Bookshelf dipole speakers - is it possible ?

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After a while I don't like the looks of H-frame. It's an eyesore :bigeyes: so I quickly returned to OB configuration, only this time I use a new woofer from Jaycar with Qts of 0.7... I think it sounds better than H-frame although little loss of lower frequency. This perhaps will be my final system for a long time until I can afford a planar that is ;)

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H or U frame gives you more bass.

Possibly from good looks point of view and improved bass you may like to try using U frame, just add more wood around and behind the woofer and then pad it down with standing wave absorbing pad.

I have tried them on mine. You would be pleasantly surprised.

Cheers, happy listening.
 
gainphile said:
ttan,

Thanks you were right :angel: ... at first I was afraid that U-frame will add some coloration like boxed speaker as it is not a perfect dipole... but I was quite stunned with the result.

Improved bass, improved slam (still not quite like box though), and most importantly the dipole character is untouched.

Amazing.


In most cases, not all, you need to do some sort of equalization if you just use pure open baffle if you require more bass, H and U frame can give you more bass without passive or active equailzation.

Only you get away without using H or U frame if your woofer has very high Qts, ie greater than 0.7, and definitely at Qts>= 1.0 whick MK is using. Most Woofers not all sold in Australia are usually around 0.4 or lower. What is yours?
 
diyAudio Member
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Hi gainphile, are you using those cheap Jaycars as purchased?? I believe that the treatment of the paper cone with th standard 50/50 mix of PVA woodglue and water a few times would improve those woofers. They do have the benefit of being cheap. How much power are you giving them before they break-up??
Regards Ted
 
Re treatment of the paper cone, In the past I've treated old paper cones with Dammar, which is good for restoring cones and stiffening them, but measurements with Synrta showed that the stiffening gives rise to a peak, similar to metal cones, although on the 8" units I did, this was at around 1.5KHz, right where it can be really noticable.
IOW, I'd be wary of doing it unless the cone is really knackered, you're using the speaker for guitar, or using a steep xover slope and crossing low....
 
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Unusual bookshelf speakers

Is there an alternative to the standard two-way bass reflex speakers? I need a pair for my new workplace, they will be placed on a shelf on the wall across the table, cca 80 cm from listening position and ca 60 cm apart, tweeter/fullranger at ear height. I would like to try any of the other configurations except from bass-reflex (dipole, horn?). As an alternative, I can use the whole shelf for a speaker in a size of an ordinary floorstander, it would have to contain both enclosures at once - then it could be placed on the bookshelf holders without the shelf. As an amp, I have an almost vintage 2x20 W Sansui integrated amp (4 ohms capable).
 
Thanks for the hint:)

If so, that would be pretty close to a fit/small U-frame with a depth of "D". So, in the back to back arrangement, the D should be large to justify the additional driver.

Then I guess if the distance of the 2 drivers is larger than a certain point, the relevance with "virtual circular baffle" should be diluted, no?

And, the accoutic center of this assembly should be at the middle point between the 2 drivers. That'll be both insteresting and odd.

I'm thinking of messing with 2 x 18inchers by this arrangement, using mininal baffles for each and keeping them 2~3ft apart.....
 
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