Now a Soviet Era Drivers for the Mets

[prem]

Some guy in Germany makes these butterfly cabinets for Saba drivers. They are not OB though. I was very tempted to try them but gave up because of the size

 

[Hari Iyer]

Fully agree with Prem. I would consider a 2 way setup over a single driver if midrange and high are more pleasant to hear.

Saba duo is a simple 2 way setup with the Saba tweeter topped off by a single cap as some DIYers in Europe have done. Alnico midrange is very sweet. I will be putting my 8PW1 in the baffle for Mid and HF and see how it sounds. It did sound very nice in earlier experiments.

The Russian driver is great but there are some other great drivers as well. And you can never judge tonality and musicality just by graphs. Has to be experimenting by putting different drivers in same baffle and line up, to be judged best among the lot, I think.

IME with using a crossover, even if its a single capacitor for the tweeter, matching the phase-shift between the drivers is a challenge. More over if the cross-over point is at the crucial mid-frequency then even more issues with them. Also to get them level matched is another issue. Not to say the timing and phase coherency issues seen in the step response.

 

[shafic]

If I were to make a budget OB speaker, this is the one I would do

http://lampizator.eu/SPEAKERS/PROJECTS/P12/opoen baffle alnico speakers project 12.html


The Saba drivers are probably the most musical drivers I have heard

Hi prem,
My thoughts exactly. I am planning this design. I have few Saba Green cones and black cones. Will ask your help soon.

 

[Hari Iyer]

Hari, I have heard the Saba on a couple of occasions. All I can say is it’s extremely musical. Tone and timbre is outstanding. I attach more importance to these things rather than how low does a driver go.

Me too liked the Saba mid-range when i heard them at FM shafic home. But the thought of going 2 way kept me away from them. I too agree on the tone and timber of the sound stage rather than how low they go. For me the bass has to be tight, non-chesty and not overpowering the mids and highs , but a seamless perfect balance. I am happy even if they are 60Hz.

 

[prem]

Yogibear, crosses over at around 6k with a PIO cap should be fine. Of course if you have the budget you can use more expensive caps like Duelund, Jupiter, etc

 

[prem]

Shafic, I would be glad to help but the truth is I don’t know anything about speaker diy

 

[shafic]

Hari, I have heard the Saba on a couple of occasions. All I can say is it’s extremely musical. Tone and timbre is outstanding. I attach more importance to these things rather than how low does a driver go.

I always respect your observations and audiophile ears.
Saba needs the perfect matching amplifier. I have tried many amps with Saba but only one amp brings out the bass of the Saba is Dual CV 40. Although my Saba is perfectly matching with my Scott LK 72b but compare to Dual, the bass is not as tight n deep. But the mid-range with Scott is heavenly.
Regards

 

[shafic]

Shafic, I would be glad to help but the truth is I don’t know anything about speakers

 

[Hari Iyer]

My OB speaker shall be fully ready and functional in another 10 days. FMs who are keen for a listen are welcome after 14th April.

 

[shafic]

One of my OB tryouts with Philips AD 1255/m7 with Dual CV 40 amplifier. This YouTube video was made 3 years ago.

 

[arunkvivek]

A familiar track?

you have put a worm in my headu (literal translation from Kannada). Trying to figure out which song.

 

[shafic]

Shafic, those Philips AD drivers sound heavenly. However Phlips AD drivers still elude me.....

That Dual CV 40 looks like a single TO-3 each side, stereo solid state. Nice amp. Never saw that before.

Yes Sameer,
Those Philips are excellent ones. Now they belongs to Joshua.
Dual CV 40 is a simple amplifier but very musical one.
Pls read this article.
http://lampizator.eu/SNIPIT/lampizator_DIY.html

 

[jmascreen]

you have put a worm in my headu (literal translation from Kannada). Trying to figure out which song.

Me too

 

[Hari Iyer]

I listened the Philips on a headphone and to be honest, they are too strong on the mids and highs though quite good, will need to discover if they can work great without a helper 15+ inch woofer.

@ Shafic - have you tried them without a helper woofer? Please advise.

 

[shafic]

I listened the Philips on a headphone and to be honest, they are too strong on the mids and highs though quite good, will need to discover if they can work great without a helper 15+ inch woofer.

@ Shafic - have you tried them without a helper woofer? Please advise.

Yes,
Even in the OB they are producing good bass.

 

[Hari Iyer]

Yes,
Even in the OB they are producing good bass.

Is Jousha building an OB with them? Any measured values? I can check with Basta simulation.

 

[shafic]

No idea Hari.

 

[Hari Iyer]

Measured two extended range / FR vintage drivers today:

Telefunken 7x10" ovals Alnico : 93dB, Re 4.8, Fs 85, Qts 2.7 Qes 3.24, Qms 16 Mms 21 Vas 3.65

R&A MK III Wolverhampton Alnico: 93dB, Re 8, Fs 74, Qts 2.7 Qes 3.34, Qms 14 Mms 12 Vas 2.26

Dunno what to infer from very high Qts of these drivers !!!

Will top these off with a Jensen Alnico tweeter I have. Will it fine topping them off with a horn slated to cross above 3K ? I plan to XO the above drivers around 6-7K.

The resonance is quite high, both drivers will require woofer support for low end.

Btw, the Qts looks quite high, hope you have measured the VC resistance and included the internal cable resistance accurately. How do you measure the added weight. Can you also post your free air and added mass impedance trace for scrutiny?

 

[Hari Iyer]

Why cello tape, I use a small ceramic bowl weighing around 23 grams for the measurement. I also distributes equal weight in the circumference of the VC. I use a digital precision balance for measuring weight.

I think the VC resistance is high, also include connection wire resistance. Btw is your sound card calibrated?.

 

[Hari Iyer]

Well I guided myself on the measurements as stated by Parts Express youtube video on DA Dats V2. I did calibrate through a 1K resistor 0.1% tolerance and used the leads with crocodile clips that came with the measuring USB jig. The cello tape weighs 65 grams.

Not sure about sound card calibration. Using an older model but nearly un-used Dell Alienware laptop as thats the only one with Windows, I have.

However I did measure a couple of new drivers with published data and compared with Dats V2 measurements and they did come close.

I was wondering, why one terminal of the vintage drivers always comes shorted with the driver chassis ?

Ok, can you also reconfirm the measurements using REW tool. Added mass should be approxiately twice the expected moving mass of the cone. If your Mms is around 10grams then 20 grams will be enough. 65 grams is way too high. This will lower the resonance for the added mass too much. Also were there too many wrinkles or resonance in the measurement in the added mass method?

Most laptop soundcard are not suitable for driver measurements as they are of average quality and dont have extended response. My Dell laptop seem to be an exception with a flat response from 20Hz till 15KHz and roll-off @ -3dB/octave after that. I have used a metal film resistor 1% tolerance of 100 ohms for the impedance jig.

I think the crocodile clips may be causing contact resistance but need to be confirmed by you.

This Russian driver do not seem to have one terminal shorted to chassis - though they are vintage. Shafic can you confirm.