tweeter advice for peerless 830883

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hi there,

i´m new here and first i have to say the discussions here are often far more interesting than in other boards.

back to topic. i recently bought a pair of peerless hdse 6-33/08, formerly peerless 180 exclusive. here in europe they renamed it that way, dont know if its the same in the usa and the rest of the world. the exclusives were an advice of someone really familiar with hifi and everything around it.
my dipole subwoofer (constructed by him) is crossed at 80hz electricaly. furthermore the advice was to make the cabinet closed. my question is: has anybody got a project in hands for this kind of driver in a 2 way construction?
maybe i will give the seas 27tdfc a try but i dont have an exact idea at this moment. fabric would be my favoured material.

i´m also really interested in a new developement. it would be my first attempt. an mce2000 measurement mic and preamp is existing, but i´m in the learning phase right now.
a little bit of help would be appreciated

greetz,
flexus
 
Hi,

http://www.rjbaudio.com/Audiofiles/FRDtools.html
http://www.geocities.com/woove99/Spkrbldg/

With the files from Jay's link and for the Seas tweeter :
http://www.rjbaudio.com/Extremis/extremis.html

You should be able to simulate a good crossover and tune it.

The Seas is a good choice if the budget is tight, IMO the bass/mid
should cost more than the tweeter for maximum cost effectiveness.

Note that both Jay's and RJB's designs using the Seas suppress
the extreme treble, however the simpler approach taken by Zaph
is to design for an off axis response see :
http://www.zaphaudio.com/audio-speaker16.html
And arguably an overall better power response, YMMV.

My speakers point straight ahead and seem to work best that way
in my room and placement, its something than can be designed for,
it seems there is always more than one way of doing it "correctly".

Speaking of which possibly RC in parallel with L2 in Jay's c/o might
be a lower component count way of suppressing the output around
800Hz, presumably finding a ideally suited and therefore cheap high
DCR inductor for L1 is not easy.

:)/sreten.
 
Speaking of which possibly RC in parallel with L2 in Jay's c/o might be a lower component count way of suppressing the output around 800Hz, presumably finding a ideally suited and therefore cheap high DCR inductor for L1 is not easy.

:)/sreten.

Good suggestion, sreten. Yeah, using a Zobel like RC can be a way to suppress an upper mid bump in an LP response. Actually, I tried it for this design. But in this particular case, a little more complicated network worked much better. If the bump were at 900 Hz to 1 kHz, the RC would work, though.
 
I used Zaph's measurement:

http://www.zaphaudio.com/6.5test/830883-FR.gif

Pretty much the same as the first one you posted (more recent one posted at Tymphany site). Good consistency, here.

The hump in my sim is also due to a diffraction hump from a 8.5" wide baffle I used for this sim. Attached is my simulated in-box response of the 830883. A problem with an RC approach is that it also suppresses the 1.2 kHz dip greatly. A high Q, dampened notch at 800 Hz suppresses the hump but doesn't affect the 1.2 kHz dip since it helps to form an LP rolloff with a bit high Q "knee."

-jAy
 

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hi
didnt get the time writing earlier.
you guys are fantastic, do you know? :)

sreten,
the distortions of the seas from 6k on are pretty high, but i guess it has the advantage of learning something about distortions in return.
if a good DCR inductor is needed i should take a look here in the german speaking countries if something good is available. maybe mundorf or intertechnik got some of them. if its needed for the design i would buy it for sure.

my options in speaker placement are nearly endless, god bless..
my room measures around 20m² (215sqft) and roomheight of 3m (118inches).
the dipole sub stands in the middle of my room. i had the feeling this works best. the plan for the 830883/27tdfc combination is to use it while sitting at the pc.

if the drivers are my taste i would target this one in the future
NaO mini
imho mtm is never a mistake. i heard lots of them and always had to say they are good.

jay,
man, a very nice offer from you developing a box with this drivers.. i would really apreciate it if you could send me the sw files too. (is it possible with private message?) it would be the first thing i build. the 27tdf is nearly ordered.
 
flexus said:
the distortions of the seas from 6k on are pretty high, but i guess it has the advantage of learning something about distortions in return.

The 27TDFC's high 3rd order harmonic distortions, excited by an input signal at 6 kHz, will be generated at 18 kHz. You won't be able to hear this effect. When you see a tweeter's distortion measurement, you need to focus between 1 kHz and 4 kHz since responses in this range form the defining characteristic of the tweeter.

Can you email me for the sw file? I can work on this xover on these weekends.

-jAy
 
cixelsid said:


There have been two versions of this driver and yes the specs are different.

Zaph tested the original version. He hasn't tested the version that's currently shipping

I don't think either of the two spec sheets represents the current version's responses. Anyway, Zaph's measurements are consistent with ones in the spec sheet posted at the Tymphany website now.
 
yeah some people said the one currently shipping is a little bit different. maybe not that good in their opinion. the driver is currently being shipped to me. the 27tdfc will be ordered maybe tomorrow.
i hope to get on with the measuring, although its very difficult.
but neverthless, i will build jays upcoming design first, maybe everything fits together.
 
flexus said:


sreten,
if a good DCR inductor is needed


Hi,

A good DCR is low ...... However the biggest inductor in that
c/o (3mH), used for minor correction has 20R in series with it.

In these circumstances a manafacturer would use the highest
DCR / cheapest inductor they could find, and probably have
it wound to 20R, eliminating the resistor and minimising copper.

.... in fact they wouldn't because a commercial design would
not contain 3 components for such a minor compensation.
Same goes for the minor tweeter compensation as well.
They would look at slight driver modifications most likely.

Anyway lets see what jAy comes up with .....

Sitting at a PC ? rather than metres from the speakers ?
They are far too big for that application IMO.
I'd use a coherent single wideband driver for that ....

:)/sreten.
 

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hi sreten,
i hope i can follow your description: you probably mean choosing another tweeter instead, right? the network would be too complicated for the given drivers.
an idea of the buddy building the sub was to use a seas Noferro tweeter. for example noFerro800 tv. i will take a look how they are called in the rest of world, but thats the only alternatives at the moment for my budget.
btw, im sitting at the pc. at the moment old bose cubes are playing my music. dont bash me for that, i know..
i´ve got the freedom to have an extra playroom where every placement is possible, table and so on. maybe the table itself could be a problem in terms of diffraction, but i dont know exactly, have to try it out.
a very nice sphere you got there, if i chose the seas t18re/xfctv2 instead of the peerless there would have been nothing against something like that!
 
Hi,

No. I'm not suggesting another tweeter is needed.
L3 is on the bass /mid unit. jAy posted two versions of the crossover
because they are relatively minor tweaks, it is optional to use them.

You also need to speficy the freedom in baffle sizing and placement.

Speakers designed for farfield away from walls on stands will not
work well nearfield, near a wall on a desk. For PC use do you have
Eq available ? Still I think they are not the best solution at a PC.

:)/sreten.
 
no jay, the table stands nearly in the middle of the room and the speakers about 1m away from the backwall, more is possible for sure. measurements of the room are about 5x4m (160*240 inches).
the room is open to the corridor and another room.
in short, acoustic placement is not that problem. do you think the table could diffract sound badly?
 
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