Replacement for Dynaudio 21W54 ?

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Hi,

I'm looking for a suitable replacement for a Dynaudio 21W54 bass driver. They apparently ceased manufacture a few years back and its been suggested the Scan-speak 21W/8555-01 might be suitable.

Has anyone identified a good replacement for those drivers? Or perhaps any useful perspectives on the issue?

Thanks in advance -- Trevor :confused:
 
Hi
Not 100% sure for woofers, but tweeters can repaired at Madisound.com. Best bet is call Madisound for advice either on repair or replacement. They may advise you to send the part to the factory in Denmark along with some authorization. I know on the Dynaudio website they say they support their discontinued products.
 
Hi Fellows,

Thanks for your responses!

First I checked with Wilson Audio and they quoted a retail price of $400 per driver (presumabley for whatever they use these days -- can't be the 21W54). Then I spoke with Madisound regarding a possible replacement and they suggested the Scan-speak mentioned above.

I had four drivers that needed new surrounds and sent them off for repair last week (Millersound in PA). However, it's always possible something could happen and new drivers could be needed (had to replace four once before do to a preamp problem -- fed DC to an amplifier and fried the coils).

I saw the surround kits at SpeakerBits while I was searching for a possible replacement driver. However, HiFiSound is new to me. I guess I would have to send them an email asking if they could suggest a replacement driver. The list of driver suppliers reminds me of Madisound and Solen's in Canada.

Thanks -- I'll see what I learn from HiFiSound.

-- Trevor :xeye:
 
Waking up an old thread.
I need to refoam four Dynaudio 21W54 woofers, but these days, many repair shops have closed or stopped doing repairs. Due to these not having dust covers, it is reported that centering them correctly after refoaming can only done by few and the cost involved sizable.

After all these years, is there no 8" woofer replacement that is high sensitivity (21W54 is 92dB, 8 ohms) and able to replace the Dynaudio?
 
It is not a difficult job to refoam a driver, just gotta be careful not to pull the surround on either side. I have done the same for my 24W75's for the first time in my life, with success. I have a 3 Hz sine wave test signal to check for rubbing of the voice coil and theoretically if it did rub, you could set the surround straight while the glue is still wet.
There is Seas ca22rny that could perhaps meet your criteria to replace the 21w's. I would still first try refoaming.
 
It is not a difficult job to refoam a driver, just gotta be careful not to pull the surround on either side. I have done the same for my 24W75's for the first time in my life, with success. I have a 3 Hz sine wave test signal to check for rubbing of the voice coil and theoretically if it did rub, you could set the surround straight while the glue is still wet.
There is Seas ca22rny that could perhaps meet your criteria to replace the 21w's. I would still first try refoaming.

Madisound suggested Seas U22REX as 21W54 replacement. Its higher sensitivity at 90.5 dB is helpful but doesn't match 21W54's 92 dB/8 Ohms. Sensitivity is on the important side, as the top mid/tweet module is 95dB/7 Ohm, via active crossover to bass box.
Bass box uses two Dynaudio 21W54 (8 ohm) woofers mounted on front of box, which is rectangular standing up tall LxWxD 25"x13"x18". Vent tube is 2" diameter, 3" long.

I would like to avoid foam surrounds, Seas CA22RNY page states it uses rubber surrounds, but I can't tell if Seas U22REX uses foam or rubber?

Seas U22REX/P-SL (H1659-08) 8" Curv Cone Woofer: Madisound Speaker Components

Seas H1471 (CA22RNY) 8" Paper Cone


I did find out Watkins Audio still refoams Dynaudio, although the cost will be basically what U22REX costs new.

BTW, where can one get 3Hz sine wave?
 
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Seas u22rex is likely of the same surround as ca22rny and surely on the photos they look identical to me. So, if I understood correctly, Watkins charges 150 bucks for the refoam job, including parts, while the kit only is being offered at Simply Speakers ($44.95), The Speaker Exchange($35) and PE($33.98)?

Test signal you can find in REW measurement suite (signal generator), mine was within Audiomatica Clio system.
 
Dynaudio 21W54 doesn't have 92dB/W/m. More like 88dB. Simple calculation will tell you that. It maybe reaches 92dB at 2kHz peak but it is hardly that sensitivity from 200-1000Hz which will ultimately limit the sensitivity of the finished loudspeaker.
 
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So, if I understood correctly, Watkins charges 150 bucks for the refoam job, including parts, while the kit only is being offered at Simply Speakers ($44.95), The Speaker Exchange($35) and PE($33.98)?

I'm thinking net cost to me, which would include shipping back to me.
Quote was $230.00/pair (two woofers) plus $24-$28 return shipping(pair).
For my net cost, another shipping from myself to them is extra, so net cost is similar to if I just order the Seas woofer.

Between u22rex and ca22rny, which would *sound* better in bass from 140 Hz and down, crossed over at 18dB slope?

P.S. As far as Dynaudio quoted sensitivity of 92dB being much lower in bass, it looks to be the same situation for Seas woofers as well, i.e. U22rex is quoted as 90.5 dB sensitive, but the bass range looks MUCH lower :(

SeasU22rexFreq by drjlo2, on Flickr

CA22rny

Seasca22rnyFreq by drjlo2, on Flickr
 
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Standard spl calculation based on tsp for the 21W54 gives 90 dB/2.83V and for other two Seas about 92dB/2.83V. The difference in presenting measured data exist because Seas measures in a 21 sealed cabinet, free space (baffle step loss of spl) and Dynaudio probably on infinite baffle.
 
90dB/2.83V/m is essentially 88,4dB/W/m for TS provided by Dynaudio for 21W54. Anyway, not even close to published 92dB/W/m.

Seas measures TS for 8" woofers on na infinite baffle per IEC standard, as can be seen in every one of their TS parameter tables.
 
.......

Between u22rex and ca22rny, which would *sound* better in bass from 140 Hz and down, crossed over at 18dB slope?

P.S. As far as Dynaudio quoted sensitivity of 92dB being much lower in bass, it looks to be the same situation for Seas woofers as well, i.e. U22rex is quoted as 90.5 dB sensitive, but the bass range looks MUCH lower


It is lower in Seas woofers because they have measured frequency response in a real cabinet with dimensions usually used by people for 8" woofers so everyone would be able to see the baffle step effect and what to expect out of that woofer in real world. They do specify sensitivity derived from infinite baffle so there are no discrepancies really, you just have to know what to look at and where.

As for your loudspeaker, i'd probably use 2 x U22REX in your cabinet (i've calculated roughly 60 litres neto volume for 2 woofers from your external dimensions). It should go a bit lower than 2 x 22RNY in that same volume with that tuning. Since it is for bass, plastic cones will be just fine.
 
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As for your loudspeaker, i'd probably use 2 x U22REX in your cabinet (i've calculated roughly 60 litres neto volume for 2 woofers from your external dimensions). It should go a bit lower than 2 x 22RNY in that same volume with that tuning. Since it is for bass, plastic cones will be just fine.

Ordered Seas U22REX x4. Madisound free shipping made decision easier.
I mean, there must have been at least some advances in woofer design since Dynaudio 21W54 was introduced, what >15 years ago?
 
After some break-in, the Seas U22REX are doing an admirable job in this box. However, it is obvious the Dynaudio 21W54 is a better built unit with sturdier basket, larger magnets, more solid connector tabs, etc. Both do a good job with most music, but when music with violent bass is played loud, Dynaudio digs harder with more authority.

SeasU22REX2 by drjlo2, on Flickr
 
It was quite expensive whan it came out so no surprise about that, especially compared to Seas Prestige. With some 8" from Scan Speak (classic or revelator series) or SBacoustics (SB23NBAC or SB23NRXC) it would be quite different story. When ever i hold 30W100 in my hands i always have a feeling that it is some modern woofer.

Your cabinets look great :)
 
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