From LS3/5A to Continuum in 40 years

In the 1970s I built a pair of LS/5A clones(they weren't called clones then) using a kit from Wilmslow Audio, or maybe Falcon Acoustics. I have forgotten which.
That was the serious start of my interest in diy audio. I had previously dabbled with full range drivers in concrete pipes and other fun experiments.

I met with Arthur Radford in the early 1980s and bought his drivers and x-over and built his TL speakers. The LS3/5As were sold to a friend and the TLs went to my son, eventually.

In 1991 I bought my first commercial speakers, Apogee Centaurs, which I still have.

When I retired, I pursued the diy hobby rather vigorously, mostly because I enjoy woodwork and have seen quite a few home brewed designs leave the workshop, usually with active x-overs. Also built a smattering of other folks designs such as TABAQ, Frugelhorns and some OBs.

However the speakers I now have in my somewhat small music room and have been there uninterrupted for over 3 months continuous use and, I believe, are the most musically satisfying speakers I have ever owned, and will probably remain there are a pair of Jeff Bagby Continuums with two Ripole subs actively crossed with a minidsp.
I took a few liberties with the cabinets which are made from walnut with 1" thick leather covered baffles and front mounted drivers.
Thank, Jeff.
These little jewels beat the socks off everything I have built to date.
Picture attached.

Peter
 

Attachments

  • image.jpg
    image.jpg
    381.8 KB · Views: 868
Erik.....The speaker was placed close to the wall only to reduce the flash shadow. They are normally 24" from the front wall for listening. No room treatment added, other than 50% floor is carpeted and a soft sofa and recliner.
I have a 30 degree sloped ceiling from left to right and the right speaker required 5db boost at 60hz to closely match the left one. This was done prior to introducing the two subs. Subs are located between the speakers against the wall and crossed at 80hz LR4. I'm toying with the idea of lowering that to 60Hz.
 

eriksquires

Member
2013-05-10 4:11 pm
So phase matters. the typical thxx crossover is a sealed satellite at 80 hz with 2nd order active high pass and 4th order active low pass to the sub. with the appropriate delay this arrangement can give you an ideal lr4 crossover. doing k
Lr4 entirely in an active stage doesnt result in an lr4 electroacoustically. put your speakers back where you like them and examine the low pass roll off. treat the sub and satellites as part of a single speaker and crossover for the most accurate integration.

Also, eq the sub! Especially look for big peaks to clip.
 
The Continuum is a great design that seems to get rave reviews. I have yet to see distortion measurements from them - has anyone seen such measurements? I have used the AC130F1 in a similar small sealed cabinet (they have quite a large Vas and prefer larger cabinets) and the harmonic distortion just goes through the roof below 150Hz. These drivers are very smooth and flat in response but don't do well in small sealed cabinets. At lower SPL's they work quite well in a transient perfect first order XO:

http://www.diyaudio.com/forums/full-range/280331-fr58ex-ac130f1-micro-fast-3.html#post4466062

506395d1443420751-fr58ex-ac130f1-micro-fast-fr58ex-ac130f1-fast-pcd-assist-xo.png


506397d1443420751-fr58ex-ac130f1-micro-fast-fr58ex-ac130f1-fast-pcd-assist-ir-sr.png


506447d1443446626-fr58ex-ac130f1-micro-fast-diffraction-control-square-scotchbrite.jpg
 
Last edited:
The woofer as tested by Zaph is probably an open baffle reference IEC standard? It has no distortion issues in the open - I have same nice result. It's when you put it in a sealed box. I tried 4 samples all but one has issues - manufacturer said the one with lower distortion is the "outlier" and others were normal. I am talking 6% HD at 80Hz with only 90dB at 1m. The outlier had 3% HD at same setting.

One other thing: the manufacturer specs for TS are way over rated. Consistently I was getting Qts much higher around 0.5 (vs 0.3 something) and fs was higher. You are best off not to trust the values of designing a speaker that requires carefully known TS parameters (vented alignment).
 
Last edited:
Hi,

Curious result of putting it in a sealed box, I wonder why.
FWIW Zaph measured Qts=0.68, Fs=52Hz, Vas=11L.
But that was ten years ago ....

Sadly the full write up of the Continuum has been removed
from the site. It was a good read, but said things that the
sellers probably prefer not to be said about bass alignment.

rgds, sreten.
 

eriksquires

Member
2013-05-10 4:11 pm
Regarding distortion in the lower regions; I prefer (subjectively) the tight bass of my scan 15/4531G and Usher 8945A but I find the AC130 to be tighter than a Peerless 830883 and my Energy 22 Conn so I doubt the distortion is too bad but like I say That's entirely subjective.


Interesting. Im using 18/4531 and Peerless 830991. Both pprted. I find the scanspeak much warmeIr, but deeper. Not the same speakers otherwise but I did attempt to match the same listening curve.
 
The Continuum is a great design that seems to get rave reviews. I have yet to see distortion measurements from them - has anyone seen such measurements?

I was at Jeff's house listening to his speakers, and he pulled out the Omnimic on the spot and measured the HD of the Continuum. It has very low HD from about 100-20k, IIRC.

Later,
Wolf
 
Not a measurement but a comment from Jeff Bagby answering a query comparing the Piccolos vs Continuums.

The Continuums came first, so when I first design the Piccolos I voiced them head to head with the Continuums. As a result, their frequency response is fairly similar, they are especially close above 600Hz. Below 600Hz the Continuum has a bit of a dip at 350Hz to match the LS3/5a, whereas the Piccolo is flatter in this region. There are differences down lower too. The Continuum is sealed, but I didn't care as much for the Piccolo sealed, so I went vented on it. The result is that the Piccolo extends to about 53Hz and the F3 of the Continuum is 70Hz. Running full-range without a subwoofer the Piccolo sounds more extended and more balanced.

Now, so far all of this appears to favor the Piccolo, but the Continuum still sounds "better" to me in some key ways. The biggest difference that favors the Continuum is in the area of distortion. The Continuum has the lowest distortion I have ever measured in any of my speakers from 100Hz up and all distortion components are exceptionally linear. The bass distortion of the Continuum at 100Hz is 15dB lower than the Piccolo's and it remains lower all the way into the tweeter range. As highly regarded as the SB drivers are, and rightly so, the drivers in the Continuum are a bit better in terms of non-linear distortion and I think this is part of the reason the Continuum resolves detail as well as it does. The funny thing is that I wasn't even tinking of this when I built them, it just worked out this way.

In summary, running full-range the Piccolo sound extremely balanced and is an exception small speaker for someone who is just looking for a small wide-range speaker for a small system. It sounds bigger than it is. However, if you are running a subwoofer than my Continuum is one of the best I have ever listened to. Period.

There you go.
Jeff
 

eriksquires

Member
2013-05-10 4:11 pm
I ttried looking up measurements for the LS3/5a but found so many versions, few of which seemed neutral that my head spun. I wonder if there is any Jeff tthought of as the reference. The docs for the continuum on the other hand make it seem like a neutral speaker. i clearly missed the connection.

Best,

Erik