Open Baffle Desktop (!) Setup

Lowther DX3 is being run full-range. Stereo subwoofers, using Eminence Alpha 15 in a sealed cabinet stuffed to brim. 2nd order filter on the woofers internally. Good combo as both are very efficient. The Lowther's need serious EQ to sound neutral, but since this is a desktop rig there's no qualms with using PEQ on the software side. More to come later in the week.

 

WTF! Lowther DX3 as desktop speakers? As if the Fostexes weren't bright enough. Resolution must be great though, as long as you're not using too much EQ.

This looks super simple to build (at least the desktop part), like even I could probably build it.

 

yeah, OB super simple construction is great.

Resolution is excellent indeed. Better than the Fostex stuff by a fair bit. I do plan on plopping in some other drivers eventually. Particularly interested in the Alpair and Tang Band stuff as that shouldn't require heroic EQ but hopefully still has the nuance that I get with these.

The one thing about the full-range stuff is that even after you EQ the treble to "perfection" (totally flat on-axis) there's still a slight tinge or lack of cleanliness that you miss coming from a good tweeter. A good soft-dome tweeter just has a much smoother, more natural treble texture.

 

Yup, you just can't EQ these resonances away. This is one of the main reasons I will probably not get a full-range speaker.

 

I'm not sure if it's necessarily the resonances per se, but rather the uneven off-axis response. 8" woofers just aren't mean to project treble that way.

 

Yeah, that's also true, but aren't the resonances (and driver geometry, idk) also reason for the uneven off-axis response? If it was a perfect 8" driver with no resonances, I'd assume that it would just beam like crazy but without funky weird shit going on off-axis. It's probably a tiny bit more complicated than that.

Which one of the TangBand drivers are you looking at? Judging from other people's impressions, neither the TangBand nor the Alpair will be close to the Lowther resolution. There's this one big, expensive TangBand driver that's generally accepted to be pretty good that I would really like to know how it compares against stuff like the Fostex Sigma and Lowther drivers. It's very hard to find reliable impressions about that.

 

Gravitating toward the W8-2145 for low cost and high Q. High Q is better for OB situation. Weakness of Lowther in this application is very low Q, which won't help the bass extension. Why I added the subs

 

The resonances are essentially the woofer flexing at different wavelengths (inner part of the cone). If it was a "perfect" driver it should have perfect pistonic motion and not have any beaming either. Not sure what that would look like actually, and I can't do cool acoustic 3D models like Mr. Speakers so.....

 

Do you think you could get any sort of meaningful bass extension out of any 8" driver in an open baffle? Then again W8-2145 Fs is at 40Hz and Q is 0.45, which doesn't seem super high to me but much better suited compared to about 60Hz Fs and 0.24 Q for the DX3. At least the crossover to a sub should be much easier.

Yes, resonances...

I don't think that's the case. Pretty sure even a perfect piston would beam depending on its size.

 

Yup. 8" drivers start beaming at around 1,8K.

 

Lowther DX3 1m on-axis


Alpha15 Sealed 1m


White noise at listening position unEQd


White noise at listening position EQd


Current EQ settings are as follows. High-shelf could be replaced by an Lpad.