Now a Soviet Era Drivers for the Mets

As much as I can infer, looks very nice for single driver OB and surprignly so down to 40 hz. A little tweak though between 150 to 200 hz.

I am not sure as why you located the driver so off centre. Given one side wing in the design, I would have centered it on the front baffle width.

Its supposed to be 10% off the total acoustic width.
The Basta simulator did not allow me simulation with the wing on one side. It allows only for flat baffle simulatio. I did not want to risk with center simulation as the peaks and dips were too peaky with that. Also the low end roll-on off was good with minimal peaks and dips with this driver placement.
 
IMO, the contribution of the wing to the baffle step is not there as the frequencies defined by the wavelength will not get increased by it. I have used them more to prevent cancellation of the frequencies rather than add to the baffle step response. As the baffle gets over by 14" the L just prevent cancellation of frequencies below that by preventing the front and rare wave from meeting.

IMO, you should not consider the L as part of your "Baffle" else you would get wrong results for the simulation. Consider the L as "Anti-wave" cancellation tool instead of "Baffle step" tool in your design. This way your simulation will be more accurate and similar to the actual measurement.

As much as I can infer, looks very nice for single driver OB and surprignly so down to 40 hz. A little tweak though between 150 to 200 hz.

The dip at 150Hz to 200Hz is due to room mode and will appear in any speakers in my room and cannot be EQed or corrected.

Four days ago, my daughter curiously asked me if i will be adding a speaker grill on the OB as the drivers are currently exposed. I said no. She then asked me to put a cloth cover. I liked the idea and she helped me select the material, design, pattern, texture and shade of the cotton cloth. This external cloth cover will now be on the OB, when they are not in use and shall protect them from dust and physical abuse. Will share image when delivered.
 
Hariji,
I am seriously contemplating these OBs now. I am concerned about the width of the baffle affecting the passage to a door if I were to try at this at home. WAF would shoot down the project because of the width of the baffle.
What is the exact width of the baffle?
Can you please simulate and see if the baffle width can be reduced to 15 inches or less? If I do such a reduction what is the negative impact that I would have to deal with?

Regards,
Arun
 
I think the image shows a bigger baffle than it actually is. These are 14" baffles, folded in one end to prevent cancellation at low frequency. I used golden ratio for deciding the height. You can simulate them in Basta for deciding for your driver.
 
14 inches is definitely manageable. Taking my wife out for a shopping date this weekend; must sneak in the project at the billing counter.
 
Lovely and imposing. Do share the dimensions and also rear photos.
H - 44.8" x W - 14" - Golden Ratio - Driver is mounted 28" x 5" - height x width - Depth is 8" with 8 kg concrete block in the base to prevent tripping. The OB modules are resting on spikes and has gold platted heavy duty connectors for speaker cables. Will post rear image in the evening.
 
Hi everyone! So this is a review on Hari's system which consists of a DIY open baffle speaker. Hari was nice to have me over to his home where we listened to his system. Since I have never heard any of the components in his setup, this is more of a system review though certain characteristics are attributed to the OB speaker.

First of I must say that he has done a fantastic job at building a setup. It will easily outbeat any entry level setup; easy. The choice of DIY DAC, 300B valve amps, cables etc. are a work of art because he has managed to put together a very nice setup without having to spend silly money. When the power cable was noisy he put a ferrite ring on it. So he has built and tuned most of the setup himself without relying on buying so called 'high end' products.

System as configured:

1. Marantz 5001 CD player used as a transport
2. DIY DAC using BB1974 + AD827 opamp
3. Dared monoblocks with 2 x 12au7 drivers + 1 x 300B per amp with their own gain/ volume control. 6W amps.
4. Speakers as Hari has described (1950's driver!)
5. All DIY cabling using single core magnet wire.
6. Power cords with DIY ferrite rings

So now onto the review:

The dac which is basically a DIY kit from China is IMHO a star. The systems sound never got muddy or confused, nor did the soundstage collapse when the music got complex which I usually attribute to cheaper DACS. Nor did it sound extremely one note-ish.
The amps, which are tube amps using 2 x 12AU7 + 1 x 300B monoblock from Dared also drove the speakers with aplomb.

When we first started, I felt that the bass response wasn't right nor were we getting enough weight in the mids. I felt that the lack in mid weight was due to some cancellation between the front and back wave of the driver as the driver, is closer to one edge of the baffle than the other. Hence we switched speakers around. After moving the speakers back and adjusting toe in, compensating for the lack of one side wall, etc. things fell into place. The aspect which we couldn't address completely was that the sound had a hard/ brash overtone to it which we later attributed to the tungsol 12au7s in the amp. Unfortunately I had only one set of RCA tubes which seemed to address this.
Hence all listening was done with the tungsol tubes.

Being a single driver speaker, the sound emanates absolutely freely, without your brain getting puzzled by two different drivers. It is like there is no stress to the brain and you want to listen to music. You have to listen to it to understand what I am trying to say. When you listen to a conventional 2 way speaker, there is always a little stress to the sound due to the crossover, two drivers having different material and profiles, etc. With a single driver speaker all this just disappears.

My rant on modern day systems:

Once again my feeling that people in the 1950s-1980s built music systems, where as we now build technology systems that are mainly about measurements and theory seemed true. This is why I hate it when John Atkinson measures equipment in Stereophile and then comments on how it isn't good engineering. He measures equipment reviewed by other reviewers mainly and yet comments on the measurements as if he is making equipment himself. The problem with this approach to reviewing is that it forces manufacturers to tune their systems to measure well, rather than to sound well so that Stereophile gives them a good review. I can understand measuring output power, impedence curves, input/ output impedence of electronics as these serve as guides for system matching but beyond that I think one diverges from the art.

Of course some people will disagree but this is how I feel:

If one wants a technically perfect system, just buy a Dynaudio studio monitor (active) and listen to it. It is matched to the amp to have enough drive and to be ruler flat and costs < Rs. 2L. One buys an audio setup to enjoy music, not to make measurements and yet we expect it to measure flat. The dynaudio will let you hear everything going on, but it is flat and devoid of any emotion. You will stop listening to music on it within 20 mins. I have tried it first hand. Even studio engineers will replay the music on a set of home/commercial/ TV/ car speakers (depending on where their music is going to be heard) to see how it would sound in the real world post mixing on their monitors.


Now back to Hari's system:

There is an ease to listening to the human voice with this speaker and you feel like listening on and on without worrying about what it lacks, which is how I described a level 3 setup elsewhere. No, this speaker doesn't and cannot extend into the upper highs nor can it go low and shake you. It is a single driver speaker which reproduces a fixed bandwidth, but does it pretty well, especially for a 1950's driver. The point
I am trying to make is that it lures you into the music by being simple rather than try and impress you with a particular frequency response.

You are not going to hear every instrument with this setup. You are not going to here someone coughing in the background. Your jaw will not drop either. What you do get is a very nice vocal, fully integrated (or should I say not disintegrated due to the single driver) with decent timing. Being open baffle you get a large sound and the speaker almost disappears. This is a speaker for the human voice, not for heavy rock music or techno.

I kept coming back to Allison Kraus, Louis Capart, etc. It makes you want to listen to the singer. You could almost get up and give a hug to Allison on some tracks. On other tracks like Peter, Paul and Mary's El Salvador the system showed it limitation. It just couldn't keep up with the fast guitar and high spl vocals.


Upsides:
1.A completely 'un-disintegrated' sound
2. Free, big and open sound, not confined into a box
3. Makes you want to listen and not worry about highs and lows and mids and people scratching their who knows what in the crowd in a smoky club
4. Easy to drive
5. Not a jaw dropping sound which is usually impressive at first but then gets tiring later on
6. Hari factored in everything. All wiring is simple magnet wire (single core). He has made an attempt to be a true audiophile on a budget. Instead of buying cheap speaker wire and then saying it sounds bad he addressed the problem by using a better option and yet sticking to his budget.
Kudos to him for that.

Downsides:

1. Will not suit all forms of music in the way people want to hear them. Blast Aerosmith on this speaker and the cone may come flying at you instead of Janie's gun.

2. Flat sounding in the lower mids (like a sudden lower mid suckout), little brash/ hard edge tone to the sound.
(though this was changed once we switched the 12au7 to RCAs. Unfortunately I didn't have enough tubes to switch both amps)

3. Got a little compressed/ confused on faster music like a fast acoustic guitar with vocals. Wasn't able to keep up with the strumming and vocals. Could be driver limitations. But its an old driver that was manufactured long ago and has been sitting around forever. Even grandpa needs a break!

4. Lacked height to the sound

I believe that you will not find a floorstander speaker below Rs. 70,000 with these positives, especially the ability to make you want to listen to music rather than focus on the attributes of sound. Infact I would go on to say that this setup will put most systems < Rs. 2L to shame.

If Hari can address the tonal hardness/brashness, lower mid weight and height aspect, then this is the speaker to beat below Rs. 1L on vocal music.

Infact I would push hifivision reviewers to go and review the speaker or system and support out DIY champ Hari. Sridhar time to visit Mumbai?
Vivek time to make a trip to Hari's home?

This system just goes to show us that one doesn't need big budgets, 300W amps or fancy multiple driver speakers to enjoy music.
A simple SET 6W amp, an ancient driver and a man with perseverance can easily put new age gimmicks to shame. If vocal music is your forte and you are on a budget then this maybe the road for you to follow.
 
The last time I measured these speakers were when I built them somewhere around March this year. Since then, I have made countless modifications to my tube amplier, interconnects, speaker cable and room( removed the acoustic panel). Now I am in my final stage of my amplifier modification that gets completed this weekend. So it's time for one more measurements.

I am doing this measurement to analyze if there is any difference in an objective measured value and subjective differences. Subjectively, I can confidently say that the difference is just humangus if my listening memory serves me right. Just wanted to confirm if the microphone and the software also things so.

FM Sachin Chavan will be home today evening to listen my setup. I may be able to play only my TT & Cassette player as I am not expecting the BDP to be delivered by that time.
 
I am not very knowledgeable from a technical stand point when it comes to speakers but I just wanted to compliment you, Hari on the work which you are doing. I have learnt so much by reading through your threads and your support for the full-range speaker community is really heart-warming. Those open baffles look really well designed and well made. Did you do the woodwork by yourself?
 
I am not very knowledgeable from a technical stand point when it comes to speakers but I just wanted to compliment you, Hari on the work which you are doing. I have learnt so much by reading through your threads and your support for the full-range speaker community is really heart-warming. Those open baffles look really well designed and well made. Did you do the woodwork by yourself?
Thanks for your kind words reubensm. I designed the OB using "Basta" and asked my carpenter to do the wood work as i have neither the skills nor the tools to do that.

I had the opportunity to measure the speakers again yesterday evening and attached are the measurement results,

1. On-axis measurement - the increasing response vis-a-vis frequency is to maintain constant directivity for improved off-axis response.
2. 30 deg off-axis measurement - the FR is flat from 40Hz to 20KHz (+/- 2.5dB)implying that this speaker need not be towed in for listening. Toe-in will increase the HF response which could be undesirable. With no toe-in i am able to get excellent 3D holographic sound stage, imaging and tonality.
3.Step Response - displays excellent coherence for which single driver are famous for..
4 Impedance - measured resonance is 34Hz and almost ruler flat at around 5 ohms nominal.
 

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Will post rear image in the evening.

I am seriously thinking of replicating the same. I am open to adding a sub(OB or Sealed) later if required.

is the baffle angled/tilted or perfect 90degrees? where can we find a cement block?

Please post images of the back.
 
Hello, from Ukraine again! I admired the work you have done during last time!.. Thank you for sharing your achievements with us.)
I would like to note about the SOVIET speakers 10gdsh-1-4 - quite a few different modifications of this model 10gdsh1 passed through my hands - and so the most expressive and noble sound, as for me, has earlier modifications with marking 10gd-36k from , but unfortunately they are difficult to find, especially in good condition!..
 
Hello, from Ukraine again! I admired the work you have done during last time!.. Thank you for sharing your achievements with us.)
I would like to note about the SOVIET speakers 10gdsh-1-4 - quite a few different modifications of this model 10gdsh1 passed through my hands - and so the most expressive and noble sound, as for me, has earlier modifications with marking 10gd-36k from , but unfortunately they are difficult to find, especially in good condition!..
Thanks Oleg for penning your thoughts. I just now checked my driver, they have the marking of 10gd-36k. Perhaps I am fortunate to find driver with this marking. I will also like to add that these Soviet era driver are the best I have ever heard so far.
 
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