Dynaudio 30W100's needing refoamed

[Mercury3]

Hi Everyone I'm new here.

I currently have four 30W100's (2 per channel) which are probably close to 25 years old. Needing refoamed. I've been debating if I should re-foam them or perhaps it's time to upgrade to something better.

I'm using them as Subwoofers X-Over 120HZ 48DB. Subs driven by Nakimichi PA-7.

I would keep my sealed box's which are very nice: 5.8 cubic foot internal/sealed. 1.5 inch's all around except front baffle 3inch's. Heavily braced. (Yes box's were a little small for two 30W100's Q approx. 1.23 used some EQ)

Anyway they served me well so I'm either going to re-foam and save a lot of money or just bite the bullet and go for something better.

Couple of choice's I was looking at which would work in my sealed box's are:

SB Acoustics SB34NRX75-6 - What I worry a little with this woofer is with two I'd be running about 3 Ohms. Might stress my ageing PA-7 to much.

Aurum Cantus AC300/75C2C 12 - Looks like a nice woofer but won't go quite as low as the SB Acoustics woofers.

I could port but would prefer to keep things simple by remaining sealed. Not set in stone though.

Any opinions/ideas appreciated!

Mark

[Djim]

Mark I did a lot of Dynaudio for studio’s and therefore seen/heard a lot of 30W100’s. Maybe these drivers could use a design upgrade from Dyn but I know what you are talking about, this typical Dyn sound. Very nice character and love these transients between 60-150Hz from this driver.

Even today these drivers are part of an international studio reference standard in their M3A and M4S systems.

So if you are pleased with the sound, just re-foam them and wait until you come across something you like even more.

[Mercury3]

Thanks yeah I agree they are pretty good woofers. I force um to go low with about 8 db boost at 22 hz another 6 at 30hz or so.

Just thinking I can proly find something that'll go lower without required eq & associated power requirments.

Sadly I fried two 30W100's when trying to drive them to hard with an Adcom amp. Not the Dynaudio's fault it was the Adcom frying that did um in.

Needless to say I am not a fan of Adcom amps.

[Djim]

We installed active M3’s with 1250watts for the low section (MC2-1250's). It never gave any problem so I wasn’t doubting your 30W100’s

[Mercury3]

Just to update, I'm gonna go ahead and refoam the 30W100's. I'm just not seeing any 12 inch woofers to replace them with that look much better. At least not with out paying a LOT of money.

[Djim]

I'm sure you wont regret it. Make sure you take time and patient to get the voice coil aligned to its right position. The rest is a piece of cake. Just let us know how it worked out!

[Mercury3]

Hey Djim (or anyone please feel free to answer) I have a quick question.

I decided to let the speaker repair place refoam them for me to be sure I don't mess it up but I have another question.

I built these subwoofers MANY years back and I just run them connected directly to my Nakamichi PA-7 via electronic crossover.

Well I've been reading a lot the last few weeks trying to learn more and some people put some kind of network across the driver's to cancel the inductance? Cap resister I believe.

While I've got them out is this something I need to do? If so can anyone tell me what to use? Again I run two 30W100's per channel in 4 ohms. I'm planing to try to cross them over a little higher too if that makes a difference. Thinking of 160 HZ for the reason of trying to limit more work out of my aging Acoustat 2 plus 2 speakers.

Any opinions appreciated.

Thanks, Mark

[Djim]

Hi Mark,

If you never have done any re-foaming yourself I can understand you want to be sure that the job will be done correctly on expensive dyn drivers.

As far your question about the network, I think you mean a network for impedance correction. In your case you are driving them active so it is not really necessary although it also depends on the amplifier. I’m not a HiFi expert so I really don’t know how your Nakamichi handles loads but your drivers aren’t the worst load for amps. Since you power them active there are no mid or high drivers on the same amp that can gain from a better impedance of your LF drivers.

About the crossover, the 30W100’s should be able to be crossed even higher then your suggested 160Hz. Actually I have seen/heard them filtered around 280Hz with a very decent definition. Personally I prefer them to be crossed below 180Hz but that’s my opinion.

Btw advice from others can be a good starting point but always trust your own ears. You have to listen to them so you decide what sounds good!

[Mercury3]

Cool thanks!

[Cirric]

Since I still love to sound of my system I have chosen to re-foam both AR-14s, replace the original magnetic fluid cooled tweeters with new ones, and re-foam my BA powered subwoofer. (Blew this playing the bombing scene from "Forrest Gump" of all things!) Never looked back. The work was done professionally.