Planning a new open baffle design with All Ahuja components

[jaudere]

IMHO,since you do not have a LP filter in place for the full ranger,at frequencies above 8kHz(and upto the rolloff point of the full ranger),the amp would see a load of both the drivers in parallel ie ~2.7 ohms.

That was my exact point. I was reading about frequency ranges of various musical instruments and voice. It seems that most of the musical data is between 80Hz to 7Khz. I agree that above 8Khz, it will be 2.7 ohm but below 7kHz , it should be much higher.

 

[jaudere]

Some pictures of test baffle

Here are some pics

 

[jaudere]

How to upload more images?
My limit is exceeded.

 

[Sumanta]

Hello Jaudere,
CONRATULATIONS:yahoo:.

How it is sounding now in bass department?

I wish I could be there to listen it by myself.

Congratulations again for the feat.

 

[jaudere]

Hold on. That is just the test baffle. The real test will be when both the speakers are ready.
There are too many things to be tried before coming to final result.

 

[Hiten]

Nice work Jaudere. :clapping:

How to upload more images?
My limit is exceeded.

Try uploading pictures with imageshack or Picasaweb.
Regards

 

[sachu888]

Re: Some pictures of test baffle

Here are some pics

Great work.

Regards,
Sachin

 

[jaudere]

There is significant progress.
The final design is done. It speakers are up and about.

It has turned out to be kind of backless box due to folded wings. I have put some thoughts into making the design.
1)The angle between the baffle and the wings is kept obtuse. 90 degree or less has its own problems.

2) obviously the wings are not parallel to each other. One wing is 12" and the other is 10". I have done this to mount the speakers offcentre effectively even though they are mounted centrally on the baffle.

3)the top plate is slanting up. The effect that I wanted is no 2 sides are parallel(for avoiding issues of standing waves). The top plate and wings are at obtuse angle to the front baffle, the base plate is at 90 degree. The speaker is kept such that the wall behind the speaker is not parallel to front baffle. The distance between room wall and speaker is about 2 feet.

4)the effective baffle width(and height) is 45". So low frequency roll off is expected at 100hz.

5)the electronics is kept as simple as possible.
A single Ahuja full ranger works without any kind of crossover/filter.
It is aided by Showa tweeter above 10khz . High pass filter is a simple 4uf MPP Cap used in fans. Search for better tweeter is on but this cheap piezo is serving the purpose very well.
No separate bass driver.

The result: Mids and highs are very good as expected. Vocals and most of the percussion is excellent. High pitch female voices appear sharp during some passages. I think this may be solved either by using a better tweeter or pushing the high pass point further up to say 12khz.
It does give feel of a live hall performance.

Bass:weak as expected when fed by marantz pm6002 without any equalization. However when the "loudness" switch is on,there is no deficiency of bass at all. Only this switch is kept on. The bass and treble knob is not touched.

So the sonic satisfaction is achieved but the fact that the loudness switch is on irritates me a bit.
The sensitivity of speaker is excellent (sensitivity of Ahuja is 97db/watt). I dont have the final figure but i am keeping the volume knob of my 45watt amp at 8 or 8:30 position at max in my 16 X 11 room.


1)i may add bass if it keeps on irritating me but i need to procure 100hz low pass filter.
However the full ranger needs to break in before I attempt anything further.


2)marantz may be the culprit of weak bass. However trying another amp like Nad may be a costly affair. How about trying a Topping tp20?

3)any suggestions about using standalone equalizer? Of course this will be the last option.

4) I am getting an itch to try tube amp. I have to visit mr Karl Heinz from Ponda (Goa) who makes tube amp as well as stocks the likes of Jolida.

 

[gopib]

Good Work Jaudere!!:clapping: Very experiential DIY. Love this. Thanks also for the write up. This will enthuse many of us to go down this road.

 

[jaudere]

Forgot to mention the final cost.
Full ranger :2900 for pair.
Tweeter :100 for pair
Capacitor: 80 for pair
Wood work and other hardware: 5500.
Speaker terminal: I already had. Costs 200 per pair.
Cables: I already had.

Total 8600. However i have wasted much more than this during experimentation which is of course part and parcel of the game. .
I dont drink/smoke/ eat non veg/travel in expensive car. How am I supposed to spend the pay hike otherwise?

 

[sachu888]

Nice work,pl post more pics.You can upload pics from imageshack.us

Regards,
Sachin

 

[avidyarthy]

I dont drink/smoke/ eat non veg/travel in expensive car. How am I supposed to spend the pay hike otherwise?

.......... there are a lot many two legged things (whites, browns, chocolatey ...err, no blacks) moving around the so-many beaches of Goa. You can indulge in them too ..... . A VFM way to blow up the extra moolah of the pay hike!

 

[jaudere]

Trying to load pics using image shack

Succeeded in loading speaker foot. I have used a sphere rather than the spike to get a single point contact. It is easy to move as this ball bearing is mobile in all directions. So at night time, the speakers come best position.During the day and when kids are playing, they are pushed back to the wall

 

[jaudere]

Here are some more pics
The set up

different level of front and back feet tilts the speaker backward and the full ranger looks into my face even though it is not my ear level.

front view

 

[jaudere]

The empty baffle from back side

Side view of full speaker

Inside the speaker. At present, the cap is sitting on the basket of full ranger

This is how the feet look when viewed from front, after removing the red cap on the feet

 

[jaudere]

.......... there are a lot many two legged things (whites, browns, chocolatey ...err, no blacks) moving around the so-many beaches of Goa. You can indulge in them too ..... . A VFM way to blow up the extra moolah of the pay hike!

I hope you are not talking about the things which have wings and keep on flying looking for fish.

If i indulge in the things you indicate to, the money won't be spent on them but on my medical bill after I indulge in them

 

[Kannan_madhu]

good one.... nice finish

 

[sachu888]

Nice work :clapping:

Regards,
Sachin

 

[jaudere]

I had this intriguing finding yesterday.
I moved my set up to bedroom. The speakers were placed such that the speakers are 1 foot away from side walls, 6 feet away from back wall and the listeing distance about 9feet. The distance between two speakers was 6 feet.

I played some songs. On all the songs where the left and right tracks were same, the sound appeared to be coming bang from centre and from the back wall(about 6 feet behind the speakers). The experience was quite exciting. The speakers were in front of me, I could see them, I knew they were working but still it looked as if there is no sound coming from either of the speakers.
The sound was originating from back wall!! Is this the well known 'disappearing act' done by good speakers?

I dont know what to call it as.
I had similar experience with my bookshelves when placed on stands in the same position in the same room. The new speakers are inherently better. So the experience was even more exciting than bookshelves.

Looks like room acoustics are playing major role here.
With open baffles, the bass was bit weaker than the other room but the overall music appeared so integrated that I was happy to let that bass go at the expense of the coherence. The music was so enjoyable that after many days I played a full CD without touching volume knob of amp.

 

[Thad E Ginathom]

Looks like room acoustics are playing major role here.

With my very un-hifi-friendly monitor positioning, sometimes some of the sounds seem to come from the corner of the room about 1.5m from the right speaker. It is kind of freaky!