Push-Push or Push-Pull

[Bigun]

Now that it's no longer a question of using two drivers I should probably start a new thread with this.

Based on advice so far I have ended up with a simple box, birch play and braced internally. Two drivers in push-push and an integrated amp to avoid microphonics (although I'm not quite convinced on this front for solid state). There's no semblance of a golden ratio in this design of course.

But it seems a bit boring not to build a push-pull instead, given that it would be a bit more challenging and less a look-alike for an off-the-shelf sub. I recognize that the benefits should be more noticeable with less linear drivers and with larger excursions - but I may not be able to appreciate the difference. You see, I've never had a sub and I will have nothing to compare it with if I build it since I don't really want to get into doing too many experiments. I've also heard that there is the risk of unwanted noises from the vented magnet. So common sense says build a push-push and yet my hands want to build a push-pull.

It's a question that no doubt has been asked before, but I thought perhaps not with these specific drivers ???

Here's the push-push version

[Bigun]

And the Push-Pull version.

A little loss of box volume, easy to compensate for with an extra cm all round.

[JLH]

Push-pull 100%

[GM]

Originally posted by Bigun

So common sense says build a push-push and yet my hands want to build a push-pull.

Well, at least you have some common sense which is more than can be said of many folks, but DIY audio is mostly about satisfying oneself, so why are we having this conversation?

GM

[MarkR]

Build both
Two enclosures shouldn't take long or cost allot. Try them out see which one yours ears like better and if they can't tell them apart pick with your eyes.

[tinitus]

Both ways ought to be possible in the same box

[Bigun]

Originally posted by tinitus
Both ways ought to be possible in the same box

It could be done, although it turns out easier if I wanted to try them both inverted rather than neither of them inverted.

I had a question about speaker grill/covers. For subs, the excursions can be large, so does this imply that the grill has to be spaced off from the cone surround by essentially xmax - which can be quite large ?

[tinitus]

Originally posted by Bigun


For subs, the excursions can be large, so does this imply that the grill has to be spaced off from the cone surround by essentially xmax - which can be quite large ?

I dont think so

The surround doesnt move outwards to the same degree as the cone Xmax
But you should be able to carefully move out the cone, and see how much change it makes on the surround

[Cal Weldon]

Originally posted by tinitus

The surround doesnt move outwards to the same degree as the cone Xmax
But you should be able to carefully move out the cone, and see how much change it makes on the surround

The surround will move 1/2 what the one way Xmax is (not P-P)

[Bigun]

My shipment arrived from Creative Sound Solutions today. First time I've seen or held a sub-woofer driver. They are quite different from the little Fostex full-range drivers. But I can say that I am very impressed with the out-of-box quality of the TRIO8s. They are nicely finished and look to me to be well thought out and made with good quality materials. Decision made. The Push-Pull will allow me to view the front and back of this lovely driver for years to come !