Sexy DIY Speakers

Nice driver. I've seen the Volt Coax's but like you said they're compression driver in the pole piece types.

Out of all the fullrangers/coax I can't believe Dean is going with the B200. Its not a bad driver but there's better out there.

 

I am not going with the b200, I am merely trying it,
if I like it then it stays, if not then I will try a coax, I have super tweeters and some phase plugs so it won't sound the same as it says on paper.
I should get them any time now I guess, I will get back to you on their performance.
the other reason I went for them is it recommends a 70 to 100 litre enclosure on their site, which I have, also most of the coaxes that have been suggested are not suitable because they are not efficient enough with my amps.

phase plugs : http://homepage.mac.com/tlinespeakers/FAL/B200-surgery/B200-surgery.html

said website : http://www.visaton.com/en/high_end/breitband/index.html

 

It wouldnt be enough for me, my speakers are 96 db, my amplifier 40 watts, and I use active filter for bass, so less work for the amp/speaker...

His amps are 12 watts...

 

the b200 is 96
I have 89 db at the moment and I have to have the volume turned right up to get a listening level anywhere near loud, and you can still talk over it.

96 should be about right, I am using my preamp in passive mode, apart from the phono stage, because it overloads the amps if I plug it in. so the amps are flat out, I want to run them cooler if possible too.

I like the sound of my amps there is just not enough spl, everything else is fine.
plus I suspect the crossover will eat up some more power, hence the insistence on no crossover etc.

 

I think the same, the crossover for my subwoofer is active, before the amplifier...

 

Not compromising the system, only limiting the choice of speakers...

 

not really, I like efficient speakers, lighter cones, surrounds etc they sound faster to me, why use a heavyweight speaker that needs a massive current to control it properly, if you don't need too ?

I don't listen to anything that needs very high spl, mainly just folk type music, if I listened to rock, and had loads of party's etc.
I would buy Yamaha ns1000m's and a krell.
but I simply don't need a system that beefy.

 

I can play party level rock with my system, with the help of the subwoofer, of course, otherwise the bass is a bit on the soft side...

As it can, and does, play movies special effects, etc...

 

Dean make this speaker a play thing then build proper ones later. You'll get the bug trust me and those won't last long.

The only reason why fullrangers exist is because people are scared of crossovers. I've heard plenty of them and none I would have in my system. Coaxs are different matter, I'm talking about fullrangers from a single radiating area.

 

I don't see why these are not proper speakers?
the drivers are in the proper cabinets (only through chance)
they are not really cheap drivers (£200) the timber was £100
so I guess you could at least double that (or more) for a commercial design when finished, although cheap ish I think they will work well for what I need them for (no sub woofer is going to be used)
the bass is not lacking at the moment in fact it is very tight and seems to go pretty low.

a lot of people seem to like lowthers and such like for low powered setups.

I have a low powered setup so why not go full range?
in my opinion I simply don't have the power to run coaxes at their best.

everything is a compromise, I would bet that these would sound as good or better (in my system) than many commercial designs due to the lack of power thing.

decent high powered valve amps cost a fortune, I have heard many transistor amps and they all sounded harsh to me, the closest thing I heard that was to my taste was a mark levinson that was about a million pound

and I'd bet I would want to mess with that too, so I am happy just messing about at the moment.

but I might build 2 gainclones soon and try active filtering with the valves just doing the super tweeters, with some coaxes wired up separately, and see if I like the way that sounds.

 

Re: Sensitivity.

96dB/1w/1m on the B200 is misleading. Its more like 82dB at 50hz in a sealed 100ltr enclosure. I bet you sit at more than 2 meter so that would be more like 76dB. You could well have 90dB in a more significant portion of the passband but that doesn't matter, all you've got is headroom/less distortion in those area's should you wish a flat FR.

If you want a flat response then you'll need to add a BSC network. The least efficient part of frequency response is the base denominator.

So for examples sake lets say with room gain your pushing 80dB/1w/2m @ 50hz. 12 watts would equate to a max overall SPL of 90.5dB and I'm betting the amp is over 1% THD at that output. You may have all that headroom in the mids etc. but since the amps don't have anything to give the bass and you want a flat FR, then thats going to be your lot.

You really need to be looking at an addition 2x 8" bass drivers to maintain 90dB+ in the bass range.

This is reason why folks horn load fullrangers

 

the amps are basically mullard 5-10's with a little more ht to get the 12w, they sound great as they are with the audax 8" 89db
just not quite loud enough, so the way I see it they can only sound better and louder than what I have. ?
(there must be some bass and they must sound pretty good or they wouldn't recommend a 100l cabinet would they?)

if that is so I am happy.
how do I work out for the baffle step correction without a sound meter ?

cheers

 

Its all about compromises. I had Audiotechnology build me some custom bass drivers and quickly found out efficiency, extension and sealed enclosures are at odds with each other. The more extension the less efficient.
So whilst you may see a bass driver quoted at 86dB sensitivity and consider a fullrange with 96 or higher, there's a very strong possibility that the bass driver walks all over the fullrange in the lower octaves regarding sensitivity in a particular loading. There's a good reason why passband specific drivers are better than a jack of all trades but master of none ie. bass driver vs. fullrange.

My own target was a loudspeaker that was around 94dB/1w/1m efficient through the range of 100hz and up. I've just about done that but have you seen the size of them? Some parts of the midrange are over 100dB efficient but the overall sensitivity, once the crossovers are in place, will be around 90dB from 50hz up.
How can a single direct radiating 8" fullrange ever hope to maintain 96dB through the same range? Its not is the answer and whatever the least efficient part of the frequency spectrum is, that will set the base efficiency for the whole speaker. Thats the part where your amps will be working hardest and because they're power limited then you don't have much to go on.

Only when that 8" is coupled to a large 12"+ high efficiency bass driver will you realise 96dB from 50hz up.

I had no idea you were using 12w amps. You need to look at horns or large vented cabinets to get the most from those.

 

I looked at horns and vented cabinets, I don't like the idea of either hence the large sealed option

is anybody any good at maths ?

sizes

baffle 1260mm x 380mm

rear panel 1260mm x 60mm

depth 360mm

the curves (halfway point of the 360mm "180mm") are 340mm across.

36mm baffle, back, top and bottom, sides are 14mm the brace is hollowed out 18mm mdf about 40mm is left round the edges,

also there is 25mm dense acoustic foam everywhere except the back of the baffle.

any help here would be greatly appreciated as I have no clue on the exact litres of these

I got it somewhere near 100l with some guessing

 

A graph thingy
using the t/s parameters and a tiny bit of guesswork (resonant frequency of the cabinet)

probably wrong

 

The best speaker for bass is a good sealed subwoofer, use an active filter, it wont degrade the sound significantely because it works in a range where our ears are not very sensitive, 80 to 100 hz, and it will relieve the amplifier and the speakers from work in the area they perform worst...

I had a reviewer from a local magazine doing a piece on my sistem, he uses a set amplifier, he had never considered a subwoofer, even wanted to listen without it, when he left he said his first upgrade would be a subwoofer...

 

Srajan Ebaen - 6moons: