DCM QED: Show me the light

Discussion in 'Speakers' started by ericj, Dec 5, 2007.

  1. ericj

    ericj Active Member

    I have a pair of these. Picked them up at the thrift store for $10 some weeks back. For reference, they just barely fit into the trunk of a MkIV Volkswagen.

    I can't wrap my head around what's supposed to be great about them. I hear some potential, I've seen people say room positioning is extra-important, but I'm at a loss.

    I'm in the process of remodeling my house. The main floor is a disaster area - I'm living in the basement.

    So far I've only tried them in the bedroom, which has a vinyl floor. The existing rig in there is a passable Sony HT receiver driving a pair of Boston A120's (also purchased at the thrift store) (why yes, I am single, why do you ask?). The A120's sound Pretty Decent in there.

    For some reason, the QED's Don't. They come off as harsh, and honky, and lacking in midbass.

    So, before i decide that these simply aren't for me, how do i get them to sound their best?

    I didn't actually know what they were when i saw them at the thrift store, but i could tell they weren't garbage, and i figured the tall & skinny nature of them could come in handy in a surround rig, as rear or side speakers. But they sound strange enough that i wonder if i would be better off passing them along to someone who will appreciate them more than i do.

    I realize that the vinyl floor in there isn't optimal. When the livingroom is redone, that'll be hardwood floors and a rug. Which probably also isn't optimal, but in the interim livingroom in the basement, the fronts are ADS L810's, and seem to sound ok with cement floors mostly covered by a rug.
  2. ericj

    ericj Active Member

  3. saltwater

    saltwater Super Member

    you think ya got something some people dont, happens to me all the time!
  4. Nat

    Nat AK Subscriber Subscriber

    You might try them on a regular reciever or amp -- they may be an odd load, and most HT amps really can't handle anything that dips past 4 ohms at any part of it's frequency response. The DCMs I've heard are between very nice and astonishing (for the price and size, admittedly), so I don't think you've heard them at anything like their best. Or there's something wrong.
  5. KingBubba

    KingBubba "Too Much Stuff" Subscriber

    There are not many QEDs around as they were the "real" DCM's swan song. It could be that you are getting no responses because few have them or has any experience with them. I would like to have a pair just for curiosity sake.
  6. butch4695

    butch4695 AK Subscriber Subscriber

    dont give up on those speaks , i`ve got a buddy who picked up a pair recently at GW and he has got them set up in his unfinished basement on a concrete floor and being driven by an old 40w per channel marantz receiver , can`t remember model # but they sound damn good .i would say try a different receiver if you can . good luck .
  7. jimbofish

    jimbofish for TRULY GREAT MUSIC

    I don't have any experience with either speaker, but I'd suspect the receiver hookup first. Connect to the same wires as the Bostons and hear what happens.
  8. Pickles1953

    Pickles1953 New Member

    The DCM QED is the little brother to the audiophile legend Time Windows. They use the same 6 1/2 inch woofer and dome tweeter as well as the same crossover network as the Time Window. But, where the Time Windows have the V-shaped front with drivers on each plane, the QED has the drivers mounted on the single front baffle. Both speakers use transmission line loading, and both are famous for their incredible imaging capabilities. Ericj, if your QEDs don't sound very good, and please don't take offense, I'd have to say it's because of the associated equipment being used with them. In my experience, Sony receivers have the same harsh, honky sound you describe. I can personally attest to this because I purchased a pair of Time Windows as a house warming gift for a friend of mine. He hooked them up to his existing Sony receiver and they sounded marginally OK. But, after upgrading his receiver to quality separates (a pre and power amp combo of less power than the Sony receiver) the speakers absolutely sang. If I might ask, in addition to the Sony receiver, what are you using as your source - what CD player, DVD player, or turntable/cartridge combination? This too may have a drastically detrimental effect on the QED's performance.
  9. suprpntr

    suprpntr closet vintage stereo fan

    Does anyone know if DCM Qed speakers are 8 ohm or 4? They have always been hooked up to a receiver that can handle 4ohm.
    I rather have them on my Marantz 2270.
  10. Nat

    Nat AK Subscriber Subscriber

    2270 shouldn't have any problem with them.
  11. ericj

    ericj Active Member

    Well, I admit that the Sony receiver in the bedroom is questionable. But they sounded bad with some other amps too. Including a Rotel RA-820bx.

    I don't want to get into source quality arguments. Ever. That's a road i refuse to go down. I'm not even going to mention what source I'm using, especially when discussing the overall tonality of a speaker.

    Anyhow. Since I started this thread, I've tried some other speakers on the bedroom rig. And i've come to an important conclusion:

    My bedroom is the room where fair quality speakers come to sound bad.

    It's not the amp, it's not the source, it's certainly not the cables - it's the room.

    I have a pair of Boston A120's that sound just fine in there. Really pretty decent. And probably nowhere else. I also have a pair of cruddy cheap yamaha speakers that don't sound bad in there, but sound pretty lackluster elsewhere.

    Last night i hauled the QED's into the livingroom and hooked them up to the Onkyo HT receiver that usually powers my ADS L810's (quite capably, I might add).

    They sound fine. They're not my favorite speakers, but I think I'll keep them.

    I've got a pair of Ohm Walsh 3's waiting for me in a basement in denver, so, I'm getting ready for the Battle of the Thoroughly Acceptable Vintage Speakers some time later this summer. At the moment i envision the QED's ending up as rear surrounds. I'm not sure where the L810's are going to end up, as the Walsh speakers are predicted to trounce them.

    For now, I've inverted the QED's and stacked them on top of the L810's.

    So, a final question. If i was gonna try and re-cap the crossovers in the QEDs, how would i get at them? Do i just remove the woofer? That looks like it takes some doing - it's been puttied in with some black, well, putty. Not nearly as much work as pulling the bottom cap off the speaker, though, I guess.
  12. MudPuppy176

    MudPuppy176 Banned

    That black goop is a royal PITA. Some kind of caulk/adhesive. HARD to remove without damaging the cabinet. Take it S-L-O-W.
  13. Nat

    Nat AK Subscriber Subscriber

    If they are like Time Windows (which of course they may not be), removing the bottom cap is the way to go. My memory is that the crossover is on the bottom cap, and so not easily accessible through the woofer hole, and as pointed out, getting them out is difficult. The top and bottom in the Time Windows is held on by a nut and long bolt, and you can pry the bottom off once the nut is released. The top should just stay put since its difficult to get the bolt back through the damping material if you remove it.
    As to how they sound -- if they sound consistently less than great on a variety of sources and in different rooms, then probably you simply don't like the way they sound. A recap might help, but even afterwards, you might find them underwhelming. Tastes differ.
  14. ericj

    ericj Active Member

    What I've heard them described as is "1/2 of a time window"

    Thing is, I don't see any evidence of a nut or bolt on the top or bottom pieces. Both ends look very much like they're glued on, and both have a thick bead of the black caulk that seals the drivers wedged into the angle.

    Shining a flashlight through the port (which i presume is the bottom), i don't see anything attached to the bottom plate.

    Since we're only dealing with two drivers here, I wouldn't be surprised if there's a single capacitor in there protecting the tweeter, and nothing else.
  15. middleMI

    middleMI New Member

    re: have a pair

    I have a pair of QED's. They are fantastic sounding, actually sold a pair of Time Window 1A's and kept the QED's. There is a bolt on the bottom of the speaker.
    I grew up in Detroit and remember when DCM came into it's own. I think it was the Grammaphone that carried the Time Windows, but, I'm getting old and that part may not be accurate. Anyway, wanted the Time Windows and couldn't afford them, heard about the QED's and contacted DCM. I was invited over to the owner or co-owner's condo in Ann Arbor where he brought a pair of QED's for me to hear and buy.
    Eventually traded in that pair on Time Windows.
    But, I must say, the QED's have sounded nothing less than fantastic in my space with either a Rogue Integrated or my current DK Design integrated.
    But, a definite bolt on the bottom, which needs tightening from time to time.
  16. middleMI

    middleMI New Member

    re: forgot

    Forgot to mention, my model is the QED 1A. And per the spec sheet DCM was kind enough to email me, the speakers are 8 ohm nominal, frequency range stated as 32Hz - 20kHz (no plus/minus stated)
    8 inch low frequency driver
    .75 soft plastic dome tweeter
    acoustic anti-diffraction lens
    tuned port
    recommended amp power, 10 to 200 wpc
    90db/1 watt/1 meter
  17. middleMI

    middleMI New Member

    ps. if anyone needs/wants a copy of the information on the QED's just send me your email and I'll be happy to forward.
  18. ericj

    ericj Active Member

    I'm starting to suspect that i need to post a series of pictures of my QEDs.

    There is no bolt. Your QED's may have a bolt, mine do not.

    Top and bottom, all i have is wood.

    3/4" plywood, from the look of things, with a light-brown finish. Painted dark brown on the edge. Flat, except for where the grain of the wood stands up a bit, probably due to exposure to moisture.

    Again, I am well acquainted with both the top and the bottom of my QED cabinets, and there are no bolts.

    One of them doesn't have a foam wrap at the moment because when i got it there was a big chunk missing and i had to take it off to repair a pea-sized tear in the woofer, so i can see right into the port on the bottom end of the cabinet, and there is conspicuously no bolt running from the top to the bottom of the cabinet.
  19. ericj

    ericj Active Member

    Here are both ends of one of my QED speakers.

    I leave it up to you to decide which end is which.

    Please illustrate for me (in MS Paint or similar) where the alleged bolt is.



    Here's the port. Sorry for the crap photography, but, a bolt running down the center should have reflected the flash, yes?


    Here's the woofer. Note black nail polish repair. Not my best work, but it will sound just the same and when it's behind the foam nobody will ever know it's there.


    And here is the name plate. The serial number is unfortunately impossible to photograph.


    fwiw the serial number is 5469.
  20. Goodwill_HiFi

    Goodwill_HiFi Super Member

    I just went downstairs to look at my QED's on my storage shelf. I don't have any bolts either. Mine are much later too, something like 108xxx, for the serial number.

    Take a real close look at the brown edges and see if you can see end-grain. The tops and bottoms of my QED's are solid oak..... yes solid, not veneered. I can see the end grain, and that the tops and bottoms are made of several narrow boards that have been glued on edge. Yours definitely aren't oak, but that second picture looks a lot like some kind of conifer..... pine, fir, hemlock, etc.

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