Stacking Speakers

[voice of the theater]

I learned here in an old thread that if you stack two pair of Model 19's for example, the ?correct? way to set them up is to have the pair on top upside down. I've recently stacked my Santana II's on top of a pair of Model 19's, and even though the Model 19's are more efficient than the Santana II's, I like the way they sound playing simultaneously. Is the same setup ?correct? or preferable for the Santana II's on top of the Model 19's? Why is this setup recommended? Is it so that you have a ?wedge of treble? in the middle with bass below and above it?better overall point source? Or is it because the bottom speaker's woofer will reflect off the floor ? enhancing it's sound and the top speaker's woofer will (when it's upside down) reflect off of the ceiling also enhancing it's sound? Or is it because this setup keeps the tweeter (or horn) for the upper speaker closer to ear level? Or all, some, or none of the above? Am I just as well served tipping the Santana II right side up and propping up the back of it so the tweeter is ?aimed? down to ear level?

[GM]

Ideally, you want drivers sharing some portion of a BW to be < ? WL apart at their -F6 point to ensure both good acoustical coupling and minimize comb filtering enough to the point where there?s no perceived ?echo?/?smearing? of the signal both on and off axis.

The reality of course is that it would take many drivers, XOs to achieve this over a wide BW, so all sorts of driver, speaker design decisions must be chosen to find an acceptable compromise.

Since the HF will need the least driver spacing, they normally should be positioned as close together and on the same plane as practical, though in your app, the XO of each speaker system should by design be ?steering? [tilting] the HF?s response upward to some extent due to being ?lowboy? designs; ergo ideally you would measure their individual polar responses and adjust the tilt of one or both systems such that they overlap at ~ear height at the Lp for best overall HF performance.

GM

[voice of the theater]

Ideally, you want drivers sharing some portion of a BW to be < ? WL apart at their -F6 point to ensure both good acoustical coupling and minimize comb filtering enough to the point where there’s no perceived ‘echo’/’smearing’ of the signal both on and off axis.

The reality of course is that it would take many drivers, XOs to achieve this over a wide BW, so all sorts of driver, speaker design decisions must be chosen to find an acceptable compromise.

Since the HF will need the least driver spacing, they normally should be positioned as close together and on the same plane as practical, though in your app, the XO of each speaker system should by design be ‘steering’ [tilting] the HF’s response upward to some extent due to being ‘lowboy’ designs; ergo ideally you would measure their individual polar responses and adjust the tilt of one or both systems such that they overlap at ~ear height at the Lp for best overall HF performance.

GM

Thanks GM! Now I have a much better understanding as to why you'd want to position the top speaker upside down--keeping the hf drivers as close together as possible.

[Old Guy]

Another benefit is you can widen the sweet spot. I used to tour with 311-60's. Stack them straight ahead for a long deep house, splay them for a wider shallow venue.

[bowtie427ss]

Thanks GM! Now I have a much better understanding as to why you'd want to position the top speaker upside down--keeping the hf drivers as close together as possible.

an additional 2 cents worth, sometimes simply unhooking one of the HF sections can be a significant improvement in a "stacked" arrangement.

[GM]

Thanks GM!

You're welcome!

GM

[GM]

an additional 2 cents worth, sometimes simply unhooking one of the HF sections can be a significant improvement in a "stacked" arrangement.

Yeah, historically I couldn't tolerate such a set-up of mismatched parts, so at best it would have been with the Santana's tweeters disconnected and cabs right side up to get the woofers closer and then reduced the M19's horn shelving as required to tonally balance it out as much as practical.

GM

[tomt]

i'm in favor of stacking speakers.

to infinity.

and beyond ...




`````````````````````````````````````````````````` ````````

one of our fellow forum members posted this on another forum.

looks good to me -

[voice of the theater]

Yeah, historically I couldn't tolerate such a set-up of mismatched parts, so at best it would have been with the Santana's tweeters disconnected and cabs right side up to get the woofers closer and then reduced the M19's horn shelving as required to tonally balance it out as much as practical.

GM

I haven't tried disconnecting the tweeter on the Santana II's, but maybe this weekend I'll give it a whirl. I've seen people add a tweeter to two way horn loaded systems for extra "sparkle", but in this case, the 19's have never needed any extra sparkle so disconnecting the tweeter on the Santana II's might be worth a try. Not to mention, I can't really hear the tweeter when both pair of speakers are playing simultaneously--the mids and bass sound "fuller" but the treble seems unaffected. Funny thing is that with the Santana II's and the Model 19's playing simultaneously, it really does sound significantly better and more full than just the 19's alone at any volume. I wonder if it's just because I'm "moving more air"/more displacement/bigger "wall of sound", or could it be because of one of these three reasons:


1) Is it because my amp sounds better with a 4 ohm load than an 8 ohm load (which I doubt would explain the significant improvement I'm hearing).
2) Could it be that the Santana II's excel at the 19's weaker points. (seems possible to me as a guess). I can't hear a deficiency, but I've read that a weak point of the 19's is the midrange at 1200 hz and just below because the woofer ideally shouldn't have to cover frequencies that high. So maybe the Santana II's twelve inch woofer excels in that range of frequencies, and are filling in or enhancing that frequency range (say, 800-1200 hz for example)? The mids do sound noticeably improved when I play the Santana II's with the Model 19's compared to the Model 19's alone. Also, could the Santana II's be better at certain bass or mid bass frequencies than the 19's—could that be why the bass sounds more full and powerful with both pair of speakers playing at the same time compared to the 19's alone?
3) Or could it just be room acoustics? The upside down Santana's woofer/bass reflecting off of the ceiling is now combined with the 19's woofer/bass reflecting off of the floor giving me a bigger “wall of sound”? I wish you guys could hear this difference. These Santana II's make my 19's sound significantly better—especially bass and mids (highs seem more or less unaffected). When I bought my first pair of Model 19's they immediately became my gold standard as far as speaker sound quality. But, the 19's combined with the Santana II's are without a doubt the best sounding speaker/stereo system I've ever heard—the sound of the 19's and Santana II's playing at the same time sounds that good to me. Anyone care to chime in as to what could be a reason for this?

[GM]

The short answer is all of them to a greater or lesser extent.

GM