Sub woofer for Quad ESL 57s with active crossover

I have a pair of stacked quads which I adore refurbished using Sheldon Stokes brilliant book. However my listening room is very large - about 10m x 8m with 4m ceiling so that the lower bass lacks ‘punch’.
I just picked up a pair of old but good B&W 801s and wondered about pursuing an active crossover set up with their enormous drivers.
Has anyone tried anything like that.?
 
I run a pair of JL 13w7 with a set of quad ESP63, crossed over actively. Since is cross then over at around 100hz, I find stereo subs a must.

These are far audio drivers but decent ones and in a low tuned ported sub and with plenty of power the reproduce the lowest note of organ music very nicely, much better than any floor-standers I’ve owned.

If you are going to do this, go some purpose designed subwoofers rather than recycled midbasses from the B&Ws.
 
I just picked up a pair of old but good B&W 801s and wondered about pursuing an active crossover set up with their enormous drivers.
Has anyone tried anything like that.?

What you're proposing is a less typical approach, so direct experience is a longshot. As the earlier posts suggest, you'll find many different opinions about what subs work well with electrostatics. Ultimately it's your ears that decide if what you want to try is a good idea.

If you like the bass quality and quantity of the 801's in your room, a quick test seems worthwhile. If you already have an extra amp and a cheap way to cross over, I'd suggest starting there. Do an initial test with as little time and money invested as possible.

If you don't have a crossover handy, Harrison Labs FMODs are a cheap and easy way to take care of that. You can get by with a low pass on the 801's and let the ESL's run full range initially.

If you like the sound of the cheap and easy setup, you can always implement a higher quality solution later.
 
Thats a great suggestion (I didn’t know about the FMODs) thanks. I’m in no immediate hurry to find the best solution and aim to have some fun with experimenting with different set ups. I agree that the only good ‘test’ is my own ears, although even ears need a bit of education sometimes. It was only when I heard ESLs that I discovered the human voice could be reproduced so faithfully. Im also intrigued by the way a good audio setup brings out the best in poorer erslr recordings from the 40s and 50s.
 
frugal-phile™
Joined 2001
Paid Member
If you have a big room then why not add some more ESL's ;-)

attachment.php


Any added woofers should be OB.

dave
 

Attachments

  • Demis-tripleQuadsm.jpg
    Demis-tripleQuadsm.jpg
    70.9 KB · Views: 970
I own Three Pairs of ESL 57's, of which Two Pairs are in a Stacked Array.
The Bottom of the Lowest Panel is 450mm in Height from the Floor.

I have a New Design for a Frame using a Steel Plate and Plywood to produce a Side Panel.
It has a design to be a Double or Triple array.

In a Triple array the Bottom Panel will lean backwards, it will be mounted out of Vertical Plumb by 200mm (8 Inch).
The Centre Panel will be mounted Vertical.
The Top Panel will lean forwards, it will be out of Vertical Plumb by 200mm (8 inch)

My Diagram shows this will fit into a 2.4mtr (8 foot) in Height Room.

The Excess Piece of wood on the Top and Bottom of the Speaker Frame at the Rear of the Speaker will be drilled to allow the Speakers to be mounted on Cross Bars with a Fastening within the Frame.

Dampers/Isolators will be used to sit the Speaker on, these will be placed between the Speakers Rear Frame and the Cross Bar to see how the coupling affects the sound quality.

I still intend on producing a Ripole Bass to try out, and some other Bass Designs as I have 4 x 15" Eminence Drivers for this role.
 
Push Pull, Dipole or Ripole...

A great thread topic... choice for pairing speakers with particular "requirements"

I ran with an *Audio Pro B270 active sub for ~15 years on Quad ESL57 (ESL63 and LS3/5a) It was utterly seamless, with a great sense of speed, incredible dynamics and slam with dual 8" push pull drivers. I will forever be a PUSH PULL SUB WOOFER fan. *the B270's sensitivity and drive level matched these speakers well, it got out of the way of the music.

I wished that I never sold B270, would like to build one like it ~ or ~ possibly build one of GR Research *dipole* Push Pull Servo driven sub(s?) But I want to use my own amplifiers on subs. **for use on ESL57 or MG3.5r.

The RIPOLE sub as mentioned [by JohnnoG] above is pretty amazing / has held my attention for many years. *I thought* that I read it was more of a spatial / "ethereal" type of bass, not one that is known for slam or pressurizing the room... [I am curious about consensus here]

I already have multiple monster (>500 wpc MOSFET) amps built, 2 and 3 way electronic crossovers... subwoofers are next on my list...
 
saving up for something *better* ;)

Push-pull is really only useful with “cheap” woofers. The configuation is often seen with OB woofers that have even numbers of drivers each side.

dave

I get it, am with you on this point. 100%


*I also like push pull, where one voice coil is always in the magnetic field,
with linear impedance / drive... when used with "modest' power amplifiers.
as portion to the budget driven basis common to DIY efforts.


I replaced my ESL63 / B270 with something *better*
used during the late 80s and 90s

Revel Ultima Studio [admittedly, love at first sight]
then added the Sub 30 Subwoofer *sort of overkill
from 2000 - 2015 *my Audio Mart ad.

~ I am driven to "OUT DO" what is shown ~
working in the DIY build world...
 

Attachments

  • revel-ultima-sub-30.jpg
    revel-ultima-sub-30.jpg
    33.3 KB · Views: 172
Last edited:
Based on considerable experience....

I'd say only add bass if you are adding treble too,

there's no false localization on music with a XO at 130 Hz to a sub, if slope is sharp and low distortion - that will let you play Quads louder; likewise adding a tweeter might do the same by removing the need to drive high freq with the ESL amp, given the load ESLs present to amps at frequency extremes,

I never thought there was much "matching" of speakers, but a Klipshorn bass will fill the air in the whole room with clean full bass kind of resembling ESL sound.

B.
 
Last edited:
For the ESL 63 I did 2 subwoofers with infinite baffle with a Qts of 0.5 using 10" peerless SLS 830688 crossed over actively at 120 Hz 4th order making a cheap and excellent sound and allows the esl 63 to play a lot louder.

My main regret is not making a nice looking replacement box with a grill before having children killed all time for diyaudio.

All best Owen