subs for Sonus Faber Cremona M floor standing

Dear Johnnyb53: Please don't misunderstood me: I'm not telling that SF does not know how to design/build subs but specialized subs manufacturer IMHO have deeper knowledge about.

Maybe the main challenge to any sub other that goes deep on the 20hz and down is to handle its frequency range with aplomb and that's means with the same aplomb/accuracy that the main speakers and this means with low low THD distortion type.

All what we have on audio and audio systems IMHO is inside DISTORTIONS whole subject. A better quality performer system that other system is better only/mainly because has lower DISTORTIONS at each link in the audio system chains than the other.

The home audio system " enemy " ( other that each one of us it self. ) to beat has a name: Distortions, as we go lower on system overall distortions as better system quality perfromance level we achieve.

When I listen an audio home systems first target is not to hear how good it sounds but look for distortions: which kind and where.

On subs is the same we have to look ( everything the same ) for the lowest subs distortions figures.

Velodyne is my bench-mark with that glorious lower than 0.5% on THD. This measure of distortion can be achieved only because Velodyne engineering level and deep research over time where brought its servo-accelerator that sense/watch 16,000 times each second the woofer movements/behavior to avoid: guess what? yes DISTORTIONS.

Johnny, when I was searching and learning about what to choose for my system I emailed to any single subs manufaturer asking for information on performance. I asked the sub THD at 120db at 20hz, 110db and 100db and guess what? no one but Velodyne gives me that information.
All answer me and give me several information around that THD measures but the true is that no one even had on hand.

Don't trust in me: send an email to SF asking the same. Could be interesting for all to read which is the Cremona sub's THD and if you can ask for its frequency response range because in its site they don't mentioned or at least I can't find out.

Yes, Johnnyb53 we have to start to learn about distortions from a different point of view that we are accustom to.

Regards and enjoy the music,
R.

Thank you Raul. you couldn't of explained it any more eloquently. To Ebm, the Cremona M is one of the finest speakers I have had the privilege to listen to. I have heard speakers well over the 100k mark. I prefer the SF. I have always had a 15" woofer on Klipschorns so this took some getting used to. There is nothing wrong with these speakers. This is my pursuit of audio nirvana and the ability to try different pieces to see how they improve or change an existing sound. As for Johnny... Raul has said it all. I am sure SF subwoofer is exceptional. Why is it that over half the reviews out there mate the SF with a Rel sub?

12-08-11: Erictye
... I am sure SF subwoofer is exceptional. Why is it that over half the reviews out there mate the SF with a Rel sub?

Maybe because REL--like SF--is also distributed in the US by Sumiko, and until SF came up with their own sub it was the package that the distributor--Sumiko--supplied to the reviewer. Also, since REL has a full line of subs, it was relatively easy to match a sub to a given speaker line (such as a T8 to the Toy series). With that in mind, the better question might be, "Why, with REL as a sister company, did Sonus Faber take on the development and marketing costs to come up with their own Cremona M subwoofer?

Raul: For all your words you haven't told me a thing I don't already know. However, I can't buy your dismissal of a general speaker maker as having a disadvantage in subwoofer design given that any company can hire just about any designer it wants. John Curl designs electronics for Parasound. Nelson Pass has done it for Adcom. D'Agostino desgined for Aragon. Hsu designed (or consulted) on the Outlaw subwoofer designs. I have no doubt that Sonus Faber hired all the specialized help it needed to come up with a subwoofer to meet their high standards of musical coherency and seamless integration--the areas most elusive in matching subs to mains.

As for Velodyne, its accelerometer/feedback design and low advertised THD is essentially an electro-mechanical version of the negative feedback loops used in amplifier design. Feedback loops were used to excess in the "THD wars" of the late '70s receivers, and only resulted in lower numbers--not better sound--to sell more receivers.

I'm not saying Velodyne's accelerometer is an ineffective gimmick, just that it doesn't prove that it's superior to JL, REL--or Sonus Faber.

Dear Johnnyb53: I don't want that you " buy " nothing I said it. This another example: Velodyne worked in the past and designed a pair of normal speakers that they marketed for no more than two years but fail to really introduce in the speaker's market and everyone knew Velodyne as a good subwoofer manufacturer.
Believe me, is more easy to hire J.Curl or other electronics designers that a top subwoofer designer: because there is not!.

Velodyne is IMHO absolutely superior to JL or REL and maybe (I because I don't hear it yet ) to SF too.

Every sub out there makes: boom boom, my point is not that but that that boom boom can be accurate and with the lowest distortion you can achieve and these two targets are the ones that makes the difference.

Now, you have to be prepared to discern and be aware about those differences and you know what: it is not an easy task to discern on that bass frequency range, you need to be trained if not almost everything will be for you: boom boom.

Specs on subs are really important because we need to know the sub behavior under some circumstances and when we are talink of Velodyne or other top sub as the ones named here we are talking not on a " new kid on the block " but we are talking of top knowledge with patents in the product design that speaks for it self.

The subjecvt here when talking about subs is what are you looking for: boom booommm or quality level performance in your system through improving the main speakers own performance along the best you can get from subs works.

Rel, SF or JL has nothing to control the woofer behavior but the inside amps that are not enough to achieve 0.5% on THD, this is vital/crucial when you are speaking about quality.

To know if those better numbers means something you have to have first hand experiences between all those different subs, there is no other way and remember that we are not in the 70's, things already improve about and about the importance of several numbers out there in each audio link in each one audio system chain.

Of course that if you are of the people that only say: " I like it " " I like what I heard " then we have nothing to talk because you really don't care on what you are hearing and my self always care on what I'm hearing.

Johnny, I don't care about Velodyne. I take it as an example not because I own it but only to exemply the importance to inform on subs before any choice could make it.

Subs as a whole is a " new product " " a new kid in the/b " where exist a lot of misunderstanding and where we have to take care about.

Good that you already know what I posted. What I can't understand is that if you already have all the knowledge level about why disagree with no real and precise arguments.

All what I posted not came from reading here or by my imagination but by experiences a lot of experiences in different audio systems.

Don't " buy " nothing but at least give us your proved arguments. I don't care whom has reason but I like to learn and and want it because certainly could be I can be wrong and need to re-set.

Regards and enjoy the music,
R.

Raul,
I own a pair of SF Cremonas along with a REL R505 subwoofer. I would like to add a second sub, and was considering another 505, but after reading your posts I am now considering a Velodyne or 2. However, I also have the option of 2 Rel 505's along with a Velodyne SMS-1 for sub equalization. What is your experience or thoughts on this combination? I have an integrated amp, so I don't think it will be possible to roll off the bottom end of the Cremonas using the SMS-1. I would use the SMS-1 only to modify the sub output.

Thanks
Mike