member's OB speakers

pheesama · « **on:** 24 Jun 2010, 02:10 pm »

My name is Pheesama.
After studying how to in many forums I am very confidence that I can build my own speakers. And here they are:

the black speakers are OB's. Each Ob contains 1 direct constantivity horn, 1 magneto -static tweeter and 2 x 15 inchers (from PA made in China). A 15" woofer has sensibility at 97 dB. so that makes 100 dB. The baffles are 120 High and 60 wide (in cm.) made of 25 mm. MDF

The speakers in the middle are of transmission line concept. Each has 1 tweeter and 1 x 15 incher woofer. The woofrs are the same as OB's. Surely I have the Titan (made by Quadral) in mind when I designed them. And here they are after modification.

These are not my 1st OB speakers. I have built many OB. But these are my best.

pheesama · « **Reply #1 on:** 24 Jun 2010, 02:25 pm »

continues.. (off topic)

here are some other speakers I have built

far left is the transmission line.
Then a 4-ways closed box with 1 tweeter, 1 5incher and 2 x 8 inchers. I had the RS3 from Infinity in mind when I designed them. And here they are after modification.

The blue coloured are pieced with focal 6 and 8 inchers. The tweeter and 6 inchers are attached on open baffle and the 8 inchers are in transmission line enclosures.

baka · « **Reply #2 on:** 24 Jun 2010, 04:28 pm »

verry, nice

please, some more informations about Set up and
some more pictures from other sides

Hank · « **Reply #3 on:** 24 Jun 2010, 05:33 pm »

beautiful work, pheesama!

pheesama · « **Reply #4 on:** 25 Jun 2010, 01:50 pm »

In fact there is not much technical things to tell about my speakers since they are open baffle. I use the x-over system from XXXX. It recommends to use only 1 high power resistor and 1 inductor air coil for each speaker unit. And capacitors if one would like to keep impedance in good fashion. I find this x-over rather flat at x-ing points.

Naturally, surface volume of 4 x 15 inchers are very much in advantage. They reproduce greater sound than i.e. 2 x 8 inchers. And not to forget that the direct constantivity horns are really great in its performance, from top to mid-range. And they are fast enough to accompany those 15 inchers.

My listening room is 4x4 metres without treatment.

I drive them with adcom 545 pre- and power amp. Sony PS1, Transporter and DAC from stello 100 series. This class-A DAC is very good, I prefer to connect via I²S port. The RCA innterconnecting cables, speaker cables and Ac cables are naturally self-made. I prefer to connect my PC instead of Stello transporter.

Now is the part I really dislike meaning when it comes to describe characteristic of sound reproduction from a system. Let say it sounds airy with good timbre and nothing is missing. And it can take very high SPL galantly. I listen to this OB louder than any other speakers I have built. Fatique is the expression that I never have to experience.

Since the OB are fast ( 100 dB) I drive them from time to time with Mark Audio tube amlifiers. There are SE 2A3 (Chinese Fabrique), SE 300B (Electro Harmonix Gold Plate) and a PP EL 34 (RSD). I must say that the tube amps cannot drive those big-volume speakers in good manner.
These tube amps are good for my another 15 incher front loaded bass horn with higher than 100 dB and tractrix mid-range.

These are the front loaded bass horn with front loaded tractrix-compression chamber horn. The side board of the bass cabinet can be removed. Then one can see horn-contour. And if the side boards are removed then one will get quasi OB + front loaded horn. I added this side bord for maintenance or in case I have to change the drivers.

The little redish speaker is 1 tweeter and a 5 incher mid-woofer in TL enclosure. It sounds great for a 5 incher. Naturally the sound stage and slace of music instruments are no match. But it stil make fun listening to them. I find that sometimes more relaxing when listen to smaller speakers. it has less details and less noise.

pheesama · « **Reply #5 on:** 25 Jun 2010, 02:00 pm »

Here is my system including DIY turn table

pheesama · « **Reply #6 on:** 25 Jun 2010, 02:01 pm »

And another TL speakers

gvimhoof · « **Reply #7 on:** 26 Jun 2010, 12:20 am »

Woof!

pheesama · « **Reply #8 on:** 26 Jun 2010, 01:03 pm »

Some of my OB's I have made long time ago

Bob in St. Louis · « **Reply #9 on:** 26 Jun 2010, 02:15 pm »

Most impressive!

You should charge admission for listening sessions.

Bob

pheesama · « **Reply #10 on:** 26 Jun 2010, 04:20 pm »

Hi Bob,
I never have any visitors to come for audition. If you should come into my neighbourhood then you would be the first one that I shall charge for.

All my speakers are x-over with ars-audio design. Have you ever heard of this? I find it very simple and with results that go far beyond my expectations.

Bob in St. Louis · « **Reply #11 on:** 26 Jun 2010, 04:28 pm »

Quote from: pheesama on 26 Jun 2010, 04:20 pm

I never have any visitors to come for audition. If you should come into my neighbourhood then you would be the first one that I shall charge for.

Good to know you have a healthy sense of humor pheesama!

pheesama · « **Reply #12 on:** 26 Jun 2010, 05:11 pm »

Hi Bob,
I though that I am the only one who is in consideribly danger.
I saw your system and I must say that your out fit is really impressive.

Bob in St. Louis · « **Reply #13 on:** 26 Jun 2010, 05:14 pm »

Thank you.

hdspeakerman · « **Reply #14 on:** 26 Jun 2010, 08:00 pm »

"All my speakers are x-over with ars-audio design. Have you ever heard of this? I find it very simple and with results that go far beyond my expectations. "
Pheesama,
Great job! I am unable to find any info about ars-audio design x-overs. Can you give me any guidance?
Howard

pheesama · « **Reply #15 on:** 27 Jun 2010, 02:41 am »

Dear Howard,
I am providing you the link for your further information:
http://www.xxxxxxxx
http://www.xxxxxxxx
have fun then... bye
Pheesama

hdspeakerman · « **Reply #16 on:** 27 Jun 2010, 05:26 pm »

Pheesama,
Thank you. I am familiar with the name but i have never tried the process. Is it as easy as they make it sound in the information? Any tips? I may just give it a try since I seem to have very little success with any of the other x over methods I have tried.
howard

pheesama · « **Reply #17 on:** 27 Jun 2010, 08:07 pm »

Dear Howard,

There is quasi well explained and just follow the hints such as begin with the woofer first. Then manipulate/adjust with L. according to your need. IMHO the R does not have big influence in bass performance.
And the L at 0.11 mH can be applied to many kinds of tweeter. I did successfully with ribbon, magneto0static, soft dome, titanium dome and even the compression chambers.

I used very high power R at the beginning and now-a-day I use only 20 watts R and cannot find any disadvantage.

Please, do try and share your experience, too!

Good Luck then...
Pheesama

pheesama · « **Reply #18 on:** 27 Jun 2010, 09:36 pm »

Quote from: baka on 24 Jun 2010, 04:28 pm

verry, nice please, some more informations about Set up and
some more pictures from other sides

I am delighted very much sharing you further information. There is only hand drawing of TL. I got the idea from my session with Quadral aprox. 30 years ago. I was impressed by Titan and vulcan. Originaly the Titan is using a 12" woofer, 1 mid and 1tweeter per speaker. I got plan of Titan from www.hifi-forum.de

I re-calculate this design for my 15" and use only tweeter since the 15" can go quite high as ca. 1KHz. The ars-over allows me to blend them together without a mid range unit. I used knob foam covering up along the partition panel.
The set-up with my TL (I name it terra) is very simple. I do not have particular position for them at this moment since they can be placed almost everywhere. Behind my speakers I use acoustic-boards for reducing echo. No further acoustic treatment. Since my listening room has only 16 m² and therefore I do not have problem with room-resonance.

If I would build a 15" TL again will shall reduce the volume.

The 4-ways speaker is a real out of box thing. It does everything in contradiction to closed enclosure speakers. It has very good high freq. respond, totally out of box sound and no resonance at all. I do not have parallel walls at both sides but front and back walls. I name it CYAN

I did fall in love with Infinity RS3 about 30 years ago. It works in 4 ways closed box. The effect of piano, bass and kick drum never let my mind a rest. Far worse than the session with titan. It was my dream speakers since.
I also use the x-over from acoustic reality in my 4 way closed speakers. It is not necesary to put too many wool for damping. To attache knob foams behind mid-range and woofers will do well.
The idea of cabinet design came from Farbinochi Princip. This princip differs the idea of RS III. I stil keep the outer dimension ca. 120 x 40 x 20 cm from RS III. I shall build another cabinet using the same lay-out as of the RSIII and with magneto-static instead of softdome tweeter. Only thenI shall have my peace.

I listen mostly to classical music. And the cyans play very well under high SPL. Not even the Terra can match its skils. No harsh sounding at all. I can listen to them for days without having the fatigue feeling in my ears.

It is joyful to use the cyans for HT well. And I have 6 pairs of them and 4 pairs are standing in my room.

From all my diy speakers I love OB with direct constantivity horns the most. I detached the magneto-static tweeter from the baffle 2 weeks ago. It has no use in this set-up. It runs in 3-way config since.

Here again the terra & cyan

hdspeakerman · « **Reply #19 on:** 29 Jun 2010, 01:47 am »

Pheesama,
I just wanted to let you know that I tried the ars crossover method and I am very surprised. I have a set of diy bookshelf speakers with a parallel crossover designed by someone on the PE board that knows what he is doing. He has measuring gear and is not a newby like me. I put together a similar combo this evening with the same woofer and a similar Seas tweeter and tried the ars xover right out of the article. It is not perfect but it is a very close match soundwise to the parallel crossover. I am very happy and will continue to play with this combo until it locks in. From my reading I understand that this is how it works. I am supposed to know it, when I hear it. Thanks for your encouragement.
Howard