The Quad thread

[Craig Sawyers]

I had the Gradient bases with my 63s back in the day -- worked well most of the time, though the integration never seemed to be quite seamless, and I found myself preferring the Quads on their own.

The crossover is somewhat naiive in the SW63. The dipole subs are rolled off at 18dB/oct and the ESL63's at 12dB/oct, which is never going to work. They need to be properly integrated with a +6dB/oct boost to compensate for dipole behaviour at long wavelength. They need a Linkwitz Transform to properly deal with the bottom end, and then a 2nd order L-R crossover with the ESL63.

I came across this posting -- maybe another option for a dipole sub?

Audio Dipole sub

Yes that is a good version, references Linkwitz's treatment of dipole speakers including subs, but like most of Linkwitz's recommended drivers the ones used are no longer available.

There is a good article on making the SW63 work properly here Homepage MT Audio Design and navigate through to Quad ESL tweaks. I've chatted by e-mail with this guy, and he knows his stuff.

I've got the circuit schematic for the SW63 as delivered if anyone is interested.

[penger]

I remember Monkey was asking about 9L actives and just saw this posted: Quad 9L Active Desktop Loudspeaker (Playback 30) | AVguide

[Craig Sawyers]

Did some sine wave tests with the ESL57's in preparation for designing the active crossover to the dipole subs. Microphone was a modified Panasonic WM61A (Digikey plus many other places). Flat from 10Hz to 20kHz+ and pennies each. Mod is on Linkwitz's site.

Anyway, even measured in-room at 1m they were astonishingly flat - within +/-5dB from 55Hz to 20kHz. Drops like a stone below 55Hz. But - quite a few buzzes and rattles from 300Hz and down.

Turned out to be two things - wiring behind the signal transformer in contact with right hand bass panel dust cover, and the hessian mat stuck to the rear grille sagging into contact with the bass panels. Wiring was easily sorted out by unbolting the transformer, moving foward and pulling the wiring well out of the way (tucking down the side of the transformer).

The hessian was more interesting. Originally it was stuck on with dobs of pitch/bitumen, presumably applied hot. In my case it has lost grip over the years at the top - hence the sag into the bass panels. I took the mats out of both speakers, carefully removing it from the bitumen dobs with a craft knife blade. I then hand washed them gently, since they are rather fragile (unbelievably filthy) and dried on the washing line and airing cupboard. Cleaned the rear grilles (unbelievably filthy). The hessian mat was then attached to the grille using spray carpet adhesive. I sprayed that onto the rear of the grille, and then applied the mat.

That has sorted the problem a treat, and has the added benefit that now the mat is firmly stuck over its whole area onto the grille, it damps it nicely.

Craig

[luvdunhill]

Did some sine wave tests with the ESL57's in preparation for designing the active crossover to the dipole subs. Microphone was a modified Panasonic WM61A (Digikey plus many other places). Flat from 10Hz to 20kHz+ and pennies each. Mod is on Linkwitz's site.

are you saying they're flat with compensation files that are usually provided, or without? I already know the answer, as I had a modded one calibrated

[Craig Sawyers]

are you saying they're flat with compensation files that are usually provided, or without? I already know the answer, as I had a modded one calibrated

The el cheapo WM61A (a couple of dollars/pounds each - in fact you buy ten of them and have plenty to play with) does not come with any calibration data, other than what is in the datasheet.

In any case, measuring in a listening room renders any quantitative measurement meaningless, which is why it is appropriate to use a cost effective measurement method rather than a calibration standard mike. The best you can hope for is a subjective peer at the data and look for obvious problems. I was actually more interested in the bass end since I'm building subs, and at least doing the measurement identified a few rattly/buzzy problems (now cured).

[luvdunhill]

There are a bunch of standard calibration files for the WM61A that get pretty close. They are not in fact flat from 10Hz to 20kHz+ though out of the box, that's what I was getting at

[mypasswordis]

I look forward to your progress and eventual completion of the dipole subs, and how well they integrate with the 57. Are you ever considering building a direct drive ESL amp at some point in time? Yes I realize that wouldn't work so well with the subs so I think I answered my own question.

[wgb113]

First post...just wanted to say hello. I picked a paid of 12L actives up used about a month ago and have been very pleased. I realize most of you are fans of their electrostatics but wanted to show their other speakers some love. This is my first pair of active speakers and I'm very happy with the results. After watching for some Dynaudio BM6AmkII on eBay for months I came across these on AudioGon and bit the bullet. They remind me of my first god pair of speakers, NHT SuperOnes, in the imaging and midrange department, with a more weighty low-end and cleaner highs. Since taking these pictures I've added a pair of Auralex SpeakerDudes which did make a slight improvement, and helped by angling them down slightly. For serious listening I pull them out to the front edge of the desk and use a much more comfy chair.

[The Monkey]

A fine first post. Nice setup.

[aardvark baguette]

Nice diy speaker stands too. At least I think they're diy.

I think more people here actually have dynamic quads than esl stuff. Its kind of a cult.

[Duggeh]

Quad stats are just so small tho.

[mypasswordis]

You don't think it would have anything to do with the ESLs needing a dedicated room, special amplification, costing a lot more, and being much rare, would you? Along with most of the vintage ESLs needing some sort of repair work to bring up to snuff.

Quad stats are just so small tho.

It's true. 6 ft tall min, but something like this is better:


I need to take a pic of me + my speakers. I've been saying it all along with all the 'stat headphones I've owned, and I'll say it again with my Acoustats: if you think 'stats lack bass after hearing them there is something wrong with your hearing.

[pussywillow]

First post...just wanted to say hello. I picked a paid of 12L actives up used about a month ago and have been very pleased. I realize most of you are fans of their electrostatics but wanted to show their other speakers some love. This is my first pair of active speakers and I'm very happy with the results. After watching for some Dynaudio BM6AmkII on eBay for months I came across these on AudioGon and bit the bullet. They remind me of my first god pair of speakers, NHT SuperOnes, in the imaging and midrange department, with a more weighty low-end and cleaner highs. Since taking these pictures I've added a pair of Auralex SpeakerDudes which did make a slight improvement, and helped by angling them down slightly. For serious listening I pull them out to the front edge of the desk and use a much more comfy chair.

First, welcome to head-case!

Second, and someone can correct me if I'm wrong, but currently Quad 12L actives might be the most popular speaker on head-case, meaning I think more of us own Quad 12L actives then any other speaker. I used to own them and sold them for some reason I can't remember.

Third, I also love those speaker stands, are they DIY or did you buy them somewhere? I see you have the Benchmark DAC-1, how do you like it? Its generally not appreciated around here but I've always been curious to hear one due to the high praise it receives elsewhere, the mainstream audio press in particular.

[wgb113]

Thanks everyone. To answer some questions:

1) Yes, the stands are DIY. A lot of people with desktop computer setups seem to go for the Ikea Lack shelf + Capita leg combo. My local Ikea was out of Lack shelves in both black and white (only had red) so I picked up the legs, swung by Home Depot and grabbed a 24" x 12" x 3/4" piece of oak and stained it to match the desk (wenge). At the time my heart was set on those Dynaudios.

2) I like the Benchmark. My goal with this computer-based setup was Keep It Simple and for it to sound revealing. I have always had a thing for headphones and I wanted some new ones. I also wanted an outboard DAC and a pair of active speakers. At the time I had a Cambridge Audio DacMagic in my HT setup connected between my AppleTV and Rotel Pre/Pro. That combo sounded better to me than the Arcam CD73 it replaced. When I got the itch to build a more serious 2-ch setup in the office, I got that headphone itch at the same time. I could have kept the DacMagic and bought a headphone amp but again, I wanted to keep it simple. I sold it off for $200 and a pair of Sennheiser 580s that I converted to 600s. I picked up the Benchmark DAC1 USB used on AudioGon as well. To me it sounds as nice as the DacMagic did and the headphone amp makes a noticeable improvement over every other headphone jack I have at my disposal (all standard). I picked up the AKGs shortly after and lastly the Quads.

I'm REALLY enjoying this setup at the moment. It leans to the analytical side for sure but that's what I wanted out of it. I'm debating between treating the room with DIY treatments combined with the Behringer DEQ2496. The latter is an interesting piece that would keep me entertained for a while.

Bill

[deepak]

You don't think it would have anything to do with the ESLs needing a dedicated room, special amplification, costing a lot more, and being much rare, would you? Along with most of the vintage ESLs needing some sort of repair work to bring up to snuff.



It's true. 6 ft tall min, but something like this is better:


I need to take a pic of me + my speakers. I've been saying it all along with all the 'stat headphones I've owned, and I'll say it again with my Acoustats: if you think 'stats lack bass after hearing them there is something wrong with your hearing.

The big Sound Labs have genuinely scary bass. The dealer even put on home theater bass test discs and I was mighty impressed.

I must have a pair of 945s or Ultimate PX-1. But I'm going to settle for Maggies for the time being, $33k speakers are just out of the question at the moment. But a kitty had been started the moment I heard them!

[Duggeh]

The big ones must be scary. I had a terrible bass distortion issue with my M3s, after I turned the volume up to a certain point I got this horrible rattling slappy flapping distortion which I assumed was the amp starting to dry heave.

It was the panels in my double glazing unit resonating. So now my next upgrade has to be curtains.

[spritzer]

Dynamat the windows, sunshine fucks up the mylar anyway...

[Craig Sawyers]

I look forward to your progress and eventual completion of the dipole subs, and how well they integrate with the 57. Are you ever considering building a direct drive ESL amp at some point in time? Yes I realize that wouldn't work so well with the subs so I think I answered my own question.

During measurement of the bass, and curing the various buzzing and rattling in the earlier post on this, I found out why although the imaging in most of a female voice was perfect, sibillants were skewed towards one speaker. Very careful measurement revealed that although the response of both treble panels was very close in shape and extension, one of them was between 4 and 6dB lower in output.

I'd got a pair of old-stock panels from One Thing Audio near Coventry UK to replace the burnt out ones originally in there. So I phoned them up. Yes, he said, that can happen - there is a progressive degradation of the coating on the mylar (perhaps through sunshine?) that leads to panels of different vintage having markedly different sensitivity.

So they are building me a new pair of panels, built onto original stators. They are going to charge me the difference between the price of the old panels (£60) and newly totally rebuilt ones (£85). So it will cost me only £50 extra for two new and matched high frequency panels. They should finish them in three weeks because it has to be fitted in with the work backlog. They apparently use a carbon graphite coating rather than the original polymer (or its replacement, DuPont Elvamide) because of its stability over time.

I'll report back on results.

Craig

[jinp6301]

question about the 12L actives,

are they only good for nearfield or are they good as real, put them on stands, sit on the couch, speakers?

[The Monkey]

Just get them, Jin. And find a pair for me while you're at it.