audio-talk

I noticed when reading about a Munich 2022- that Monitor Audio have a concept, which is similar to something I have been toying with, mind of course has horns
https://www.monitoraudio.com/en/concept ... nnovation/

Woofers look similar to Vic's OB's-

Maybe as the drivers face each other.. it’s a point source that’s the bit I like bass/midbass driver at same height as the tweeter and midrange. The kef blades do it with the bass drivers outwards to give that pseudo point source. Both copied from the masters of speaker design Beolabs.

Other than as marketing bull... where is the innovation?

Everything in the design illustrations has been used before... for instance I did a circular array of small wide band drivers a few years ago based on older circular arrays for speakers and for radar arrays (same theory) and front to front mounted woofers are old hat (as Ali points out) as are vertical slot loaded woofers... so what am I missing?

Point taken, none of the elements are new or novel, but the implementation is new, for a commercial offering from what I have seen, read about recently. Placing the woofers in the same vertical plane as the mid&HF gets the point source and will generate a nice polar plot, without the loving, we normally see with offset drivers. Depending on where they cross the woofers will depend on whether it’s of any benefit.

Thats true and its good marketing copy as its a distinct story rathercthan a rehash of the usual stuff.

With regard to lobing the circular array has its own lobing pattern across its full frequency range and throughout the crossover region to the tweeter as does the woofer to circular array but in the orthogonal plane foward of the speaker but for the woofer lobing the room reflections swamp them for steady state signals at least in my experience but that is true for any psuedo point source as any multi driver array will be...

Having said all that it may sound really nice and be an attractive design...

It’s not that far from the Kef Blade which has the woofers firing the other way..https://uk.kef.com/products/blade.

My concept was using an Air Motion Transformer, for the main driver, which is Bipole, in a front and rear firing wave guides. It was just integrating the 400 hz downwards to it. I was thinking about 2 outward firing woofer, so they were bipole too. Reversing the woofers and slot loading them makes the dipole, loosing the benefit of bipole, which is room modes. Need to understand the benefit of the MA woofer arrangement over the KEF one.

Interesting challenge

There are some interesting examples of slot loaded woofers / subwoofers in the diy community some worth checking out are j-c morrisons:

https://www.labjc.com/?p=4230
https://www.labjc.com/?p=4471

and XRK971 dipole https://www.diyaudio.com/community/thre ... ker.385717

vinylnvalves wrote: ↑Mon May 23, 2022 5:21 pm It’s not that far from the Kef Blade which has the woofers firing the other way..https://uk.kef.com/products/blade.

My concept was using an Air Motion Transformer, for the main driver, which is Bipole, in a front and rear firing wave guides. It was just integrating the 400 hz downwards to it. I was thinking about 2 outward firing woofer, so they were bipole too. Reversing the woofers and slot loading them makes the dipole, loosing the benefit of bipole, which is room modes. Need to understand the benefit of the MA woofer arrangement over the KEF one.

... Isn't bipole just omni, when the wavelength gets much larger than the cabinet(s)?


The Monitor Audio thingy looks reasonable. I'm still not keen on having all the woofers clustered together, though - floor/ceiling bounce is an issue worth solving IMO.

Chris

chris661 wrote: ↑Wed May 25, 2022 4:24 pm
... Isn't bipole just omni, when the wavelength gets much larger than the cabinet(s)?


The Monitor Audio thingy looks reasonable. I'm still not keen on having all the woofers clustered together, though - floor/ceiling bounce is an issue worth solving IMO.

Chris

So if your willing to sacrifice the gain from having a woofer close to the floor, you can trade it with reflections if high up.... with proper LF drivers and cheap power that’s probably not a difficult trade. Flies in the face of the Beolab 90 though, which was designed allegedly to control room modes, which is like the early Allison speaker which has woofers at floor level firing in all directions.

So many seemingly contradictory approaches to achieve the same goal.

I was talking specifically about the upper-bass response dips that come from floor/ceiling reflections. Vertically distributed LF sources seem to help.

DSP can't help here, since late(r) arrivals are the source of the cancellations.

Chris