|
|
Post by pnystrat on Jul 25, 2013 3:52:10 GMT
Hey Everyone, I was hoping someone out there has or has trialled the Vox AC15C2 which is 15 watt tube amp with twin Celestion Green Back speakers. The reason I'm looking at this particular amp is because currently I am borrowing an friends amp (I usually use a Fender Super Champ XD at home) and would like to have that chimey Vox sound in something louder.I have started gigging again with a live band and was looking for something that has enough head room to be heard at smallish venues and the general reviews sound positive. Please don't suggest an AC30 as, although its a great amp, its in the "222" category for me (2 heavy, 2 loud and 2 expensive) so I'm hoping the AC15C2 would be a good compromise. Any feedback would be appreciated. Cheers pnystrat  |
|
|
|
Post by didier on Jul 25, 2013 16:08:39 GMT
The AC30 was fitted with two speakers only because each speaker could handle 15W only, so a single speaker would not have resisted long...
Two speakers are totally useless on a 15W amp, I think you'd better stick to the AC15C1...
Didier
|
|
|
|
Post by twang46 on Jul 25, 2013 18:04:37 GMT
Two speakers are totally useless on a 15W amp, I think you'd better stick to the AC15C1... Didier Controversial statement there Didier  2 speakers on the AC15 works very well in my opinion Dick. |
|
|
|
Post by gitfenburn on Jul 25, 2013 20:13:26 GMT
Hi,
I have an AC15C2 and find it excellent for Shadows sounds, but have only used it at home and never gigged with it,there is certainly plenty of volume available.
The AC15C2 has the same cabinet dimensions as an AC30 and is comparable in weight.
It has a weight of 30.2kg compared to about 32 - 33kg for an AC30. For comparison the AC15C1 has smaller cabinet dimensions and a weight of 22kg.
Hope this helps,
Alan.
|
|
|
|
Post by didier on Jul 26, 2013 8:03:54 GMT
Two speakers are totally useless on a 15W amp, I think you'd better stick to the AC15C1... Didier Controversial statement there Didier 2 speakers on the AC15 works very well in my opinion Dick. What two speakers will bring when one is enough ? It will not make the amp louder, the power comes from the valves, not from the speakers. Speakers are passive devices, transforming only a fraction of the electrical signal into sound. Speaker's power rating only indicates how much electrical power it can handle without being damaged, the sound level will depend on the speaker's efficiency : 98 dB/1W/1M for the Celestion Greenback 12" 100 dB/1W/1M for the Celestion Blue Alnico 12" An AC15C1 is quite loud enough for small venues, is cheaper and lighter than the AC15C2. The interest of the AC15C2 is only cosmetic... The AC15C1X with its Celestion Blue Alnico 12" speaker would be the best, but it's more expensive. Didier |
|
|
|
Post by rogerbayliss on Jul 26, 2013 17:08:17 GMT
I thought that the AC15 was done as a Twin amp back when the Beatles were using them ?
|
|
|
|
Post by pnystrat on Jul 27, 2013 4:50:43 GMT
Many thanks Didier, Twang46, Gitfenburn and Rogerbayliss for your comments. they have been helpful.
I will continue to consider the options as I would prefer my final choice to be final.
Cheers
Pete (pnystrat)
|
|
|
|
Post by didier on Jul 27, 2013 8:08:31 GMT
I thought that the AC15 was done as a Twin amp back when the Beatles were using them ? The AC15 twin was introduced in 1961 as a budget AC30. The Beatles were unknown at this time, and played no part in its design, unlike The Shadows who requested amps louder than the AC15, which led to the design of the AC30. John Lennon bought an AC15 Twin in 1962 (while George Harrison got an AC30). John's AC15 twin was traded in when he got an A30 in 1963. Didier |
|
alanbakewell
Member
Be nice to people on the way up, you might just meet them on the way down.
Posts: 147
|
Post by alanbakewell on Jul 27, 2013 10:02:10 GMT
An interesting thread. I have toyed with the idea of an AC15 2 ( twin speakers )recently.
The salesman in the shop in Birmingham asked why I'd chosen to look at an AC 15 2 ( twin speakers ). I told him that due to the weight of the thing an AC 30 is out of the question these days and an AC 15 would be quite loud enough for my purposes.
He then informed me that an AC 15 2 ( twin speakers ) is almost as heavy as an AC 30. ( Check the specs. for yourselves ).
At the time of this conversation I never thought to ask why two speakers? I will however ask the next time I'm in the shop.
I have to say Didier, that certain manufacturers might disagree with your theory. Particularly the ones who fit two, or even four speakers to their amps. and cabs.
For the record. For the last four years or so, having used many amplifiers, I am now using a Peavey Valve King 112 ( Single speaker ). I find this amplifier has a great sound ( in my opinion ).
And, I can lift it. ;D ;D Further to this, check 'em out on E-Bay. Mine cost £170.00 second hand.
In the last four years it's needed the attentions of my good friend Amanda Hambidge for two things, valves and a bit of soldering.
You might want to try something on these lines before parting with hard earned cash.
I've never regretted it.
Will I try something else in the future? Possibly, but not for a while yet.
If you're anywhere near to me and want to try it, send me a message and we can arrange something. I'm near to Lichfield in Staffordshire.
Cheers, Alan.
|
|
|
|
Post by didier on Jul 27, 2013 15:29:51 GMT
I have to say Didier, that certain manufacturers might disagree with your theory. Particularly the ones who fit two, or even four speakers to their amps. and cabs. The first AC30 models had only one speaker, but this was quickly dropped, because the speakers used at the time couldn't handle more than 15 W. Using several speakers has some consequences because of inteferences which leads to some directional effets. But placing two speakers side by side is totally illogical, they should be placed one above the other. It may improve a little the lower bass response, but this is of little use for guitars amps. Another consequence is that in a 15W amp with two speakers, each speaker will only get 7.5W, which mean they will work well beyond saturation. The Celestion Alnico Gold 12" handles 50W when the Celestion Alnico Blue handle 15W. The only difference between both is that the paper voice coil from the Blue has been replaced by a more resistant material in the Gold (kapton or similar). I don't think there is a major difference in sound between the AC15C1 and the AC15C2. The only advantage for the AC15C2 is that the owner will have an AC30 lookalike at a lower price... I have heard AC15s and AC30s in many different situations, and for small venues, the AC15 is largely loud enough. I know bands who have dropped theirs AC30s for AC15s (mono)... Didier |
|
|
|
Post by rogera on Jul 28, 2013 8:31:25 GMT
Having two speakers gives a much better distribution of sound and of course is able to move more air than a single speaker.
One of the best sounding Vox amps that I've ever tried was a 1962 AC15 twin and seemed as loud as an AC30.
|
|
|
|
Post by didier on Jul 28, 2013 16:54:26 GMT
Having two speakers gives a much better distribution of sound. Depending on frequency (wave lengh), sound from both speakers will add or substract themselves, because of interferences. This leads to some directional effect.  Putting several speakers one above the others (vertical speaker columns) give a narrower vertical sound dispersion, hence less reflections on ground and ceiling, which is generally better than a narrower lateral sound dispersion. The Bose L1 speaker system is based on a vertical line array of serveral small speakers. Each speaker receiving half of the power, there will be no more air moved, apart at lower freqencies where coupling between cone and air will be improved. It all depends on how these amps were set and which speakers they used. There are no miracles in electro-acoustics. Didier |
|
|
|
Post by rogera on Jul 28, 2013 17:21:39 GMT
Didier each of us is entitled to our own opinion and I think that it is best left at that.
|
|
|
|
Post by stramocaster on Jul 28, 2013 18:10:08 GMT
For us debate watchers, "each is entitled to his own opinion" does not help much. We tend to lean towards an opinion backed by facts rather than one backed by observations.
|
|
|
|
Post by rogera on Jul 28, 2013 18:53:13 GMT
Stramocaster the best advice that I could give is to try listening to a single speaker Vox AC30 and then compare it to one with two speakers.
Almost all of the most famous combo amps have had two speakers.
|
|
|
|
Post by didier on Jul 28, 2013 20:02:00 GMT
Stramocaster the best advice that I could give is to try listening to a single speaker Vox AC30 and then compare it to one with two speakers. Almost all of the most famous combo amps have had two speakers. The one and only reason why "famous combo amps" had two speakers is because speakers of this time couldn't withstand enough power, it was only a reliability issue. The was no sound improvement in mind. Placing the two speakers side by side shows that those who designed it knew nothing about acoustics. It was done so only because it was more practical for the cabinet design ! But with time, defects can become qualities...  I have heard so many times different kinds of amps, and for small venues, an AC15 single speaker is perfect for tone and quite loud enough. One of the most renowned French Shadows' tribute band has long stopped using AC30s in favor of AC15s (single speaker), which are miked when they play in large venues. Not being a player myself allows me to be more objective on a very subjective issue... Didier |
|
|
|
Post by twang46 on Jul 29, 2013 0:55:35 GMT
Hi Didier
While it is good to be objective & your seemingly encyclopedic knowledge of facts & figures is to be admired............music is about much more than engineering & design.
Some of the best sounding amps/speaker cabs are quite flimsy & use cheap "off the shelf" components.
A notable example of this is the original Marshall 4x12 cabinet that was deliberately made as small & as cheaply as possible yet is loved by all who play the Marshall amps.
I personally don't care what the technical characteristics of a amp or combo are.....................if it sounds good, it is good.
I also like the sound of twin speaker (side by side) combo's & do prefer them over the alternative single speaker combo's.
The only drawback I can see with the AC15 twin is the weight which is only a few kilo's less than the AC30. In real terms there is little difference in volume between the two.
Dick.
|
|
|
|
Post by allclaphands on Jul 29, 2013 6:29:19 GMT
Must say the members are making this thread very interesting to follow.The opinions of each varies considerably .Interesting debate. Keep Smiling Pete  |
|
|
|
Post by didier on Jul 29, 2013 8:07:37 GMT
Hi Didier While it is good to be objective & your seemingly encyclopedic knowledge of facts & figures is to be admired............music is about much more than engineering & design. Some of the best sounding amps/speaker cabs are quite flimsy & use cheap "off the shelf" components. A notable example of this is the original Marshall 4x12 cabinet that was deliberately made as small & as cheaply as possible yet is loved by all who play the Marshall amps. I personally don't care what the technical characteristics of a amp or combo are.....................if it sounds good, it is good. I also like the sound of twin speaker (side by side) combo's & do prefer them over the alternative single speaker combo's. The only drawback I can see with the AC15 twin is the weight which is only a few kilo's less than the AC30. In real terms there is little difference in volume between the two. Dick. You are right, the main thing is to have a sound you like, but hearing is highly subjective and listening memory isn't very reliable. What players very rarely do with amps is to do blind tests to eliminate subjectivity. At some of our meetings such blind tests were done. In one case it was about a "box" which was supposed to give Hank's tone. Thanks to a switching system, a band played live with the lead guitarist using or not the box, but the audience didn't know when the box was used or not. The difference in sound was almost inexistant, and when asked when the box was used, around 50% of the audience got it wrong. I was part of those who were right, but this was pure luck, as I didn't notice any difference. Yet many people are happy with this box... In another case we listened to two AC30s, one fitted with greenback speakers, the others with blue alnico speakers. The same guitarist played alternatively both amps with instant switching. The difference in sound was very slim, and it was difficult to say wich one was the best... But when you buy expensive equipment, subjectivity will make you feel it's much better ! Didier |
|
|
|
Post by shadowkarl on Jul 29, 2013 13:26:54 GMT
Hello Didier,
two comments on your elaborations:
1. I do have an expensive HI-FI Loudspeaker system and as you said, the speakers, (incl. a bandwidth hi-tone element) are designed as one above the other. Was that not called a D'Appolito-Design?
2. Was that box in your last comment not the ARIAB from Roberto?
Kind regards on that ever interesting subject of amps and loudspeakers.
shadowkarl
|
|
|
|
Post by didier on Jul 29, 2013 14:27:31 GMT
Hello Didier, two comments on your elaborations: 1. I do have an expensive HI-FI Loudspeaker system and as you said, the speakers, (incl. a bandwidth hi-tone element) are designed as one above the other. Was that not called a D'Appolito-Design? The d'Appolito configuration is based on a tweeter placed between two identical bass/midrange speakers vertically spaced and working in parallel. When matched with a carefully designed filter, this is supposed to reduce interferences between the tweeter and the two other speakers.  I own a pair of Hi-Fi speakers (KEF C75) which use a different system :  The two 8" speakers work in parallel for bass only, they are filtered so that only the upper one works for midrange, and the tweeter is in the middle of this upper speaker (concentric, the same as the famous Tannoy speakers wich were used in the Abbey Road studios as monitor speakers). No interferences and phase problems ! I didn't gave any name on purpose, as I don't want anyone being upset... Didier |
|
|
|
Post by rogerbayliss on Jul 29, 2013 14:59:35 GMT
My observation re the vertical placing is that the bass speakers go at bottom to increase bass response at floor level and the mid clearly goes above that and naturally the tweeter belongs at the top. That's a HiFi arrangement and most guitar combos have 2 side by side possibily to increase bass response from speakers and for looks and design needs. Point here is no tweeters and mid range horns just 2 speakers for guitar cabs.
A HiFi arrangement is an ideal arrangement for the reproduction of recorded sounds the guitar amp is a different beast.
The design has lasted for decades and you can lift cabs off the floor onto stands to change the sound and projection a bit.
There are many manufacturers who have made 2 speaker combos at 15 watts or less and yes you guessed it the speakers are nearly always side by side and I think the manufacturers would know ?
Two speaker cabs sound different to single speaker cabs and there is some phase changes in the twin speaker versions. Why would modellers like Line6 model 2 x 12 and 1x 12 speakers if there was not a difference for example.
There are lots of different speakers and they are all different in their responses and sounds and a greenback and a blue celestion are different in sounds else we would not bother would we ?
|
|
|
|
Post by didier on Jul 29, 2013 17:22:58 GMT
My observation re the vertical placing is that the bass speakers go at bottom to increase bass response at floor level and the mid clearly goes above that and naturally the tweeter belongs at the top. That's a HiFi arrangement and most guitar combos have 2 side by side possibily to increase bass response from speakers and for looks and design needs. Point here is no tweeters and mid range horns just 2 speakers for guitar cabs. It's a very well known issue that placing speakers near the floor increases the bass, because of reflections on the ground, but not necessarily in a good way (too much bass decreases sound clarity). This is why Hi-Fi speakers are often placed on stands, sometime specially designed.  I have long been using a pair of Kef Coda speakers, and I built myself stands, and got a significant improvement in sound clarity. The laws of acoustics are the same for everyone, but the purposes of Hi-Fi and guitar amps are not the same. The Shadows almost always used their famous chrome stands... As long as their amps sell well, why should they care ? The look of an amp is almost as important as its sound ! It's like low profile tyres on large wheels for ordinary cars... It's true there are differences for two reasons : With two speakers, interferences will alter the response. With two speakers, and for the same sound level, each speaker will work at half power, further away from saturared sounds. As I wrote, immediate comparition test showed very little difference in sound between the greenback and the blue, while the difference in price isn't small... Anyhow the most important thing is to be pleased with the sound you get from the gear you have chosed ! Didier |
|
|
|
Post by Charlie Hall on Jul 29, 2013 18:10:55 GMT
The manufacturers apparently didn't know.
It is a known fact that vertically arranged speakers disperse sound horizontally, and horizontally arranged speakers disperse sound vertically. I don't know beyond that, it's what I have learned from reading. I have to assume it only applies when identical or near identical speakers are used. What I'd really like to know is if a rectangular baffle makes a difference whether set up vertically or horizontally, with a single speaker, apart from the contact area with the floor assuming a stand isn't used.
Fender probably had realised in the 60s when they made the vertical Dual Showman cabinet instead of the previous horizontal Dual Showman cabinet. I never owned either one so I can't talk from experience.
People talk about how directional an AC30 sounds. There has to be a reason for that. Not that we can do much about it as they would all overheat if arranged vertically.
Whether we prefer one or the other is something else. I prefer the look of the horizontally arranged speakers of a 2 X 12 cab or combo.
It must matter less as far as the sound out front is concerned if the sound is reinforced with the PA. What remains then is how the back line sound is dispersed for the players on the stage.
Regards,
Charlie
|
|
|
|
Post by glyderslead on Jul 29, 2013 18:50:16 GMT
I understood from Didiers comments earlier that a 30watt amp with with two 15watt speakers can't be improved upon (other than speaker sensitivity) so it seems that an extension cabinet is a waste of time. But I have just seen a comment on a vox site regarding the AC30 Custom hich is copied here:
"Power Sharing
The AC30C2 and the AC30C2X amps make use of 3 x 12AX7 preamp tubes and use 4 x EL84 tubes to deliver 30 watts of power. The AC30C2 uses two 12" Celestion G12M Greenback speakers. The AC30C2X uses two 12" Celestion Alnico Blues. All models in the Custom Series offer a switchable 8/16 ohm output jack for powering an external speaker cabinet when you need to speak with a little more authority; using this jack will mute the internal speakers. Additionally, a 2nd extension speaker jack allows you to run an extra 16 ohm cabinet along with the internal speakers for a fuller sound."
So, just how does it speak with extra "authority", where is it coming from? All a bit confusing really.
Mick
|
|
|
|
Post by Charlie Hall on Jul 29, 2013 19:38:08 GMT
I think additional speakers can help. I remember seeing a band whose lead guitarist used an AC30 on top of a Vox Supertwin extension cabinet. In effect, a 4 X 12 AC30. It did seem to sound bigger than a combo on its own would have done. Certainly bigger sounding than the AC30 I owned and used at the same gig. Maybe it has something to do with the speaker cone break up. It would occur at a higher volume level with more speakers. Then there is also the compression effect of alnico speakers. This too would change with more speakers.
Regards,
Charlie
|
|
|
|
Post by neil2726 on Jul 29, 2013 19:44:56 GMT
Dumb question ? Why were speakers in guitar amps placed horizontally and PA speakers (columns) vertically?
|
|
|
|
Post by Charlie Hall on Jul 29, 2013 19:59:34 GMT
Good question and totally relevent, because the sound is better dispersed horizontally with column speakers.
I have to say that while relevent, little of this is really helping Pete to decide which amp to buy. I really don't have an answer other than to try both before buying if possible.
Regards,
Charlie
|
|
|
|
Post by didier on Jul 29, 2013 20:14:24 GMT
Dumb question ? Why were speakers in guitar amps placed horizontally and PA speakers (columns) vertically? PA speakers are placed vertically because it allows a better sound dispersion in large halls. Guitar amps speakers are placed horizontally because it allows a more practical case... People who designed Fender Twin and AC30 didn't care about sound dispersion, they cared only about sound level and reliability. Remember that the very first AC30 models were single speaker... But now that people have been used for many years to such prestigious amps with two speakers side by side, it would be a marketing suicide to propose something else... The recent AC30-CC1 single speaker amp was certainly an excellent amp, and got excellent reviews, but didn't meet commercial success. An AC30 must have two speakers, regardless how it sounds... Didier |
|
|
|
Post by rogerbayliss on Jul 29, 2013 21:36:42 GMT
Regarding the AC30 being very directional (Charlie Hall above) I can say my own AC30 proved often to be so and a friend of mine who builds his own cabinets agreed it was . He built several cabs with redesigned speaker baffle boards with various angles to direct the sound outwards and sidewards better giving a better spread with success. So I believe the baffle board can be sorted to reduce the issue if an issue.
|
|
