| VanJerry |
| quote: | Originally posted by Scottmoose
It all comes back to exactly what you want. The problem is, you don't appear to have heard anything even remotely approaching what is being discussed here (an observation only -no criticism implied), so you don't really seem to have a particularly good idea of exactly what it is you're after based on practical experience. Always difficult, I know.
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You are quite right. And if one were to look at my thread you would say that though it's a shame it has to be such a mess it is practically unavoidable.
That wasn't my intent originally though. Not to duck this reality, or contrive an instrument to manipulate more help than my share, but I actually believe that by applying some information design to the mass of experience represented by everyone here that it could be possible to surmount those impediments. - To create a "Rosetta Stone." For somehow, parents find a way to enlighten their young about things not yet experienced. And there are other common examples. Unfortunately, I feel, I come off more like: "Nudge - nudge - know what I mean? Say no more... say no more... Um... What's it like?"
-Jerry |
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| MJK |
Please keep in mind ....
The measurements in the link I posted are real data for a real driver and enclosure design. These are accurate results.
Unless somebody has measured the other AN drivers used in the simulations, you should consider the simulations as purely speculative results.
Trying to do an apples to apples comparison between simulations based on manufacturer's spec sheet values and actual measurements of a working sytem is probably not a great idea. Recognize that real measurements are accurate and simulations based on spec sheets are approximations. |
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| rjbond3rd |
Hi VanJerry,
Oh it's definitely not all in the graphs! But the goodly folk here post them so you and I can scrutinize them. I didn't mean to imply that the graphs contain the whole story, though it's amazing what a very knowledgeable person can glean from them. Let's see what the gurus say.
In terms of a huge Metronome, I say go for it! But the major unknown that can't be shown on a graph is: will you like how the drivers sound? Are they sweet and magical, or harsh and nasty, regardless of the box they are in?
Regarding baffle step, I forgot one approach: wings on piano hinges that fold out of the way when not in use. Godzilla is doing this to his BiB's, last I heard. |
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| GM |
| quote: | Originally posted by rjbond3rd
.........I didn't mean to imply that the graphs contain the whole story..........But the major unknown that can't be shown on a graph is: will you like how the drivers sound? |
Most folks have no idea just how non flat a response can sound life-like or how one little 'bump' that doesn't show up in a minimally smoothed one can sound fine to some and doom it to becoming a practice clay pigeon at the local skeet shooting range with others.
GM |
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| Scottmoose |
| True... how true. I have memories of a kevlar midbass unit (IIRC it was a Scan Speak, but don't quote me on that) with a beautifully flat response with 1/3 octave smoothing applied from its lower mass-corner to around 3KHz -pancake flat in fact. In practice the blasted thing sounded like shattering glass. The smoothing obscured an apparantly minor break-up at about 2.4KHz. Given me a deep suspicion of kevlar ever since. |
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| VanJerry |
Hi MJK,
That design reminds me so much of the Metronome. And as I mentioned, the AN 10 ML TQWT and the AN 10 Metronome are within a few inches in size. Oh and thank you for the Martin!
I think I have to appreciate your position. You can't really be expected to answer a question like "which is better?" without the risk of inflicting collateral damage to potentially innocent designs and designers.
So, what I understand from your response is that as it looms, the AN 10 Metronome is theoretical and may remain a good choice. But here is an opportunity to observe confirmed results from a built variation.
May I ask, though, what would you call this
or what property becomes different once you change the port from the lower front as in the ML TQWT vs the bottom as in the Metronome.
And secondly, would these have similar transient quality to the TL's proposed for the AN 12 whilst potentially having more weight (due to the fact the 12" TL's are near aperiodic?)
- Not asking which is a better speaker :)
-jerry |
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| VanJerry |
Here's an aesthetic enclosure good for either a folded Metronome or (adding a vent low) a folded version of that ML TQWT.
Have to use a photo of a paper model. My graphics program is on the fritz. The relative cutout size is just a guess. |
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| GM |
| quote: | Originally posted by Scottmoose
The smoothing obscured an apparantly minor break-up at about 2.4KHz. Given me a deep suspicion of kevlar ever since. |
Well, increasing stiffness = a wider break up modes BW, so if that's all it had they did a good job overall, but you're right, if it's not all damped, then QA didn't do their job at the end of the assembly line.
GM |
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| MJK |
| quote: | Originally posted by VanJerry
That design reminds me so much of the Metronome. And as I mentioned, the AN 10 ML TQWT and the AN 10 Metronome are within a few inches in size. Oh and thank you for the Martin!
I think I have to appreciate your position. You can't really be expected to answer a question like "which is better?" without the risk of inflicting collateral damage to potentially innocent designs and designers.
So, what I understand from your response is that as it looms, the AN 10 Metronome is theoretical and may remain a good choice. But here is an opportunity to observe confirmed results from a built variation.
May I ask, though, what would you call this
or what property becomes different once you change the port from the lower front as in the ML TQWT vs the bottom as in the Metronome.
And secondly, would these have similar transient quality to the TL's proposed for the AN 12 whilst potentially having more weight (due to the fact the 12" TL's are near aperiodic?)
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In my opinion, the ML TQWT and the Metronome are essentially the same acoustic design, an expanding line with a port near the large end. I would not expect one to greatly outperform the other, the differences would probably be subtle.
The point I was trying to make is that even though you take the manufacturer's specs and put them into a simulations there are no assurances that the actual driver and enclosure will perform as simed. Suppose the actual fs is 10 Hz higher then the spec sheet would indicate. So you are kidding yourself if you try and assess a 12" driver against a 10" driver in two different enclosure designs with the resolution of 1 or 2 dB or 5 to 10 Hz of bass extension based only on spec sheets ans simulations. To compare simulation results for a different enclosure against the measured results in the link and trying to draw conclusions is also a risky proposition.
Personally, I only use manufacturer's specs to scope out a potential driver and enclosure. If there is promise I buy the drivers, measure the T/S parameters along with an impedance curve and SPL curve, and then do the detailed simulations to finalize the design. After building I remeasure the entire system to see how I did with the calculatons, tweak the last little bit of performance, and learn how to improve for the next time. Going directly fomr a spec sheet to building is a risk, you are really working in the dark. |
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| Nihilist |
"quote:
Originally posted by Scottmoose
The smoothing obscured an apparantly minor break-up at about 2.4KHz. Given me a deep suspicion of kevlar ever since. "
"Well, increasing stiffness = a wider break up modes BW, so if that's all it had they did a good job overall, but you're right, if it's not all damped, then QA didn't do their job at the end of the assembly line.
GM"
Are you guys serious ? ? ?
You can look at nearly ANY frequency response graph and see cone breakups. You said they did a good job overall so what do you mean QA didn't do their job ?
Look at one of the "heavenly" Lowthers( if you can even find a graph), and you will see a response that is PLAGUED with cone break ups and resonances.
This from a driver that is reknowned for it's articulation.
I fail to see how a driver loaded with resonant cone breakups can be called articulate. Perhaps QA was out to lunch ?
Perhaps we should be suspicious of paper cones now, too.
Sometimes you guys really make me wonder. :rolleyes:
................................Blake |
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| VanJerry |
| quote: | Originally posted by Scottmoose
I was refering to using a vented alignment or a variation thereof. It will loose some of the transient response of sealed / aperiodic / TL (although an EBS tuned very low will ~match them -that's more applicable to subs) while gaining some LF extension & weight. |
Thank you Scottmoose,
| quote: | | 4) Short of going down the DC Gold (or something similar) route, then a big driver is what you need. Which limits you (aside from the aforementioned & their 9.5) pretty much to the AN 10in & 12in drivers, or the cheaper Eminence Beta 12LTA PA unit, which I doubt you'd want to look at. |
Yes, there we are with the AN's.
| quote: | | 5) If you don't want the extra extention (especially if you can use a pair of subs) & are fixed on on transient response, then the 12in in one of the options presented to you will probably be your best bet for mains, assuming they don't utterly dominate the room. Remember that although we can squeeze some surpising performance out of them in a small volume, they'll likely only improve until Vb ~ =Vas (around 8.9ft^3) |
A language question: Is this kind of "dominance" something that can respond to volume control - which can be handy to fuller low volume performance? Or the kind that winds up putting a hole in your room LF?
| quote: | | 6) If you find their size too much to stomach, something similar can be done with the slightly smaller 10in units, at the price of some directivity & transient response, which, by FR standards, will still be of a high order. |
I don't know if I'm exactly fixated on transients. I just figured transients were one of those things making HIFI that you just can't patch up later or work around with something like EQing. So, have I got this right: the solutions for the 12's will give good transient response but similar ones for the 10 will sacrifice some transient response?
Hm... if the 10's would be a little worse in directivity might that actually make them better centers in the sense of casting a wider pattern for a larger sweet spot?
| quote: | 7) Remember: practicality. It's no use having the most wonderful drivers in the world if you can't use them effectively in your room. Unless it's a dedicated environment, you have to live in it, so keep this in mind. Nobody likes compromise but sometimes, we just have to do what we can, rather than what we'd like to do in an ideal world. We just have to keep the compromises as minimal as possible.
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| VanJerry |
| quote: | Originally posted by rjbond3rd
In terms of a huge Metronome, I say go for it! But the major unknown that can't be shown on a graph is: will you like how the drivers sound? Are they sweet and magical, or harsh and nasty, regardless of the box they are in?
Regarding baffle step, I forgot one approach: wings on piano hinges that fold out of the way when not in use. Godzilla is doing this to his BiB's, last I heard. |
If a driver doesn't sound right - and everybody here talks about it - how do the manufacturers sleep at night not pulling them off the shelves? Geez - if it's not hard enough to solve the physics of the problem there seems to be no such thing as recalls in the audio driver marketplace! Doesn't Ralph Nader like FR?
I've often wished I could ignore the size/Xmax issue and go with one of the smaller, sweeter drivers that competent people have suggested to me in this thread. I guess it's inevitable that I'll wind up with a stable of speakers like everyone else.
Wings on hinges.. I like that... |
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| MJK |
In your very first post you wrote.
| quote: | | Can a larger full range with a 1 mm excursion provide the visceral weight and body to instruments and voices at lower to medium volumes? |
And now you have started to worry about Xmax which I assume to be a requirement driven by higher volume levels. You seem to have lost the original thrust of your search. Based on the orginal post, I still think smaller drivers like the FE-167E are the ticket in your relatively small room at sane volume levels. |
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| GM |
| quote: | Originally posted by Nihilist
Are you guys serious ? ? ?
You said they did a good job overall so what do you mean QA didn't do their job ?
Look at one of the "heavenly" Lowthers...........
I fail to see how a driver loaded with resonant cone breakups can be called articulate.
Perhaps we should be suspicious of paper cones now, too.
Sometimes you guys really make me wonder. |
As a heart attack.
They didn't get it all damped enough during assembly and the QA station let it go anyway. Obviously, I'm making the assumption that their 'go/no go' tolerances were close, but considering it's a high SQ Scan-Speak it's a reasonable assumption. Then again, my limited exposure to S-S ended in the '80s, so maybe they've lowered their standards since then.
Anyway, what does Scott's observation/opinion of a Kevlar S-S driver's response have to do a Lowther's? Zilch to my way of thinking.
Study human hearing perception to get a grip on how we hear and how we interpret it if you want to delve into the finer aspects of driver design.
Nothing in audio is sacrosanct to me, but properly designed/manufactured paper based diaphragms come pretty close.............
Well, 'wonder' is good IMO, but I have a cure if you don't agree........... put me on your Ignore List, so you don't have to needlessly suffer.
GM |
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| VanJerry |
| quote: | Originally posted by MJK
In your very first post you wrote.
"Can a larger full range with a 1 mm excursion provide the visceral weight and body to instruments and voices at lower to medium volumes?"
And now you have started to worry about Xmax which I assume to be a requirement driven by higher volume levels. You seem to have lost the original thrust of your search. Based on the orginal post, I still think smaller drivers like the FE-167E are the ticket in your relatively small room at sane volume levels. |
Oh but I do worry about losing the thrust of my search, MJK. For this dishonors the kindness and effort of all of you. And I have lost it a few times so I know what that's like. But it's interesting how it comes back. It must like me.
It seems that what I have demonstrated is that I know what I need, but I often don't know why it is I need it. Not knowing why, I have often been inept in my choice of how to deliver it. But I assure you it's not been about maximum volume levels.
Let me explain the distinction in my thinking.
I believe that weight is visceral in a way that may not necessarily show up on a freq curve. And, really, a bump in the LF part of the curve isn't my idea of weight as much as a synthetic version of it. But above all I believe for HT weight is essential, not as a thrill in and of itself, but as vital information.
I believe it's less about the loudness than about the primitive significance a sound has to us. If our brains first and foremost evolved the ability to locate and size a sound source for our protection, then a sound of greater palpable size and substance will naturally be more interesting to us. It's akin to modern mankind's fascination with fear and adventure - it stimulates and even excites. But it borrows it's vitality from a simple prioritization towards protection.
It just so happens this is easiest with lower frequency sounds: say a grizzly or an elephant at some distance. It can work with higher frequencies, but mostly when the sound that connotes danger is very nearby such as a viper's sudden hiss or the ominous hum of a swarm of angry bees. Though mostly high frequency, their closeness lends a forceful element often including - in full circle - infrasonic infusions.
And through all this greater volume may never have entered into it. Though it can certainly intensify it. For those who can tolerate it. Which I partly cannot.
To achieve this, appropriate amps aside, what I'm guessing is needed and some here also believe, is an appropriate speaker.
If for HT I could allow myself woofers, extending in first order to 500 Hz, I would gladly consider a FE-167E. However, when I came to understand what I'm describing above, it became imperative that the bass be amply and easily available - again not to be loud - but to inform. And as that is it's purpose to me, it must be delivered with the least amount of time/space affect. Essentially a single driver alone. With as innocuous a sub(s) as the main driver can tolerate. Anything short would probably "sound" better (sweeter, clearer, more musical etc) but "mean" less - provide less significant information to my primitive brain.
Mind you, after a therapeutic diet of this to ground me in my acoustic body, I suspect I will soon be craving occasions of what you suggest and will be quite happy to join those of you who walk erect on two legs! And after that? Who knows!
A point of departure was John Watkinson's Putting the Science Back into Loudspeakers. But don't blame him if the above doesn't gibe - this is my own thinking.
-Jerry |
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| Nihilist |
"Anyway, what does Scott's observation/opinion of a Kevlar S-S driver's response have to do a Lowther's? Zilch to my way of thinking."
What does Scotts bad experience have to do with every other Kevlar driver ? Zilch to my way of thinking.
If you heard ONE bad sounding paper cone speaker that was from a "quality" manufacturer , would you immediately suspect ALL paper cones were bad ?
That's pretty ridiculous.
I won't be putting you on the "Ignore" list just yet ;)
Van Jerry is asking for a cabinet with a ballpark "max" size of 3.5 cu. ft. , then you propose a 16cu.ft. TL .
Was this just to show him an optimal cabinet , or was that a real suggestion ?
Just another thing that made me wonder. . . . . . .
...........................Blake |
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| Nihilist |
VanJerry said ;
"I don't know if I'm exactly fixated on transients. I just figured transients were one of those things making HIFI that you just can't patch up later or work around with something like EQing. So, have I got this right: the solutions for the 12's will give good transient response but similar ones for the 10 will sacrifice some transient response?"
Exactamundo ! ! !
I'm slightly amused by all the different directions this thread has taken. There was a simple question , with simple, logical answers . Yet we now have a NINE page thread that has gotten not much further than where it started.
VanJerry asked about a SINGLE FULLRANGE DRIVER with limited bass extension, yet I have seen posts/recommendations about almost every speaker combo/format under the sun.
What about what VanJerry wants ?
Hmm, seemed a simple enough request. Single fullrange driver with bass extension to 80hz and a cabinet no larger than 3-3.5cu.ft.
Enough surface area to provide real visceral "slam".
Excellent transient response.
Quality sound.
The answer is here VanJerry. You know what it is, you keep returning to it.
12"AN.
Build Scott's Aperiodic cabinet with a seal-able vent and enjoy the fruits of your labour.
12"AN.
Large surface area, good midrange(by your accounts) , good sensitivity (which some seem to discredit, yet which makes your amp's job that much easier) , largish but acceptable cabinet size , simple cabinet construction , reasonable extension.
I know I said it once before, but this will be my last post on this thread .
Good luck with your project , VanJerry. I hope that I have made some sense to you, even though my opinion is in the minority.
...............................Blake |
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| VanJerry |
Hi Nihilist,
I was just reviewing the thread for your opinions as you were typing. And bang! Here you are restating just what I was going to validate. The (aperiodic) AN Cast 12 has returned as the reliable workhorse which was there from the beginning.
Yes, this has been a twisty thread. It's taken me enormous resources to follow down each lead - some of them with surprise endings, but this has left me with a stronger awareness than if things were a little less difficult. So I appreciate your concerns on my behalf and wanted to acknowledge the value of your positions and the fact they remained true to my expressed concerns throughout this thread.
My appreciation for the 12 has been as twisty, but the core insights I posted in #216 above have reestablished it as a rational and mature choice. I can't help continue to have a natural curiosity about a scant few other possible solutions but - I repeat - the aperiodic 12 has become established as the one to beat. The more it has been knocked down, the stronger it has come back, at least for my needs.
I've really tried to better understand the 10, and some its enclosure possibilities have had my creative juices going for some time, but I'm just not getting the ammunition I need to get my head around how it can work better for my purposes than the 12 - based on what I've read so far.
-Jerry |
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| Scottmoose |
| quote: | | Are you guys serious??? |
Deadly.
| quote: | | You can look at nearly ANY frequency response graph and see cone breakups. You said they did a good job overall so what do you mean QA didn't do their job ? |
Er, kind, but neither GM nor I really need you to tell us that all cones suffer breakups, thanks all the same.
As GM mentioned, what we are talking about is that somebody along the line clearly messed up, and while you can generally do a decent job, all the previous good work can be thrown by a single, and often simple, error. It happens.
| quote: | What does Scotts bad experience have to do with every other Kevlar driver ? Zilch to my way of thinking.
If you heard ONE bad sounding paper cone speaker that was from a "quality" manufacturer , would you immediately suspect ALL paper cones were bad ?
That's pretty ridiculous.
Sometimes you guys really make me wonder. :rolleyes:
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Sigh. You know, I wondered after I wrote that if somebody would
a) misinterpret it & assume that I'm somehow condeming each & every kevlar cone, in every set of circumstances, and
b) completely miss the point. All it was, was a slightly OT example supporting GM's comment that in some situations, a non-flat system can sound extremely life-like, while in others an apparantly minor abberation in the wrong place (even one small enough to be hidden by a light degree of smoothing) can result in it being ~unlistenable for some people. Anyway, like GM, simple solution: if you don't like it, you can always put me on your ignore list and save yourself the raised blood pressure. |
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| Scottmoose |
| quote: | Originally posted by VanJerry
A language question: Is this kind of "dominance" something that can respond to volume control - which can be handy to fuller low volume performance? Or the kind that winds up putting a hole in your room LF? |
I meant physically. As in big cabinets. They can visually dominate the room. |
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| GM |
| quote: | Originally posted by Nihilist
Van Jerry is asking for a cabinet with a ballpark "max" size of 3.5 cu. ft. , then you propose a 16cu.ft. TL .
Was this just to show him an optimal cabinet , or was that a real suggestion ? |
In a previous response I explained to Jerry my apparently seeming lack of consideration of his stated size requirements.
GM |
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| Kofi Annan |
If I'm hijacking this thread, then just ignore me and I'll start a new one.
I was thinking that the AN 12s may work well in my GIANT LIVING ROOM as I currently lack bass with my 8" 206Es. I know I'd need some beefy woofers to get the room loaded properly, but that's probably for another day.
Anyway, in reviewing GM's size-is-not-an-issue design here:
| quote: | L = 85.468"
CSA = 335.121"^2
zdriver = 32.197"
All dims approximate and sim assumes 1.091 lbs/ft^3 of polyfil. Compared to a sealed version it has a much lower Q Fs impedance, ergo flatter phase and slightly better impulse response, faster roll off below Fs and slightly more gain BW above it. If SS driven I doubt you can hear these subtle differences in-room though since it dominates down low, but you can always seal up the terminus (port) to test it.
Note that if you end load the driver its impulse response further improves a bit with the trade-off of its response mirroring the sealed's down to Fs.
GM |
And some recommended dimensions from rjbond3rd:
| quote: | Hi Nihilist, regarding GM's cab unfolded, alternatively keeping WxD in a 1:1.4142 ratio (1 to square root of 2):
height: 85.468
width: 15.39
depth: 21.767
Or in other words, the refrigerator. Hey, nobody said hifi was easy!
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I was not able to find details on the recommended port. Would someone be so kind as to advise on port dimensions? Since I would not (at the moment) be crossing over to a sub, would this design be advisable?
FYI-- this would be driven by an ~8W SET 300b DRD.
Thanks,
Kofi |
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| VanJerry |
Welcome Kofi Annan,
Be my guest. Anyone? |
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| rjbond3rd |
Hi guys, that particular ratio (1 to the square root of 2) is not necessarily the best. As GM notes in #151, it's beneficial for folding, but if you're not folding, there might be a better ratio to use. (I honestly don't know myself.)
| quote: | | Note that if you use a 1.0:1.4142 bend width:depth ratio, then the divider board(s) winds up equidistant from all three walls in the bend. For other ratios you'll either need to scale it out as I do or use a CAD system to calc it. |
http://www.diyaudio.com/forums/show...128#post1569128 |
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| Scottmoose |
| Kofi -there is no vent. It's a straight transmission line. The terminus is left completely open. |
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| GM |
| quote: | Originally posted by rjbond3rd
..........there might be a better ratio to use. |
Probably no better acoustic ratio for a bend, but wide baffles up to at least 30" are a plus, so calculating a bend for the widest practical cab you can tolerate without exceeding a 9:1 ratio worked well enough for Bell Labs/W.E./Altec, so ditto for me (rear view of a pair of cinema screen mounted folded, bifurcated, quad compression driven 'pancake' ~50 - 10 kHz exponential horns:
GM |
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| VanJerry |
| quote: | Originally posted by GM
....so ditto for me (rear view of a pair of cinema screen mounted folded, bifurcated, quad compression driven 'pancake' ~50 - 10 kHz exponential horns:
GM |
That's a mouthful, plus pancakes! :) |
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| Scottmoose |
| Whenever I see those monster cinema horns, it reminds me I have yet to see 2001: A Space Odyssey on a decent size screen, with an equally decent audio setup. :bawling: |
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| GM |
Your loss for sure!
GM |
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| VanJerry |
I sympathize...
There are many, many movies I have postponed for myself for various reasons. From those that would need a larger screen to those who must have the best sound, or both - even those that I do not want brought down by not being in my best spirits.
I know if I cave in too soon and let myself see 2001 now - having scarred myself seeing it on television once since I first saw it's premiere in a very large theater - that it will undermine what I hope to experience when I have everything in place.
You can only have that experience once - I feel it is well worth protecting.
-Jerry |
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| GM |
| quote: | Originally posted by VanJerry
That's a mouthful, plus pancakes! :) |
Yeah, the pic doesn't really give you much sense of scale if you're not familiar with the size of the drivers, so here's a front view of one:
GM |
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| GM |
| quote: | Originally posted by VanJerry
You can only have that experience once - I feel it is well worth protecting. |
Right, and why my sound system of choice has historically been multi-way ;) Altec based and cinemas are just big screen TVs compared to three strip 70 mm Cinerama.
GM |
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| Scottmoose |
Yeah, pity screens have shrunk so much with the advent of the multiplex.
Still, I'm lucky in a sense in that about 75 minutes up the road is Bradford (a bit like the Bight of Benin -there's one comes out for forty goes in), in which lurks an IMAX screen (kind of like putting a shark in a goldfish bowl). OK, it's over-rated, but it's not bad, and the only surviving big screen technology left. Certainly better than nothing, especially as they seem to be blowing a few things up for it these days to decent effect. You'd think that 2001 would be a good candidate, come to think of it, especially having been shot in 70mm. |
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| GM |
Yeah, this IMAX is only a few miles away, but it just doesn't give me quite the same thrill as Cinerama did. Maybe if I had some depth perception...... Its sound system is overrated IMO. Maybe it's just because I don't care for the JBL 'sound'.
GM |
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| planet10 |
| quote: | Originally posted by MJK
In my opinion, the ML TQWT and the Metronome are essentially the same acoustic design, an expanding line with a port near the large end. I would not expect one to greatly outperform the other, the differences would probably be subtle. |
Indeed, based on an early comment from Martin, and some detailed sim-research by Scott, all the Mets are modeled as ML-Voigts and ignore the slight thin-waisting that occur in the Mets as the results from simming the actual Met shape led to considerable more complexity with insignificant gain in detail.
dave |
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| VanJerry |
Trivia:
DC Gold links to Acoustic Artistry Marine. Acoustic Artistry president, Scott Hanna, who recommends the DC Gold upgrade for his "concert on the lake" tower speakers (hence the link), "was a member of the team that designed, built and installed IMAX loudspeakers and sound systems." [from the linked page]
(Don't bother googling Scott Hanna - I'm afraid he must not have been a very senior member of that team for there is only scant else connecting him to IMAX on the web). |
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| VanJerry |
| quote: | Originally posted by planet10
Indeed, based on an early comment from Martin, and some detailed sim-research by Scott, all the Mets are modeled as ML-Voigts and ignore the slight thin-waisting that occur in the Mets as the results from simming the actual Met shape led to considerable more complexity with insignificant gain in detail.
dave |
Hi Dave,
Can these designs be folded?
Here's a paper model of what my aesthetic for such an enclosure would be. Imagine the top of the wedge or pyramid toppling forward and down. |
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| planet10 |
| quote: | Originally posted by MJK
I still think smaller drivers like the FE-167E are the ticket in your relatively small room at sane volume levels. |
I've just been reading the last 9 pages of posts i missed while on a road-trip, and something struck me...
Jerry is pursuing a 10 or 12 to get (he thinks) a better blend with a single sub way low down. To my mind this is throwing out the baby with the bath-water -- sacrificing the critical mids & the top to get a FR to meet his sub.
I'd suggest that instead investing in a 2nd sub, and a pair of less expensive smaller FRs would end up with a much superior overall system. The downward dynamic range of the mids & its coherance with the top are a huge contributor to supplying the information your brain needs to make it easy to create the verisimilitude necessary to provide a good musical/HT experience. (in a 350+ m^3 room, i find FE127eN (5 watts) crossed each side to a pair of 7s (with 75W) satisfies my HT (& music) needs just fine -- GM is going to say i need more power :), that is in the works)
Martin suggests FE167s, my experience would lead me to even smaller drivers. I have trouble getting excited about 8" drivers, let alone 10s or 12s.
And Jerry, at the rate you are procrastinating, you might as well wait the 4 weeks & come over to the Aug 23 diyFest and actually listen to some of these things.
dave |
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| planet10 |
| quote: | Originally posted by VanJerry
Can these designs be folded? |
Sure. Just look at Mileva or Demetri... the whole idea was to fold a Met/MLV into a monolith shaped box. If a less severe width to depth ratio is chosen one can get away with 1 divider (check Bob Brines folded MLV for the 1354) or here.
There are some perhaps useful concept pics here too....
http://www.t-linespeakers.org/FALL/bipolar/index.html
dave |
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| VanJerry |
| quote: | Originally posted by planet10
I'd suggest that instead investing in a 2nd sub, and a pair of less expensive smaller FRs would end up with a much superior overall system. The downward dynamic range of the mids & its coherance with the top are a huge contributor to supplying the information your brain needs to make it easy to create the verisimilitude necessary to provide a good musical/HT experience. (in a 350+ m^3 room, i find FE127eN (5 watts) crossed each side to a pair of 7s (with 75W) satisfies my HT (& music) needs just fine -- GM is going to say i need more power :), that is in the works)
Martin suggests FE167s, my experience would lead me to even smaller drivers. I have trouble getting excited about 8" drivers, let alone 10s or 12s.
And Jerry, at the rate you are procrastinating, you might as well wait the 4 weeks & come over to the Aug 23 diyFest and actually listen to some of these things.
dave |
Hi Dave,
How high would subs in this config need to go up?
Checking:
Coherence is what I thought I wanted to protect by having no crossovers and not even helper woofers down low except at the lowest being the sub. So I am attempting to maximally protect coherence there.
But there is also a coherence between the mids and highs.
So:
Lets say a simplistic example of coherence is taking two sheets of very thin graph paper: one representing the highs and the other the mids. Placing one over the other so the grids line up in the x and y directions would be coherence. Now, in the case of the large FR the paper representing the highs becomes tattered and develops holes. The one representing mids is stained or occluded. Now when superimposed they still can line up but there are fewer spots where you can see they are aligned - there is less usable quantity of coherence. But information that can still contribute.
This, I'm sure happens. Though I never thought of it till now... The brain needs information to calculate location and size. I'm sure the brain is talented at filling in holes but can be fatigued or distracted by the effort. Is this fatigue or distraction so bad that we would be better off sacrificing some of the coherence down low by using crossovers and multiple drivers? Not sure...
However, the question is, does this also happen:
Do the grid lines figuratively also bend or become blurry or in some other sense cause an inability to align well or at all in some places or ways - no matter the effort. I would say then that here there is not only a loss of information but actually a form of destructive information that can further sabotage whatever happened to make it through the first kind of loss.
Yet people enjoy this kind of large full range experience.
Perhaps the problem is that it can allow the enjoyment of music but there is such a greater demand for location information in HT that this falls apart.
I believe this is what you are saying Dave?
Can you, or anybody supply me with any research link to this aspect? A name, anything? I want to look into it but I need an entry point. (I'll admit what I haven't had time to do is sit down and start at the beginning with a textbook which is what I always used to do before this danged internet came along and made me think I could skip things and get to the heart of the matter.)
By "7's" do you mean SDX7's?
Moving up from smaller, what has already been lost by the time you get to 8" drivers?
Yes, the fest. But trust me - my delays are due to how long it takes me to research or grasp things. Procrastination isn't this exhausting. If it were a case of procrastination I'd simply pick something that sings out of a hat. Because these two traits work together. Unfortunately I'm too deliberate.
-Jerry |
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| tinitus |
You dont automatically get coherent sound just by leaving out an xo
Although I have a friend who plays on a small surround setup
VERY small FR drivers in 5" cubes all way round and a silly little active BP sub
All I can say, it plays scaringly good
It doesnt have the power and substance of my big 3way speakers, but nonetheless impressive sound from a very small and cheap system
I wonder how it would work with small arrays with say 4 small TB drivers each ... and 4 subs
And maybe some kind of equalizer |
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| VanJerry |
You know, even though I dont have a crossover, I still often feel incoherent...
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| rjbond3rd |
Hi VanJerry, in my limited experience, adding a helper woofer crossed low will not ruin the coherency thing, if you have the right xover and xover point.
But you can't have absolutely everything at once. Either you accept a compromise somewhere (like a low xover), or you are on a "purist" path.
Do you really want the purist path? It's a long, frustrating, lonely and expensive journey. You end up making tremendous, almost insane sacrifices. In the end, your system might not sound any better than a far less purist one. Then you start all over again. It's madness. |
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| planet10 |
| quote: | Originally posted by VanJerry
How high would subs in this config need to go up? |
with a sub like the rythmik i'd guess a max of 80 Hz. I designe my woofers to be able to go alot higher. With the Fonken i XO at 100, with the µFonken 250-350 (we are still working that one out)
| quote: |
Coherence is what I thought I wanted to protect by having no crossovers and not even helper woofers down low except at the lowest being the sub. So I am attempting to maximally protect coherence there. |
But you have to consider the driver's coherance as well. Despite being a single driver, a FR can have internal coherence issues -- in particular any FR with a whizzer is really 2 drivers with a mechanical XO.
| quote: |
Is this fatigue or distraction so bad that we would be better off sacrificing some of the coherence down low by using crossovers and multiple drivers? |
Your brain is more tolerant of XOs in the lower frequencies -- certainly partially dueto the long wavelengths involved (ie spacing issues decrease dramatically)
| quote: | | Do the grid lines figuratively |
At hi frequencies you have a very fine grid. At low frequencies you won't get a single grid square on your piece of paper.
| quote: | | Yet people enjoy this kind of large full range experience. |
You can compare the FR experience to typical commercial multiways (in which case even a budget FR of any size can catch you by surprise), or you can compare to other FRs. Sort of like comparing a good single malt to blended vrs single malt vrs single malt. And of course taste, preferences, rooms, and amps all factor in.
| quote: | | Perhaps the problem is that it can allow the enjoyment of music but there is such a greater demand for location information in HT that this falls apart. |
Once you get a music system that can image then doing HT is a breeze (just don't ruin it by putting a centre in)
| quote: | | By "7's" do you mean SDX7's? |
yes. My SDX7s anyway.
| quote: | | Moving up from smaller, what has already been lost by the time you get to 8" drivers? |
midrange is what i miss most.
dave |
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| udailey |
I know its already been posted but I feel it deserves attention and recognition. Lets not forget the real measurements made by Andrea
http://www.audiodesignguide.com/Nir..._filtera_1m.jpg
And his statement :
"After many drivers tested finally a true full-range and not only good medium and sufficient high frequency.
This is the first full-range tested with good bass as impact and as deep.
The filter show is necessary to get a good flat frequency response, with this filter only a little hole is present at 2KHz.
The peak at 55Hz is caused by my room and loudspeakers position and can be reduced with a longer bass reflex tube (5.5cm instead of 4.5)."
From this site
http://www.audiodesignguide.com/Nirvana/index2.html
Again, I own the AN12s and they freaking pound. The mids are not lacking the bass is not lacking the highs are not lacking. I wish I could measure them for you, but Andrea already did and using some pretty sophisticated equipment. If I ever measure I will probably buy a Radio Shack SPL meter and run some test frequencies.
Uriah |
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| Kofi Annan |
| quote: | | Again, I own the AN12s and they freaking pound. The mids are not lacking the bass is not lacking the highs are not lacking. |
What cabinet are your AN12s in? Are they cast or stamped?
Kofi |
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| udailey |
I have the stamped. I am told that the cast are actually a newer design and supposedly sound better. In what ways I dont know.
I am using the 2.8 single driver design on the CSA website with 2 3" holes for ports on each cabinet.
Uriah
Edit: I might add that I used 3/4 ply with nearly zero voids in it. Nice stuff. Not Baltic Birch, but some type of Birch. I used carpet felt on top of the box down to the bottom of the driver on the back and the sides. None on the front. Then I layered about 3 inches of pillow stuffing and put another layer of felt overtop of that and tacked it all down for a quilted pattern that is about one inch thick. I like the sound alot. Its fantastic :)
Edit again: I dont think I have mentioned this. I was upstairs sitting in my couch. It has wood legs to a wood floor. I had my arm on the arm of the couch. I felt a truck go by the house, but I couldnt see it. It went by again and again. Hmm pretty regular interval. ****... could that be the speakers? Dear lord thats some low low bass. The speakers are in the basement by the way. |
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| VanJerry |
| quote: | Originally posted by udailey
...I own the AN12s and they freaking pound. The mids are not lacking the bass is not lacking the highs are not lacking. I wish I could measure them for you, but Andrea already did and using some pretty sophisticated equipment. If I ever measure I will probably buy a Radio Shack SPL meter and run some test frequencies.
Uriah |
Hi Udailey,
Sorry, but you are the only AN 12 owner to ask here:
And maybe you've already given your fullest answer, but if you were me and could do things different, how would you respond to the idea that compared to a combination of a smaller FR and a woofer crossed in at a few hundred Hz as Planet10 suggests that you are sacrificing the critical mids & top?
-Jerry
[edit - Ugh! It's not a decent question to ask you - you're obviously happy. It's my struggle.] |
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| Scottmoose |
| Interesting. I suspect it's possibly not so much low bass as extremely powerful down to about 60Hz (where a lot of LF energy is located). If they're positioned near a rear wall (within about 20 - 30in), they should have sufficient in-room grunt to obviate the need for a BSC circuit. |
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| udailey |
Yeah I am obviously happy. But, your question is the reason I posted that last post. I believe Dave is probably right with Fostex. Well, I am positive he is right. He probably knows more about Fostex and a lot of other speakers, especially FR, than just about anyone on DIY. He also knows a huge amount about cabinet design. However, I disagree with him on the mids and bass with larger FR designs based only on my experience with the ANs.
Also, If I were to pair my Fostex with a sub I would not be as happy as I am with my ANs. Why? and How Do I Know? Because my ANs do the bass already and because the ANs sound better on every song in every frequency range and I prefer them totally and completely. I liked the Fostex quite a bit mind you. But, I bought the ANs and had a new experience and it is much better. The quality is better in my opinion as well, but that is a really subjective statement whereas I believe I am stating fact with my statements about the comparison between the sound of both speakers. The AN is really and truly a fantastic speaker and its the honest truth that the ONLY time I have ever heard something better was when I listened to some Thiels on a ridiculously priced system with multi-thousand dollar cables. It was stupid expensive. So, I am really happy with these speakers.
You really should take Dave up on his offer to listen to so many different speakers. Besides helping you it is probably a great experience in general and you will make some DIY friendships to boot.
Uriah |
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| GM |
Not to mention there's normally a near/at ideal room gain curve in a basement, rendering the need for a sub moot in all but the lowest desired frequency reproduction apps. Obviously, the 'floating' floor(s) required above it will resonate at their Fs(s)/harmonics if excited unless they are designed/built to isolate them, which isn't the norm in home construction.
GM |
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| udailey |
I might add that if I was doing home theater in my own home I would probably NOT put AN12 or AN10 as the surrounds. To big. Like I have said, I do like the Fostex as well, just not as much, and I think they would make fine and complimentary surrounds while taking up much less space. And I forget who said it, but I would avoid a center channel until you heard all four channels first. With the spectacular soundstage and the way the voices on a stereo recording ALWAYS are very well represented exactly in the middle of the soundstage I dont see the necessity for a center channel.
This will save you some bucks and some space.
Uriah |
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| udailey |
| quote: | Originally posted by GM
Not to mention there's normally a near/at ideal room gain curve in a basement, rendering the need for a sub moot in all but the lowest desired frequency reproduction apps. Obviously, the 'floating' floor(s) required above it will resonate at their Fs(s)/harmonics if excited unless they are designed/built to isolate them, which isn't the norm in home construction.
GM |
GM,
Definitely no isolation build in here. I did not know that about basements. Nice to know I have them set up in the right room :)
So why is the basement so ideal?
Uriah |
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| rjbond3rd |
| Hi udailey, maybe the curve showing the room gain is almost the "mirror image" of the curve showing the speaker's roll-off, and when they sum, you end up with flat response in the low end. That would be a heck of a nice thing. (Just speculating based on GM's words.) |
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| VanJerry |
| quote: | Originally posted by udailey
I might add that if I was doing home theater in my own home I would probably NOT put AN12 or AN10 as the surrounds. To big...
...And I forget who said it, but I would avoid a center channel until you heard all four channels first. With the spectacular soundstage and the way the voices on a stereo recording ALWAYS are very well represented exactly in the middle of the soundstage I dont see the necessity for a center channel.
This will save you some bucks and some space.
Uriah |
Thank you very much again, Uriah
- for sharing your experience. I need as much as you can think of posting whenever you think of something and have the time.
Scary bass.
And, having heard your description of the sound, uh...yeah - I can see not needing 12's or probably even 10's in the rear. Cast 8's likely. Frankly, David at Commonsense uses 8's all round for his HT so between his and your estimation I'm sure 8 will do just fine in surround.
Centers could be kind of an habituation. Might be hard to break but what you say is good to know.
I'm studying the ramifications of Dave's thoughts on incoherence within a large cone because I can see his point. But it's reassuring to know it's not spoiling your time with the Super 12. And maybe the Cast 12 has some additional protection on this count.
Perhaps someone could mention what the audible symptoms of internal coherence and breakup problems are. Then, Uriah, if you could let us know whether you hear those or to what extent it may help indicate whether the Nirvana at least might turn out to be a partial hedge against the rule.
-Jerry |
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| planet10 |
| quote: | Originally posted by udailey
Dave is probably right with Fostex. Well, I am positive he is right. He probably knows more about Fostex and a lot of other speakers, especially FR, than just about anyone on DIY. |
Just to make it clear... the only Fostex i could live with stock (that i've had sufficient time with to form a decent opinion) is the FX120... but i'd rather live with the FE127eN.
dave |
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| GM |
The main difference between a small driver and a big one is that the former is a point source to a higher frequency, hence its low directivity to a higher frequency before it begins to beam, while the latter requires much more attention to detail in its design/manufacture to be otherwise comparable for a given SQ, so to arbitrarily say smaller = better mids is just plain wrong, though unfortunately there's too small a market these days for such large, high SQ drivers in a B@$3 centric marketplace, so it's mostly true in reality. To get comparable HF > 12-13 kHz with a large driver OTOH is no trivial pursuit and depending on the person's HF hearing demands can be an exercise in futility.
The main problem with large, ultra wide BW drivers, or any driver with a whizzer or DC for that matter, is standing waves and comb filtering with itself due to the diaphragm's out of sync bending wave modes at varying frequencies. The $0.98 tweak, damping the DC and its glue joint, phase plugs or the radical 'whizzerectomy', etc., solve the former, while careful node damping solves the latter, though manufacturers/DIYers typically just take the 'shotgun' approach and do whole sections.
GM |
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| udailey |
Jerry,
Dont know if anyone has mentioned Enabling to you yet, but Dave hints to it in his part number there of the Fe127eN. Dave sells these and other speakers eNabled and you can buy the enabling kits if you are brave enough. It is recommended to try the technique on older speakers you really dont mind messing up. I think my Fe127e will add an "n" someday when I am up to it. I have the kit but have not tried yet. Right now my creative energies were in building some new OFC Teflon Multistrand Silver Coated speakers wires. I hear no difference and chalk it up to snake oil. (okay I hear the tiniest difference but it could just be my mind. What do they call that, psychoacoustics or something?) Also building a huge compost bin in the backyard. Lots of projects in various stages but most for some reason 90% done.
Anyway, I hear that the "n" makes a huge difference with the Fostex and there are a few detractors from that theory. I am a believer however have not heard it for my own ears. Its basically painting on some interference to those standing waves with some, I think, acrylic. There are many threads on it in the forums and seemingly many benefits. Check it out if you have not heard of it. I am betting you will either buy enabled speakers or will enable your own. You can enable any speaker and if it is one that has not been enabled before BudP will help you come up with the correct design for your driver.
edit: Jerry, you talk alot about coherence. Dave, dont you think that enabling would take care of that problem for him?
Uriah |
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| planet10 |
| quote: | Originally posted by udailey
edit: Jerry, you talk alot about coherence. Dave, dont you think that enabling would take care of that problem for him?
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Can't tell for sure without trying, but i'd be surprised if they can't be improved.
dave |
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| planet10 |
| quote: | Originally posted by GM
The main difference between a small driver and a big one is that the former is a point source to a higher frequency, hence its low directivity to a higher frequency before it begins to beam, while the latter requires much more attention to detail in its design/manufacture to be otherwise comparable for a given SQ |
My 1st measures of FE127eN in Fonken (with woof, without and with XO in for most) showing quite good dispersion. Upper end fall-off is a limit of my measuring kit so i don't know how high they really go -- if i hadn't gotten the same results with something i know goes past 20k, i'd call these realistic for the top end.
dave |
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| udailey |
So, without woofer and without XO you are getting like 45Hz at around 90SPL or am I reading SPL into this in the wrong place?
Either way it looks like the driver is putting out 45HZ at same volume as 10khz. I have to be missing something. How can this happen with a 4.5" driver? Mine isnt enabled, but it doesnt even hint at doing this.
Uriah |
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| planet10 |
| quote: | Originally posted by udailey
So, without woofer and without XO you are getting like 45Hz at around 90SPL or am I reading SPL into this in the wrong place?
Either way it looks like the driver is putting out 45HZ at same volume as 10khz. I have to be missing something. How can this happen with a 4.5" driver? Mine isnt enabled, but it doesnt even hint at doing this.
Uriah |
the bass extension can only be explained with room lift. The 127 by itself doesn't have authority down that far. The woofer may only add 5 Hz (by the measures) but gives authority & with the XO in place, mids get better.
The fall off at the top is about 15k not 10k (blue curve). The red curve is ~45 degrees off axis. That is the curve that is really a surprise.
Haven't done measures on the stock drivers yet (i do have a set of Fonken with stock drivers)
dave |
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| udailey |
I need the room you are testing these in. Man that is incredible. I understood that they were not stock. I suppose this is why I have seen people testing outside.
I need to keep an eye on ebay for a cheap cheap cheap SPL meter.
BTW Just got a new toy in the mail. I got an SMC SMCWAA-G. Bought it on ebay for 6.99 plus shipping. It came in original packaging and plastic! :o
So Now I can stream music from the computer. I have to set it up. Not expecting great performance but now my collection can be browsed through and played instantly or I can shuffle my whole collection or play playlists, etc. Anyway, hooking it up after this post :) Happy day.
Uriah |
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| VanJerry |
| quote: | Originally posted by GM
The main difference between a small driver and a big one is that the former is a point source to a higher frequency, hence its low directivity to a higher frequency before it begins to beam, while the latter requires much more attention to detail in its design/manufacture to be otherwise comparable for a given SQ, so to arbitrarily say smaller = better mids is just plain wrong, though unfortunately there's too small a market these days for such large, high SQ drivers in a B@$3 centric marketplace, so it's mostly true in reality. To get comparable HF > 12-13 kHz with a large driver OTOH is no trivial pursuit and depending on the person's HF hearing demands can be an exercise in futility.
The main problem with large, ultra wide BW drivers, or any driver with a whizzer or DC for that matter, is standing waves and comb filtering with itself due to the diaphragm's out of sync bending wave modes at varying frequencies. The $0.98 tweak, damping the DC and its glue joint, phase plugs or the radical 'whizzerectomy', etc., solve the former, while careful node damping solves the latter, though manufacturers/DIYers typically just take the 'shotgun' approach and do whole sections.
GM |
Yes GM,
As far as the manufacturer's attention is concerned, I know Commonsense builds speakers by sound, embracing the Edison approach of trial and error, rather than modeling etc.
So asked about the issue of internal coherence or improvements in cone breakup, Commonsense speaks in relative terms:
Over the Super versions the Cast 10 and 12 "have better control and precision" with a more open midrange.
By a subjective 25 to 30%.
I won't fault this kind of language - I accept it's how some people express certain ideas when they admit their approach is somewhat analog. Including myself at times.
In this modern age we often want something more technical. But in FR drivers I tend to remember we are dealing with a technology that reached quite a level of sophistication in the 30's. And that in some ways modern improvements in audio are about returning to what worked in the past before certain other tangents were taken. (Such as solid state and multi-way speakers for instance.) I imagine when Edison was improving his incandescent bulb that he would refer to a certain filament material in these terms - and some of those bulbs went on to last for decades. While I find quite a few modern - I would think modeled and spec'd bulbs, burning out in a month. If udailey reports that his "bulb" is still burning that's fairly significant.
-Jerry |
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| VanJerry |
| quote: | Originally posted by udailey
Jerry,
Dont know if anyone has mentioned Enabling to you yet, but Dave hints to it in his part number there of the Fe127eN. Dave sells these and other speakers eNabled and you can buy the enabling kits if you are brave enough. It is recommended to try the technique on older speakers you really dont mind messing up. I think my Fe127e will add an "n" someday when I am up to it. I have the kit but have not tried yet...
...Anyway, I hear that the "n" makes a huge difference with the Fostex and there are a few detractors from that theory. I am a believer however have not heard it for my own ears. Its basically painting on some interference to those standing waves with some, I think, acrylic. There are many threads on it in the forums and seemingly many benefits. Check it out if you have not heard of it. I am betting you will either buy enabled speakers or will enable your own. You can enable any speaker and if it is one that has not been enabled before BudP will help you come up with the correct design for your driver.
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Thank you Uriah,
I made sure I looked into Enabling fairly early in this thread. Mainly because I knew single vs multiple drivers had it's trade-offs and I wanted to know every means to minimize those.
I find the idea plausible enough. Perhaps budget for an extra experimental driver "for the cause" to maybe send out to Dave - to know it was done right if I felt nervous doing it myself.
-Jerry |
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| GM |
| quote: | Originally posted by planet10
My 1st measures of FE127eN in Fonken (with woof, without and with XO in for most) showing quite good dispersion. |
45 deg?! This is a truly excellent power response for a point source driver and better than some so-called CD horns and certainly far better than the early rising-on-axis 'small' cinema horns, making it a 'poster child' for why much larger point source drivers with their attendant increased directivity combined with some form of CD loaded mids/HF (not to mention a CC) are absolutely essential to assembling an HT sound system for anyone who at least wants to pay 'lip service' to experiencing a movie's soundtrack as envisioned by the director/whoever unless it's a ~near-field one or the room is very well damped WRT the screen and rear surround wall system's early reflections.
Thanks for the compelling 'evidence', I 'rest my case'. ;)
GM |
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| GM |
| quote: | Originally posted by udailey
So why is the basement so ideal? |
Assuming yours is typical, it's at least partially underground and built using either concrete blocks or blocks ~filled with concrete (better) or poured concrete (best), so its Fs is much < stick built (framed) above ground construction as well as much higher Q, ergo its room gain curve more closely follows the theoretical 12 dB/octave increase below its first eigen (standing wave) mode rather than the latter's rolling off one as it reaches Fs, becoming an increasingly resistive acoustic damper below it.
'One note' car 'boom boxes' are excellent examples of this. Inside you hear a nice extended LF from a high tuned sealed cab when properly designed, but outside all you basically hear is the various body panel's summed resonant frequencies at high amplitude and one reason why there's been a concerted effort in recent years to lower a car's summed Fs.
GM |
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| GM |
| quote: | Originally posted by rjbond3rd
..........and when they sum, you end up with flat response in the low end. |
Right, in an ideal enclosed space you can use a sealed T/S max flat alignment with its 2nd order roll off and when the room's inverse gain curve is matched to it will yield a flat response to near DC without straining the driver assuming its Xmax is high enough not to be exceeded normally, i.e. its Xmax curve tracks the cab's roll off.
GM |
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| planet10 |
| quote: | Originally posted by GM
45 deg?! This is a truly excellent power response for a point source driver |
To my mind almost too good to be true, you can be sure i'll be repaeting these measures as well as working to get my "gang-plank" rig up (ie 12-15' minimum distance to any reflective surface)
dave |
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| planet10 |
| quote: | Originally posted by GM
Right, in an ideal enclosed space you can use a sealed T/S max flat alignment with its 2nd order roll off and when the room's inverse gain curve is matched to it will yield a flat response to near DC without straining the driver assuming its Xmax is high enough not to be exceeded normally, i.e. its Xmax curve tracks the cab's roll off. |
One of the reasons i figure sealed is the only way to go in a car....
dave |
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| VanJerry |
Hi GM,
I've been trying to read up on what you've been saying regarding HT. Make a long story short, since the Cast 10 uses the same size magnet/smaller cone - and has a higher acceleration factor and probably better impulse and transient response, while having less comb filtering with itself etc. may I ask how you'd use it for HT? I suspect it wouldn't be something similar to the tapering TL you mentioned for the Cast 12?
I ask because the other AN 10 enclosures mentioned here recently were both expanding lines with a tapering closed end.
-Jerry
[edit: And 10's would be one step of a nod at least towards Dave's legitimate concerns about the importance of the quality of the highs. Keeping to single driver, that is.] |
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| GM |
| quote: | Originally posted by planet10
To my mind almost too good to be true........ |
Yeah, I was planning to have this 'conversation' again in private as getting accurate, repeatable off axis plots is no trivial pursuit, though I will say that my crude measurements from way back when showed much improved off axis response when I selectively damped nodes, so not about to discount the possibility of Enabling's affect on it.
GM |
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| VanJerry |
| quote: | Originally posted by udailey
YThe AN is really and truly a fantastic speaker and its the honest truth that the ONLY time I have ever heard something better was when I listened to some Thiels on a ridiculously priced system... |
Hi udailey,
I was looking for handy symptoms of incoherence etc and it's a deep topic. To save time, here's a simpler approach that gets to the heart of the matter.
What you get with a coherent, or phase-aligned sound is sonic clarity and a preservation of the source's harmonics. This gives you a keen sense of realism. An incoherent sound lacks definition, intelligibility, and that "real life" quality compared with the original performance - even though it may be accurately reproducing the correct frequency range and with good dynamics.
It's interesting you should mention Thiel because that's one of their main things. I know you're careful about how subjective your observations can be but I think two useful and specific questions I can ask you are:
1. When you hear something on your 12's how is their sense of realism?
2. And what are they like for clarity and intelligibility of dialog?
I know watching a movie with good headphones I've had to pause and take the phones off thinking I heard someone at my door - only to find it was happening in the film - that sort of thing.
-Jerry |
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| GM |
| quote: | Originally posted by planet10
One of the reasons i figure sealed is the only way to go in a car.... |
It's certainly a good one overall, but a properly designed BP is still the best overall and the latest 'craze' for 'sub' systems (tapped horns or pipes) has shown some incredible results in quite compact cabs for the gain BW, though until recently not a relatively easy design/build for many (most?) speaker DIYers: http://www.diyaudio.com/forums/show...&threadid=97674
GM |
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| rjbond3rd |
| quote: | Originally posted by GM
The main problem with large, ultra wide BW drivers, or any driver with a whizzer or DC for that matter, is standing waves and comb filtering with itself due to the diaphragm's out of sync bending wave modes at varying frequencies. The $0.98 tweak, damping the DC and its glue joint, phase plugs or the radical 'whizzerectomy', etc., solve the former, while careful node damping solves the latter, though manufacturers/DIYers typically just take the 'shotgun' approach and do whole sections. |
| quote: | Originally posted by GM
...though I will say that my crude measurements from way back when showed much improved off axis response when I selectively damped nodes, so not about to discount the possibility of Enabling's affect on it. |
Pardon my asking, but in general, how do you determine what nodes to damp? Or is it trial an error? (I'm asking generally, not specifically about eNaBLing.) Thank you in advance! |
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| udailey |
| quote: | Originally posted by VanJerry
[B]
What you get with a coherent, or phase-aligned sound is sonic clarity and a preservation of the source's harmonics. |
Well, thats tough because I was not there for the original recording.
| quote: | | This gives you a keen sense of realism. An incoherent sound lacks definition, intelligibility, and that "real life" quality compared with the original performance. |
They do not lack these things at all, aside from me not being there. Does it feel like I am "there?" Depending on the recording, yes. There is a very good soundstage and this stage is not only stereo but has depth as well and yes the speakers to "disappear." A problem I have had with the Fostex is that they get confused with several different sounds happening all at once and it gets tough to discern different instruments from each other. I dont have this problem with the ANs. Treating with eNable is said to cure the Fostex of this problem and to do it VERY well.
It's interesting you should mention Thiel because that's one of their main things. So two good questions to ask you are:
| quote: | | 1. When you hear something on your 12's how is their sense of realism? |
Again, it has to do greatly with the recording. Poor quality or poorly place microphones or to many microphones can ruin this. With the right recording you can feel like you are there, or more like they are here. Yeah, I would say its more like the band is present rather than you are present with the band. Get my meaning?
Bruce Springsteens "The Rising" can put him in the room with you. BTW its a wonderful disc with every song full of emotion and it really rocks.
| quote: | | 2. And what are they like for clarity and intelligibility of dialog? |
I use this word a lot in describing them. Fantastic. There is no muddling. This speaker will knock your socks of Jerry. I have no doubts at all. And it will do it better than most. For cheap. In an easy box. Its to good to be true? Nope. Its to good to cost so little and its to good to be so easy to make sound good.
| quote: | | I know watching a movie with good headphones I've had to pause and take the phones off thinking I heard someone at my door - only to find it was happening in the film - that sort of thing. |
Only had it "freak me out" once so far. I was at the computer at the back of the room. They are in the front with a couch between us, but they are taller than the couch. In Floyd's "Wish You Were Here", or maybe it was Roger Water's "Amused to Death" I forget which one. Anyway, I was sitting in the back and a car raced by me. WHAT?! That got my attention :) But as I say its the only time they pulled a fast one on me like that. Depending on placement I get a soundstage that, with speakers at 10:30 and 1:30 gives me about 9:30 and 2:30. Its not enormous, but I dont put a lot of time into perfection. I get it as good as I can quick and then get down to listening. I am sure with some software or help from GM or DD or someone who knows a lot about room size and placement that it could get a bit better.
There is no need for center channel. I would wait on the CC until after you set up and listen for a short time.
Uriah |
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| GM |
| quote: | Originally posted by rjbond3rd
Pardon my asking, but in general, how do you determine what nodes to damp? Or is it trial an error? (I'm asking generally, not specifically about eNaBLing.) Thank you in advance! |
I grew up in a simpler time back when mechanics, technicians had to diagnose problems before they could repair them rather than hooking up their ODB II/whatever testers to get a readout for a parts/entire system replacement, so factoring in my primary hobby was hotrodding/racing most of my life, I learned early on how to take advantage of a mechanic's stethoscope, though I imagine there's software available today to measure them as I've seen some sims that ~accurately predict them.
Considering they can be had now for < what my first one cost in 1960 IIRC, no self respecting DIYer should be without one IMO.
GM |
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| rjbond3rd |
Hmm, a stethoscope -- cool technique.
Would it be as simple as using test tones to get the cab to vibrate, then you use the stethoscope to pinpoint the area that's resonating? And bingo, that's where you add a brace or or damping? That sounds like something even I could do. |
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| VanJerry |
Thanks Uriah,
My apologies - of course you would rarely get to be "there" :)
But, yes - when something is "here." Familiar, universal things. As a demonstration of coherence. But you answered with Bruce in the room. Though it's also great to hear about the soundstage and complex simultaneous sounds - bonus.
Fantastic intelligibility is... well, surely these have a significant degree of internal coherence.
I've been trying to figure out myself how it could be possible the AN's can be so good and yet not more widely supported on this forum. It was pulling at me all along. But I finally pieced this together and I can say I feel pretty secure about Commonsense and the AN's.
It's his approach. It's true he doesn't pay much attention to specs or use software to design either his drivers or his enclosures. And I'm guessing that sometimes that puts him at odds with how a lot of experienced DIYers like to do things around here. Though I think everyone would admit, publishing parameters and freq response charts make his drivers WAY easier to consider than DC Gold's.
So how does he do it? Picture Edison trying out all those materials for electric light bulb filaments. David Listens to a huge amount of music, tells engineers what he wants and lets them worry about the math. So each current model's been through at least 10 prototypes. Then he asks several people who's ears he respects to also spend a lot of time listening with him. In the end they always agree on which prototype is the best.
So basically Commonsense's approach is to make the best sound in each size. And how the specs come out isn't a big deal. Take that Vas for instance. It's a big one. But I guess pursuing the best sound no matter how unpopular some specs turn out is working surprisingly well.
I have to say, guys, I'm pretty impressed and I think I've considered enough of the positives and trade-offs to say I'll make the smaller OB FR and large woofer crossed below 200Hz my second project for down the road. Right now, I've found my drivers in the AN Cast 12 and I'll be ordering them in the next few days as soon as I finalize what I'm going to do with the center. And I'm getting a couple of Cast 8's for surrounds.
-Jerry |
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| rjbond3rd |
Hi VanJerry, congrats on your decision. Let us know how it all turns out. Just catching up here but earlier you had mentioned:
| quote: | Originally posted by VanJerry
...What you get with a coherent, or phase-aligned sound is sonic clarity and a |
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