However, as evidence of what the "celestion technician" said, this woofer works well even in a adeguate closed volume like any existing woofer on planet earth. The fact of not using the bass reflex causes only a lost of a part of the extension at the bottom. Nothing to do with sounds bad or doesn't sound at all. No relevance with regards to making 1x12 or 2x12 but it was of few words: if Celestion is not interested in the same care for customers and the sale of their products...
see pdf file
btw this is from the celestion site, not my plan
I'm sorry I didn't realize that I had followed the PDF project I thought I had done an open back with custom sizes
Yes. The specs give the length and diameter of the tube. The maths on the acoustic properties of the port tube will have been done by the designer. I would have to agree with Nightlight that the dual speaker thing is a complicating factor for sure. You could split the cab by inserting a divider which would halve the volume and stop the drivers interacting. You could also wire it in stereo.
This split design is used in some commercial cabs. Mesa Boogie make a split 2x12 cab for the Road King line. It has a sealed box in one half with a Mesa V30 in it and the other half has a ported back and a C90 black shadow. You can mic either or both and the matching Roak King heads are swiss-army knife designs with multiple channels with different preamp circuits covering everything from fender clean through classic rock to high gain stuff.
yes you are absolutely right. I reasoned like a typical box while perhaps it is better to think differently. One of the two cones is already on its way to Thomann. The 1x12 project is under construction
Do both speakers have the same impedance curve?
You may have said it already and I just missed it but does it sound better with just one of them hooked up?
As I wrote in my last post I have not yet measured both but only one. During rehearsals I realized that only one "played correctly", ie one sounded "decidedly bad as if it was broken", the other sounded better. I do not overreact to say that one sounds good because the judgment would give it only at the end of all the tests. The disappointment remains regarding the "technical support", which is definitely non-existent.
digbob I'm still waiting for the answer, thanks
The saga of the F12 cones continues. Celestion technical assistance leaves me a little perplexed about the "very little technical answers". Answers a little pre-packaged against my detailed report. Now I have submitted to him the graph of the impedance module measured with a 100 Ohm peak (see previous post), let's see if the defect or difference I hear by ear between the two cones can refer to that. In fact, only one of the two had been measured and it is precisely what I think feels worse between the two. Later I will repeat the measurement on the other.
The only certain data is that 1 F12 cone works well in a volume of 50 liters in a closed box (in addition to the reflex project already seen), only a bit of extension at the bottom is lost. No particular shapes or magic, for them this speaker has to sound good in such a case.
something must be wrong
my 1x12 is great
I'm glad your cab goes well. Out of curiosity, could you post the project? Exact measurements and everything else, so as to make a couple of arguments on a concrete basis. Thanks!
EDIT: I'm conversing via email with Celestion support, for now I have made them aware of the tests carried out just as described on the forum pages.
I decided to render Thomann 1 speaker because doing the tests individually, one sounds different from the other.
I will continue with the 1x12 project by remaking cab's front baffle.
I have hunted back through the thread a couple of pages but didn't spot what you are using for amplification, Jeega. If it is alredy there somewhere would you mind posting again what is driving these?
Hi, I have a powered Kemper rack.
Today I connected another my custom 2x12 closed back. Inside there's a Mesa Black Shadow C90 (as in the other cab) and a V30 UK. The profiles sound a little bit darker and closed than the Vox open back cab but can be listened to and played very well. I could try to open the cab with the F12-X200 to hear the differences.
A little update: I tried several rigs in 1x12 " configuration and I'm totally disappointed with the sound. I just wrote to Celestion describing the situation and asking for an opinion and measures for a cab. I am seriously considering returning the speakers to Thomann under the 30-day guarantee.
Maybe go with Thiele dimensions for a cab? Assuming you want FRFR reproduction, this is the reference I would use for dimensions if I didn't have the luxury of building multiple boxes for experimentation.
sure today I will experiment with the 1x12 version and if I have the desired results I will move in this direction. Bad that I go I will have a spare cone or I'll sell it
guarda, sono giunto al punto che lo proverò in versione 1x12 che SEMBRA che funzioni meglio e dia meno problemi
Not sure I can give you the answer you'd expect. It would be like asking so what do you suggest to do in order to become a great guitar player, not in theory but in practice.
How to build a F1 car? Not in theory, but in practice? It requires skills, competence, experience, and a lot of work. You can't just take any frame, install the most powerful engine you can find, design a body you like, and hope that it won't crash at the first turn (provided it actually runs, or even starts, and doesn't gets on fire).
It's the same for a linear cab: a cab able to work in a linear way (that is, with a more or less faithful way to the input) is the result of the optimisation of an intricate set of parameters, many of which conflicting with each other; it's designed and built through computer-aided parameters simulation, going through a number of compromises among physical quantities, and through long listening sessions in order to fine tune the involved parameters and the sound.
Even varying the size of the front panel, other things being equal, changes the sound because border diffractions change.
Basically, the short answer would be "you have to know what you are doing, be equipped with the needed tools, and have a great ear".
IIRC you read Italian. There are several apps meant to guide to the correct dimensioning of parameters for an acoustic cabinet, this one being one of them.
A very long post. Audio for Windows, thank you, I didn't know him (sarcastic).
I've never built a cab, but I've been in electroacoustic since a while.
You can't expect to just mount a speaker in a box and get a great sound: box' metric volume and proportions, resonance modes, front diffractions, distance between the loudspeaker and the ground/base... are all aspects that receive a lot of attention at design stage, and can't be left to chance.
Things get much more complex when you place two loudspeakers in a box: even when they are phase-coherent, the distance between them will unavoidably create a phase filtering which will be (also) function of the listening point.
Things are much easier with a mid-woofer such as those used for guitar cabinets, because there are much less frequencies involved and a linear response is not required. But you can't just place two linear cones in a box and hope they will sound good (if they do, it will just chance).
In this specific case, if the cab seems to produce an out-of-phase sound, it might be worth putting them out of phase: chances are it will sound better (but, again, not the way it was supposed to).
Basically, I believe we can't judge the way these cones sound by a random installation.
so what do you suggest to do, not in theory but in practice
Yes, me !!! I've seen them live 3 times (1994, 2015, 2016) really a great band
I'm super curious! Are these done with or without the cab sim button on, monitor cab off? Any tests with the aboved mention while using Pure cab? Thanks!
hi, with cab sim and testing different settings about pure cab
They might be electrically in phase, but they might not be phase aligned.
As far as jeega's report on strange sense of the location of the sound, I was thinking about the effect on imaging of two tweeters ~14" apart. Not exactly a point source. The twin driver cab might be better in stereo than in mono.
for this reason I am curious to try also the operation of a single cone
it being understood that the loudspeakers are electrically in phase, the following tests will be disconnected one (short-circuiting it so that it does not behave as a passive radiator) and repeating the tests on the rigs, finally it occurred to me to change the type of connection (series -parallel) to hear if there may be sonic differences.
The suggestion by PaulTS on phase reversal looks to be well worth checking into. Users often comment that speakers with a compression driver tweeter sound better at a decent distance - ie not at home but on stage or in a large rehearsal space.
i will check the phase asap
EDIT: i confirm that they are electrically correctly in phase
something must be wrong
i have a 1x12" cab with the Celestion F12
and its glorious sounding with any Kind of Profile
there must be a problem with your build
maybe this it's the key ? i mean, it sound better in 1x12 version? it's just a hypothesis...
I was hoping the review would be positive. I was seriously looking at this speaker for a DIY FRFR powered cab with the Dayton Bi-amped plate amplifier that Xitone is using in the MBritt cabinet. I apologize if this is covered in earlier posts, but Jeeega, did you build the cab for this speaker? If you did, can you post pics or links to the plans you used? I'm curious to see what kind of cab you have the speaker in, and what you powered it with. Also, do you think that the speaker could benefit from disabling the high pass filter and using an active programmable crossover such as offered with the above mentioned Dayton plate amp?
Me too :-/
I used a Marshall box with a generous internal volume, it is amplified with the Kemper, I don't use external amplifiers. I also modified (or rather built from scratch) the baffle to mount the speakers from the outside and flush with the panel minimizing the deleterious effects of mounting them with a step on the edge of the woofer. Pics of everything can be found in previous posts.
The high pass filter protects the tweeter and makes it work (actually) little. I have no acute problems (they are sweet and do not pierce the eardrums) nor of bass (full, full-bodied and present) but of perception of sound (it seems to come from the other room) and of sound quality (off, dead, lifeless, plasticky, fake). Could we do it again in a passive way? Sure. You could use an active crossover, surely, intercepting the tweeter wiring but I don't know what the advantages. In theory it should already sound like this.
Aggiornamento sull'ascolto della mia FRFR: trovo i suoni privi di vita ed emozione, il suono in generale è molto asettico, plastico e di una precisione chirurgica che mal si abbina a tutti quei suoni vintage-style. Suona molto lontano da un valvolare, molto più vicino ad un brutto transistor. L'unico vantaggio è che i suoni tra loro si distinguono meglio mentre con la cassa tradizionale distingui un Mesa da un Marshall ma poi le differenze si assottigliano con gli ampli della stessa tipologia. Con la cassa tradizionale e con qualche accorgimento, non solo a livello di suono ma anche di dinamica i suoni sono molto più simili ad un valvolare, specie i crunch che reagiscono proprio bene e restituiscono molte più sfumature rispetto a questa FRFR. Attendo con ansia il confronto con Paradigma, nel frattempo continuo gli ascolti e a breve trasferirò il tutto in sala prove per verificare non fosse un problema di volumi. Mi è venuto in mente anche di scrivere alla Celestion per verificare se il progetto della cassa in cui ho racchiuso i coni non fosse sbagliato. Ciao!
So I tried the FRFR cab a bit (with apartment volumes without the neighbors calling the police), the same volumes I use the traditional guitar cab. The first fault I find in this FRFR is that the sound seems to come from the next room. While disabling any effect such as delay or reverb, this unpleasant feeling remains, confirmed by the fact that as soon as the traditional case is reconnected (2x12 Vox open back loaded with Black Shadow and Vox by Wharfedale) the sound is there, precisely, it comes out of the speakers and it is precisely where it should be. This issue of the point of emission displaces me a little. Secondly but not least the sounds: by using the cabinet section correctly you get more marked differences between one amplifier and another compared to using it with the traditional case but unfortunately the sounds are very aseptic, with a surgical precision that is not suitable for everyone those vintage-style sounds while they probably go better with modern-style sounds. They also lack something I could define as "life". With the traditional case the crunch sounds for example react at the level of dynamics exactly as a true tube amp would do, which I own and can connect at any time to verify. They don't make your heart beat, they don't convey emotions, they don't push you to linger on a sound for half an hour just to try to listen to all the nuances because they are missing ... they are rather flat and precise, they look much more like a bad amp transistor than a tube. They sound a bit fake and plastic. Reserve the right to make a new session of similar listening, after which I will transport the whole system to the rehearsal room where I will do the same tests at a bit higher volumes. It will take three or four days but it will be done and I will update you on the results. I could write to Celestion to see if I did something wrong in the project for example. Post Scriptum: I can't wait to compare my system with the J&F Paradigma. Ciao!