Hi Fellows,
Two easy questions for Push Push Subwoofer:
a. Are these 2 Push Push woofers wired In-Phase or Out-of-Phase?
b. In a sealed enclosure, then the internal enclosed volume, the designed volume is for 1 woofer and not two. And similarly for a ported enclosure.
Thanks.
Two easy questions for Push Push Subwoofer:
a. Are these 2 Push Push woofers wired In-Phase or Out-of-Phase?
b. In a sealed enclosure, then the internal enclosed volume, the designed volume is for 1 woofer and not two. And similarly for a ported enclosure.
Thanks.
Wired electrically in phase, mechanically opposed (sort of mech antiPhase).
The designed volume of any enclosure is twice that of what you would use for a single driver.
dave
The designed volume of any enclosure is twice that of what you would use for a single driver.
dave
Not trying to be argumentative but there are at least a few isobaric designs which this is not the case. Also (not sure here) but I thought the new kef micro sub with back to back coupled magnets (idk if it pushing or pulling)was designed in ‘half space’ ?
2 drivers magnets back to back, both run in-phase=push-push? So if you run 1 out of phase doesn’t that become push-pull? Now if you physical turn one driver around and run both in-phase doesn’t this become a push-push isobaric design? If you then reverse the phase of the rear driver it becomes push-pull again? In these cases I assume only the push-push designs would be vibration canceling? Please tell me if I’m lost it’s been over 25 years since I designed an isobaric box
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But we are not taling about isobarik which is a completely different concept.
You are not accounting for the need to mechanically orient the drivers. In push-pull you are physically flipping a driver so it needs to be wired anti-phase electrically to be in phase acoustically.
Push-push requires a specific phycical configuration of the drivers. Push-pull the orirntation of the drivers wrt the box.
dave
You are not accounting for the need to mechanically orient the drivers. In push-pull you are physically flipping a driver so it needs to be wired anti-phase electrically to be in phase acoustically.
Push-push requires a specific phycical configuration of the drivers. Push-pull the orirntation of the drivers wrt the box.
dave
Dave????
I have a quick question: how many experiments did you have to accomplish before you actually started to 'SEE' what was happening?
Like you have pointed out, there are so many variables, that responding to these 'quotes or questions' is too time consuming. NO-ONE will ever figure it out, until they have experimented exhaustively.
We haven't even introduced the problem of amplification. Voltage source vs Current source.
I see why most of the guru's have simply stopped ready these threads.
To the OP; build countless boxes, try every possible combination, try every etc. etc. etc. .... Once completed, you will know.
There is no answer to your question.
It is not the destination. The journey is everything.
I have a quick question: how many experiments did you have to accomplish before you actually started to 'SEE' what was happening?
Like you have pointed out, there are so many variables, that responding to these 'quotes or questions' is too time consuming. NO-ONE will ever figure it out, until they have experimented exhaustively.
We haven't even introduced the problem of amplification. Voltage source vs Current source.
I see why most of the guru's have simply stopped ready these threads.
To the OP; build countless boxes, try every possible combination, try every etc. etc. etc. .... Once completed, you will know.
There is no answer to your question.
It is not the destination. The journey is everything.
I recognized the benefits the first time the idea was suggested (even before the KEF 104ii).
Many experiments leading up to a very specific experiment using 15 mm BB and 2 SDX10 that conclusively (AFAIC) showed the benefits of force cancelation.
And following what others are doing. KEF, NAIM, Martin Logan, and a growing number of others.
A simple expedient that brings huge benefit.
dave
Many experiments leading up to a very specific experiment using 15 mm BB and 2 SDX10 that conclusively (AFAIC) showed the benefits of force cancelation.
And following what others are doing. KEF, NAIM, Martin Logan, and a growing number of others.
A simple expedient that brings huge benefit.
dave
Yeah I’m not getting my head around the need for physical orientation, why aren’t any 2 drivers, in a common space enclosure, run out of phase with each other acting as push-pull, regardless of either drivers physical orientation? If a drivers opposed in a sealed box (magnets coupled) and run out of phase is not isobaric then what is it? The only difference I see between a sealed 1 subwoofer box with 2nd speaker coupled onto the outside (a common iso design) and a push-pull design is the side of the speaker/wave your using, what am I missing?
That is push-pull.
I am talking about push-push where the reactive force of one driver is tightly couped to the second driver. The drivers are in mechanical anti-pase so most of the reactive energy is actively canceled, and electrically and acoustically in phase.
dave
Ok I thought about that and can see why physical orientation could be important but can’t acoustic phase be resolved in any orientation by changing electrical phase?
Thanks Dave, I actually didn’t think of that cause I didn’t think it would work, I thought the rear waves would cancel as the reactive energy does
Yes.
A good driver benefits little from push-pull, and while one can get some reactive cancelation but it is not as effective as push-push orientation (and not as pretty).
dave
A good driver benefits little from push-pull, and while one can get some reactive cancelation but it is not as effective as push-push orientation (and not as pretty).
dave
What? At least some of his content was relevant...I could be mistaken...correct me if I'm wrong.
Isobaric clamshell configuration is akin to push-pull and should exhibit some of the 2nd order harmonic reduction. Clamshell or the opposite where the magnets face. The coupling of the drivers should induce the same affect as the non isobaric push-pull config we are speaking of right? The super rigid dbl motor forced mechanics of isobaric, along with opposite facing woofers...I wonder if isobaric is under appreciated...
Heres my version of push push slot load. I designed it in Horn resp and so far it looks to be relatively accurate to the design...I won't know until I put it together fully and measure.
Attachments
True but off topic. And reduced 2nd may or may not be a good thing and only with cheap woofers.
Nice looking woofers. A but fiddly looking.
dave
Ok....thats good to know about pros of push pull (or lack thereof). Ty for the compliment. As for fiddly...fingers crossed lol.
Did you guys cover the dispersion affects of side mounted woofers in push push? Its a particular polar pattern is it not?
Did you guys cover the dispersion affects of side mounted woofers in push push? Its a particular polar pattern is it not?
I quick thought experiment was enough, no need to see what was happening. I have tried it BTW, works like a dream, of course, it puts more demands on the cabinet, one way or another, so is debateable how desireable it is, it stops a subwoofer from dancing around though. 🙂
Thot experiemnt clearly showed the benefits. Series of experiments did greatly improve the effectiveness of the way we achieved coupling.
dave
dave
Basically omnidirectional below 60Hz or so, with a pair of side lobes developing above, their directionality depending on cone size and frequency.
Start by learning about the Ka factor:
Speaker directivity / off axis response: theory and measurement techniques - Acoustic Frontiers