D'Appolito configuration practically
King Arthur
started on a question i asked a few weeks ago. The final system design
i've made is a soort of D'Appolito using the Dynaudio ESOTEC D-260
filtered passively first order at 2 kHz, then the mid/bass range is done
by two 17 W-75's in a closed cabinet placed symmetrically under and above
the tweeter. The bass section is done with two 17 W-75 XL's in a bass
reflex cabinet, placed symmetrically above and under the D'Appolito
formed by the mid and tweeter. The filter between them is a first order
active filter at 250 Hz. The whole system is thus symmetric build. The
tweeter is placed back on the baffle to get all in line.
A big advantage with this system is that the both bass/mid drivers have a
sound pressure of 86 dB (two makes thus 89 dB) and the tweeter has a
pressure of 89 dB. So these are equal and i don't have to correct
everything anymore (thus leaving out any resistors before the drivers).
Has this system any chance of being the exellent system it should be when
looked at the total price per speaker (about $1400). Please give me some
opinions and if possible correction so i can implement them before i go
building them.
Thanks in advance,
--
PS : Sorry, if you miss a t somewhere, my keyboard is nearly broken.
Mattijs de Vries.
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Arther Dent
>
> Has this system any chance of being the exellent system it should be when
> looked at the total price per speaker (about $1400). Please give me some
> opinions and if possible correction so i can implement them before i go
> building them.
>
> Thanks in advance,
It DEFINATELY can be a VERY good system. You know Cello? Mark Levinston's
ultra-high-end company... They use Dynaudio drivers exclusivley in all
of their speakers. I think the speaker that uses a few of the drivers
you are planing to use (17-W-75) cost about $45,000. So, I dould say
that you got a good deal, yes.
Arther.
tINY
>A big advantage with this system is that the both bass/mid drivers have a
>sound pressure of 86 dB (two makes thus 89 dB) and the tweeter has a
>pressure of 89 dB. So these are equal and i don't have to correct
>everything anymore (thus leaving out any resistors before the drivers).
If these drivers are in phase, you will have closer to a
6dB gain from using two drivers (unless you run them in series.
Few things require no tweeking.
-tINY
tINY
DIEMEL J.A.
> Thanks all for the great discussion on the D'Appolito configuration. It
> started on a question i asked a few weeks ago. The final system design
> i've made is a soort of D'Appolito using the Dynaudio ESOTEC D-260
> filtered passively first order at 2 kHz, then the mid/bass range is done
> by two 17 W-75's in a closed cabinet placed symmetrically under and above
> the tweeter. The bass section is done with two 17 W-75 XL's in a bass
> reflex cabinet, placed symmetrically above and under the D'Appolito
> formed by the mid and tweeter. The filter between them is a first order
> active filter at 250 Hz. The whole system is thus symmetric build. The
> tweeter is placed back on the baffle to get all in line.
>
double the money of the esotec. However, there are people who have tried
twenty different best tweeters (including the esotec) from; Eton, Dynaudio
, Thiel, Focal, Scan Speak, Seas ,Vifa and Morel. The second most expensive
tweeter (~125 $ =200 Gld) came out best, although you have to design a very
good cross-over to tame this little beast. The tweeters from Dynaudio are
more tolerant of cross-over design: a simple 6dB/oct. filter is already able
to create a reasonable sound.
I am currently playing with a D-28AF/Focal 4N411T Daline combination, parallel
to a 2*KeF B139B in a bandpass double chamber. I think you had better invest
your money in bigger woofers than the small 17 W75-XL's. Eton 8'' or 10'' are
much more neutral, while Vifa has a big 12'' (WN300D I think it was) which is
comparatively cheaper and has more surface and greater sensitivity (94 dB/W).
There are also 15W15XL's which are better suited as midranges than the 17W75's.
Furthermore I think d'Appolito is ok for high and mid frequencies, but becomes
increasingly irrelevant at lower frequencies (directionality !). Steer clear
off the little networks Dynaudio uses for getting the tweeter in line with
the woofers.
Jasper
Craig Stark
[snippage to save bandwidth]
> started on a question i asked a few weeks ago. The final system design
> i've made is a soort of D'Appolito using the Dynaudio ESOTEC D-260
> filtered passively first order at 2 kHz, then the mid/bass range is done
> by two 17 W-75's in a closed cabinet placed symmetrically under and above
> the tweeter. The bass section is done with two 17 W-75 XL's in a bass
> reflex cabinet, placed symmetrically above and under the D'Appolito
> formed by the mid and tweeter. The filter between them is a first order
> active filter at 250 Hz. The whole system is thus symmetric build. The
> tweeter is placed back on the baffle to get all in line.
>
> sound pressure of 86 dB (two makes thus 89 dB) and the tweeter has a
> pressure of 89 dB. So these are equal and i don't have to correct
> everything anymore (thus leaving out any resistors before the drivers).
Be careful here. How are you planning on wiring the 17W's? In
parallel? You will have dropped your impedance in half and thus get
another 3dB out of them. Also, remember that your tweeter will be on
a baffle that will contribute significantly to it's output (same goes
for the high-end portion of the mid/bass in all probability) given
that it will be radiating into 2pi, not 4pi space. Unfortunately,
simply relying on manufacturers specs of sensitivity *never* works.
My advice is to drop $60 and get CALSOD or some such beast (I know of
no better for the price that will do this sort of work) and make a
full model of the system and drivers. Your dropping a lot of cash and
good to make it work as well as you can. CALSOD, while not the
easiest program to use, does an *excellent* job of taking much of the
guesswork out of crossover design. I cannot reccomend this product
(especially the non-commercial version b/o the price) enough. While
not all-powerful, it gets good tools in the hands of DIY speaker
builders. (Rave review aside, don't try using it as your only program
to help design the box. While it *can* do it, it's ugly.)
One question in the design. Why use the 17W's as your bass drivers as
well? They really can't move much air being only 17cm. Granted,
they're very nice 17cm drivers, but... Get some mid-priced 10 or 12"
drivers and drop the active xover point to 150Hz or so and you'll keep
your sweet midrange setup and be able to reach down into the lower
octaves while keeping power (and saving money-- 17W's are expensive.)
FWIW, that's what Joe himself does in the Swan IV.
BTW, you've got some excellent drivers spec'ed. Done up well with an
optimized (both by computer and by hand) crossover and a good solid
box, and you'll beat out anything in the price range (not counting
your time as money of course.) Of course, you'll also have the
satisfaction of building them and of watching friend's jaws drop when
they hear the final product. Send me e-mail and let me know how
things go.
- Craig
Chris Christensen
>In Article <3vi9e3$8...@driene.student.utwente.nl> "mattijs...@student.utwente.nl (King Arthur)" says:
>> Thanks all for the great discussion on the D'Appolito configuration. It
>Furthermore I think d'Appolito is ok for high and mid frequencies, but becomes
>increasingly irrelevant at lower frequencies (directionality !). Steer clear
>off the little networks Dynaudio uses for getting the tweeter in line with
>the woofers.
I am _very_ interested in these comments.
First of all, I would agree that the d'Dppolito configuration is great for
mids and highs. I haven't a clue as to what you mean about directionality
and irrelevant as it relates to the LF portion of the audio spectrum.
For me, having two LF drivers in a two way system speak of 'better' LF
performance.
What's your point?
--
Just My opinion, worth the price paid and not a reflection of my employer.
D.R. "Chris" Christensen chr...@shasta.gvg.tek.com
Grass Valley Group Inc. 916-478-3419 Voice 916-478-3887 FAX
P.O. Box 1114 Grass Valley, California, 95945
Trevor Pearson
> Thanks all for the great discussion on the D'Appolito configuration. It
> started on a question i asked a few weeks ago. The final system design
> filtered passively first order at 2 kHz, then the mid/bass range is done
> by two 17 W-75's in a closed cabinet placed symmetrically under and above
[snip]
> Has this system any chance of being the exellent system it should be when
> looked at the total price per speaker (about $1400). Please give me some
> opinions and if possible correction so i can implement them before i go
> building them.
If you get the crossover right, it should be great. However you may wish
to rethink a first order crossover at 2kHz, the tweeter will be the
first thing to go when you crank it up. Such a system would otherwise
provide good SPL's.
Trevor.
ed.l...@ix.netcom.com
J.A.) writes:
>, there are people who have tried
>twenty different best tweeters (including the esotec) from; Eton,
Dynaudio
>, Thiel, Focal, Scan Speak, Seas ,Vifa and Morel. The second most
expensive
>tweeter (~125 $ =200 Gld) came out best,
Not clear here on which tweeter that is?
--
ed.l...@ix.netcom.com Ed Light Los Angeles, CA, USA
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