So Thorsten has broken cover ...

Have you toyed with transmission lines at all? They suprised me a while back as I had assumed (incorrectly) that a sealed enclosure would be the most accurate, and that ported would be less than ideal. I presumed a TL would be pretty much the same as ported. How wrong I was! The TL's I have heard have been by far the most accurate start/stop bass I've ever heard. They also seem to make smaller drivers sound even deeper on extension than larger drivers in any other type of enclosure. It almost seemed to good to be true - more accuracy with as much depth as anything else I've ever heard. I know these enclosures are much harder to design properly, but the pay off is quite something in the right room.
 
bottleneck said:
Shinobowain

I think my meaning didn't come across in my post.

It did, honest :) But...

People often associate high SPL with dynamics.....i.e. - "my system goes very loud, listen to the loud bangs and thumps!"

Dynamic indications in music are often gradual, often subtle. A highly dynamic transducer can illustrate amazing dynamics even at very low SPL.


Let me take a quotation from Wikipedia to illustrate my point:


"Dynamic indications are relative, not absolute. mp does not indicate an exact level of volume, it merely indicates that music in a passage so marked should be a little louder than p and a little quieter than mf.

Gradual changes

In addition, there are words used to indicate gradual changes in volume. The two most common are crescendo, sometimes abbreviated to cresc, meaning "get gradually louder"; and decrescendo or diminuendo, sometimes abbreviated to decresc and dim respectively, meaning "get gradually softer". Signs called "hairpins" are also used to stand for these words. These are made up of two lines which connect at one end and get gradually further apart. If the lines are joined at the left, then the indication is to get louder; if they join at the right, the indication is to get softer. The following notation indicates music starting moderately loud, then becoming gradually louder and then gradually quieter: "

I said not to get too concerned with the SPL thing. There's bigger things at work here.

You confusing my talk about peak vs. background SPL range as my entire opinion on what makes a dynamic sound - there was more ;) The SPL thing was simply talking about 'life sized' proportion in relation to dynamics. The rest is covered with the impulse/step response which is basically a foot print on how a loudspeaker performs, including what can be attributed as 'dynamics'.

The rest of the text about gradual changes is covered by the whole step blah blah thing.

I can see that you disagreed with me because you took meaning from the word SPL.
 
BBV,

The two people I know seemed to feel their own systems were better in a number of areas, not being overly impressed by the big PMC's IIRC. Hardly conclusive I think you would agree.

Why rely on paper specifications when you readily admit your record player sounds more dynamic when it obviously isn't on paper?
 
BTW Bottleneck, I was more interested in comments on 'accuracy' and was simply adding commentary about dynamics rather than asking to be included in the Adders pit.

Here's what I was more interested in:

Wouldn't you agree that is better to approach what's considered the the baseline for reproduction of sound - the recording. And rely on the recording to best try capture the venue?

I understand that's somewhat of loaded question with so many subjective opinions on how it should be done. Its just my opinion that you should narrow the variance between recording and the final measureable output of the system as a whole, including room. Its certainly accurate in terms of tracking the source and the onus is then the responsibility of the recording.

If you start voicing this and voicing that your dealing with not only imperfect recordings but also other more damaging distortions. Lessen the variables I say and it works very well for me.

I'm *not* saying this is the only way to get where you need to go but its certainly a very valid approach.
 
ShinOBIWAN said:
BTW Bottleneck, I was more interested in comments on 'accuracy' and was simply adding commentary about dynamics rather than asking to be included in the Adders pit.

Here's what I was more interested in:


Hi!

It's my humble belied that the more we play with EQ, filters, and other ways of manipulating the sound the more stagnant and stale sounding the eventual sound becomes.

I'm sorry to use words like 'stagnant and stale' - but this is the difficulty of describing sound in words.

The approach I would take (if I could) would be the simplest possible signal path (from beginning to end) - and ensure that the listening environment could do justice to that.

This method has produced the best sounds I have heard.

Of course, I use EQ myself and any trick I can to make a poor room sound okay - but when you start from a fatally flawed position there is only so much shine you can put on your turd.

In short I believe in lifting veils rather than adding them - but find that this works best in a good acoustic space.
 
ShinOBIWAN said:
Also say it quickly: heard the 30th anniversaries, which I've said about 3 times now...
Sorry, but why should this "bother" me? You heard them, apparantly, in a "demo", and then go on to froth seemingly endlessly about how much better your "implementation" is than ATC's. If you can't see the gaping hole in your logic, perhaps we had better leave it at that?
 
ShinOBIWAN said:
Wouldn't you agree that is better to approach what's considered the the baseline for reproduction of sound - the recording. And rely on the recording to best try capture the venue?

I understand that's somewhat of loaded question with so many subjective opinions on how it should be done. Its just my opinion that you should narrow the variance between recording and the final measureable output of the system as a whole, including room. Its certainly accurate in terms of tracking the source and the onus is then the responsibility of the recording.
.

An admirable objective. Sad to say I have yet to hear a system developed from this base point that has convinced on any level when making comparisons with live performance. I would go so far as to suggest that it is a high end dead end that many explored in the eighties and nineties before setting off in more rewarding directions.
 
brizonbiovizier said:
Well I can hit 126 db in room peak. 1.6 kw rms into 92 db/wm. ;)

This is quite simply the saddest and most pathetic statement I've yet to read on this forum. It also shows an absolute lack of understanding regarding the concept of distortion.

It does however illustrate BBV's audio priorities quite nicely as well as his irrepressible urge to willy wave.
 
Last edited by a moderator:
Devil, it's no big deal. Someone has improved upon ATC's standard design. Even the ATC factory tweek their basic off the shelf products for special custom instals (*I know someone who has this on 100's with special ATC amps and subs etc). I'm sure someone could also tweek PMC for a benefit. Anything can be improved. Even an already tweeked ninja!

*This service is only offered to those in the trade, not for home users.
 
Kub3, image shack delete images after a while so we can' see my old pics. Despite its thickness, the cone is VERY light and it doesn't move that far to get down to 30Hz, much due to the use of a transmission line which provides near ideal acoustic impedance loading of the driver.

woofer1bm6.jpg


woofer2ta1.jpg


woofer3zx0.jpg


Talking of light weight cones… I don't think light is the ultimate goal for bass. You need it ridged as well. The cone in my Eminence 12" drivers is very stiff and probably quite heavy (mms 75.3g) but the absolutely huge magnet still gives it a lot of control with a fast rise time. The cones damping is also important to the decay rate. In other words you need to strike a compromise!

Shin, for a driver with a near perfect impulse / step response look at the Manger ;) Indeed, it is VERY dynamic.

Nick, I'm sorry to say you system will not likely achieve that level of SPL. You need to take in to account the cones maximum excursion and thermal power limit not just its sensitivity and power available. The midrange will probably be the weak link for SPL at the lower range of its ability. Probably more like 110dB SPL.
 
KUB3 said:
Devil, it's no big deal. Someone has improved upon ATC's standard design. Even the ATC factory tweek their basic off the shelf products for special custom instals (*I know someone who has this on 100's with special ATC amps and subs etc). I'm sure someone could also tweek PMC for a benefit. Anything can be improved. Even an already tweeked ninja!

*This service is only offered to those in the trade, not for home users.
Of course, anything can be improved upon. The point is that Shinpads doesn't actually know whether his "tweak" has made things better, worse, or left them the same because he hasn't compared nor measured the standard-issue ATC model with his own under the same conditions. That is the point, and nothing but the point. If he has genuinely made improvements, fair play to him. I remain sceptical, and in any case, I can't hear any of this alleged dreadful ATC distortion which apparantly assails other people's ears.
 
Thanks for the new sharper pics. I didn't fancy unscrewing my AML's :D

P.S my cones hardly move at all when I play music, even up to high levels.
 
Tenson said:
Nick, I'm sorry to say you system will not likely achieve that level of SPL. You need to take in to account the cones maximum excursion and thermal power limit not just its sensitivity and power available. The midrange will probably be the weak link for SPL at the lower range of its ability. Probably more like 110dB SPL.


BBV isn't interested in trifling details like this. He's done the sums and knows that if he feeds his midrange driver with 1.6KW it will hit 126 dB a fraction of a second before it passes his head and goes through the wall.

What the hell has excursion got to do with anything?!!!
 
I have some more pictures of the AML1 and its internals but its a 150mb zip file so let me know if you want it and I'll upload to my server.
 
I wouldn't reccommend that!

My mid dome's on my old speakers died without excess volume*. Those dome's are a touch delicate in reality. I know a guy, Kevin, who's been through three pairs and some over on audio circle forum have had the same fate. I wonder if the ATC's have the same weak point? - as they used to have the exact same midrange unit years ago. Odd, as the rest of the components are rock solid.

* I did sample very excess volume AFTER I got the replacements - just to check!
 


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