In yours that is the case
But for camplo the dip is at more like 270Hz, which is not terrible but not ideal either. As you say putting the drivers on either side of a box of whatever size keeps all the main benefits without the air mass cancellation.
A 12db/oct low pass at 21hz on a sub to knock the response more flat is a little bit of eq? I would call that beating the response into submission with a ton of eq. I don't mind the plan, CD waveguides often utilize a 6ish db highpass set at 10-20ishkhz for similar purpose, but calling it a little bit of eq is quite a stretch.
Carry on.
A much more accurate assumption of the results of eq would be had looking at GD and FR. Fluid showed that there is more one way to skin the cat and his design was improved over my idea.
Both ideas ended in very low GD. 👍
um When I can get a result, be it the anechoic version, thats +\-2.5db or so with just 3 filters...that is, a little, eq.
Both ideas ended in very low GD. 👍
um When I can get a result, be it the anechoic version, thats +\-2.5db or so with just 3 filters...that is, a little, eq.
That idea makes sense to me, if you need that much woofer and find the box vibration to be a problem.
It could be the case that I never noticed the vibration because my speakers are on a poured concrete floor. That's not going to vibrate very much at all. But on a wood structure it could be an issue. It should be an easy problem to isolate the speaker from the structure. I mean they isolate an engine from its structure all the time.
Semantics I guess. Flattening your beginning response can be done many ways. All of which call for a difference of what, over 20db of some form of eq to get there? Even if you used a single filter to do it I would still call that a lot of eq. I must have missed fluids solution. Apologies for not following this thread word for word.
No, absolutely not...as duscussed, what I did was similar to gain used in a Linkwitz transform..... Fluids iteration did not have 20dbs of gain but,...as you say, the semantics are neither here nor there...lets analyze the results.
Even with the gain boost that you are speaking on, you must conclude; no drawbacks...I posted measurements, no issues.
Even with the gain boost that you are speaking on, you must conclude; no drawbacks...I posted measurements, no issues.
Lol.... of course SD is doubled, like in any double driver box.
And front baffle being smaller is not a plus for SQ at sub wave lengths, it's the opposite in fact unless you really want omni.
It's not cool imo, to redefine terms to our own liking. PPSL has conventionally stood for either Push-Pull-Slot-Loaded, or Push-Push-Slot-Loaded.
Orientation, sideways, upways, downways, diagonally ways.....is immaterial. Foot print is immaterial.
Vibration reduction is the real bonus.
I think we are on the same page.
I do believe camplo's design works just fine with only a 24 dB/oct low pass...IF he will use the box as a sub. (crossed at around a 100Hz +/-)
It's nice to have subs on concrete....i know that helps a lot.
I often wonder if or how much sub vibration effects boxes stacked on top of the sub. With no way of really knowing.....
Are you kidding ? at sub frequency wavelengths?
If you mean tightening c2c distance with low-mid woofers, how does a ppsl do that any better than any other design?
Started here and a few posts below
https://www.diyaudio.com/community/...w-distortion-with-a-2-way.334757/post-6919033
Pretty conventional EQ with either a little boost or all cut
Indeed, I think it would be better as a dual opposed sub but that ship has sailed
I understand what you are saying. But, so far, a keel hasn't been laid. Blueprints are still being speculated about.Indeed, I think it would be better as a dual opposed sub but that ship has sailed
I considered it...a TMM with side facing sub woofers is a win. I wanted to keep all sources on the front baffle. PPSL got me there... having all sources as close together as possible being the goal along with keeping direct energy potential as high as I can.
The mid bass driver is able to couple with sub drivers, much more efficiently with a PPSL tucked under it vs side firing.
listening at 24-40" the errors that bass can allow are less forgiving...maybe thats why I am so sensitive to these issues some ignore.
The mid bass driver is able to couple with sub drivers, much more efficiently with a PPSL tucked under it vs side firing.
listening at 24-40" the errors that bass can allow are less forgiving...maybe thats why I am so sensitive to these issues some ignore.
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If the sources are within 1/4 wavelength or less they will (almost always) appear and couple as one source.
Even at 200Hz more than an octave above the crossover frequency 1/4 wavelength is 43cm.
Add that with the wavelengths involved and the number of cycles needed for the ear to recognize a frequency...
Even at 200Hz more than an octave above the crossover frequency 1/4 wavelength is 43cm.
Add that with the wavelengths involved and the number of cycles needed for the ear to recognize a frequency...