Hi Jaudere,
Well I see HFV everyday, I just didn't find anything to talk about recently.
I was the silent follower.
Beauty of an Open baffle speaker
- Thread starter Sumanta
- Start date
Hi Jaudere,
Well I see HFV everyday, I just didn't find anything to talk about recently.
I was the silent follower.
jaudere
Well-Known Member
My room is 16X11. During listening sessions, speakers are pulled into room by 3 feet and later pushed back to wall. The feet are made up of metal spheres which work as wheels as well as give good isolation by reducing point of contact hugely. Regarding room acoustics I see no reason why OBs should be afftected more than any other speaker by contents of the room.
In fact OB utilize room walls to give wider stage images.
jaudere
Well-Known Member
Recently I did some reading on room acoustics. During the study, I found few good points about room acoustics, which are really simple to practice.
1) Sit in your listening position. Ask someone to stand in the same plane as that of speakers and ask him to clap loudly. If you hear echo, you room needs some treatment.
2) No two parallel surfaces should be reflective. Each room will have 6 surfaces. So you need to treat only 3.
--So my room has one big bookshelf (open, without any glass doors) and contains books of odd sizes.
--The wall behind my listening seat is covered by thick mattress.
-- I am in search of good mattress for the floor. I am not in hurry because , the sound is very pleasing even without any mattress on floor and there is no echo after clapping from speaker position.
-- Keep the window glasses covered with curtains (preferably thick).
-- As someone has suggested in recent a new thread, you may keep doors open if possible.
All this prevents standing waves to major extent but does not prevent reflections in Toto. Boominess is treated by these measures.
Reflected sound is very important in day to day listening and creates atmosphere of wider space. Listening experience in anechoic chamber may not good with a lively speaker may appear recessed.
So no reflections may be as bad as too much of reflections.
@ Sumanta, How are you planning to clone Jamos? Are you going to use same drivers?
Have you thought about cloning Orions since you are going biamp/triamp way?
@ mpw, your tweeters seem to be very good. For few moments, I thought of getting them. However, in my speakers, the full ranger plays from 50Hz to 9Khz and tweeter is left to do work from 9khz upwards only. Secondly, the sensitivity seems to be about 90 db in the range that I would need.The full ranger has sensitivity of 97dB. So don't know how they will match. Thirdly, my 3 year old son has uncontrollable urge to poke speaker centre with pencil. Dust caps of my full rangers are already gone. Luckily the tweeters are still holding on. So can't spend big amount on tweeters till he is at least 6-7 year old.
1) Sit in your listening position. Ask someone to stand in the same plane as that of speakers and ask him to clap loudly. If you hear echo, you room needs some treatment.
2) No two parallel surfaces should be reflective. Each room will have 6 surfaces. So you need to treat only 3.
--So my room has one big bookshelf (open, without any glass doors) and contains books of odd sizes.
--The wall behind my listening seat is covered by thick mattress.
-- I am in search of good mattress for the floor. I am not in hurry because , the sound is very pleasing even without any mattress on floor and there is no echo after clapping from speaker position.
-- Keep the window glasses covered with curtains (preferably thick).
-- As someone has suggested in recent a new thread, you may keep doors open if possible.
All this prevents standing waves to major extent but does not prevent reflections in Toto. Boominess is treated by these measures.
Reflected sound is very important in day to day listening and creates atmosphere of wider space. Listening experience in anechoic chamber may not good with a lively speaker may appear recessed.
So no reflections may be as bad as too much of reflections.
@ Sumanta, How are you planning to clone Jamos? Are you going to use same drivers?
Have you thought about cloning Orions since you are going biamp/triamp way?
@ mpw, your tweeters seem to be very good. For few moments, I thought of getting them. However, in my speakers, the full ranger plays from 50Hz to 9Khz and tweeter is left to do work from 9khz upwards only. Secondly, the sensitivity seems to be about 90 db in the range that I would need.The full ranger has sensitivity of 97dB. So don't know how they will match. Thirdly, my 3 year old son has uncontrollable urge to poke speaker centre with pencil. Dust caps of my full rangers are already gone. Luckily the tweeters are still holding on. So can't spend big amount on tweeters till he is at least 6-7 year old.
2chFreak
New Member
Audio Artistry Beethoven (4 units) are a speaker system my dad speaks about hearing at a demo given by Siegfried Linkwitz & Jeff Rowland using Rowland's amplification & George Cardas's cables. I was just abt a toddler then - 
However, with open baffles, the room loading feeling is completely absent. To a regular dynamic speaker user, he's likely to feel "as if something is missing" b'coz we tend to get so used to the room loading effects on the longer run & accept it in a good way.
Its also like listening to a Kawai digital Grand piano v/s a Steinway Grand Model-D in a regular large room.
However, with open baffles, the room loading feeling is completely absent. To a regular dynamic speaker user, he's likely to feel "as if something is missing" b'coz we tend to get so used to the room loading effects on the longer run & accept it in a good way.
Its also like listening to a Kawai digital Grand piano v/s a Steinway Grand Model-D in a regular large room.
jaudere
Well-Known Member
I use OBs for music and regular bookshelf speakers (MTM design), in a different room, for movies and extremely occasionally for music. While regular bookshelf speakers are quite ok for movies, the bass is bit extra and mids are recessed while highs are not great. the overall sound is totally different.
Audio Artistry Beethoven (4 units) are a speaker system my dad speaks about hearing at a demo given by Siegfried Linkwitz & Jeff Rowland using Rowland's amplification & George Cardas's cables. I was just abt a toddler then -
Ausio artistry makes Orion for Linkwitz, isn't it? I love the look of Orion like a Crane.
Thank you for such beautiful explanation and comparison.
I think there can be loading for the floor if drivers are close to floor. And other reflections add space if they are 10ms away (or more).
This no loading and less or no colouration add so much value to the mid that you can enjoy old songs the most. Tonight my Father in law listened to gems of S. D. Burman for almost an hour and said, he is happy with my such odd looking, BIG speakers.
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Hi Doc,@ Sumanta, How are you planning to clone Jamos? Are you going to use same drivers?
Have you thought about cloning Orions since you are going biamp/triamp way?
I wanted to clone Jamo just for the first love kind of feeling that that Jamo R909 gave me. Infact that two one minute auditions changed me a lot as a listener.
Second, I love the look, presence of Jamo R909.
There are reasons for not doing Orion as well. I do not have such small woofers in Ahuja's stable. Orion will not look good with 12 inch drivers. Orion is not as good looking as R909 is another reason. Most important reason is, I do not know how and why push pull work? If it works with two woofer drivers having opposite phase then it is beyond my capability to do so. I do not want 4 amp active design. That will be too muh for me.
On the other hand, I do not want to use foreign (costly) drivers for the mid. Peerless or such mids which look like Jamos are having poor SPL, so they are not good for my amp. And I like Ahuja FR drivers. They are so right there and so full of music.
I am happy with present setup, I even know that if I design like you did, I will be happy as well. So, it is now only a question, what will I gain cloning Jamo R909?
And if I do put two 15 inch drivers and one 12 inch FR and one tweeter, it will not look like a Jamo909. It will still look and sound fabulous though.
It is at present a question for me?
I have another hybrid cabinet design ready with me (even in paper) with the same full ranger of 16 ohm and a tweeter. I think this design will take less space, has good WAF and ofcourse good music reproduction capabilty. And it will be quite efficient too.
So, confusion is increasing.
Out of all this mess, I just wish someone buys my Cabasses, so that I have all the excuses fulfilled to make two pair of speakers.
corElement
Well-Known Member
The drivers in the 907 and 909 are pretty expensive.
I believe the 909 use the scanspeak revelator and seas excel drivers for high and mid and custom inhouse made woofers for the low.
If you do pursue that design make sure the low woofers are configured in the crossover properly.
If I copy Jamo at all, there will be changes as well. It will be a copy of the look (some).
My speakers will be without passive cross overs, will be made with Ahuja drivers only. I do not think I need 20Hz to 35 Hz that much so I do not bother much about them. If they are reproduced, it is a welcome gift.
Those Scanspeak and Sears drivers are damn costly one. Those woofers looks meaty in real life.
My first reason for DIY is cost saving, so I am going to make it all the way with Ahujas only.
corElement
Well-Known Member
That's fine, it'll be fun seeing the result with ahujas. Where do you source them from anyway?
Yes the woofers for lows they use is very meaty in real life and have very high sensitivity and excursion.
jaudere
Well-Known Member
@ Sumanta Most important reason is, I do not know how and why push pull work?
>>> Even though it is push pull, the cones of both the woofers move in same direction. They are wired out of phase and placed reverse to each other so that the cones are actually moving in same direction. Even I did not understand exactly the logic but probably it is related to getting more uniform dispersion of low frequency waves.
You do not need 4th amp for it. The speakers are wired in series but out of phase (negative terminal of first speaker is connected to negative of second. Positive of first is connected to positive of amp and positive of the second are connected to negative terminal of amp).
Anyway, I am getting adequate low end with single full range driver (after adding EQ). The thump at the start of "yeh jo des hai tera" from Swades is heard and felt in full glory. Recently I started the song in presence of guests who were chitchatting and the moment the thump came, everyone became silent and started listening to the song.So I am not even thinking of adding a sub.Isobaric subwoofers work on same principle (but with a box). I had made an attempt to build isobaric sub. The attempt was so hopeless that when I remember that, i can't help laughing.
What I have tried to achieve is the least possible artificial dissection of audio signal . So there is no filter between Ahuja and amp while the tweeter just has a 2.5microF cap (high pass at around 10KHZ). Amp provides full range signal to the speaker(highs are allowed to roll off naturally rather than putting a low pass filter at 10Khz).
I am looking at Ahuja 12 inch full rangers 200w RMS. Qt is 7.2 (as compared to our driver with QT of 7 and the X max is 2.5mm as compared to 1.5mm of the present driver. This driver will surely tolerate low frequencies even better while it 'may' perform somewhat better on OBs with that slightly higher QT. Planning to stock them so that when the present ones are damaged (cortesy: My kids, they may do it at any time), I can use those. You never know when the manufacturer will suddenly stop producing them.
>>> Even though it is push pull, the cones of both the woofers move in same direction. They are wired out of phase and placed reverse to each other so that the cones are actually moving in same direction. Even I did not understand exactly the logic but probably it is related to getting more uniform dispersion of low frequency waves.
You do not need 4th amp for it. The speakers are wired in series but out of phase (negative terminal of first speaker is connected to negative of second. Positive of first is connected to positive of amp and positive of the second are connected to negative terminal of amp).
Anyway, I am getting adequate low end with single full range driver (after adding EQ). The thump at the start of "yeh jo des hai tera" from Swades is heard and felt in full glory. Recently I started the song in presence of guests who were chitchatting and the moment the thump came, everyone became silent and started listening to the song.So I am not even thinking of adding a sub.Isobaric subwoofers work on same principle (but with a box). I had made an attempt to build isobaric sub. The attempt was so hopeless that when I remember that, i can't help laughing.
What I have tried to achieve is the least possible artificial dissection of audio signal . So there is no filter between Ahuja and amp while the tweeter just has a 2.5microF cap (high pass at around 10KHZ). Amp provides full range signal to the speaker(highs are allowed to roll off naturally rather than putting a low pass filter at 10Khz).
I am looking at Ahuja 12 inch full rangers 200w RMS. Qt is 7.2 (as compared to our driver with QT of 7 and the X max is 2.5mm as compared to 1.5mm of the present driver. This driver will surely tolerate low frequencies even better while it 'may' perform somewhat better on OBs with that slightly higher QT. Planning to stock them so that when the present ones are damaged (cortesy: My kids, they may do it at any time), I can use those. You never know when the manufacturer will suddenly stop producing them.
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I got it now, it was so simple. Thanks. But, again I like the look of Jamo. Push pull driver position help reducing vibration, just like BMW bike's engines or like any V8 or V12 engine in cars.
I thought of using 12FRZ as higher impedence brings out higher power from analogue amplifier (from what I read). So, with higher power supply, lesser distortion is likely to happen as I do not need to push volume.
I will check 200W drivers. 2.5mm Xmax and .72 Qts is interesting. I can use them for my hybrid cabinet design. and for OB too. thanks, I always learn something from you.
I have in the mean time added a phase plug. Since your kids have already damaged the dust cap, I request you to cut it out nicely with a half blade. Then stick a 2 inch long 3/4 inch dia rod with the magnet. You can keep the rod hollow or fill in part of it. I have filled part of it. I haven't done any calculation yet for the length of the fill, I feel it should be done by Helmholtz rule. As it is, sound has distinct difference in higher frequency seperations.
There is a nice article of Steve Deckert of Decware on his design of phase plug.
My first designed OB already had wonderful bass. Only problem was the low staging. I obviously get much more fast, accurate and non boomy bass without any humming background now. I am happy with active cross over system as it is effectively less costly yet more customizable even at operating situation. Digital equalizer by software is effective.
I thought of using 12FRZ as higher impedence brings out higher power from analogue amplifier (from what I read). So, with higher power supply, lesser distortion is likely to happen as I do not need to push volume.
I will check 200W drivers. 2.5mm Xmax and .72 Qts is interesting. I can use them for my hybrid cabinet design. and for OB too. thanks, I always learn something from you.
I have in the mean time added a phase plug. Since your kids have already damaged the dust cap, I request you to cut it out nicely with a half blade. Then stick a 2 inch long 3/4 inch dia rod with the magnet. You can keep the rod hollow or fill in part of it. I have filled part of it. I haven't done any calculation yet for the length of the fill, I feel it should be done by Helmholtz rule. As it is, sound has distinct difference in higher frequency seperations.
There is a nice article of Steve Deckert of Decware on his design of phase plug.
My first designed OB already had wonderful bass. Only problem was the low staging. I obviously get much more fast, accurate and non boomy bass without any humming background now. I am happy with active cross over system as it is effectively less costly yet more customizable even at operating situation. Digital equalizer by software is effective.
Ahuja's are available in all Metros and many cities in India.
Paper on woofers on R909 in reality looks like dry goat skin, alomst. I think they have quite high SPL compared to the mid and tweeter.
Beauty of OB is that it uses both sounds of back and front of the drivers (without loss like in cabinets) and hence is more efficient.
I was listenning Zakir Hussain, John McLaughin and others "Remembering Shakti". Tabla has emotions.
I was listenning Zakir Hussain, John McLaughin and others "Remembering Shakti". Tabla has emotions.
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corElement
Well-Known Member
Yes they do. The r909 requires a LOT of power, and by lot I mean a LOT! no 100w amp will even come close to enough.
jaudere
Well-Known Member
Reading more about phase plugs. Seems that they do world of good for HF.Not sure if one needs phase plug if separate tweeters are used for HF.
I did try Foobar EQ (including the 31 band version.) . somehow, although effective, i did not like them and the PC is not the only source that I use. i use DVDp quite frequently. So I needed external EQ.
By the way, please go through the link in the first post of following thread, download the file, check your speakers and let me know.
http://www.hifivision.com/speakers/5584-speaker-test-tones.html
I checked my speakesr yesterday. No useful output below 40Hz. Good at 40Hz but somehow the 50Hz tone was not adeqaultely loud and then 63Hz was good again. Now I am wondering if my speaker has a dip at 50 Hz. It is possible technically because 50Hz is the resonating frequancy of the Ahuja driver where the speaker impedance is quite high due to which the output may be low. Anyway, I did not touch any EQ setting because the overall sound is to my liking.
Just watch your speakers at 20Hz, 25Hz. They vibrate visibly. otherwise I have rarely 'seen' these drivers move.Don't keep volume high. It can damage speakers.
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jaudere
Well-Known Member
Sumanta, please go through the post 62 (2nd post on the page) in the following link.
Phase Plug? - Page 7 - diyAudio
The author has made some statements about the whizzer cone which may be important in our case. He is saying that the whizzer cone itself may act as phase plug. What do you say?
Edit: just went through the whole thread. Huge information. many authors seem to be driver manufacturers or professional speaker designers. After going through the thread, I am in serious doubt whether I am going to try phase plug or no. In addition, I am confused about what to do with the damaged dust cap. What ever I do, I will have to wait till my son grows up.
Phase Plug? - Page 7 - diyAudio
The author has made some statements about the whizzer cone which may be important in our case. He is saying that the whizzer cone itself may act as phase plug. What do you say?
Edit: just went through the whole thread. Huge information. many authors seem to be driver manufacturers or professional speaker designers. After going through the thread, I am in serious doubt whether I am going to try phase plug or no. In addition, I am confused about what to do with the damaged dust cap. What ever I do, I will have to wait till my son grows up.
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