Doubling Speaker Dimensions

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I can predict this. If you double the dimensions you will quadruple the
internal volume and the driver will fall out of the mounting hole.
Phil

"Randy Yates" <yates@ieee.org> wrote in message
news:lll0bm90.fsf@ieee.org...
> I've never taken the time to learn about Qts, Vas, or
> the other abc's of loudspeaker design, so I'm going to
> put this to the group in ignorance.
>
> Is there an easy and reliable way to predict the performance of a
> Klipschorn bass unit if all dimensions were simply doubled, assuming
> the same or comparable driver? Specifically, how far would this
> extend the low frequency response?
> --
> % Randy Yates % "Though you ride on the wheels of
tomorrow,
> %% Fuquay-Varina, NC % you still wander the fields of your
> %%% 919-577-9882 % sorrow."
> %%%% <yates@ieee.org> % '21st Century Man', *Time*, ELO
> http://home.earthlink.net/~yatescr

Archived from groups: rec.audio.tech (More info?)

"Randy Yates" <yates@ieee.org> wrote in message
news:lll0bm90.fsf@ieee.org...
> I've never taken the time to learn about Qts, Vas, or
> the other abc's of loudspeaker design, so I'm going to
> put this to the group in ignorance.
>
> Is there an easy and reliable way to predict the performance of a
> Klipschorn bass unit if all dimensions were simply doubled, assuming
> the same or comparable driver? Specifically, how far would this
> extend the low frequency response?

Well you will probably get less perceived bass output and not an increase in
perceived output. And this is probably not what you are looking for. In
simple non-technical terms, which I assume you want here, the high pass
filter shape becomes flattend and begins to roll off at higher frequencies
which will give you less bass in the end, even though it rolls off less
steeply. Not knowing if this is a vented or sealed system is of some
importance. Here's a rough example of what you could expect from a sealed
cabinet. Let's compare the relative output (0 db = reference efficiency
rating) of two theoretical sealed cabinet scenario's at 5 low frequencies,
first a "normal" sealed and the next one with the volume doubled. The
comparison would something like this:

20hz 40hz 80hz 160hz 320hz
normal -12 -3 -1 0 0
double size -10 -6 -3 -2 -1

Figures are in db. Theoretically you get a little more output way down low
(20hz) but at a huge tradeoff in overall useable bass response. In the
imaginary scenario above, doubling the volume gives you much less bass. Of
course this is just an approxiamation but the general effect will be the
same in any sealed system. In a vented system you could decrease the port
length (or possibly lengthen it in some scenario's) to compensate but this
will still probably not give you what you want but it does matter how it was
originally designed; to be as small as possible or to go as low as possible.
If the later, increasing the size will not help (see above). If the former,
you can eek more bass out of it by making it bigger but you should not just
guess on the port length or volume.

Wessel

> --
> % Randy Yates % "Though you ride on the wheels of
tomorrow,
> %% Fuquay-Varina, NC % you still wander the fields of your
> %%% 919-577-9882 % sorrow."
> %%%% <yates@ieee.org> % '21st Century Man', *Time*, ELO
> http://home.earthlink.net/~yatescr

Archived from groups: rec.audio.tech (More info?)

"Wessel Dirksen" <wdirksen@p-we.com> wrote in message
news:407c2dc2$0$977$a0ced6e1@news.skynet.be...
>
> "Randy Yates" <yates@ieee.org> wrote in message
> news:lll0bm90.fsf@ieee.org...
> > Is there an easy and reliable way to predict the performance of a
> > Klipschorn bass unit if all dimensions were simply doubled, assuming
> > the same or comparable driver? Specifically, how far would this
> > extend the low frequency response?
>
> Well you will probably get less perceived bass output and not an increase
in
> perceived output. And this is probably not what you are looking for. In
> simple non-technical terms, which I assume you want here, the high pass
> filter shape becomes flattend and begins to roll off at higher frequencies
> which will give you less bass in the end, even though it rolls off less
> steeply. Not knowing if this is a vented or sealed system is of some
> importance.

Very true, as its actually a horn loaded system making the rest of your post
irrelevant.
The name Klipsch-horn should have been a give away even for those not
familiar with this well known system.

TonyP.

Archived from groups: rec.audio.tech (More info?)

Randy Yates wrote:

> I've never taken the time to learn about Qts, Vas, or
> the other abc's of loudspeaker design, so I'm going to
> put this to the group in ignorance.

> Is there an easy and reliable way to predict the performance of a
> Klipschorn bass unit if all dimensions were simply doubled, assuming
> the same or comparable driver? Specifically, how far would this
> extend the low frequency response?

Not at all, flarerate matters. See the text that goes with the Duelund
horn on my site.

> % Randy Yates % "Though you ride on the wheels of tomorrow,
> %% Fuquay-Varina, NC % you still wander the fields of your
> %%% 919-577-9882 % sorrow."
> %%%% <yates@ieee.org> % '21st Century Man', *Time*, ELO
> http://home.earthlink.net/~yatescr

--
*******************************************
* My site is at: http://www.muyiovatki.dk *
*******************************************

Archived from groups: rec.audio.tech (More info?)

"Peter Larsen" <SPAMSHIELD_plarsen@mail.tele.dk> wrote in message
news:407E48B8.4B6132E4@mail.tele.dk...
> Randy Yates wrote:
> > Is there an easy and reliable way to predict the performance of a
> > Klipschorn bass unit if all dimensions were simply doubled, assuming
> > the same or comparable driver? Specifically, how far would this
> > extend the low frequency response?
>
> Not at all, flarerate matters. See the text that goes with the Duelund
> horn on my site.

Isn't flare rate a dimension? He did specify all dimensions were doubled,
(admittedly a silly notion) and we are not dealing with a simple box here.

TonyP.

Archived from groups: rec.audio.tech (More info?)

TonyP wrote:

> Of course if you actually doubled all dimensions, then
> its not really twice the size but 8 times the size!

Indeed.

> I can't imagine a Klipshorn that big though,

It is the acoustic size it theoretically has from being a corner horn, I
think I still have that brochure from them .... real world corners may
be less perfect, but enclosing a horn in a living room always has it
"somewhat near" a corner. Generally and much simplified that is why
living room horns are somewhat different than stadium horns.

> TonyP.


Kind regards

Peter Larsen

--
*******************************************
* My site is at: http://www.muyiovatki.dk *
*******************************************

Archived from groups: rec.audio.tech (More info?)

"Peter Larsen" <SPAMSHIELD_plarsen@mail.tele.dk> wrote in message
news:407F7D55.F14B105A@mail.tele.dk...
> TonyP wrote:
>
> > Of course if you actually doubled all dimensions, then
> > its not really twice the size but 8 times the size!
>
> Indeed.
>
> > I can't imagine a Klipshorn that big though,
>
> It is the acoustic size it theoretically has from being a corner horn, I
> think I still have that brochure from them .... real world corners may
> be less perfect, but enclosing a horn in a living room always has it
> "somewhat near" a corner.

We were talking about a horn with a PHYSICAL size of maybe 8 times the
original, to achieve an even lower cut-off in a room corner I assumed.
But who knows, the OP is not providing further details of what he actually
means, if indeed he has any idea himself.

TonyP.

Archived from groups: rec.audio.tech (More info?)

"TonyP" <TonyP@optus.net.com.au> writes:

> Well yes, he did specify "same or comparable driver", but the effect is
> similar.

If the driver is required to change to accommodate the new design, so be it.
I intended for a new driver optimized for the new dimensions to be part of
the question.

> Of course if you actually doubled all dimensions, then its not really twice
> the size but 8 times the size!

Right. I stated this myself a few days back in an adjacent thread to this
topic.

> I can't imagine a Klipshorn that big though, you would need a very large
> room for stereo :-)

Of course I only intended to double the bass unit dimensions, which would
put it roughly at 90x62.5x57 inches. The room is roughly 22x15 feet, so I
don't think this is a problem. I don't know what I'd do with the treble
unit, though.
--
% Randy Yates % "Rollin' and riding and slippin' and
%% Fuquay-Varina, NC % sliding, it's magic."
%%% 919-577-9882 %
%%%% <yates@ieee.org> % 'Living' Thing', *A New World Record*, ELO
http://home.earthlink.net/~yatescr

Archived from groups: rec.audio.tech (More info?)

> Is there an easy and reliable way to predict the performance of a
> Klipschorn bass unit if all dimensions were simply doubled, assuming
> the same or comparable driver? Specifically, how far would this
> extend the low frequency response?

There are a number of articles in 1950's Radio-Electronics magazines
describing really large bass horns. Some of them contain the formulas
for designing them. One article shows a very large hyperbolic horn
(wrapped around the wall of a basement, with an 8'x8' mouth) reproducing
a 25Hz sine wave.

I don't think scaling up the design would necessarily work. I personally
would also look at other designs, since the K-horn design has minimum
size as a primary objective. The scuttlebutt when I was looking at horn
speakers in the 60's was that the original JBL Hartsfield design was
better.

The formulas weren't very difficult; converting them to wood or concrete
is the real problem. There is also the problem of obtaining a suitable
driver (the cone has to be stiff to resist deformation, and the horn can
double the impedance of the speaker in circuit.

I used a pair of JBL D130's (130 and 130A - the latter is the bass-only
version of the 130) in a pair of EV Centurion horn cabinets and, above
cutoff, the bass was incredible. I didn't like the EV 15WK which was
the speaker often used Klipsch
>
>do you not understand? There is a dictionary at www.webster.com if
>you need one.
>--
>% Randy Yates % "So now it's getting late,
>%% Fuquay-Varina, NC % and those who hesitate
>%%% 919-577-9882 % got no one..."
>%%%% <yates@ieee.org> % 'Waterfall', *Face The Music*, ELO
>http://home.earthlink.net/~yatescr


--

Mike Squires (mikes at cs.indiana.edu) 317 233 9456 (w) 812 333 6564 (h)
mikes at siralan.org 546 N Park Ridge Rd., Bloomington, IN 47408

Archived from groups: rec.audio.tech (More info?)

"Randy Yates" <yates@ieee.org> wrote in message
news:4qri21zu.fsf@ieee.org...
> Which part of:
>
> Is there an easy and reliable way to predict the performance of a
> Klipschorn bass unit if all dimensions were simply doubled, assuming
> the same or comparable driver? Specifically, how far would this
> extend the low frequency response?
>
> do you not understand? There is a dictionary at www.webster.com if
> you need one.

It seems to me I wasn't the only one who wasn't sure whether you were
including flare rate, (often referred to as doubling distance) and you
yourself now admit that despite stating "same or similar driver" you now
state "I intended for a new driver optimised for the new dimensions to be
part of
the question."
Since many had no idea what you "intended", then clarifying these issues
seems far more useful than referring to a dictionary IMO.

TonyP.

Archived from groups: rec.audio.tech (More info?)

TonyP wrote:

> It seems to me I wasn't the only one who wasn't sure whether
> you were including flare rate, (often referred to as doubling
> distance)

Now I finally grasp how to read that wording, whereever and by whomever
it is "often used" need to understand that it reads in more than one way
and should be avoided, especially as a standardized term is available,
non-confusing and commonly used in the literature.

> TonyP.


Kind regards

Peter Larsen

--
*******************************************
* My site is at: http://www.muyiovatki.dk *
*******************************************

Archived from groups: rec.audio.tech (More info?)

"Randy Yates" <yates@ieee.org> wrote in message
news:vfjp1lod.fsf@ieee.org...
> Thanks for the discussions. Tony's point made me back up
> and think that maybe it would be better to just do my
> own design instead of trying to make something like what
> I was proposing work.

Good luck. Just use the Klipschorn, JBL Hartsfield, Tannoy GRF etc. as
examples of corner horn design.

TonyP.