If i make a 3 way speaker with woofers connected in parallel in different chamber with different volume and tuning. Does it work?
They may not combine with as much output as expected, due to differing phase.
The way to be sure would be to put both the responses in a simulator as separate woofers and play them in parallel.
Then you try designing a box for the pair that is the same for both, and see if it's necessary to use separate boxes or tunings.
Then you try designing a box for the pair that is the same for both, and see if it's necessary to use separate boxes or tunings.
I know it can work for sealed boxes with different Qtc [ I think it was with a 3.5 speaker a mate built] but never ever thought of trying with a ported box, too many variables for this little wood duck
I ask the question because i can see that Børresen is doing something like this in their new 3 way speaker. I listened to it this weekend. 1,9M EUR for the system 🙄
Are they different tunings for sure?
If the boxes are different volumes maybe the tuning could be the same
If the boxes are different volumes maybe the tuning could be the same
The 2 upper, and 2 bottom 'woofers' shares the same volume for 2.
The 2 'mids' each have a identical ported enclosure both.
So a large 3/3.5 way. With 2 sets of ported woofers. Possible the lower one is slightly larger and lower tuned ?
Rolling it off before the upper pair or something similar.
Fully possible to do but not really much benefit to it, and plenty of headaches to solve.
The smaller volume upper chamber uses a shorter, wider port than the lower larger chamber, so definitely has a higher Fb (Frequency of Box tuning) if the cutaway diagram you posted is accurate.
If the Fb output of each is within 1/4 wavelength (90 degrees) they sum still constructively.
That said, the speakers appear to be multi-way, considering the higher Fb of the upper cabinet would benefit from a higher frequency high pass, for 1.9M EUR, I'd expect DSP would be compensating for any time/phase differences 😉
What did you think of the speaker's sound?
It sounded nice and with good fundament in the bass. The level from theese 4,5 inch drivers was stunning. They played loud as from a huge three way with 12-15 inch woofers??? The bass was a little «one note» compared to my more articulated and efforteless Acoustic Elegance TD18H+ subwoofers which i use from 20-140 Hz.
They had bypassed the crossover for the bass for this occation and used an active analogue crossover and off coarse then a dedicated amplifier for the bass. That explains the impressing body and punch maybee?
They had bypassed the crossover for the bass for this occation and used an active analogue crossover and off coarse then a dedicated amplifier for the bass. That explains the impressing body and punch maybee?
Interesting 🙂
https://www.dali-speakers.com/media/3398/dali-18-mkii.pdf
And the woofers lowpass is 800 Hz.
https://www.dali-speakers.com/media/3398/dali-18-mkii.pdf
And the woofers lowpass is 800 Hz.
This is thinking outside one box and into two boxes. I like this sort of thing, since I never would have dreamed it up in the first place. No doubt, there must be adequate testing/experimentation involved to achieve the goal. In the end a good listen would tell me all that I need to know.
The top enclosure has a 10 cm foam plug in it. -Making it aperiodic?
They were sold (en masse I imagine) in Norway early 90ies. You can often find them for cheaps, if you want to play with them.
They were infamous for needing a powerful amp, and were falsely I believe, claimed by some to go below 2 ohm. My experience was no. But I had to turn up the volume high regardless of what amp, before they sang. That changed when i converted them to active crossover. So my suspission is that they were born with a "sluggish" crossover if such exists.
I have 2 pairs and plan to make a before and after recording before selling one.
Cheers
JBL did something like that in their K2 series. They called it "Imaginary Equivalent Tuning".
Maybe a search will reveal more details than the desccription here: https://www.audioheritage.org/html/profiles/jbl/k2.htm
Regards
Charles
Maybe a search will reveal more details than the desccription here: https://www.audioheritage.org/html/profiles/jbl/k2.htm
Regards
Charles
4x4.5" drivers would need to have almost double the excursion to equal the output of a single 12".
The suspension of these 4.5" does not look like that would be possible.
That said, ~103 dB at one meter should be achievable with one cabinet in the >40Hz range if they have ~6mm Xmax.
In room, that could boom 😉
Most music has little content below ~40Hz, if high passed you can get fairly impressive body and punch with no audible signs of distress even from small drivers.
There is a member here that furcates his transmission lines into perhaps a dozen separate hoses of differing lengths.
I see no problem with two bass compartments of different volume playing togeter, as long as the phase and group delay are matched.
Since DSP's are common today, if you control volume and program material, you can make four 4.5" woffer sound quite mighty and fool listeners. Just a matter of set-up.
Don't expect any high end company at an audition to ply fair and not use any trick in the book to make their products shine.
Børresen and Audio Group is a highly sophisticated snake oil destillery, mixing some nice products with rediculous overpriced esoteric stuff.
Since DSP's are common today, if you control volume and program material, you can make four 4.5" woffer sound quite mighty and fool listeners. Just a matter of set-up.
Don't expect any high end company at an audition to ply fair and not use any trick in the book to make their products shine.
Børresen and Audio Group is a highly sophisticated snake oil destillery, mixing some nice products with rediculous overpriced esoteric stuff.