I recently came across a pair of these DIY enclosures advertised with Zenith drivers. The drivers had a similar look, but were actually not Zenith and sounded ok, not great. I then bought a pair with date code 49CZ860. There are 2 versions with alnico magnets, but I think they sound same. I listened to the bare speakers for 5 hours, and thought they had a lot of potential. Then I placed them in the cabinets, man they sounded amazing. Mids were great, soundstage crazy. Bass was not deep, but present. Everything was more composed. By the way, I'm driving them with a SET 45. If you have a pair of these speakers, you owe it yourself to put them in a cabinet. If anyone is interested, here are the measurements:
Height=19.75 inches
Width=17.75 inches
Depth=9.5 inches
Port= 12 x 3 inches
I don't think these speakers are fuzzy when it comes to the size of the enclosure. I would love to make a taller one so the drivers are at ear level. Maybe with an active sub to help the bottom. I will be a happy camper.
Height=19.75 inches
Width=17.75 inches
Depth=9.5 inches
Port= 12 x 3 inches
I don't think these speakers are fuzzy when it comes to the size of the enclosure. I would love to make a taller one so the drivers are at ear level. Maybe with an active sub to help the bottom. I will be a happy camper.
I have these drivers. Instead of going the usual pine board open baffle route, I ordered some finished dining tables for these Zenith drivers. Still..I doubt they'll be anywhere near my DIY horn setup, but we shall see..
I didn't want to deal with the usual 3/4" plywood, finishing the wood, etc, and I found these dining table and bench combo on sale for $50! (one table and two bench chairs). The tables measure 3/4" thickness already came braced around the edges. I think I will attach one bench on side as "wing."
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Can't beat $50. I've imagined night stands can be nice speakers enclosures with a bit of work. Has anyone try?
This little OB project keeps growing and gave me an excuse to finally order some JBL 077 crystal slot tweeters 😎 If they don't work out for the OB, I have horn projects waiting for them..
Zenith 49CZ is ~96dB sensitive, and my newly-arrived JBL 077 prism tweeters are 105dB sensitive. I usually hate to pad down a tweeter that much, and I need to figure out how and where to mount the JBL on the Zenith open baffle..
In the meanwhile, I mounted the 077 on top of my Altec horns (with Radian CD), and 077 is about 4-5 dB shy of the horn. Such is life...
0206251606_HDR_1738899383143 by drjlo2, on Flickr
In the meanwhile, I mounted the 077 on top of my Altec horns (with Radian CD), and 077 is about 4-5 dB shy of the horn. Such is life...
0206251606_HDR_1738899383143 by drjlo2, on FlickrHow do you know the Zenith is 96dB? Please share the specs? I don't think they need a tweeter at all.
Somebody DATS tested the Zenith and got T/S parameters:
https://hifihaven.org/index.php?threads/tested-t-s-parameters-for-zenith-49cz852.5515/
https://hifihaven.org/index.php?threads/tested-t-s-parameters-for-zenith-49cz852.5515/
So how to use this Qts1.67 "852" if space-constrained? Say max volume=Vas70L sealed above 120hz, vs OB above 200hz?
I actually have two pairs 12" Rola USA; there's a pair Zenith "looker" available for what both Rola pairs together cost.... Are they all comparable anyway?
Extracted from link @drjlo thanks.
(J. Frum)
Re: 5.85 ohms
Fs: 84.79 Hz
Qts: 1.67
Qes: 1.86
Qms: 16.11
Le: .26 mH
Mms: 21.14 g
Vas: 2.6 cu. ft.
BL: 5.92 Tm
Dia: 10.5"
Sensitivity: 95.81 db/w
I actually have two pairs 12" Rola USA; there's a pair Zenith "looker" available for what both Rola pairs together cost.... Are they all comparable anyway?
Extracted from link @drjlo thanks.
(J. Frum)
Re: 5.85 ohms
Fs: 84.79 Hz
Qts: 1.67
Qes: 1.86
Qms: 16.11
Le: .26 mH
Mms: 21.14 g
Vas: 2.6 cu. ft.
BL: 5.92 Tm
Dia: 10.5"
Sensitivity: 95.81 db/w
So with a Vas of 2.6 cu ft., does it mean it would do better in a smaller enclosure than a large one? I would love to try it in a 100-150 liter box. Here's a plan for the Lii Song Fast 12 I'm interested in:
I pulled the trigger on the 49CZ852 so will be experimenting in due time. The closest I have in terms of TS-param is actally 6x9 car woofer Infinity Kappa 693c aka JBL Stadium 962cf (some permutation of those letters). Time to learn to use them properly.
p.s. idlefish market, seller sent videoclips both music and each naked-driver tone-sweep, useful range 60hz-14khz (I can only hear 12.5k sinewave), some 50hz and 15khz.
Listening now after a quick tone sweep by ear. 49CZ852 placed atop 25L steel can. Bass extension not bad (still loosening up), should do 40s vented or fine as is, 50s small sealed cab. Fairly obvious hump 2-5khz needs taming along with BSC. Then maybe very high frequency would show a bit better. Let run awhile.
@wchang
Excuse my ignorance, but what apmplifier are you using for these?
Lately I am playing with variable impedance amps, and (again) found that fullrange speakers like this one sound better with a high output impedance amp (20 ohms or so).
Then, it is fairly easy to passively apply some EQ (hint: Read the article by Nelson Pass on fullrange speakers and transconfuctance amps)
Excuse my ignorance, but what apmplifier are you using for these?
Lately I am playing with variable impedance amps, and (again) found that fullrange speakers like this one sound better with a high output impedance amp (20 ohms or so).
Then, it is fairly easy to passively apply some EQ (hint: Read the article by Nelson Pass on fullrange speakers and transconfuctance amps)
Thanks @Vix for reminding me of Papa's current-source amplifier paper... 'been a dozen years. For diy I generally use sets of upgraded TPA3221-on-steroids-bridged (the one recommended on diyaudio forum) with very heavy-duty PSU. If I needed 1dB-stepped attenuator for balancing I have single-3221 set and also very good TA2024 pairs. They are neutral, robust, and not finicky. Of course I have amps of many types, just not current-source. I'm in Beijing so would have to semi-diy one.... Since none of my fullrange drivers are "perfect" stand-alone as is (closest maybe Supravox TLonken), the typical up-tilt response can be mitigated at the same time, if I felt the need. Looking again at all the charts in the paper, very enticing indeed.
How I'm re-running them in. Getting better and better. Best realism for solo keyboard is to listen as if it were one of a pair in equilateral triangle with me (30° to one side); I can look straight ahead, or give it a sidelong glance without turning my head, or close my eyes -- image floats above and beyond the omni isobaric with HF booster over a steel can.
Attachments
0220251622 by drjlo2, on FlickrI bought a pair of Goldwood GW-1558 15" woofers for this project, but I was able to resist the urge to add everything to the baffle, in order to test the simplest possible single-driver, crossoverless concept. Sounds encouraging so far...