DIY is all about denial - can I borrow that? It certainly applies to more than just full-range speakers - esoteric cabling and capacitors, anyone?
Funny you should mention the 12LTA - our buddy DaveD came up with a big enclosure design for that one a few years back, and even with extensive tweaks of the polka-dot variety, I could never quite cotton to them either. I can still sensate enough above 8kHz to know they need help, and the best they sounded was with a pair of ESS AMTs.
Funny you should mention the 12LTA - our buddy DaveD came up with a big enclosure design for that one a few years back, and even with extensive tweaks of the polka-dot variety, I could never quite cotton to them either. I can still sensate enough above 8kHz to know they need help, and the best they sounded was with a pair of ESS AMTs.
Yea, 12lta and celestion 200tc (I'd like to try) need a supertweet past 8khz.
I love my double whizzed fane 12" with a bunch of eq, but I'm sure 12lta or 200tc with single capped supertweet would be better.
I think the cele could drop into a 50hz tranny line that I'm hoping to get done for my fane.
I love my double whizzed fane 12" with a bunch of eq, but I'm sure 12lta or 200tc with single capped supertweet would be better.
I think the cele could drop into a 50hz tranny line that I'm hoping to get done for my fane.
Well, a full range speaker and a single driver are not necessarily one and the same thing. Full range can also imply a multi-driver design.
As far as "full range single driver" speakers having to reproduce the entire audio bandwidth, it's riddled with challenges. For the driver to reproduce deep bass with low harmonic distortion it must have suitable displacement. This usually translates to a larger diameter and low excursion, as larger excursion and smaller diameter may introduce modulation distortion, overshoot and possible ringing in the impulse response. There are design considerations for each of these, but there is no escaping the physics. As the diameter increases, so does the beaming and unevenness at high frequencies.
I once considered transmission lines as a solution, but a properly designed line is devoid of essentially any fundamental resonance. The benefit is low group delay, but the driver is unloaded at subsonic frequencies and that raises the distortion. It the subsonic frequencies are filtered that adds group delay. The gain is also lower than a bass reflex enclosure, as demonstrated in the math sheets.
It's a bit of a vicious cycle.
As far as "full range single driver" speakers having to reproduce the entire audio bandwidth, it's riddled with challenges. For the driver to reproduce deep bass with low harmonic distortion it must have suitable displacement. This usually translates to a larger diameter and low excursion, as larger excursion and smaller diameter may introduce modulation distortion, overshoot and possible ringing in the impulse response. There are design considerations for each of these, but there is no escaping the physics. As the diameter increases, so does the beaming and unevenness at high frequencies.
I once considered transmission lines as a solution, but a properly designed line is devoid of essentially any fundamental resonance. The benefit is low group delay, but the driver is unloaded at subsonic frequencies and that raises the distortion. It the subsonic frequencies are filtered that adds group delay. The gain is also lower than a bass reflex enclosure, as demonstrated in the math sheets.
It's a bit of a vicious cycle.
I think what can be said is the Bose 901 almost worked. The best I heard these was about 1980 in Kirklands Wine Bar Liverpool where they were up high and pointing down. Bose knew the limitatons and made money from not being too worried about it. I've heard them sound dreadful at times. Some of their limitations are worse when Quad ESL ( off axis ). The speaker I use now is 90% full range. Below 250Hz it gets some help and above 8 kHz. If the help is removed the sound is bland without obvious reason. Most music gets very little out of the helpers. some very old 78's do need them and sound like a time machine when so ( space and atmosphere ). I used a pair of 901's in a church in Tournai Belgium, also great results about 1990. The same pair awful in the guys house. If you design a full range the standard tone controls once common are good focusing points. You could do worse than a NAD 3020 to set benchmarks. KISS. Happy Christmas all.
It seems odd that in some speakers the tweeters are used to reproduce sounds from 3kHz upwards. (Crossover point is 3kHz). Using my phone music player app eq to cut everything below 3 K and boost everything above shows me that most of the music is in the 3K upwards range.
I would think that using full ranges to cover the range upwards and below 3K, the entire spectrum seamlessly would really go a long way towards accurately reproducing the sound.
Just a thought.
I would think that using full ranges to cover the range upwards and below 3K, the entire spectrum seamlessly would really go a long way towards accurately reproducing the sound.
Just a thought.
A guy I met designed larger horns for the Motorola piezo's ( $10 types ). He used JBL ones at first. He insisted if crossed over with great care this really worked. Like myself he felt the usuall 3 kHz a bad idea that can be explained by polar graphs. It's the cheapest route. Dynaco A25 was the better old design that tried to do it better.
Not sure I understand. If tweeters can cover the 3kHz upwards, whats to prevent creating a sat-sub system with two tweeters on thin stalks supplemented by a subwoofer or a simple woofer?
Think of it, and it's been done before:
https://en.wikipedia.org/wiki/Tweeter#/media/File:Ohm_speaker_cropped.jpg
Full review here.
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Assuming that the "simple woofer" can blend smoothly with the tweeter in terms of frequency response and dispersion pattern, you'd want to pay closer attention to driver center to center spacing as the crossover point rises, as well as to consider enclosure diffraction effects.
And I think you'll find that "most of the music" is definitely not in the 3K and upwards range.
And I think you'll find that "most of the music" is definitely not in the 3K and upwards range.
The ear is more sensetive in the 3 kHz region if you take the octaves above and below into account where crossover phase shift will be far from subtle. One designer I know thinks this phase shift gives us listening fatigue. He reasons that we a very able to make a phase shifted signal sound as if it isn't in our brain ( we have always needed to when living in forests ). This has been mistaken for we don't care. This requires the use of considerable brain power. The eyes have evolved for a different world that may despite changes in habitat have similar bandwith use in prehistoric times to now. The sound picture has changed greatly and hi fi is a big manipulation of our normal ear use. My feeling is our ears are the bit of hi fi that gives us the most problems. A Speaker that can produce a near squarewave at 1 kHz with low distortion often seem to have a special kind of magic. The Fourier for that has 1/3 F3 as the next term. Quad ESL being a speaker that is good in this way.
The idea of finding a true tweeter that might do 500 Hz using an active brick wall filter might have something to offer. Some of the Klipsche mid horns look to be nearly there. JBL pro units more so.
I use an Eminace 12 Lta. I have a tweeter at 7 kHz and a bass at 250 Hz ( 15 inch OB ). Whilst far from perfect it takes the problems away from 3 kHz. It has 1st order passive at 250 Hz with active EQ. Tweeter also 1st order passive at 7kHz and again active EQ. If you wonder why active plus passive mix the reason is that it is an evolving idea.
The idea of finding a true tweeter that might do 500 Hz using an active brick wall filter might have something to offer. Some of the Klipsche mid horns look to be nearly there. JBL pro units more so.
I use an Eminace 12 Lta. I have a tweeter at 7 kHz and a bass at 250 Hz ( 15 inch OB ). Whilst far from perfect it takes the problems away from 3 kHz. It has 1st order passive at 250 Hz with active EQ. Tweeter also 1st order passive at 7kHz and again active EQ. If you wonder why active plus passive mix the reason is that it is an evolving idea.
So between 250Hz and 7 KHz is covered by overlap between the two? How does it work out?
It is almost doing a good job. One or two people think compared with my Magnepans it's the right way to go. The largest improvement I could make is a 2 x 24 x 48 inch polystyrene baffle ( building grade ). This takes away a colouration of the ply+MDF baffle. This is important to know as what is wrong with the sound seems it must be the wizzer cone. As far as I know it isn't the main reason. The polystyrene has supurb bass and proves how a baffle speaker works. The problem is how to make it last. I think a large surround like a picture frame would work and mini plywood baffles front and rear to use compression clampling ( 6 mm ply ).
The theory I used was what I call the Caruso effect. That is if I listen to a first class transcription of Caruso my brain can invent the rest. Ironically Caruso still sounds better with the full range. It is where to put 90 % of the music by quatity.
The theory I used was what I call the Caruso effect. That is if I listen to a first class transcription of Caruso my brain can invent the rest. Ironically Caruso still sounds better with the full range. It is where to put 90 % of the music by quatity.
One unexspected bonus of my 7 kHz first order cross to the tweeter is a much wider HF window. 12Lta and DT74/8 in same phase disregarding the capacitor. As I haven't measured the polar dispersion it might be how I think things are working rather than the reality. I doubt it is imagined as without the tweeter it is very directional like my Magnepans. I can sort of see how this could work. If I am truthful the tweeter gave me 400 % more than I dared hope for. I can only guess the phase shifts are by pure chance working well together and reducing the brickwall mechanical 8kHz filter of the 12 Lta. The hyper cheap DT74/8 was the only tweeter that could match the 12 Lta. Idealy active to get the optimum curves and output, one day I will . As an absolute test 1940's 78's still are easier to listen to with this tweeter working ( and 1920's more than should be so, again I think I know why). The 12 Lta will EQ to give 12 kHz. It isn't a subtitute.
I was listening to my friends BBC LS5/9. They are equally flawed in other ways. Where it crosses is so obvious. After five minutes I could ignor it. At first it was almost comical that it could be like that. To be honest my JPW Minims ( £80 ) are no worse on that used in my kitchen. Once I had adjusted I thought the 5/9 very good. I have some old Dynaco A25 that could be better in some ways. Not least in a big room. My baffles used the A25 as inspiration.
I was listening to my friends BBC LS5/9. They are equally flawed in other ways. Where it crosses is so obvious. After five minutes I could ignor it. At first it was almost comical that it could be like that. To be honest my JPW Minims ( £80 ) are no worse on that used in my kitchen. Once I had adjusted I thought the 5/9 very good. I have some old Dynaco A25 that could be better in some ways. Not least in a big room. My baffles used the A25 as inspiration.
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