Hi all,
Having seen the Fs / Qes calculation regarding the choice of sealed vs ported enclosure, it would appear ported is best for a Beyma 6cx200fe but if using this driver only as a mid/high, crossing over at approx 100Hz to subwoofers, would a sealed enclosure be suitable?
Cheers
Having seen the Fs / Qes calculation regarding the choice of sealed vs ported enclosure, it would appear ported is best for a Beyma 6cx200fe but if using this driver only as a mid/high, crossing over at approx 100Hz to subwoofers, would a sealed enclosure be suitable?
Cheers
I'll give your thread a bump by linking to the parameters: https://www.beyma.com/en/products/c/coaxial/106CX2FE8/altavoz-6cx200fe-8-oh/
It is less than one octave. above the Fs You are risking too much disto if you pump up the volume. And also there is the 3 to 4 dB baffle step to deal with if it is for normal living room environment.
Also the 70° spreading by the horn is maybe a narrow spread choice because you listen to a little far field ? 5 meters and plus ? If yes it means more exursion so more disto, so maybe a 200 hz XO will be more conservative whatever sealed or ported (sealed is good for mid driver range with low enough QTS).
That's theory at least... But many 6" pro driver are made to be XO higher than 6" drivers. Vented to refer to your question could be the best choice at 100 he because the steeper slope.
Also the 70° spreading by the horn is maybe a narrow spread choice because you listen to a little far field ? 5 meters and plus ? If yes it means more exursion so more disto, so maybe a 200 hz XO will be more conservative whatever sealed or ported (sealed is good for mid driver range with low enough QTS).
That's theory at least... But many 6" pro driver are made to be XO higher than 6" drivers. Vented to refer to your question could be the best choice at 100 he because the steeper slope.
For a medium/large home entertainment/social area and to be used outside in the summer too.
Yeah, as a general rule we want at least -24 dB/Fs, so assuming a max flat sealed alignment's 2nd order roll-off = 65*2^2 = 260 Hz.
There are good 15" in GB according your budget and good suppliers : Blue Aran and so on. i would look at a Fane for instance for the 15", or SB Audience according the budget.
You can make it in two cabinets : more portable. The idea is you need to push a little hard the drivers so higher XO and vented give both better protection w/o corrupting the listening quality in those higher spl needs. (you do not want to stop the nigth or party cause a driver is broking).
You can make it in two cabinets : more portable. The idea is you need to push a little hard the drivers so higher XO and vented give both better protection w/o corrupting the listening quality in those higher spl needs. (you do not want to stop the nigth or party cause a driver is broking).
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Thanks for all the responses. Makes sense.
I will go with a higher crossover point. With a 400Hz crossover, is sealed still not a good idea with this driver? I'd prefer sealed for the simplicity....
I will go with a higher crossover point. With a 400Hz crossover, is sealed still not a good idea with this driver? I'd prefer sealed for the simplicity....
With the parameters given, WinISD beta says, "very much" in the ported camp. An EBP way up there at 191.2 says ported, the decision point falls around sixty to one-hundred...at 191.2 "it is decided".
I got "tweaked" values of Vb of 6.5 liters, a fb of 83 hertz, running a port of 68mm diam. by 189mm long...for a response of -3.04 Db @ 81.25 Hz. Cube root of 6.5 liters is 186mm..??? so playing with box dimension ratios, we can get that 189mm long port tube in there.
-----------------------------------------------------------------------------------------------------------------------------------Rick...
I got "tweaked" values of Vb of 6.5 liters, a fb of 83 hertz, running a port of 68mm diam. by 189mm long...for a response of -3.04 Db @ 81.25 Hz. Cube root of 6.5 liters is 186mm..??? so playing with box dimension ratios, we can get that 189mm long port tube in there.
-----------------------------------------------------------------------------------------------------------------------------------Rick...
Having the bass region in the crossover stopband is a significant consideration. You can control the excursion of the woofer using the crossover, and you can increase the response in that region using the crossover filter resonance to act as a replacement for the action of the vented box. In addition to this, the single impedance peak of a sealed box should be easier to work with for your filter. The 400Hz vs 100Hz is just icing on the cake, but my answer would be the same in both cases. All of this could be simulated if you wanted.
Thanks Allen. I'm thinking active (MiniDSP) as for me, passive crossovers are probably a step too far at this stage.
It's mostly the same, using a vented box may add up to a needlessly steep slope for crossing to the woofer in either case.
I'd presume you'd aim for a target curve rather than applying a random DSP preset, or there will be differences in the end result.
I'd presume you'd aim for a target curve rather than applying a random DSP preset, or there will be differences in the end result.
Also meant to ask, with the tweeter being a compression driver, can it be connected directly to the amp outputs in an active setup? Or do compression drivers require some kind of additional protection?
The usual concerns apply. The amp shouldn't have a problem with DC offset or excessive switching thumps. The signal should be reasonably filtered. Otherwise you can connect them directly.
I prefer sealed because you do not have the vent(s) huffing and puffing (noise).
Vented enclosures also cause delay of the ported sound: Phase shift.
Sealed enclosures and cone excursion cause air compression distortion: little discussed fact. Your ears do not hear woofer low frequency air compression distortion. In my experience port huffing and puffing noise is much more auditable.
If the XO point is above the lower frequencies where compression causes distortion. Sealed enclosures are best for mid-range drivers.
Enclosure Qts is not that important for the mid-range enclosure, the XO point is normally a couple of octaves above the enclosure resonance frequency. If anything make the sealed enclosure somewhat larger to decrease the air compression distortion. A sealed enclosure will still be smaller than a vented one.
Build a couple of test enclosures; measure and listen.
Thanks DT
Vented enclosures also cause delay of the ported sound: Phase shift.
Sealed enclosures and cone excursion cause air compression distortion: little discussed fact. Your ears do not hear woofer low frequency air compression distortion. In my experience port huffing and puffing noise is much more auditable.
If the XO point is above the lower frequencies where compression causes distortion. Sealed enclosures are best for mid-range drivers.
Enclosure Qts is not that important for the mid-range enclosure, the XO point is normally a couple of octaves above the enclosure resonance frequency. If anything make the sealed enclosure somewhat larger to decrease the air compression distortion. A sealed enclosure will still be smaller than a vented one.
Build a couple of test enclosures; measure and listen.
Thanks DT
For the tweeter you will likely want to use a resistor voltage divider (L-Pad) to attenuate the amplifier output, including amplifier hiss. DC protection capacitors are often a good idea.
Thanks DT