Hi everyoneI've a question. I'm going to build separate enclosures for my WAW FR speakers with different alignment(Fc 95hz Qc1.0 for Woofers and Fc 126hz Qc0.8 for FR). Will there be any problems? Crossover point will be close to 300hz (LR2 Active) as suggested by Planet10.
Not massive from an operating perspective; a Qtc of 0.8 on the wideband isn't likely to affect the acousic high pass all that much. Unlikely for the woofer, although whether you'll like the Fb peaking with a Qtc of 1.0 is another matter. Your call on that front.
Yes, but i don't want to make new enclosures for my existing sealed woofers. Not worried about midbass peaking because the -3dB point is very high, around 70hz (Fc 95hz at sensitivity/ 93db~1W/1M) and i don't consider this setup as hifi..only diy fun. I choose Qc 0.8 (14L sealed) for FR drivers because of size/design constraint and to maintain 1/4 wavelength criteria. i can make smaller enclosure for shorter driver spacing but i also want as much flatness as possible within size limitation. i thank you for expressing your views
Have a good day.
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You don't need to make explanations: the matter of a peaking response at Fb is a separate matter primarily for the woofer and your own personal taste (which is your business and requires no justification to other people). As noted a Qtc of 0.8 will not have a major impact on the acoustic slope with a 300Hz active LR2 high pass.
Sorry but It's not about my taste & i was not giving any explanation. I actually made a mistake while making the woofer enclosure which i realized later. In theory a Qtc of 0.707 gives maximally flat response but this is not necessarily the ideal Q. Higher Q gives more LF output below the cutoff frequency at the expense of response peaking. Some consider a Qtc1 as a best compromise alignment, so i look forward to Regards.
Regards.
Sorry but It's not about my taste & i was not giving any explanation. I actually made a mistake while making the woofer enclosure which i realized later. In theory a Qtc of 0.707 gives maximally flat response but this is not necessarily the ideal Q. Higher Q gives more LF output below the cutoff frequency at the expense of response peaking. Some consider a Qtc1 as a best compromise alignment, so i look forward to
Actually, that is a matter of taste since it is a question of personal opinion and 'what you look forward to' rather than being a fixed quantity that is universally applicable. QED. As a minor note, a Qtc of 0.707 is certainly not 'the ideal Q' since no such ideal exists, but in terms of extension the clue is in the name 'maximally flat' (aka 'lowest possible F3). As you increase Q, you raise both Fb and gain peaking around Fb, so if you like or require that, so much the better, the tradeoff being it is at a higher frequency with less output lower down. However, this is a side matter that I merely noted, because the primary object was to answer your question (which I've done) about whether a Q of 0.8 will significantly affect behaviour with an active LR2 high pass at 300Hz. Which is 'not significantly'.
You didn't understood me, who doesn't want something better(In your words..'maximally flat aka lower possible F3')? But currently i've no other choice than that
because i don't want to spend to much on these cheap woofers and it's really annoying to start all over again.
I know about different alignments & their effects, there is no need to say anything about that. Since i'm building WAW for the first time i don't want to make any mistakes (time, phase or so) again and this was the reason of my query. It's almost impossible to know everything about audio and acoustic is quite complex(at least for me).
Ok now i don't want to drag this post anymore. I appreciate your input, thank you.
Nice trick
It reduces peaking quite effectively, maybe 1.5dB or so. I'm not concern about widerangers but somewhat for the Sealed woofers. 1.3dB peak at 125hz(Qtc1.0) 
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Err, blunder again
I've mixed electrical Q with enclosure Q(i was talking to someone then). Actually my query was about woofer+widerange as a whole system(WAW), not only about wideband driver and its Q (driver+box combo). This is what i know about enclosure alignments.. Now i need to rest, thank you all. 
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I have zero experience with active XO beyond using a very early ['71, several years before SL published his XO paper] Altec bi-amp system that was a horrible performing waste of $$ that swore me off them and recently from auditioning these speakers done 100% with a dbx DSP whole audio management system that when done sounded like one freaking big single driver system, such that I've forever sworn off passives, T/S spec sealed alignments: Altec Lansing Based Compostela Loudspeaker Review - Audiophile Nirvana
Re WAW, I was taught to solve acoustic problems with acoustic solutions, so having been 'encouraged' to preserve as much tonal balance [aka PRaT] as practical, normally used multiple 'FR' drivers with the mid/HF in whatever cab alignment best overall rolled it off below its power handling limit [normally OB or boxed equivalent due to having very high Q for ~open back tube radio/TV apps], then used damping to fade/blend the woofer
Thanks to some '50s RCA, Jensen speakers, was an early adopter of column/tower BR [aka MLTL nowadays] and corner loaded pipe horns similar to 'BIB' except floor loaded with a vent area [Av] = driver effective area [Sd].
Power wise, depends on the needs of the app, but the basics for inefficient speakers [< 1% = 92 dB/W/m] is to have at least 10 W of Class A in an AB amp and at least +3 dB of dynamic headroom, i.e. double the power likely ever needed to ~ensure never triggering its clipping protection ckt. or +6 dB [4x] to make doubly sure.
.If multi-amping, strongly recommend using prosound gain structure theory to choose:
Gain Structure for Home Theater: Getting the Most from Pro Audio Equipment in Your System | Home Theater Forum and Systems
GM
Hi everyone
Greets!
No way to answer this without knowing driver responses. For all I know either driver could be +/- 6 dB/300 Hz due to differing driver designs. In general you ideally want an octave of flat BW on either side of the XO point per slope order = 75-1200 Hz BW for 2nd order. With cheap drivers, good luck meeting this.
GM
OK, then you'll need to reverse the polarity of the HF. To wire them in phase you'll have to shift the HF backwards enough to account for the 2nd order's 180 deg phase rotation.
GM
edit: ~34400/2/300 = 57.33 cm
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i have never seen Jensen speakers
How fortunate you are!
I haven't read it yet, but i'll. All i'm going to do is, same four channel amplifier(gc) with same gain setup(24dB), and a good tone control unit with gain boost between CD/mp3 player and Xo+amplifiers.
I said cheap but that doesn't mean bad
i believe my woofers are good upto 800hz-1Khz without break up & widerangers upto 8K or more. But that's just my assumption On the other hand, though Planet10 recommends to Xo below or close to 300hz(because of some good reason), i changed my mind after reading a book by D.self. Because at 300hz Xo point; signal will be down to -6dB; and the -3dB point is at 190hz. Maybe i'll loose all of the midbass because my woofers aren't good below 70hz. This is why my plan is to cross them below 500hz, -3dB point is at 300hz. Please correct me if i'm wrong, i need advice.Yess! But in my case i'll invert lowpass section using an op-amp, so no change in driver's wire/polarity
Sir please see my previous post about XO point,
i'm afraid because i'm not going to use giant amplifiers and my woofers(93dB 1w/1m) aren't good below about 100hz(Fc95hz, F3 68hz).
i need you guidance here.
This XO point is solely about baffle step compensation [BSC] considerations:
General Speaker Related Articles
GM
Hi everyone, i'm back I was going through various threads to understand BS compensation theory. Anyway as you know i have made separate enclosures for woofer and fullrange drivers and that's why maybe the matter has become a bit complicated, i need advice. BS of the woofer is around 350hz and 500hz for the fullrange(alright, i know BS compensation only applicable to woofers ). I was thinking to cross (LR2) them at around 497hz(315hz, -3dB) to cover both drivers. I think you understand what i'm trying to say.
The speakers will be placed close to the corner of the room and against the walls. The xover frequency i calculated is very close to 1/4 wavelength criteria, 1/3 of the wavelength of sound.
Regards
Nirupam
I was going through various threads to understand BS compensation theory. Anyway as you know i have made separate enclosures for woofer and fullrange drivers and that's why maybe the matter has become a bit complicated, i need advice. BS of the woofer is around 350hz and 500hz for the fullrange(alright, i know BS compensation only applicable to woofers ). I was thinking to cross (LR2) them at around 497hz(315hz, -3dB) to cover both drivers. I think you understand what i'm trying to say.The speakers will be placed close to the corner of the room and against the walls. The xover frequency i calculated is very close to 1/4 wavelength criteria, 1/3 of the wavelength of sound.
Regards
Nirupam
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