Monacor corbon fiber cones - Experiences sought

[Henrik Juhl]

Hi,

Does anyone have hands-on experience with the Monacor (Number one) carbon cones?

I'm especially interested in the (sub)woofer unit SPH-300CTC (Link: http://www.monacor.com/int/en/produk...pr=EN&typ=full)

My primary concern is whether the FR is really so smooth and extended as this somewhat simplistic response diagram of Monacors web would leave me to believe?

I considering using 2 nos. drivers (Left+Right) in an equalized (Linkwitz/Grainer) closed box (50-70 Liter) with a 150-200 Hz 12 db/octave (2nd order) XO point. Many other 'dedicated' subwoofers seems to have nasty breakups in the 500 Hz range calling for steeper slopes, which I'm hoping to avoid.

Possible/advisable ??? - or just plain old inaccurate data from Monacor combined with wishful thinking on my behalf??

Your thoughts are most welcome. Any other suggestions for 12" woofers that would be up to this daunting task?

[454Casull]

I believe that drivers with rigid diaphragms typically exhibit very smooth response up until the first breakup mode (the response then gets all messed up) - but that response graph looks like it's made of straight lines... However, the thickness of the lines can hide some minor irregularities, but even so, it looks like it's a bit smoothed out.

Examples of rigid driver responses (these are completely unmodified):

SEAS W18E
http://ldsg.snippets.org/graphics/seas/e0018fr+imp.jpg

SEAS W15CY
http://ldsg.snippets.org/graphics/seas/e0015fr+imp.jpg

I still don't understand why they don't use an infinite baffle to test their drivers. Sure, it might be indicative of real-life use without BSC, but who would listen to a response like that?

[rcavictim]

Corbon fiber cones are made from Corbonite, a very powerful reactionary susbstance discovered on an early Star Trek episode. While using speakers manufactured with such cones be very careful not to exceed Xmax or you could take out a large portion of the neighborhood in which you live.

[Henrik Juhl]

ROFL

Mind you - I got it right second time around................

PS: How does one edit the subject line

[validator]

Henrik,

I use Monacor SPH-275C and I'm quite pleased with this woofers. Sometimes they have to act as subwoofers and sometimes as bass support up to 400Hz for my small fullrange drivers.

Monacor in general has a good value/money ratio!

Regards
Thorsten

[rcavictim]

Hi Henrik,

Yes indeed you did. The moderators are the gatekeepers and on these forums IMO the authors of posts are not given sufficient time to edit their posts. This can be a real big problem when the site becomes unavailable due to unknown difficulties as happened to me recently and I was not aware that I had successfully submitted a post which I was still working on. When I got back into the site later in the day my incorrect post was there posted and I was frozen out from making changes or deleting it. Moderators please consider taking the 30 minute edit time limit off and making it unlimited. What harm can this do? If someone makes a change that is unnacceptable or rude they will be reported as now and you can still deal with them, as now.

As for my post here about Corbonite, I was taking literary lisence for the joke. The Star Trek episode to which I referred was actually called "The Corbomite Manouver" if I remember correctly. "No not chess Mr. Spock...poker!"

[Henrik Juhl]

Originally posted by 454Casull
I believe that drivers with rigid diaphragms typically exhibit very smooth response up until the first breakup mode

Thanks 454Casull,

I think you are right in assuming some 'smoothing' has been applied. Too much for my taste, that is.

Working along the assumption that they are 'useable' up to their first break-up (around 1.3 KHz) I gues I should rephrase my question to:

How trustworthy are FR curves (and TS data) published by Monacor in general? - Any comments from those who have made measurements of Monacor drivers (validator ??)

Based on the published parameters I would tend to agree with validator that they seem good value for money.

Any suggestions to what other drivers to consider for the job at hand ? (as outlined in my first post)

[Dr.EM]

Sorry to revive such an old thread .

Validator, I am interested in the SPH-275C driver but can't find a huge amount about it. What enclosure type are you using? It seems ideal for TL and could give some excellent results I hope. Do you have pics of yours? How is the excursion, it sounds good at +/-6mm, is that accurate?

[validator]

Good morning,

I still have the SPH-275C as subwoofers. I used the Monacor recommended design = 55 liters reflex. 6mm Xmax is correct.

In this thread you will see a picture. The "round stuff" on top is just decoration.

http://www.diyaudio.com/forums/showt...79#post1260479

Regards
Thorsten

[Dr.EM]

Many thanks for that

Looks like the mounting ring is just metal? I hoped it was but had seen another picture of it with raised cardboard around the mounting ring. Any ideas how deep it goes in that enclosure? Since you say they are used as subs I take it they go pretty low, and you mentioned earlier that they go up to 400hz quite easily; should be good for a 3 way as woofers crossed around 250hz