Qts was tested around .79, so 3ft makes for a sealed qtc 1.1
The manufacturer's ported box is less than 3ft3 ported to 50hz and has a hump near 100hz (box too small).
I'd bet it would want 12ft3 for an ideal ported box, too big for me but might be a fun bachelor project.
So, it should work well for open baffle.
I think it is a more than safe assumption.
The manufacturer's ported box is less than 3ft3 ported to 50hz and has a hump near 100hz (box too small).
I'd bet it would want 12ft3 for an ideal ported box, too big for me but might be a fun bachelor project.
So, it should work well for open baffle.
I think it is a more than safe assumption.
I briefly tried my similar 12 LTa of a 4 x 2 x 2" polystyrene baffle ( 8 foot sheet for building work at about $20 ). I had in mind to make a picture frame U section to make it stronger and use 1/2" plywood mini baffles clamped with bolts and wing nuts ( front and rear ). The 50/50 plywood and MDF of 1" sounds more 1950's. The polystyrene reduced the shout as the frequency limit is reached. It would cost about the same either way. I am glad I did go the conventional way as if not I suspect nothing would have moved on. If anything the polystyrene had the batter bass. I was surprised as although low in mass it seem to have an unpleasent sound when tapped. 78's seemed very open.
Thanks looks good for a OB project then with the .79 Qts.
Nigel I think the LTa is maybe not as similar to the Fane. Different cones and companies, parameters etc.. If I get the Fane and go OB it will be atop a pair of the MJK H-Frames I have with the 18" Goldwoods.. I'm thinking maybe a 20"X 22" baffle in a U-frame style or a stuffed open back box maybe.. Thanks for the info guys!
Nigel I think the LTa is maybe not as similar to the Fane. Different cones and companies, parameters etc.. If I get the Fane and go OB it will be atop a pair of the MJK H-Frames I have with the 18" Goldwoods.. I'm thinking maybe a 20"X 22" baffle in a U-frame style or a stuffed open back box maybe.. Thanks for the info guys!
I realise that to the point of thinking I should buy some Fane's. From my experiments 4 x 2 " is a minimum size. You win more than your loose by rejecting the box. Quad pointed the way of that. 4 x 2 is what the DIY store has. At first it not having a 1 to 1.618 look made it seem less than pleasing to the eye. BTW 1:1.618 to me has no automatic " rightness " about it.
I also have a 15 inch much like an Alpha 15 " at the baffle base ( rolling off at about 400 Hz ). This gives a total cone area of about 19 inches. The Qts of the 15 is 1.2. 40 Hz is strong and 30 Hz still giving good ouput. Neither driver is botoming due to EQ ( about + 12 dB 30 Hz ).
I also have a 15 inch much like an Alpha 15 " at the baffle base ( rolling off at about 400 Hz ). This gives a total cone area of about 19 inches. The Qts of the 15 is 1.2. 40 Hz is strong and 30 Hz still giving good ouput. Neither driver is botoming due to EQ ( about + 12 dB 30 Hz ).
Because the baffle will be atop my h-frames although at a diagonal angle, the front length of the baffle will effectively be the 22'' + the 21.5" of the h-frame so 43.5". Then if I U-frame the 20'' width I could easily make it see 30" or more etc.. Dunno until I try though and sealed may also be an option.. One thing I love about the H-frames for the lows is they sound very good and make things compact, but I do not like them used like many do where they're crossed high enough to hear vocals come out of them. So I cross mine at 24db @ 70hz or so.. Basically I put my ear to them and dial down until any vocals just disappear, I find they are excellent performers used more as subs or augmenters. When you have a woofer in the middle of a square box like in the H-frame design it just doesn't sound right to me having vocals coming out from being inset in a box.. I haven't done any modeling yet and will need the Fanes to get down to 60-70hz so we'll see when I actually get a pair ordered..
Mine is the lazy version as we had at school in the 1960's. The 15 inch just about takes me to where the Quad ESL went in terms of bass. Some will say the Quads lack bass. Not really, much bass is made by the box. After a few weeks the "new bass" is the prefered bass. I would not pretend these speakers equal the ESL's. They keep up very well and will take any amount of abuse. I am convinced that the baffle material is the one thing holding them back. Like the Fane the polar response is not fantastic higher up ( > 6 kHz), the ESL's also. In the ideal world I would roll off at about 6 kHz and have a tweeter going up to 30 kHz. At this point it will have to be active. I have been offered some JBL pro tweeters. Perhaps I could use them. At that point the low cost idea goes out of the window if I had to buy them. Right now I use some DT74/8 with some EQ crossing at 6 kHz 1st order. The tweeters almost sound as if doing nothing. I can remember some LP's before they were fitted that sounded very boxed in, not now.
A friend has 15 inch Tannoy's in Lancaster cabs. I'm trying to get him to do some baffles. I suspect they would be fine with my 15 inch bass units. The Tannoy's sound very dark as designed. Audiophile crossovers don't seem to have changed that ( not my idea ). We fitted some very cheap Motorola type tweeters with good results ( $8 the pair ). Adding correct crossovers made them less good !!! Some put them behind the speaker and fire against a rear wall.
A friend has 15 inch Tannoy's in Lancaster cabs. I'm trying to get him to do some baffles. I suspect they would be fine with my 15 inch bass units. The Tannoy's sound very dark as designed. Audiophile crossovers don't seem to have changed that ( not my idea ). We fitted some very cheap Motorola type tweeters with good results ( $8 the pair ). Adding correct crossovers made them less good !!! Some put them behind the speaker and fire against a rear wall.
I use a 25 mm MDF and ply single baffle with gate hinge and 2 inch fence post prop prop. Making the polystyrene work is difficult. The Fane would be worth trying. Also a sub from 12 ( - 20 dB at a guess) to 40 Hz ( stereo, not least more air moved).
Phi+1 = (5+root5)/(5-root5). It's a nice example of how to calculate 1.618 or it's square Phi+1 = 2.618 (0339887499 using a cheap Nokia phone as calculator ). I always called Phi and Pi real numbers, seems I am not alone. Pi/1.2 = Phi+1 reasonably well. Pi= root2 + root3 also. Phi is more usually ( root5+1)/2. Phi^10 = 123 Phi^11 = 199, these numbers become more accurate as the powers increase. The number 5 says to me 5 fingers might be better than the " ideal " 6 people speak of ( 1,2,5,10 verses 1,2,3,4,6,12 and even 8,9 ). The fact 123 is Phi^10 looks rather useful in the system of 10. Also 1 and 2 in the classic Phi approximation. One thing that doesn't help is ( Phi,Pi,e,0 )^0 all = 1. Although it is nice to have an exact solution for Pi. 0^0 seems unlikely the more I think about it. If that is right it could suggest why linear maths can get complicated. That implies there is no such thing as 0 except as a point of reference which can be imagined and approached. i^i has an accepted solution and it is positive. It isn't 1 ( i= root -1 ). i is called an imaginary number, yet i suspect in Quantum paradox it is a reasonable explanation. 0 and infinity seem imaginary, infinitity put simply hasn't happened yet and never will. Thus two things we state as fact are limits of equations and one we think daft must exist although irrational ( I hope you like the word play ). i^i might even be easy to state as transindental. If it is, it certainly should exist.
I put this in as the use of Phi is often suggested without any reference to why it might work.
Phi+1 = (5+root5)/(5-root5). It's a nice example of how to calculate 1.618 or it's square Phi+1 = 2.618 (0339887499 using a cheap Nokia phone as calculator ). I always called Phi and Pi real numbers, seems I am not alone. Pi/1.2 = Phi+1 reasonably well. Pi= root2 + root3 also. Phi is more usually ( root5+1)/2. Phi^10 = 123 Phi^11 = 199, these numbers become more accurate as the powers increase. The number 5 says to me 5 fingers might be better than the " ideal " 6 people speak of ( 1,2,5,10 verses 1,2,3,4,6,12 and even 8,9 ). The fact 123 is Phi^10 looks rather useful in the system of 10. Also 1 and 2 in the classic Phi approximation. One thing that doesn't help is ( Phi,Pi,e,0 )^0 all = 1. Although it is nice to have an exact solution for Pi. 0^0 seems unlikely the more I think about it. If that is right it could suggest why linear maths can get complicated. That implies there is no such thing as 0 except as a point of reference which can be imagined and approached. i^i has an accepted solution and it is positive. It isn't 1 ( i= root -1 ). i is called an imaginary number, yet i suspect in Quantum paradox it is a reasonable explanation. 0 and infinity seem imaginary, infinitity put simply hasn't happened yet and never will. Thus two things we state as fact are limits of equations and one we think daft must exist although irrational ( I hope you like the word play ). i^i might even be easy to state as transindental. If it is, it certainly should exist.
I put this in as the use of Phi is often suggested without any reference to why it might work.
Here's some measurements of the 12-250TC that were posted on the Czech website Prodance.cz a year ago: http://www.prodance.cz/data/attachments/Sovereign_12_250TC.pdf
Qts is interesting. My 12Lta is 0.5 measured ( 0.4944 ! ). Not quite the drop in replacement I thought. I find the price in the UK is better than 12Lta. Fane was a cheap brand in the past. Funny how things change. I would call it a 10 kHz speaker and the 12 Lta as 6 kHz. 7 kHz is said to be the ideal point to add a tweeter as that's where you can best hide the phase change. If I find I am happier with what I have I guess I will sell the Fane's with ease.
https://www.bluearan.co.uk/index.php?id=FANSOV12-250TC
https://www.bluearan.co.uk/index.php?id=FANSOV12-250TC
That's very close to the qts of the Acoustic Elegance dipole drivers so a great candidate for OB then. Of course the AE would be in a whole other league over the Fane, but looks like some good fullrange fun could had with nice high sens for us in the low watt tube camp.
If my link is opened the Fane Qts stated is 0.63. I tend to trust Fane. The graphs look really good. I will have to get some units. They might solve the shoutiness I have. It is very little so I suspect the Fane's will not solve it. The problem is I exspect these speakers to beat my Magnepans. Mostly they do. The Maggies are free of colouration where even the best cone speakers are not. I had some LS3/5A clones to try last night ( a gift ). Most of the time they are very excellent. My OB is actually less coloured over most of the range. I have been spoilt. The idea of this 4 x 2' OB speaker was to play any music from any source (and go on the road if asked, 2 minutes to do that ). Often a friends iPhone. All are shocked when I say here is the cable lets try it. The only source I have had problems with was CD. I now have the Crystal 20 bit DAC from years ago. This seems to be how I like CD best ( was in Quad CD 67 ). The transport is an old Marantz CD67 signature which is not my cup of tea as a stand alone unit ( harsh ). TV , LP12, Quad FM3 and Roku box all work well. I must get my old Sony Short Wave out of the loft ( ST 3950 with FM,LW.MW.SW ). The shortwave can be very good on a high quality tuner. All I ever seem to get on short wave is religion and classical music. The music can be OK. The FM not as good as the Quad although excellent. The Quad is nearer a Marantz 10 of old than would be imagined. Nothing is as good as the 10 that I'ver heard. Becoming uniprortant as FM often is from a DAB feed I suspect.
I have been a fan of Fane speakers since 1980.
I bought 4 off Fane 50WRMS 12 inch drivers and fitted 2 in each speaker box for a mobile disco. I paid £28 each for them.
They were very impressive, great sound and very loud. They were good enough for small to medium sized venues.
About 10 years ago I got into Eminence drivers but was never happy with them, they seemed to need driving harder to get a decent volume.
So I went back to Fane. I got a Fane 18 inch 600WRMS driver. I also got some Fane Sovereign 200 and Fane Sovereign 250TC's and was much happier with the sound and volume. I also have a Fane Sovereign 12-500 and 15-600.
Running out of space now so probably need to sell some.
I feel rather stupid I never thought of a tripple cone. I thought the graphs too good to be true. A small bit of genius to do what they have. For obvious reasons the polar output is narrow. I won't be able to use my phase plug if Fane. I used to sell very cheap Fane TV speakers ( 5 x 3 inch ). I always remember the duck egg green paint. They were ultra cheap ( £1.50, $2 ).
I have this slight shoutiness with the 12 Lta. Slightly filtering it lost the magic. I can see on the graphs the brick wall at 8 kHz. It must be that. The baffle is not innocent. The phase plugs are mini paint rollers that almost touch the cones. Held with a curtain spring and eyes vertically with black heatshrink to make it look good. Painting just the dust cap with PVA glue ( 10 % water , 3 coats ) helped. Even against Spendor BC1's the are not a disgrace. The Spendor sometimes completely avoids some bass notes ( port ) and sounds thin. My OB is a much more accurate speaker in that way. My baffle is 50/50 MDF and Ply.
I have this slight shoutiness with the 12 Lta. Slightly filtering it lost the magic. I can see on the graphs the brick wall at 8 kHz. It must be that. The baffle is not innocent. The phase plugs are mini paint rollers that almost touch the cones. Held with a curtain spring and eyes vertically with black heatshrink to make it look good. Painting just the dust cap with PVA glue ( 10 % water , 3 coats ) helped. Even against Spendor BC1's the are not a disgrace. The Spendor sometimes completely avoids some bass notes ( port ) and sounds thin. My OB is a much more accurate speaker in that way. My baffle is 50/50 MDF and Ply.
Trust the 3rd party measurements in this case. Last I checked, Fane simply copied T/S parameters from their 12-200LT PDF and pasted a photo of the 12-250TC and graphs on it. So much for integrity. Also, I've found the measurements posted on that Czech site to be accurate, as in.. parameter measurements for drivers from reputable manufacturers (Eminence and B&C, for example) are usually very close to spec, just as those brands are known to be close to spec. So, I'd expect a Qts of around 0.9 for the 12-250TC.
I would be happy if so as I can exploit that very nicely. Win, win I hope. I can build my ex boss some with the 12 Lta perhaps. He likes what I have. " Better than some $50 000 designs" he says ( He is a friend, they are given to say things like that. say $5000 maybe and $1500 certainly ) . I feel I shouldn't do this. As any who know me will say I am so very tight with money.