My tactics for improving vintage 3 way open baffles

Bumpy · « **on:** 20 Nov 2018, 01:40 pm »

I have set myself a challenge to improve on these open baffle speakers assembled by Slawa of SW1X Audio Design

They are currently running with:

Tweeter: Saba Greencone 4" dipole
Midrange: Saba greencone 8" dipole
Base: Altec 416 8A 15" dipole

All drivers are vintage with alnico magnets, paper cones and mid 90s sensitivity. All are about 6-8 ohms.

At the moment they sound fantastic but I love a challenge

More to follow.

PS If ANYONE CAN TELL ME HOW TO STOP THIS SOFTWARE LAYING PICTURES ON THEIR SIDE I WILL BE MOST GRATEFUL.

Folsom · « **Reply #1 on:** 20 Nov 2018, 04:14 pm »

Crossover? That's where the magic comes together.

Bumpy · « **Reply #2 on:** 20 Nov 2018, 04:25 pm »

Quote from: Folsom on 20 Nov 2018, 04:14 pm

Crossover? That's where the magic comes together.

No resistors, all silver wired and parts like Audionote capacitors chosen by ear - and Slawa has excellent ears.

One of my main aims initially is to select mid range drivers with similar capacitance and sensitivity to the Saba Greencones. So for now, during evaluation the crossovers values should suffice.

Bumpy · « **Reply #3 on:** 20 Nov 2018, 04:50 pm »

I now have a choice of two 8" drivers to evaluate against the Saba Greencones.

The first are vintage Supravox T215 RFT 64. These have similar characteristic to the Greencones. They are from France in the 60s and have the required Alnico magnets and paper cones, I have purposely avoided the model with wizzers.

Here is one shown alongside the Greencone. In terms of cost, the Greencones can be found below £100 in the UK and the Supravox are about £400 a pair. If it was a boxing competition the Supravox would take the prize, but its not

Bumpy · « **Reply #4 on:** 21 Nov 2018, 12:59 pm »

The second alternative 8" driver breaks the mould in that it is modern. But, it does have alnico magnet, papyrus cone, is 8ohms and about 95 sensitivity.

Its the SEAS X2 Exotic W8 - the model without wizzer. There are not a lot of reviews of its application in open baffles, so its a bit of an expensive gamble.

Here it is being put through some audio gymnastics whilst sill playing music. Dont ask me why the creator did it

https://www.youtube.com/watch?v=orC1QXULd5w

Bumpy · « **Reply #5 on:** 21 Nov 2018, 04:29 pm »

The Saba Greencone hole in the front baffle will take neither of the new drivers and I am hesitant to hack it about until I know where I am going. At present, I plan a new circular baffle into which will be mounted the selected new driver. So as not to disturb the current tweeter (for now) the new baffle will be cut to clear it and allow it to breath.

Here is a paper template for the circular baffle. Sorry but the software here has again put the picture on its side. HELP ANYONE?

Bumpy · « **Reply #6 on:** 22 Nov 2018, 06:33 pm »

Am I talking to myself?

Monte Verdi · « **Reply #7 on:** 23 Nov 2018, 05:05 pm »

Bumpy I have the same problem with photos being flipped on there side as well, rather frustrating. I rephotograph using an Android app on my tablet and that seems to help.

Bumpy · « **Reply #8 on:** 24 Nov 2018, 02:18 pm »

My first experiment is not to cut the existing piano black front baffle, but to place the new circular baffle on the floor. This presents the greatest challenge to the driver.

Bumpy · « **Reply #9 on:** 24 Nov 2018, 05:55 pm »

Sorry, I cant post pictures now as I get error messages and it locks me out

JohnR · « **Reply #10 on:** 27 Nov 2018, 01:29 pm »

For technical issues with the site, better to open a thread in Requests for Help or Bug Reports.

mcgsxr · « **Reply #11 on:** 27 Nov 2018, 01:48 pm »

In terms of improvement, have you considered going active?

PartsExpress sells an affordable DSP these days, and being able to adjust bass vs mids vs treble easily can be a great way forward.

I ran active Xover in my own OB explorations for a long time. I could not have done it without biamping the mains and subs.

Bumpy · « **Reply #12 on:** 27 Nov 2018, 05:51 pm »

Quote from: JohnR on 27 Nov 2018, 01:29 pm

For technical issues with the site, better to open a thread in Requests for Help or Bug Reports.

When I get locked out, I really get LOCKED OUT and cant even send a bugs report.

Bumpy · « **Reply #13 on:** 27 Nov 2018, 05:54 pm »

Quote from: mcgsxr on 27 Nov 2018, 01:48 pm

In terms of improvement, have you considered going active?

PartsExpress sells an affordable DSP these days, and being able to adjust bass vs mids vs treble easily can be a great way forward.

I ran active Xover in my own OB explorations for a long time. I could not have done it without biamping the mains and subs.

I have played with DSP in my days with a TACT. Its not for me as its just more digital processing of the music, which I try to avoid.

mcgsxr · « **Reply #14 on:** 27 Nov 2018, 06:27 pm »

Tact has been around a long time, some of their 2 channel DSP tech is from around 18 years ago.

I respect that you're not interested, but even the new $200 DSP from Dayton can do a remarkable number of things to help crossover, time alignment etc.

I would not want to try to integrate drivers without an external crossover (ideally in the digital domain).

Looks like you do have access to some great drivers!

Bumpy · « **Reply #15 on:** 28 Nov 2018, 01:11 pm »

Thanks, but most changes to digital over the years have involved yet more processing and filters. It all robs the music of its magic. But I agree some people seem to enjoy it

chips666 · « **Reply #16 on:** 28 Nov 2018, 06:20 pm »

http://lampizator.eu/SPEAKERS/PROJECTS/P17/Endorphine%20from%20Kingston%20Kitchen.html

Hello Bumpy,

Have a look at Lampiztors P17 loudspeaker
I am sure you will recognize it
Crossover is also attached
I personally like no bandpass filter on the fullrange
It makes the magic disappear
1 Cap on helper tweeter is ok
Helper woofer Altec is to weak to give sufficient bass with a 6 or 12 db lo-pass filter

Enjoy...
Ronny
Enjoy...

Bumpy · « **Reply #17 on:** 28 Nov 2018, 06:54 pm »

Quote from: chips666 on 28 Nov 2018, 06:20 pm

http://lampizator.eu/SPEAKERS/PROJECTS/P17/Endorphine%20from%20Kingston%20Kitchen.html

Hello Bumpy,

Have a look at Lampiztors P17 loudspeaker
I am sure you will recognize it
Crossover is also attached
I personally like no bandpass filter on the fullrange
It makes the magic disappear
1 Cap on helper tweeter is ok
Helper woofer Altec is to weak to give sufficient bass with a 6 or 12 db lo-pass filter

Enjoy...
Ronny
Enjoy...

Thanks for getting involved

Yes my speakers were put together by Slawa at SW1X. They started life as a clones of the p17s, but Slawa improved upon the design and components. The crossovers at present work fine and give a complete spectrum of frequencies. Despite the predicted lack of bass from the Altec 416 8A 15" dipole, I find with the slight side wings it is perfectly fine for me.

I haven't interrogated the crossovers fully, but believe the Greencone is 'managed' at both the low and high frequencies. My initial aim is not to mess with the crossovers until the selected midrange is bedded in. But I note that the midrange can operate with no bandpass filters. I suspect my selected alternatives can do this better than the Greencones, which can become a bit ragged at its extremes.

As far as I know, the crossovers are at about 650 Hz and 6.5Kz. I am no expert but that looks a pretty wide mid range

Bumpy · « **Reply #18 on:** 29 Nov 2018, 09:09 am »

I am posting a picture of smaller size and it seems to work.

Rather than cut into my nice piano black baffles just yet I will evaluate the drivers in the new circular baffles propped up on the floor. This is a real stress test for SQ. The wires were un-soldered from the Greencones and re-soldered onto the new drivers. No other mods were made.

Bumpy · « **Reply #19 on:** 29 Nov 2018, 10:38 am »

Observations on the vintage Supravox T215 RFT 64

As its vintage there is no need to run it in, and it demonstrates very similar characteristics to the Greencones but is better in all aspects. It integrates well into the system, has more 'drive', is more dynamic, more transparent and would prove a big improvement to the Saba Greencones. If there was no alternative I would be very happy here.