Hi, Thanks for your message. It is nice to see somebody local gives information
about things which I need. It gives confidence. I want to build a good OB with the
following specifications:
1. Full range speakers to avoid any crossover or very little as in the
Wharfedale sfb3 above.
2. The baffles should be of reasonable size.
3. Of course it should sound great.
I need only the drivers. Other things I can do myself. I can do woodwork also.
Now please tell me where do I get the drivers. I know precious electronics in Mumbai
sales drivers. I also know many who import complete speaker setup from big
companies but do not know anybody who sales imported drivers.
My budget on drivers is around Rs 15000/-
Thanks and regards
Roushon
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Directly connecting a driver to the amp, if it is a woofer, is not a problem. You will experience some distortion and erratic SPLs as the woofer begins to operate beyond its intended range.
Dop not try this with a tweeter. The low frequencies will easily destroy the tweeter.
Adding an inline choke or coil to the woofer attenuates the high frequencies some. The same with a cap.
However, if you place a cap across the terminals of an amp you are shorting the high frequencies to ground. The amp will see a short circuit at the higher frequencies (depending on the resistive load at the amp) and it could blow the amp.
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OB of Martin King
Thanks Loren for your comments and reply and sorry for the late acknowledgment. I
always learn in this forum.
In the mean time I have finalized my plan: It is the Open Baffle of Martin King. I do not
have much time for experiments anymore. So ordered the parts for the King's
OB design. The Fostex 103En and the Inductors and caps already arrived by courier
yesterday. The Eminence Alpha 15a are on its way. International shipping!
More expence! Started with a budget of about US$300 and now it is crossing US$600 as
the custom duty is enormous ( I did not expect). One Fostex was damaged on transit
but madisound was kind enough: sending a replacement. Praying it does not happen
with the Alpha 15.
I could not find any of the drivers in India although there are distributors of
both Fostex and Eminence in India.
Special thanks to Pico and to others of course for educating me in such a
short time.
Regards
Roushon.
Thanks Loren for your comments and reply and sorry for the late acknowledgment. I
always learn in this forum.
In the mean time I have finalized my plan: It is the Open Baffle of Martin King. I do not
have much time for experiments anymore. So ordered the parts for the King's
OB design. The Fostex 103En and the Inductors and caps already arrived by courier
yesterday. The Eminence Alpha 15a are on its way. International shipping!
More expence! Started with a budget of about US$300 and now it is crossing US$600 as
the custom duty is enormous ( I did not expect). One Fostex was damaged on transit
but madisound was kind enough: sending a replacement. Praying it does not happen
with the Alpha 15.
I could not find any of the drivers in India although there are distributors of
both Fostex and Eminence in India.
Special thanks to Pico and to others of course for educating me in such a
short time.
Regards
Roushon.
Replaced fostex damaged again
I received the replacement of the fostex fe103en from madisound.
This was also damaged (most likely by some custom official). I attach
some pictures of the damaged driver and also of the undamaged
driver. Can someone kindly tell me if the damaged one will still work?
The investigation regarding the fostex drivers damage is ON by both
madisound and fedex courier.
Some pictures of the eminence driver are also attached.
Best regards
Roushon
I received the replacement of the fostex fe103en from madisound.
This was also damaged (most likely by some custom official). I attach
some pictures of the damaged driver and also of the undamaged
driver. Can someone kindly tell me if the damaged one will still work?
The investigation regarding the fostex drivers damage is ON by both
madisound and fedex courier.
Some pictures of the eminence driver are also attached.
Best regards
Roushon
Attachments
My desperate fate did strike again. Firstly it was the Fostex driver (two of them were
damaged on its transit path). And secondly few days back a small toroid which was
powering the remote control, speaker protection, soft start, relays in the attenuator etc
burnt and destroyed most of the ICs before the fuse trip. It was a 12v-0-12v 2Amp toroidal
transformer. Now it is even harder work.
Fortunately the amplifier is OK and working.
Was the toroid bad? It never heat up. I checked but there was no short circuit either. What
can be the reason for a toroid to burn?
Roushon.
photos
The baffle is 5 degree tilted towards back. The polish was not good as I did not
find a competent carpenter. But he did a good job in cutting and making the back support.
Roushon
The baffle is 5 degree tilted towards back. The polish was not good as I did not
find a competent carpenter. But he did a good job in cutting and making the back support.
Roushon
Attachments
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Thanks!
Hi,
Thanks for your response and asking. I see this thread and only see I am posting continuously without any response or anything from my colleagues who were helping me
before.
At the moment I am playing the OB for long stretch of time so that the drivers covers it
bedding time. I think the fostex has 100hrs. So far it is really good and expecting it
to be excellent after some more time. Also I am moving to a bigger apartment within
couple of months. Now I hear more the fostex than the eminence, that is the
bass has not yet opened up completely. But that could be because it is too early and also
the selection of music and the space around the OB. As a whole I am very happy that
I built it and I am smiling too!. The sound is very natural and pleasant and not booming.
Also there are many ways I can improve the OB which is not possible to a closed box.
Regards
Roushon
Greetings!
So how do you like the MJK OB? I finished mine almost a year ago, only with an H-Fram
for the 15A, which allowed me to narrow the baffle to 16 inches. They still make me smileLooking forward to a review!
Hi,
Thanks for your response and asking. I see this thread and only see I am posting continuously without any response or anything from my colleagues who were helping me
before.
At the moment I am playing the OB for long stretch of time so that the drivers covers it
bedding time. I think the fostex has 100hrs. So far it is really good and expecting it
to be excellent after some more time. Also I am moving to a bigger apartment within
couple of months. Now I hear more the fostex than the eminence, that is the
bass has not yet opened up completely. But that could be because it is too early and also
the selection of music and the space around the OB. As a whole I am very happy that
I built it and I am smiling too!. The sound is very natural and pleasant and not booming.
Also there are many ways I can improve the OB which is not possible to a closed box.
Regards
Roushon
Two questions
Now that I know somebody shows interest in my project I can ask a couple of questions.
1. In second order crossover the tweeter needs to be connected in reverse polarity, but
in the MJK's notes it is maintaining polarity. Is it because the fostex is a full range driver?
2. Due to lack of availability I replaced the 9mH inductor by 10mH and the 68mfd cap by
70mfd. Is it OK?
Thanks and regards
Roushon
Now that I know somebody shows interest in my project I can ask a couple of questions.
1. In second order crossover the tweeter needs to be connected in reverse polarity, but
in the MJK's notes it is maintaining polarity. Is it because the fostex is a full range driver?
2. Due to lack of availability I replaced the 9mH inductor by 10mH and the 68mfd cap by
70mfd. Is it OK?
Thanks and regards
Roushon
answers
I believe the answer to question one is "correct." However, I am no where near an expert on this.
Question two... it depends. I built mine with the H-frame, but ordered the parts for the plain baffle before I discovered this option. I left mine with the 9mH and 68mfd and haven't looked back. The 15A is an interesting animal. I did some research when I realized my "mistake" and found a lot of variables among people using it. One person thought it was too muddy X-ing at 200Hz, so he lowered it to 125Hz. Another person runs it with no X-over at all and just raves about the natural sound of his. I think it comes down to room acoustics and personal tastes. Running mine X-ing at 200Hz is just plain delightful to my ears in my living room.
I work in a concert hall (just got home from work @ 11:30pm) and I really like the balance I get between the FR and the 15A in my living room. I listened to an orchestra tonight perform Beethoven's 3rd piano concerto and Mahler's 4th Symphony in our big concert hall, and when I get home and listen to these speakers the balance of the bass frequencies is spot on. Most of what I hear coming over the radio, or on other people's systems, is an EQ curve that is really heavily skewed towards the bass regions. After a couple of weeks of listening to these with a more realistic balance, I actually reset the EQ on my car stereo pulling down the bass.
Hope this helps!
I believe the answer to question one is "correct." However, I am no where near an expert on this.
Question two... it depends. I built mine with the H-frame, but ordered the parts for the plain baffle before I discovered this option. I left mine with the 9mH and 68mfd and haven't looked back. The 15A is an interesting animal. I did some research when I realized my "mistake" and found a lot of variables among people using it. One person thought it was too muddy X-ing at 200Hz, so he lowered it to 125Hz. Another person runs it with no X-over at all and just raves about the natural sound of his. I think it comes down to room acoustics and personal tastes. Running mine X-ing at 200Hz is just plain delightful to my ears in my living room.
I work in a concert hall (just got home from work @ 11:30pm) and I really like the balance I get between the FR and the 15A in my living room. I listened to an orchestra tonight perform Beethoven's 3rd piano concerto and Mahler's 4th Symphony in our big concert hall, and when I get home and listen to these speakers the balance of the bass frequencies is spot on. Most of what I hear coming over the radio, or on other people's systems, is an EQ curve that is really heavily skewed towards the bass regions. After a couple of weeks of listening to these with a more realistic balance, I actually reset the EQ on my car stereo pulling down the bass.
Hope this helps!
Thanks again!
Thanks a lot for your explanation and detailing me your experience. To tell
the truth I do not have enough experience to judge audio reproduction.
The OB is my beginning on this matter and I like it so far. I will experiment
with it and see if I like some other configuration. In future may add the H-
frame etc...
I just saw the pictures of your H-frame OB in your profile. Nice painting and
the system.
Regards
Roushon.
Thanks a lot for your explanation and detailing me your experience. To tell
the truth I do not have enough experience to judge audio reproduction.
The OB is my beginning on this matter and I like it so far. I will experiment
with it and see if I like some other configuration. In future may add the H-
frame etc...
I just saw the pictures of your H-frame OB in your profile. Nice painting and
the system.
Regards
Roushon.
Hi Pico!
It is nice to see you back. I also thought of adding spikes, but
not sure if the gap between the baffle and the floor will affect the sound.
I did see baffles on the net which has spikes. May be I will try it...
Thanks and Regards
Roushon
It is now very long time since I logged in last. How are everyone doing? Giving life to this thread again as my Open Baffle is dead. It was
kept unused for some time and termites have sneaked in (Mumbai weather is very humid). It looks the same except the weight, it is hollow from inside. I am really sad. Fortunately the drivers are in perfect condition. I need to look for better materials for the baffle. Searching the net. There are many suggestions.
1. Plywood, 2. mix of plywood, MDF board, 3. mix of plywood, MDF board and acrylic, 4. only acrylic.....even sand filled...
Only acrylic sounds good. But what should be the thickness?
Help me with the best possible...
Regards
Roushon.
kept unused for some time and termites have sneaked in (Mumbai weather is very humid). It looks the same except the weight, it is hollow from inside. I am really sad. Fortunately the drivers are in perfect condition. I need to look for better materials for the baffle. Searching the net. There are many suggestions.
1. Plywood, 2. mix of plywood, MDF board, 3. mix of plywood, MDF board and acrylic, 4. only acrylic.....even sand filled...
Only acrylic sounds good. But what should be the thickness?
Help me with the best possible...
Regards
Roushon.