceived loudness in any amp: speaker efficiency."
Aren't most people smart enough to understand that reasonably equivalent speaker efficiency, reasonably equivalent speaker harp-friendliness and sufficient power to push the speakers should all be assumed when comparing the effect of different amounts of speaker area? Perhaps we should also specify that the amp should be standing upright with the speakers pointed at the audience, rather than lying face down on the stage. Oh, and turn the amp on, guys, that one's really, really important.
"I know it is uncomfortable to get your biases challenged, but some of the lore that floats around harp forums is just silly."
Buzz, buzz, buzz, goes the bluebottle . . . some of those straw men seem to have been through the horse already. Try sprinkling those shredded challenges on some pasta, Rick. Bon appetit!
|
Post a Message
|
