HoneyComb Speakers

[avguy]

Hi,

I had owned a pair of speakers which were 2 flat speakers in which the drivers would resemble like a honey comb and that was from Technics which were wall hanging type and was resembling like a small square wall clock. about 12 years back. Now I am trying to search the details regarding that kind of speakers, if anybody has more information about it can anyone please give me the details about that.


please

avguy

 

[usekgb]

These speakers basically just have transducers attached to the flat piece. As the transducers vibrate, the cause the flat piece to vibrate. Unfortunately, It's just not the best technology in the world. X-max is very low, transient response is poor, and they just don't sound that great.

Cheers,
Zach

 

[avguy]

flatpanel speaker

🙂
Thanks for your information. Actually the speaker which I had was that it was a driver inside and not any transducer. The actual speaker inside. The construction was such that it use to appear like a honeycomb if we remove the grill. And as far the technicalities that may not be the best technology. But the sound in those speakers are noteworthy.

So any people having more information. please feel free to share it.

Thanks

Avguy

 

[Variac]

Steve at www.apexjr.com had some until very recently. These were round drivers with a tweeter in the middle surrounded by a midrange surrounde by a "woofer" On the front, they were all flat.

You should contact him, sometimes he has a few extra of things
even if they aren't listed.

 

[markp]

I actually have some of the old 'honeycomb' drivers by Technics from an old 12"3 way they made. The woofer and midrange are built like conventional drivers with normal conical cones that are covered by a flat 1/4" thich plastic honeyconb disk that is light and very rigid. This makes them act like a flat piston radiator. The tweeter is a thin disk glue to the voice coil of what would be a normal soft dome tweeter. They sound just OK with the factory setup and tend to be on the bright side. They are all still available from Technics parts dept but ain't cheap. Last I looked it was $180 for a woofer.

 

[avguy]

Thanks,

Thanks Variac for your information and I have contacted apex Jr and awaiting reply. And the link which you have given to check out for your speakers is marvellous and I have to commend you for the work done on the speakers. Those are really excellent and quite cool stuff. You have to get some award for the finishing done on those speakers.


Thanks Markp,

Would you attach the pictures of the speakers of Technics if possible and can you give me the link of the technics where they have listed that speakers for sale just to check it out. Thanks for your sharing of information.

Regards,

Avguy

 

[Variac]

Apexjr still has them listed, I was just looking in the wrong place
Check this out:

http://www.apexjr.com/new.htm

You have to scroll about 3/4 of the way down
Maybe these weren't what y ou were looking for.

Thanks for the comments about my speakers.
They are all disassembled at the moment to make the open baffle bigger, and to switch in my new JBL woofer. Might not be as pretty after, but should sound better!

Mark

 

[avguy]

Thanks

Hi,

Thanks for the link, yesterday I had got a mail from apexjr and was told to look at the same section of the webpage. But I could not find it. Today when you sent me this link and I got that speakers on the page. But the one which I was talking about was not this kind but it was something different. But this is of more advanced type. Anyway thanks for helping me to find out similar stuff.

And regarding about your speakers can I suggest you something. Which JBL driver are you using. Could you not find anyother better option than JBL. Because these JBL speakers according to me at certain times sounds very bright more than natural. What do you feel. Any way best of luck for your modification.

Anand

 

[Variac]

whoops, I wasn't clear. The JBL is a 15" woofer for the bass box, so it would be hard for it to be too bright. JBL's are pretty polarizing- some like 'em some don't, but I think in this application they will be an improvement- more x max, maybe flatter, lower Fs
They are the ME150H and were used in the S3100 and 4344 Mk 2 speakers. The 4344 was only sold in Asia as far as I know. Because the drivers were only used in completed JBL speakers I don't have much info on them. I talk about them too much in the "Great 15" drivers -who has 'em" thread!!!

 

[avguy]

Honeycomb speakers

Hi,

Markp : Have you finished your project. I mean the replacement of the drivers and finetuning your speakers ? Just let us know about that.

Any other comments on Honeycomb speakers ? If anybody others have any opinions about that kindly share the same.


Avguy

 

[navin]

I had owned a pair of speakers which were 2 flat speakers in which the drivers would resemble like a honey comb and that was from Technics which were wall hanging typeavguy

not 12 years back but try 15 or 17.....🙂 just kidding...is this the speaker that came with a wall hanging system SB300 or something like that. it was available in 2 models each about 50mm thick. the system had a tuner and tape...???

the speaker have a foam surround. they hardly last 5-7 years in India (mumbai atleast). what apex has is a close relative.
http://www.apexjr.com/images/APEX JR 12IN TECHNICS WOOFER #1.jpg

are your cones white, silver or black? i saw white and black back then and steve seems to have something that is silver.

 

[markp]

That is the same tweeter style used in the 12" 3 way I have. I'll get the part numbers to you as soon as I can.
The foam only lasts a few years on the woofers but the mid has a cloth surround as does the tweeter. One of these days I'll get a new anulus ring for the woofer if I can find the slightly odd size.

 

[markp]

The woofer is available from Panasonic parts as number SASS32PL01-T for $153. Mine is foamless so I dont know the specs on it. It does not look like a $153 woofer, more like a $60 witha stamped frame and 30 oz magnet!

 

[avguy]

Honey comb enclosure

Hi, Navin, Marp,

What about the enclosure for the speaker if the driver is bought.
Can you give me the link of the panasonic site on which it is listed.
I just want to compare the technics and panasonic if possible and I was also just thinking on the different possiblities of the enclosure for the speaker of that dimension.

If you people have any ideas on that please share the same.

regards,

Anand

 

[navin]

i'd build one.

 

[kelticwizard]

I have an article in the Journal Of The Audio Engineering Society from 1980 about the Technics SB 10. It is a 3 way with a 10 inch flat honey comb disk, a 4 inch flat honey comb disk mid, and a leaf tweeter, for which they did not go into much detail.

It is a conventional enclosure.

Far from just filling in the cone, these honey comb diaphragms are actually diaphragms. The flat diaphragms are made of expanded plastic covered by a stiff outer layer. The expanded plastic at the core is composed of units that grow larger in length as you go from the middle toward the edge, concentrating all the vibration nodes at one circular node. Then the voice coil is hooked up at exactly that node, making the honeycomb diaphragm essentially node free.

Below is the illustration of a flat diaphragm with material expanded the "normal" way, and the node pattern. Multiple nodes-no good.

 

[kelticwizard]

Now, here is a flat diaphragm where the material is expanded differently from center to edge. See how the little "bubbles" are smaller at the center than toward the edge?

The second picture I had to doctor up to emphasize the appearance of the main node. Because the main node is driven by the voice coil, it doesn't resonate and barely appears on the picture-I had to bring up the "contrast" to show the main node exists at all.

I know the core of these flat disks are plastic of some sort, but I am not sure of the skin material. Aluminum is used for skin a lot, but this might be some sort of polymer-not sure. The article goes into technical "shear factors" which I had trouble following. But the principle-construct a flat disk so that the main node is in one place, then attach your voice coil exactly on the main node to get smooth response-is clear enough.

 

[kelticwizard]

Here is a picture of the frequency response, etc, for a 10 inch woofer made in this manner. All in all, it seems to resemble the response of an aluminum cone woofer-when the response finally breaks up, it breaks up in a big way.

But the honey comb diaphragm seems to allow it to go very high before it breaks up. In this case, the 10 inch honey comb speaker goes all the way up to about 3 kHz before the first breakup-pretty good performance!

They don't list the frequency response of the four inch mid, but I would think that would be even more interesting. The cavity in a cone would affect the frequency response of a mid more than a woofer, I think, and the flat diaphragm should give a clearer source for a speaker that might go up to 3 or 4 kHz. But this is all speculation on my part.

But I would like to hear those mids.

 

[kelticwizard]

Finally, here is a picture of the Technics SB-10 loudspeaker. I believe they made other SB models as well. The surround for the 4 inch mid doesn't come out in the picture, but it is constructed just like the woofer.

The article has lots of charts of graphs on how they made this honeycombdisk, and I will Email the entire article to anyone who is interested. These graphs here are just the high points.

Just Email me and I will send the article. It's nine pages, and each page is about 200k. I don't zip, I don't pdf, and I don't OCR. I send straight .GIF which will print out nicely. If you have enough room in your email box, I will send the article. If you don't have enough room, I can send a few pages at a time. 🙂

 

[markp]

Just go to the Panasonic site and click on the parts link. Technics is Panasonic so all the parts are available at that location http://www.pasc.panasonic.com/epartr/
Just for refernce I have the SB-700 12" 3way.
Those nodal plots are very interesting, the node is exactly where the inner 'cone' part of the driver connects to the flat disc.