Accurate Studio Monitor Project

[Felnik]

Hello,

I'm just beginning to learn about speaker design. I've become
quickly obsessed about it. I want to build a pair of Very accurate studio
monitors for my digital Mac based studio I've been going out of my mind trying to mix a CD on cheap monitors and I'm fed up. I would like to build a sealed box
design incorporating a 7'' Scan Speak or Vifa shielded driver with an appropriate tweeter. I've thought about using an existing PE Dayton 2 way crossover. maybe its too much to ask. I guess a good box dimension would be a good place to start . ANy advice would be greatly appreciated.

thanx

jf

[planet10]

Originally posted by Felnik
ANy advice would be greatly appreciated.

Crossover is far to critical to just use off the shelf... my approach is usually to just try to take the XO out of the equation as much as possible, by either going active or by pushing the need for an XO out to the point where a single cap does the job... have a look at the Joran JX125 or JX150.

dave

[sreten]

Maybe for hi-fi P10 is on the right track but not IMO
for studio monitoring.

For high accuracy you would need to source your drivers
from the premium suppliers who provide measured matched
pairs, and build a fully documented and measured design.

Of great importantance here is whether monitoring is
going to be near or far field, as the response needed
is quite different for these two applications.
(Basically near field has no or only minimal baffle step
correction, compared to far field which has full or near
full baffle step correction for away from the rear wall.)

P10 is certainly correct you should go nowhere near
a stock off the shelf crossover.

17cm units suited to sealed box loading are few and
far between nowadays.

The ultimate near field monitor would probably be a WATT
clone, try here :

http://www.users.nac.net/markowitzgd/david/david.htm

Far field monitors are much more like normal hi-fi speakers,
so choice here is far wider. But as food for thought you
could do a lot worse than this : with a much more serious
cabinet (a good bracing regime, double thickness baffle)
and offset mid and treble drivers, 45 degree bevel to
the front baffle :

http://www.speakerbuilder.net/web_fi...a/lyramain.htm

or this :

http://www.geocities.com/diyproac25/index.htm

there are lots of others.......

sreten.

[rabbitz]

Have a look in the Loudspeaker Design Cookbook, sixth edition.

In chapter 12 there's a studio monitor using Scan Speak drivers and designed by Vance Dickason. Might suit your needs.

If you're getting obsessed with speaker design you should get this book anyway.

[Felnik]

Thanks very much for your input.
I use nearfield monitors with my setup. I like the Lyra 3 way
design. I realize that an accurate monitor is an ambitious
first project. My weakness is in the crossover, I have to learn
how to build a proper one. A t this point anything would be better than
my cheap Alesis Monitors. I'm hurting in the Low/ mids department.
at the moment in order to get a decent mix of a tune I have to burn about
20 CD versions over the course of weeks until I get lucky.
I could stand for a pair of speakers that I could listen to for long periods
without loosing my mind. I'm holding out from dumping $1,000 on off the shelf
monitors. My instinct is that I can get better performance by Making them myself. I ordered the Speaker cook book. I'm shot

[Karoliina]

What would you say about my studio monitors (they are prototypes):


I haven't released any kit plans so far, but a friend of mine said
on Saturday that they sounded better than
- Gradient Revolution (http://www.gradient.fi)
- Amphion Xenon (http://www.amphion.fi)
- Three way Genelecs (http://www.genelec.fi)
- Any B&W speaker we were able to try in store (no matter the price)

So I actually began to wonder that perhaps they are rather
good speakers after all. I have two choices to make:
1) Should I release them as a kit. The crossover is extremely
complex because of excessive fine tuning and lots of components
that were added during the process. The network was never optimized.
2) Or pehaps what if I would make a commercial versions of them
and would start trying to sell them as a hobby.
3) Or I could do both, I could make them as a kind of "open source"
in the loudspeaker technology and just sell a kind of
"distributions" of the speakers (in other words, the physical
version of the speakers - there are still many many many people
who are not willing to build them by themselves).

They are a three way design. Bass and midrange drivers
are in sealed cabinet. There is a circular waveguide in front of the
1 inch dome tweeter. Crossover points are 150 Hz and 1.5 kHz.
Drivers are from Seas standard line. One thing which is
surprising is that Amphion Xenon uses quite similar design,
but for some reason it doesn't play that well fine details than
my design. I don't know why, but for some reason my design
after all sounds better. Also Amphion uses Seas drivers but
they are custom drivers with proprietary parameters.

The enclosure is a bit tricky to build. It is dual layer enclosure which consist of the wooden outer enclosure and the MDF inner enclosure.
All drivers of course are housed in a separate enclosure.
There is plenty of wool inside the midrange enclosure and in addition to that there is rubber in all interior walls. I tried to make
it as isolating as possible and I think I succeeded quite well after all.

Only one thing is missing from my design, they don't reproduce the deepest bass. But that wasn't the intention. My intention was
optimize the transient response as much as possible and
use subwoofer for deepest bass. In my living room the speakers seem to reproduce down to 35 Hz that is better than I initially expected. The design permits placement close to walls and is very directive (the directivity in my case was achieved with extreme sound isolation not with a hypercardioid enclosure like in Amphion Xenons).

Despite they are relatively small speakers, they weight a lot and they are very hard to carry. In fact, I have trouble to lift them by myself alone, but on the other hand, I have a history of building
regularly bigger speakers than what I can actually move by myself...

Best Wishes,
Karoliina Salminen

[Karoliina]

Hi again,

I might add that despite they are the main front speakers in my home theater now, they were designed as monitor speakers. The driver placement was designed so that one can put them to the desk without disturbing the sound quality. The tweeter placement ensures that
the tweeter is quite much at ear level if the speakers are placed in desk. Because of space restrictions I don't use them as monitor speakers currently with my home studio work, but I may use them in that purpose possibly later. I have some plans to make a updated
version of these which would be based around digital DSP crossover
and digital amplifiers, but it is too early to say what I will succeed to do in the end. Anyway, this design gives quite headphone-like experience in accuracy if listened close.
Nearfield monitoring works very very well. The placement of the instruments is very vivid and the three dimensional imaging in optimal listening position is breathtaking. These are the only speakers that still can make me surprised again and again.
And of course they can also be played quite loud if a high power amplifier is being used. Because of the overly complex crossover network, they are not optimally efficient currently.

Best Wishes,
Karoliina

[sreten]

Originally posted by Felnik
Thanks very much for your input.
I use nearfield monitors with my setup. I like the Lyra 3 way
design. I realize that an accurate monitor is an ambitious
first project. My weakness is in the crossover, I have to learn
how to build a proper one. A t this point anything would be better than
my cheap Alesis Monitors. I'm hurting in the Low/ mids department.
at the moment in order to get a decent mix of a tune I have to burn about
20 CD versions over the course of weeks until I get lucky.
I could stand for a pair of speakers that I could listen to for long periods
without loosing my mind. I'm holding out from dumping $1,000 on off the shelf
monitors. My instinct is that I can get better performance by Making them myself. I ordered the Speaker cook book. I'm shot

You can use the Lyra fairly nearfield but you'd need to passively
EQ out the bass boost you get from listening nearfield.
This is not difficult to do.
You could probably do this with the Alesis monitors.

Whats the problem ?
too much or not enough bass on your mixes ?
If mixed to sound right on the Alesis monitors.

sreten.

[Guss]

Would you start a new thread for your speakers Karoliina, and maybe add your system to the album btw...

EDIT : we've got the same mixer yeah who cares

[ooheadsoo]

I've heard those alesis, and I think at least part of the problem with the midrange is the 8th order crossover slopes it uses at 1.5khz.

Karoliina's monitors look amazing! However, the cabinet also looks very difficult and time consuming to build. I think a kit would be a fabulous idea, keeping the spirit of the DIY community, but those cabinets would be very expensive for you to make. Perhaps something like Ellis Audio? He offers both assembled versions and kit versions. I'm sure that this will not be an inexpensive system, especially with a quality amp