DQ-10 Stacked

[E.P.111]

Could someone please tell me why you never see Dahlquist DQ-10s stacked woofer to woofer? Is it not a sonically correct method for some reason? Thanks in advance for your input.

 

[crazy-in-az]

I think I've seen an AKer do just that, but he had to get real creative with the way he mounted them. Most people are probably just satisfied with one pair.

 

[BigElCat]

Not sonically correct. Look at most modern speaker designs. Tweeters and mid-ranges go in the middle, at ear level.

Bass drivers are on the bottom, and top.

 

[E.P.111]

Not sonically correct. Look at most modern speaker designs. Tweeters and mid-ranges go in the middle, at ear level.

Bass drivers are on the bottom, and top.

Thanks so much. I was just thinking about it, wondering if it would expand the soundstage.
As for “satisfied”! We’re never satisfied, that’s why we have Audiokarma...

 

[GordonW]

Stacking just doesn't work quite as well with a discrete-driver speaker like a DQ10, as it does with a planar speaker such as a Quad. It's a matter of comb filtering between the midrange and tweeter drivers...

Regards,
Gordon.

 

[E.P.111]

Stacking just doesn't work quite as well with a discrete-driver speaker like a DQ10, as it does with a planar speaker such as a Quad. It's a matter of comb filtering between the midrange and tweeter drivers...


Regards,
Gordon.

Exactly what does that mean Gordon?

 

[GordonW]

With a planar speaker such as a Quad (which is an electrostatic speaker)- the entire surface is a radiator- the sound is coming from every point on the surface. Stacking them just makes that surface bigger.

For a speaker with separate woofers, mid-drivers and tweeters- each one of those has a point-source dispersion (sound coming from one point). When you combine multiple drivers at the same frequency, the waves interfere with each other, like rocks dropped into a pond. Some places, they add, some places, they interfere and subtract. That makes for an uneven dispersion of sound, due to different interference in different angles away from the speaker- which means that the speakers likely aren't putting out optimal response anywhere- and some locations will sound different than others, depending on your angle to the speakers.

With a speaker that is specifically designed with driver offsets for time-alignment, like a Dahlquist- these interference pattern get a lot more complicated and pronounced. It basically defeats the time alignment- there is no longer any one place, where all the drivers "focus" to the same point anymore, due to the vertical offset of the stacked speakers.

Regards,
Gordon.

 

[Blue Shadow]

Nicely explained, Gordon.

 

[swechsler]

With a planar speaker such as a Quad (which is an electrostatic speaker)- the entire surface is a radiator- the sound is coming from every point on the surface. Stacking them just makes that surface bigger.

The Quad is a planar but it's not a full range or line source, it has discrete bass and treble sections, and the tweeter is in the center, so stacking ESL-57s could indeed cause comb filtering.

 

[GordonW]

The good thing about the Quad, though, is that by being a planar- all the wavefronts originate from the same plane, at the same time. There may be some comb filtering in the upper highs, off axis- but at least, if you, as most brackets for stacked Quads allow, vertically toe them toward the center of the listening position- they can get pretty close to a uniform balance, over the area that a Quad normally has for its sweet spot. It's not like the Dahlquist, where drivers are offset horizontally AND vertically- which makes it impossible to get even one small area where a stacked pair will sum properly.

Regards,
Gordon.

 

[swechsler]

The good thing about the Quad, though, is that by being a planar- all the wavefronts originate from the same plane, at the same time.

Interesting, but wouldn't that make the sweet spot, already narrow for ESLs, even narrower in the vertical plane?

 

[GordonW]

Interesting, but wouldn't that make the sweet spot, already narrow for ESLs, even narrower in the vertical plane?

It would- but at least it would maintain width in the horizontal plane. That's the trouble with stacking Dahlquists- you get NO horizontal width to the sweet spot.

Regards,
Gordon.

 

[E.P.111]

It would- but at least it would maintain width in the horizontal plane. That's the trouble with stacking Dahlquists- you get NO horizontal width to the sweet spot.


Regards,
Gordon.

Gordon, thanks so much for your input.
Exactly the kind of explanation that I was hoping for. Understood. Regards, EPIII

 

[BigElCat]

The DQ-10s are quasi-open baffle around the mids and tweets.

I think they would work great, stacked, tweeter to tweeter, mid to mid. Maybe even reduce the original baffle area around the mid / tweets. Have a larger air gap.

 

[GordonW]

The DQ-10s are quasi-open baffle around the mids and tweets.

I think they would work great, stacked, tweeter to tweeter, mid to mid. Maybe even reduce the original baffle area around the mid / tweets. Have a larger air gap.

The only way it would remotely work, would be with two pairs of mirror-imaged Dahlquists- a right on top of a left, and a left on top of a right. That would put the drivers in as close to vertical alignment, as possible.

Regards,
Gordon..