Horizontal vs. Vertical Orientation for Bookshelf Speakers?

[jfburk]

The ideal space for my L/R speakers in a 7.1 system would be horizontally oriented in bookshelves on the sides of my monitor. I could put them on stands outside the bookshelves in a vertical orientation, but I would prefer in the shelves.

The speakers are Ascend Sierra2 Ex's, so the RAAL tweeter can be properly oriented either way. I'm wondering if there would be any trade-offs between the two options all other things being equal (i.e. disregard the factor of being in a bookshelf!) Have any studies been done on this?

Ultimately, I'll probably do a blind-test to compare one speaker in the horizontal orientation compared to the other in the vertical, but I'm interested in reading about any of the acoustical science on this first.

 

[mansr]

Horizontal placement might mess with stereo imaging since the angles from the listening position to the midrange/woofer and tweeter differ. The extent of the effect depends on the distance to the speakers, the separation between the drivers, and room acoustics.

Try and see. If you do place them sideways, orient them symmetrically with the tweeters on the inside or the outside. If you're up for some experimenting, try both.

Placing the speakers on stands away from the walls would probably make for more of an improvement. I understand that may not be as practical in your situation.

 

[Sancus]

Horizontal with 2-ways is generally bad because their vertical directivity is usually really bad compared to horizontal. I imagine this would be even worse with a ribbon tweeter, which are notoriously bad at vertical off-axis response. You can see some very basic measurements of this on the Ascend site:

That said, if you are sitting nearfield and always exactly in the sweet spot, it may be tolerable. It comes down to how much the reflections are noticeable/bothersome and that depends on you and your room more than anything else. Regardless, these speakers definitely won't operate at their best this way, nor will any normal 2-way.

Coaxials like the LS50 or speakers designed for horizontal positioning like the Revel C52 are best for this kind of placement.

 

[jfburk]

I imagine this would be even worse with a ribbon tweeter, which are notoriously bad at vertical off-axis response.

Thanks. To be clear, the ribbon tweeters get rotated so they're in the proper orientation either way. Here's a picture of one being used as a center channel.

 

[Sancus]

Thanks. To be clear, the ribbon tweeters get rotated so they're in the proper orientation either way. Here's a picture of one being used as a center channel.

Oh, I didn't realize that. That's not so bad then. I didn't see measurements for that rotated configuration and no idea where the crossover is, but shouldn't be too bad to figure out what things will look like if you do know that...

 

[goldark]

I own the Sierra 2-EX's and they sound as good as they measure. You can manually rotate the tweeter yourself and find out first hand. Probably a good question for Dave Fabrikant...

 

[0bs3rv3r]

I think a bigger issue is going to be the space behind them for the rear firing port. If sitting in limited space on bookshelves, you might get reduced, or "boxy" sounding bass.

 

[Hipper]

I'm no expert but some of the issues have been mentioned:

1. Turning the tweeter 45 degrees will surely effect its integration with the mid/low driver because of the non symmetrical ribbon tweeters sound distribution.

2. The baffles on the side look rounded and that apparently has some effect on the off axis sound.

3. Normally speakers are positioned with the tweeter at ear height. You still want that but again how will that affect the sound you hear from the mid/low driver.

I've read of people using a three way speaker with ribbon tweeters and mids as a centre channel lying sideways with apparent success.

It would be interesting if you report back what your findings are.