MJAO G 098 - The Anagram - Crossover revision

nicoch · « **Reply #40 on:** 15 Mar 2009, 09:53 am »

I forgot, as my fist post, to salute all OB boys

I use supravox 215S bicone in OB ,guys, as this tecnology came from 1950 work very well with turntable !!!!

here an interesting cheap USA fullrange [url]http://www.diyaudio.com/forums/showthread.php?s=&threadid=139935&perpage=30&pagenumber=1[url]

Scorpion very nice work

Best Manu

scorpion · « **Reply #41 on:** 15 Mar 2009, 03:26 pm »

Welcome here nicoch,

As I said above I will put DT-28N on the back also to investigate dipole qualities fully. But remember that all fundamentals are reproduced by the midrange in dipole. That's a big difference from the Orion+ for instance which crosses to tweeter at 1400 Hz. I tested a magnetostat ribbon from Monacor also in this design but simply felt that I liked the dome better. Neo 3 is probably a very good altenative.

/Erling

nicoch · « **Reply #42 on:** 15 Mar 2009, 06:50 pm »

HI
rigth scorpion, I forgot that my bicone cannot have rear emission on the higth

Telstar · « **Reply #43 on:** 15 Mar 2009, 08:33 pm »

Quote from: nicoch on 15 Mar 2009, 09:53 am

I forgot, as my fist post, to salute all OB boys

I use supravox 215S bicone in OB ,guys, as this tecnology came from 1950 work very well with turntable !!!!

I was considering these drivers for OB, as they seem very nice.
Can you describe your setup (maybe in a new thread)?

nicoch · « **Reply #44 on:** 15 Mar 2009, 08:48 pm »

nottingham analogue TT
koetsu black
erno borbely phono
erno borbely amp (fist 16w in A ,bias 1A)

Telstar · « **Reply #45 on:** 15 Mar 2009, 08:54 pm »

Quote from: nicoch on 15 Mar 2009, 08:48 pm

nottingham analogue TT
koetsu black
erno borbely phono
erno borbely amp (fist 16w in A ,bias 1A)

Oh, sorry I meant the speakers setup

jkelly · « **Reply #46 on:** 16 Mar 2009, 10:37 pm »

Hi Scorpion,

I am having some trouble getting the DT-28N tweeter.

Do you have any sources besides BMM?

Jeff

scorpion · « **Reply #47 on:** 16 Mar 2009, 11:19 pm »

Hi Jeff,

Try http://www.lautsprechershop.de/english/index_hifi.htm . They have an English translation and the Monacor in stock. But you should negotiate shipping cost with them. DT-28Ns are so light that they easily could be sent in a letter.

Or subsitute with Monacor DT-25N http://www.monacor.de/typo3/index.php?id=75&L=1&act=8&act_sub=25&artid=3574&spr=EN&typ=u (BMM has them) which is very similar and should do fine.

/Erling

ecir38 · « **Reply #48 on:** 16 Mar 2009, 11:55 pm »

Here are the links from BMM

http://www.bmm-electronics.com/Product.asp?Product_ID=2700

http://www.bmm-electronics.com/Product.asp?Product_ID=7248

BTW, haven't said it yet, great job Scorpoin. Between you and Martin all passive OB's are things of the past. Great job guys!!!

Brad

jkelly · « **Reply #49 on:** 17 Mar 2009, 11:31 am »

OK BMM replied - "We have to order this part from Monacor and delivery time is about 7 days"
So I can wait on that.

Thanks.

Jeff

jkelly · « **Reply #50 on:** 20 Mar 2009, 11:28 pm »

Mids are in and tweeters arrive Monday.

Scorpion - do I want to add a low pass filter to the mid crossover?

Jeff

scorpion · « **Reply #51 on:** 21 Mar 2009, 06:41 pm »

While writing this I am listening to live Opera from the Metropolitan in a superb transmission.

jkelly,

This is the 64,000 dollar question. My MS-100CHQs fall quite a bit earlier than suggested by the published response curve from Monacor.
Also the DT-28N with 4.7 uF HP is responding a bit earlier than expected. My measurement of mid- and treble-units with their respective filter component is as follows (measurement corresponding to responsecurve in the first post):

I tried some different values for HP capacitor but stayed with 4.7 uF which I thought provided the best integration with the midband.
If you can measure you will of course find out how units behave and adjust accordingly. If you have the feeling that mid and treble overlap too much then a good quality coil of 0.20 to .25 mH for a mid LP ought to solve this issue. I am glad you venture to try this project.

/Erling

Polarbear · « **Reply #52 on:** 22 Mar 2009, 02:01 pm »

Nice job Erling

You have tricked me in to order all the components

Not too much money for the lot either. I'm looking forward hearing it.
A question on the baffledesign: Is the height important? Could it be like 1m? Would also a more narrow baffle against the top be better for midrange performance?

Best
Bjørn

THWO · « **Reply #53 on:** 22 Mar 2009, 03:28 pm »

Hi all,
my first post here. I recently tried an OB-design with the 15" Ciare together with Omnes Audio L8.

Sound is dynamic, open, warm and yet clear. Very realistic.

I am about to replace the Ciare 15" by Alpha 15As. When playing loud, the huge Ciares are the first ones to reach its extention limits.

Till

scorpion · « **Reply #54 on:** 22 Mar 2009, 04:58 pm »

Hi Björn,

So you will try MJAO, that's interesting, I suppose you still have the Bastanis to compare. Would be fun to hear about.
Going down to 1 m should be alright, adjusting midrange height slightly and put tweeter just above. You could go with square baffle or like me 100/110 cm.
Mid and tweeter a bit offset or placed in the middle, I cannot see anything than very small differences in simulation. Since basses occupie 80 x 40 cm there will not be very much to play with up to 1 m but feel free to experiment. Something like 'fivestring's baffle with a flat top-section (in fact a bit important) just above the tweeter might look nice. But I don't think that any difference could be heard.

Hi Till,

Welcome, very nice baffles ! I have heard the Omnes L8 only on DIY Hi-Fi World in Gelsenkirchen and then in an aperiodic enclosure. They are very good I am certain. Perhaps more people should try it in OB. It appeared in the days when Ciare CH250 was the big hit and lived a bit in it's shadow. But I don't think L8 will need any frequency correction having a quite flat response like Monacor SP130X/8 which I have used. Can you do without a tweeter ?

/Erling

dmiller · « **Reply #55 on:** 22 Mar 2009, 05:54 pm »

Quote from: THWO on 22 Mar 2009, 03:28 pm

Hi all,
my first post here. I recently tried an OB-design with the 15" Ciare together with Omnes Audio L8.

Till

Very nice, I like the light color. Let us know how it changes with the alphas.

jkelly · « **Reply #56 on:** 22 Mar 2009, 09:27 pm »

Scorpion - what do you think are the power requirements for this setup?

Jeff

JoshK · « **Reply #57 on:** 22 Mar 2009, 09:33 pm »

Till,

Nice speakers. I like how the pin stripes make the baffles visually less obtrusive. Can I ask how you chamfered the back around the mid like that? Can't imagine that was done with a router.

Josh

Polarbear · « **Reply #58 on:** 22 Mar 2009, 09:35 pm »

Thanks Erling

Excatly what do you mean by flat top-section?

Bjørn

scorpion · « **Reply #59 on:** 22 Mar 2009, 10:06 pm »

Jeff,

1 watt is enough and I think 20 undistorted watts in 4 ohm will provide a soundlevel that will satisfy most demands.

Björn,

Have a look at the pictures in the thread: http://www.audiocircle.com/index.php?topic=65818.0 . The flat section at the top is not there by mistake it helps minimizing diffraction. A rounded top would have been worse.

/Erling