supravox OB

[vega65]

This is my OB projekt. 2 x supravox 400exc, 1x 215 exc and for the top: not settled.
The baffles are 160 cm h x 130 cm w.
A fellow Norwegian diy'er ("pengesluk "at this forum) helped me with the drawings and Production of the baffles.

All choices and stupid decisions are me to blame though.

I have enjoyed construction and building of tube amplifiers for several years, but are quite a newbie when it comes to loudspeakers...

There are several things I do not understand yet, and so the speakers are not finnished

I will get back to this after a short presentation..

 

[vega65]

I constructed and made psu for each speaker. lc supply separate transformers and rails for each driver, With different voltage taps and a few resistors I can vary fieldcoil voltage
almost over the entire allowed range. at the back of the baflles are regulators for each coil
some might recognize them as Rod Colemans filamentregulators

 

[vega65]

umik-1 and rew
1m infront of speaker and just below the edge of 215 exc
So far best results With firstwatt B5 crossed at 80 and 160 hz.
a homebrewed 13e1se amp for the 215 exc and a dual mono transistor amp for the 400's

 

[mirekti]

Wow!!!
I am very interesting in this project. Maybe RAAL 140-15D dipole as the top? ;-) Would it work?
Will you use DSP i.e. will it be active or you have some other plans?

 

[Eldam]

Any open ribon around 98 dB efficienty and if too damped : a setup by putting a felt at the back of the ribbon (different thick to try ?!)

Idem with an ESL ? A Ribbon should be better here as you need a XO around 7/8 k Hz depending on the slope ? (ask the specialist here) ! But maybe the AMT ESS Heil which is said to sound its best good upon 6 Kto 8 K Hz... But more complicate for integration in an OB!

Maybe more choice if you use active filtering... Fountek Neo ribbon range or a simple open Back B&G Neo3 (loaded with a felt because to damped : depends on the taste of the owner)

Ask member in the Multiway thread like Juhazi e.g.


If you XO lower, this speaker worth maybe a try but is expensive : MA 5 at the end of this link : Products made by Fertin (I mean Monsieur Fertin who made the whole line for his daughter !)

Just two cents, not a specialist myself,

Good luck

Regards

 

[vega65]

Response without crossover, and with 10mH,16mH and 22mH in series.
voltage on coils 400 exc about 10.5v

Second pic is B5 crossover With settings from 40 hz and upwards.

Third pic is With B5 80 hz-160 hz (first order in the high pass)

I could not manage to get the passive filter right, hence the attempts With
The B5 filter. If I choose 40 or 60 hz for the lowpass, sound gets "thin"

Are there other ways to level down the rising wooferresponse seen without filter, and maybe cross the woofer higher.

I am sure there are better solutions than those shown here, and appreciate suggestions and hints.

I think it is best to get the transition between the 400's and the 215 right, before proceeding With the tweeter.

 

[Eldam]

You should have a look for the bass and the 21 cm size as well on Joachim Gerhardt wrote in his OB design (vendor section if iremember !) : using a little damping at the back while staying OB can help. The famous speaker of G. A. Briggs have like a velvett felt behind the bass driver to load it a little (or to change a little the OB behavior towards something with less radiating energy behind the baffle ? (aka cardioid?)

Anyway, you can both try the Joachim Gerahdt tip with e.g. compressed wooden dust brick for ecological wall isolation (eco construction) :it's without volatil bad substances... or any thick felt on one or two of the 40 cm subwoof ! You may need the tweeter for subjectiv transcient feeling....