Depends on the drivers, usually the FR driver. Lowthers, Feastrex, and a lot
of others are happy in phase, Low Qts, higher resonant frequencies. Moths
for example have a higher Qts and a lower resonance, and they like being
out of phase.
Interesting, I will look back at my sim.
However, the point I was trying to make was slightly different, my english was probably not good enough. What I meant is: is there any chance that the slot loaded woofer in a configuration like the one just posted by Guyri need to be opposite phase to the other one in the main baffle for having a correct response?
my understanding was to use 1/3 Sd of mouth opening, and the troat height is also 1/3 of the mouth height. I used same dimension with original drawing but only differ on its width 78cm.
if my calculation is correct:
Sd : 1660 cm2
front mouth : 78 x 7.5 = 585cm2 (35% Sd)
there is a part of me that want this stay as not working, so i dont have to buy another pair 21"
Attachments
No, I expect you would want those drivers in phase, although I have not
tried such an arrangement.
Did you build the SLOB and experience no bass, or was that a simulation?
Unfortunately no space at home for open baffle so just a simulation of a plain one without slot loading.
I just read that Gadut's and Gyuri are having troubles getting that double woofer arrangement to work.
I then remembered the phase thing and that in the simulation I had to invert the woofer to get it properly matching the full range so I thought that their problem may be due to the two woofer having to be in opposite phase.
Unfortunately I can't simulate the slot loading. What I may do is to simulate the definimax and the pm6a in a simple baffle and see if numerically they want to be in phase or not. My previous simulation was with the beta 15 and the tb w1808
I'll post the result when done
The performance of the slot loaded vs front mounted woofer are not going
to be so different as to require more than modest adjustments to the
crossover electronics. I have not seen it make a difference in driver phase.
The default for 2 pole high pass and low pass would be in phase for all the
Lowthers and most other drivers. Most of the time the crossover frequency
for the woofers would be about 80 Hz and 160 Hz for the high pass filter.
to be so different as to require more than modest adjustments to the
crossover electronics. I have not seen it make a difference in driver phase.
The default for 2 pole high pass and low pass would be in phase for all the
Lowthers and most other drivers. Most of the time the crossover frequency
for the woofers would be about 80 Hz and 160 Hz for the high pass filter.
good evening.
I have followed this topic very carefully, having built a 3-way OB, I was very happy if I could use the components and do some with slot loading? And if it would be an advantage over what have I got?
4 x eminence beta 15
2 x monacor sp200x without central cone
2 x bmc 1 "with horn 8"
The speakers are these :
Thank you very much for your attention.
I have followed this topic very carefully, having built a 3-way OB, I was very happy if I could use the components and do some with slot loading? And if it would be an advantage over what have I got?
4 x eminence beta 15
2 x monacor sp200x without central cone
2 x bmc 1 "with horn 8"
The speakers are these :
Thank you very much for your attention.
I eventualy had time to go back to the simulation in Basta. This time I tried the definimax and the pm6a. I still find that having them out of phase gives the smoothest response. I however realize now that this is true only if "far field response" OR "common microphone position" are used.
Interestingly, user naca5 reported here similar findings. His best response curve was measured with drivers out of phase and microphone in between the two drivers. This seems to confirm my findings but it may very easily be possible that one of his amplifiers was of an inverting type while the other not and thus the necessity of inverting one of the drivers. I cannot say!
I attach to this post the Basta models for the definimax and the pm6a for anybody interested in having a look (note you have to reset mic position as this is apparently not saved). Clearly, given the above, there is a high chance that something is wrong with the simulation so don't trust the result...
Hi naca5, I would be interested in your findings if you will do this. I'd also appreciate if you could let us know if any of the amplifiers you have used are of the inverting type.
I have some examples where the drivers end up out of phase, but the PM6A
has not been one of them.
It would depend on the frequencies you cross them, though. For the
~4'h x ~3'w varieties, I like ~80 Hz 2 pole for the bottom and
~160 Hz 2 pole for the Lowther. If you measure these running out of
phase, you get a pronounced null at ~160 Hz which goes away with
in-phase wiring.
Speakers which seem to do better out of phase in this situation are ones
with a higher Qts.
has not been one of them.
It would depend on the frequencies you cross them, though. For the
~4'h x ~3'w varieties, I like ~80 Hz 2 pole for the bottom and
~160 Hz 2 pole for the Lowther. If you measure these running out of
phase, you get a pronounced null at ~160 Hz which goes away with
in-phase wiring.
Speakers which seem to do better out of phase in this situation are ones
with a higher Qts.
Hi,
I played this afternoon with sloated bass reverse, without measuring the result, I'm in Summer mood....
Sound seems tighter that way, less muddy on particular recording, giving less output so I slightly increase it through the potties on B5....
It deserves a measuring session....
You are right Gyuri, thanks!
I didn't have that last picture. But it is clearly that there is "Professional Series' written on it. The Delta and Beta are 'American Standard Series'.
It's a pitty, those Definimax are more than twice the price
Would a 'Eminence Lab15' be a even better choice?
I didn't have that last picture. But it is clearly that there is "Professional Series' written on it. The Delta and Beta are 'American Standard Series'.
It's a pitty, those Definimax are more than twice the price
Would a 'Eminence Lab15' be a even better choice?