Hi Guys!
I’m a full range fan! And most of my designs are crossover less!
Now I’m planning to create a high efficiency tower.
This will be a 2 way tower, and my thought is to make it crossover less by placing a sealed full range roll off at 80hz and designing a 4th order bandpass sub which rolls off at approx 75-76 hz to avoid peak at the crossover. Both drivers have similar efficiency post modelling (3db boost on the sub due to BP)
Question is:
Has anyone tried this method?
How can I merge these 2 simulations to get a combined output?
P.s: it’s a 12 full range 96db with 12 sub 93db drivers.
Total volume will be 4cft. (1.25 sealed + 3.75 BP)
Thanks in advance.
I’m a full range fan! And most of my designs are crossover less!
Now I’m planning to create a high efficiency tower.
This will be a 2 way tower, and my thought is to make it crossover less by placing a sealed full range roll off at 80hz and designing a 4th order bandpass sub which rolls off at approx 75-76 hz to avoid peak at the crossover. Both drivers have similar efficiency post modelling (3db boost on the sub due to BP)
Question is:
Has anyone tried this method?
How can I merge these 2 simulations to get a combined output?
P.s: it’s a 12 full range 96db with 12 sub 93db drivers.
Total volume will be 4cft. (1.25 sealed + 3.75 BP)
Thanks in advance.
Have a look (eventually with translator):
https://www.donhighend.de/?page_id=8974
6,5 inch seaked fullrange with 4th order bandpass (also 6,5"), crossed over at around 150 Hz.
You will have to consider baffle step, which may reduce total sensitivity.
Also, for max efficiency you could consider 6th order parallel bandpass.
Crossing over a woofer that low may require impedance linearising of helmholtz resonator peak(s). Respective coils can be quite large and expensive.
https://www.donhighend.de/?page_id=8974
6,5 inch seaked fullrange with 4th order bandpass (also 6,5"), crossed over at around 150 Hz.
You will have to consider baffle step, which may reduce total sensitivity.
Also, for max efficiency you could consider 6th order parallel bandpass.
Crossing over a woofer that low may require impedance linearising of helmholtz resonator peak(s). Respective coils can be quite large and expensive.
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At one audioshow I heard a small 3-way standmount with such layout between 6,5 in woofer and 4in mid. I remember very clean, fast and dynamic sound.
Unfortunately, no construction details.
Unfortunately, no construction details.
Just saw that you plan no crossover - no linarisation required in this case, of course.
Keep in mind port and enclosure resonances exiting the port!
Would still use a coil and highpass.
just simple cap clean up fullrange.
Coils for sub be rather large.
With bandpass could probably get away with.
Smaller coil
just simple cap clean up fullrange.
Coils for sub be rather large.
With bandpass could probably get away with.
Smaller coil
If my sealed enclosure handles high pass and bandpass handles, well, bandpass, why would I still need to put a 1st order components?
Because the sealed fullrange will still make unnecessary excursions (bad for sound) and a bandpass producing no port and enclosure resonances is quite hard to design.
3db bandpass efficiency boost is peak and not average……..you’ll need a high efficiency 15 or 18 to balance this out
So we’re not talking ‘sub’ in the conventional thinking…..each channel will be driven with a single channel of amplification….no seperate sub amp?
Why?
So we’re not talking ‘sub’ in the conventional thinking…..each channel will be driven with a single channel of amplification….no seperate sub amp?
Why?
Somebody...must have been Teac or JVC.
Like others have mentioned, there are some things to be considered.
The speakers that I refer to had a 3"/15 Ω midbass with a HP filter made by 100 uF+ 2.2mH. A 1" tweeter .
And a 6" woofer inside the box, partitioned for the three volumes ( one for the little 3", one for the back and one for the front of the woofer). The woofer( which worked unfiltered) had a passive ( rectangular) instead of the duct.
The benefit of having a two way system is not driving bass into the high frequency driver. With the bass note sending the driver out of its linear region creates intermodulation distortion. The bass notes amplitude modulating the midrange and highs. The best way to avoid this is with a 4th order Linkwitz Reilly crossover.
Without an electrical crossover the high pass frequency of your sealed full range is determined by its mechanical properties, the spring constant of the spider and the box air volume. The spider spring becomes loose with use and then recovers when not used for a few days or weeks. You see this as the "break in" with new drivers, but the recovery is not talked about. So effectively this mechanical 2nd order high pass filter varies in frequency depending on how often you use the speaker. This will result in peaks or dips in the response at the crossover frequency depending on how much you use the system.
If you want a really high fidelity system I recommend you build a sealed subwoofer rather than a bass bell that rings at two frequencies ( aka bandpass woofer) With four channels of amplification and a miniDSP digital crossover you can create a modern design with all the low Q bass extension you desire and excellent 4th order LR crossovers. It is easy to build the small sealed bass box and then EQ the low bass with an Linkwitz transform (asymmetric shelf filter) Or you can have four different crossovers and room EQ that you select from the remote control if you want to hear the difference between no crossover, 1st order, 2nd order and 4th. It's all easily adjustable from the PC app. I expect you already own two or more amplifiers.
Without a crossover you will find the impedance of your system will be very low with the exception of the two driver resonance peaks and above the upper midrange where the woofer coil impedance rises.
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