My first Open Baffle DIY

[Sumanta]

I was following Jaudere for some time and was in contact with him since my Abudhabi days.

Post my arrival in Baroda, I read some papers, write ups on OBs and BLH and decided to try an OB first.

Following Jaudere, I opt for Ahuja speakers.

Day before yeaterday I bought Ahuja 12FRX of 8 ohm and two Ahuja tweeters with capacitor. Gave them to a cabinet makers suggested by Ahuja dealer.

All three party (including myself) got the interest of making something new. OB design is a complete new thing for both Ahuja dealer and the cabinet maker. I have opt for clothing the baffles both sides.
It cost me 5000 rupees including transport.
Yesterday night I got the set from him and played at home.

They sound clear, open, real, spacious, powerful. I played my Cabasses just after that to compare. Yes, Ahujas lack finess but Cabasse can not give the open, clear mid. Even the bass from Cabasse is more than what I think is real.

Norah Jones, Roja, Hotel California (live), Sona Mahapatra, Dali's demo CD ... all of them came live (at least to me). I think one 12 inch has more presence than some 5 or 6 inches.
I am not an audiophile...I hear music and heard some good speakers recently. I heard some floor standaers and some few bookshelves. Floor standers were from JBL (2 and 3 ways), Mission, Bang and Oluffsens, Infinity, Klipsch, Jamos.
The best to me was Jamo R909 for home application.
I have two Cabasse Joursey, two Mission 702e, two Jamo 402 (I guess) for Floor Standers. My guage reference are them as immediate as it can be. And I always try to remember what I listen in other speakers. That Jamo R909 will always be in my ears.
To me, this OB with my Music Angel tube plays what I like. The tube with th Cabasse Joursey is also quite to my liking.

I want to thank Jaudere for all his support. I did some basic calculation in Xvaffle excel and then followed writting in Enjoy the Music.com - High End Audiophile Audio Equipment and Music Reviews. The Absolute Sound, Superior Audio, hi-fi+ and Review Magazine and followed my mind.
Baffles are of 20" X 36" with two tapered wings starting from 1" to 8" and of 33" high. Baffle has an arc at the top. I also have a 4"X9" plate on top of the Tweeter. I just thought it will be good. I have used MDF of 9mm thick and used two plates per baffle to get 18mm thickness. They were bonded with Fevicol and some nails.

Bottom line, such DIY project gave me a lot of joy in reading, thinking, calculating, planning, executing and owning two good speakers. All of this for not so much money.
I will post photos pretty soon.

I think I will make atleast one set of BLH and another Ob with three way set up. And probably all from AHuja only. Cross over will probably be from my Friend Ashok Mandal in Kolkata.
regards,
Sumanta

 

[Sumanta]

Here is one photo of those OBs and with my Cabasse Joursey to have a perspective in referencing.

 

[Sumanta]

Here are other two

 

[GeorgeO]

Looks good.

 

[stevieboy]

Looks very nice sumanta! Congratulations on a clean build am sure they sound lovely too

Do post close up pics of your tube amp too. I'm a die hard tube lover

Regards


Sent from my iPhone using Tapatalk

 

[omishra]

Nice! Congratulations. I would like to listen these kind of speakers.
BTW what amplifier you are using?

Regards

 

[ukjeyaraj]

Looks really good

 

[t.antony]

Good work with the baffles. You can bring in a lot of finesse in the upper mids by adding a baffle step correction circuit (BSC) for the 12" driver.

Some useful links on BSC from quarterwave.com - General Speaker Related Articles

 

[jaudere]

hi, where do you sit while listening to speakers? Try sitting on floor. You should get much better sound. I think so considering position of full ranger.You are getting good bass as you have placed full rangers close to the floor.by the way finish is good. The sandwich baffle is also supposed to improve sound by damping. So good thinking there. Who built the baffles for so less cost? My baffles went to around 7k and then the drivers took my price to about 10k.

 

[Sumanta]

Wow!
I didn't expect this many replies.
Thanks to you all for following this post.

Omishra, I use a mere Chinese make Music angel tube amp with 2 valves per channel. EL34A and 6N2.

T Antony, I am not good in understanding so much technical terms. I had tried to understand MJK, then many others but failed to concentrate .
I then have given an excuse to myself that if I try to be accurate in sound reproduction (too much I mean), I will be missing the charm of music. When I listen to music, I want to enjoy it rather than noticing where is pitch, fall of sound or something like that unless it is too disturbing or can be better with easy solutions. But since you said, I will try again.

I think my ignorance and lathergy is too much.

I am thinking of making a 3 way OB (from Indian drivers only). Let's see.

Dear Jaudere, I sit quite low in a recliner, where ear is of the same height of the tweeter. But I prefer to sit at floor when we listen to music at night. a local cabinet maker made the baffle and his son did the soldering. I paid 3040 rupees for drivers (with 10% discount) and 1800 for assembly including material, plus some money for connector, wire and transport home.

 

[jaudere]

Well, I think the dictum that the tweeter should be at ear level may not hold good for this design (as well as my design). In usual designs, the tweeter is crossed at about 2 to 3khz while in this design, the tweeter plays frequncies only above 8khz or so. So full ranger is covering more than 90% of spectrum of music (50 hz to 8khz). So in this model, it is likely that keeping the full ranger at ear level will give better results. I would also like to know why you have kept so much gap between the full ranger and tweeter? Closer will give better result with co-axial being best. However I don't know how to mount tweeter co-axially. A member here (Goldy) tried to help me but I think I was too lazy to follow what he suggested about co-axial mounting. By the way, which tweeter model you are using?

 

[kaushik]

Nice build ... noobs like me learnt a thing or many from the posts

 

[Sumanta]

Dear jaudere, I have used APT016 tweeter.

I have a question for you. What will happen if we use AS12-X100?
Its Qts is still 0.69.
But it has higher SPL.
Teach me please.

Plus I am think of pushing the design with another woofer with a 3 way cross over.
But I do not know much about either driver or cross over.

 

[jaudere]

Dear jaudere, I have used APT016 tweeter.

I have a question for you. What will happen if we use AS12-X100?
Its Qts is still 0.69.
But it has higher SPL.
Teach me please.

Plus I am think of pushing the design with another woofer with a 3 way cross over.
But I do not know much about either driver or cross over.

Hi,
Both the speakers look quite similar. However, the Fs (resonating frequency) for the AS12-X100 is 70 Hz while that for SK12-FRX is 50Hz. So the SK12 is going to perform better in lower frequencies (between 50 to 70Hz) as compared to the AS model. The Vas is different as well and AS12 has slightly better Xmax. However, the sensitivity is same. So SPL will be same. So I would stick to SK12 unless I have any plan to add subwoofer .

The beauty of full ranger is evident when it is used in cross-over-less design.
Readymade 3 way crossovers are difficult to get and more difficult to match with the drivers. Additionally, cross over, however good it may be, is going to degrade sound quality. Not only that, the amplifier is supposed to have poor control on drivers when cross over is there in-between. The overall sensitivity reduces as well. Will make it difficult for low powered tube amps.So I would like to stay away from crossovers.
In the design that you have made, the amp is controlling full ranger without any crossover while the tweeter is through a capacitor(1st order crossover). So it is probably the best solution.

If you are firm on 3 way design, you will need a lot of reading.I will try to help you as much as possible but after reading a lot and some experiment with 2 way-3 way crossovers, I have stopped reading on passive crossovers

However, all these problems are mainly with passive crossovers.3 way active will be the way to go if you want 3 way design. but then the wire clutter increases and you need 3 stereo amplifiers or 1 multichannel amp (with at least 6 channels) to use 3 way active crossover. So think about it.

 

[Sumanta]

Got the point about those drivers. Clear. Thanks.

Regarding 3 way speaker OB design, I think it is difficult for me. I mean too much difficult for me.

The first and foremost reason to go for OB for me was simplicity.
I myself now should not go for a cross over, be it passive or active.
And my tiny amp will probably get damaged to run so much power to drive those drivers. Plus I am happy with my speakers any way (except for the space requirement, which I knew though).

But again the bug knows no logic.
Let's see....

What I really want right now is to sell off my Cabasses and Mission 702es. But I am not authorised to sell here in this forum.

Please help me selling these speakers.

Sumanta

 

[jaudere]

Keep on participating in discussions. Increase your post count (but don't write bump posts like 'nice design' etc. You can easily have the needed count to start 'for sale' thread. Secondly, keep a watch on 'wanted' section where people needing various equipments post their needs.by the way, crossover , for me, is a really complicated matter. Howvere, for the bug in you, you can buy full kits which include drivers, matching crossovers and box plan. All you have to do is get hold of crapenter and assemble everything. Howver I don't know hwteher anything is availabe for open baffle. Try to go through some hybrid designs as well where the woofer is in box while mid and tweet is on open baffle. Such builds are also interesting.

 

[t.antony]

T Antony, I am not good in understanding so much technical terms. I had tried to understand MJK, then many others but failed to concentrate .
I then have given an excuse to myself that if I try to be accurate in sound reproduction (too much I mean), I will be missing the charm of music. When I listen to music, I want to enjoy it rather than noticing where is pitch, fall of sound or something like that unless it is too disturbing or can be better with easy solutions. But since you said, I will try again.

I think my ignorance and lathergy is too much.

I am thinking of making a 3 way OB (from Indian drivers only). Let's see.

All OB designs will charm us with the open sound... and it's normal to get very accustomed to the sound of personal DIY builds. However good it might subjectively be, if it causes listening fatigue, then don't hesitate from doing the required tweaks. The beauty of DIY are these endless tweaks we could do to evolve and optimize the design.

OB optimization is a complex subject, and I would recommend some reading before venturing into it. These sites have a wealth of information in the subject along with some practical designs.

OB Theory
Tech
Linkwitz Lab - Loudspeaker Design

IMHO for a novice OB DIY'er, going active is the best way forward. Use the PC as the active crossover and (cheap) chip amps to power the drivers.

I have used this foobar plugin for active xo with some good results - foo_dsp_xover

 

[Sumanta]

Dear Antony,
Thank you for the link, but they are too difficult for me concentrate on them and understand.

All I need now is a three way OB.
Not that I am unhappy with my present OB. I want to have a Jamo lookalike in my home. Is it possible with local drivers and cross overs? With reasonable and practical sound quality output?

My first hurdle are those existing floor standing speakers. I have to sell them off.

 

[kuruvilajacob]

I made my first open baffle speakers yesterday with Goodmans odium 15" Full range speakers . I tried placing the speakers in my music room but I felt bass was booming and higher frequencies cancelled. So I moves the speakers to my drawing room and what a difference it has made. I am driving them with Quad 303 power amp. they appear to go well with each other. I don't regret the effort and the money spent on it

kuruvilajacob

 

[Sumanta]

Dear Kuruvillajacob,
Thanks for putting photo of your OB design.

I didn't know even a 15inch can be a full range driver!
I wish I can be there and listen to the sound.

Congratulations for your design. I like the oval top. Will it be better if you fold part of your baffle to reduce its presence?
Have you tried placing the baffle on ground? If yes, then did they give any changes in sound? What are the differences (accoustically) between your two rooms that you think are the reason for different putput from your OBs?

Plus, I feel you should put a separate post for your OB, as it is worth!

Sumanta