AVS › AVS Forum › Audio › DIY Speakers and Subs › 21" Driver showdown, my RCF LF21N451 arrived today.
New Posts  All Forums:Forum Nav:

21" Driver showdown, my RCF LF21N451 arrived today.

post #1 of 37
7/14/12 at 11:26am
Thread Starter 
I now have a B&C 21SW152, an 18Sound 21LW1400 and RCF LF21N451. I plan on taking some measurements and subjective listening to decide which driver to use in an array of 4.

Pics incoming.

Initial impression of the RCF is that there is a TON of voice coil visible through extensive venting, the suspension has low compliance out of the box similar to the B&C, and the thing is unbelievably light for its size. Hopefully the specs are accurate and the performance is as badass as the specs would indicate.

This will be fun.
Reply
Reply

AVS Top Picks

post #2 of 37
7/14/12 at 2:23pm
neat!

just be sure to e.q. them the same before the subjective listening or you may just be hearing the native frequency response...and nothing more, but you know that...

lurking this one for sure.
Reply
Reply
post #3 of 37
7/14/12 at 4:25pm
Ahhh, finally got it! Yes. smile.gif

Should be a fun comparison. Let us know how they sound.
Reply
Reply
post #4 of 37
7/14/12 at 5:42pm
Thread Starter 
Here is all 3 together:

450
450

18Sound Magnet detail:
450

B&C magnet detail:
450

RCF magnet detail(HUGE vents):
450

18Sound Cone detail:
450

B&C cone detail:
450

RCF cone detail:
450


I like this little plaque on the basket of the RCF, identifies it exactly:
450


18Sound and B&C stacked next to a Zv3 18 and pair of B&C 8s. The RCF is mounted and running in the 8.6 cube box underneath, directly behind my computer chair:
450


Thus far the RCF looks, feels, and sounds the best of the three even without break in. I have been going back and forth between the B&C and 18Sound in this enclosure for a few weeks now trying to asses the subjective sound quality. The 18Sound seems to lack attack and pitch, seems very one note wonder after 2 weeks of listening. Swapping to the B&C made a significant improvement in transient response, and the RCF so far is the best of the three. I would attribute this to the 18Sound liking a bigger box, the B&C having such a low compliance suspension, and the RCF being a proper balance. The B&C and 18Sound both feature straight profile ribbed cones, while the RCF is a curvilinear profile made of unpressed pulp. The RCF is also the only one of the three that has insulated tinsel leads. The spider diameter is similar between the RCF and B&C, while the 18Sound is quite small in comparison.

I was hot on the 18Sound because of how it measured so flat, but the raw response was deceiving and after further listening the character of the driver came out. It measures flat but seems to smear the time domain more than the other two drivers. I have the RCF loaded and plan to remeasure the big 10 cube cabs with all three drivers. The cabinet design was originally centered around the RCF, so it will be interesting to see how it measures. I also want to beat on it and see how long it takes to get it out of shape.
Reply
Reply
post #5 of 37
7/14/12 at 6:19pm
Two questions please:
- what bandwidth are you using these drivers over?
- taken any measurements?
Reply
Reply
post #6 of 37
7/14/12 at 6:33pm
you better provide some measurements or purchase some fire fighting gear with those comments...;-)
Reply
Reply
post #7 of 37
7/14/12 at 10:25pm
Thread Starter 
Quote:
Originally Posted by A9X-308 View Post

what bandwidth are you using these drivers over?

That decision will be made soon depending on some simulations and measurements. I currently have a couple of different angles to attack my subbass.

Most likely there will be 6 Sealed Zv3 18s running 0 to ~35, and the 21s running ~35 up to ~300 depending on how high they reproduce cleanly and with good dispersion. I have a midrange cabinet that is flat from 200-2k, so the 21s may become the kickbins. The big pro drivers run out of displacement for the super low stuff, and a ported cabinet for that bandwidth is just too big to be portable so even though a sealed cabinet is less efficient, there will be less risk of damage and more output than an unloaded vented alignment.

I have a cabinet designed for the Zv3, and a driver to test with. I may however be revising it to match the form factor of the 21 cabinet that is another decision yet to be made.


Quote:
Originally Posted by A9X-308 View Post

taken any measurements?


Only the ones contained in this thread, none of the RCF yet:

http://www.avsforum.com/t/1412302/graph-overload-5-drivers-zv3-21lw1400-21sw152-lms-r12-sa12-4-cabinets/0_50
Reply
Reply
post #8 of 37
7/14/12 at 11:24pm
What are you doing with those BC 8's?

I have always wondered about the 21 comparisons and glad someone could do it. I love the BC speakers but have been wanting to try the RCF for a while now also. Wii you seem to go through drivers like crazy. You and Ricci must have a hundred plus drivers. Lucky

.
Reply
Reply
post #9 of 37
7/15/12 at 1:51am
Quote:
Originally Posted by WiSounds View Post

That decision will be made soon depending on some simulations and measurements. I currently have a couple of different angles to attack my subbass.
Most likely there will be 6 Sealed Zv3 18s running 0 to ~35, and the 21s running ~35 up to ~300 depending on how high they reproduce cleanly and with good dispersion. I have a midrange cabinet that is flat from 200-2k, so the 21s may become the kickbins. The big pro drivers run out of displacement for the super low stuff, and a ported cabinet for that bandwidth is just too big to be portable so even though a sealed cabinet is less efficient, there will be less risk of damage and more output than an unloaded vented alignment.
I have a cabinet designed for the Zv3, and a driver to test with. I may however be revising it to match the form factor of the 21 cabinet that is another decision yet to be made.
Only the ones contained in this thread, none of the RCF yet:
http://www.avsforum.com/t/1412302/graph-overload-5-drivers-zv3-21lw1400-21sw152-lms-r12-sa12-4-cabinets/0_50

Pimp. Mega pimp.
Reply
Reply
post #10 of 37
7/15/12 at 6:22am
Thread Starter 
Quote:
Originally Posted by chrapladm View Post

What are you doing with those BC 8's?

They are 8MDN51-8, I have 4 of them, and have been trying to sell them as my mids are now dual 10s.
Reply
Reply
post #11 of 37
7/15/12 at 8:13am
PM sent
Reply
Reply
post #12 of 37
7/15/12 at 9:28pm
Wi,

I know we have gone over bandwidth needs for a long time for the genres you mainly play, but please take a listen to "Project X". All of the content in this graph is from the music in the film...peak vs avg:

378

17-32 Hz boosted, correlating to an octave below a 34-64Hz fundamental (the main low bass freqs in most genres)

Amazing effect. They essentially take the lowest octave of the music in the film and run a subharmonic generator and boost the 1st subharmonic by about 6-10dB. It is something else, and something you could offer that no one else can match, hardly any pro sound rigs can dig this low. Maybe a few Alpinegeists (sp?) for ULF support??

JSS
Reply
Reply
post #13 of 37
7/15/12 at 9:39pm
what is project x?

that spectral content does not look like anything that i have seen in any music anywhere.

it has a 25db rise at 25hz relative to the midrange in the average.

normally, it would be the other way around.

metallica: whiskey in the jar, for example.

375

wi, it would seem that you would get the most bang for the weight by dumping the sundowns and doubling up on the rcfs.

6 cubic footers tuned to 28hz. how much content are you running below 25hz that makes it worth the give back of the additional rcf cabs?
Edited by LTD02 - 7/15/12 at 10:08pm
Reply
Reply
post #14 of 37
7/15/12 at 9:53pm
John....Project X is a party movie that recently came out.

http://www.imdb.com/title/tt1636826/
Reply
Reply
post #15 of 37
7/15/12 at 10:25pm
thanks scott, i'm behind the times on such things.
Reply
Reply
post #16 of 37
7/15/12 at 10:27pm
Project X seems like the Krypto EQ curve.

Dual 10's wow. I Hpassed the 8's at 300hz and with a pair I can not feed them enough watts to hit Xmax. Probably melt the driver first and you have dual tens now .....must be killer. Are you crossing them down to 200hz or natural roll off?
Reply
Reply
post #17 of 37
7/18/12 at 10:11am
Thread Starter 
I watched the Matrix last night running the RCF off my Sherbourn 2/150. Crushed the house it was awesome. I'm starting to really like this driver.

I have a FaitalPRO 18 arriving today, it is comparable in specification and price to the Peavey LowRider, one of the best values in 18s right now. I'm debating on whether to do 4 21s or 8 18s. It will all come down to performance vs price vs space.


Ergh, it never ends smile.gif
Reply
Reply
post #18 of 37
7/18/12 at 7:57pm
IIRC, The Matrix (first one) doesn't have much oomph below 25-30Hz....

JSS
Reply
Reply
post #19 of 37
7/18/12 at 8:47pm
You're right about that ....but this is a 21" pro driver and all the fun stuff isn't necessarily below 25hz. wink.gif
Reply
Reply
post #20 of 37
7/18/12 at 9:15pm
I'm surprised about what you find with the 18sound driver. Mark Seaton assisted me with the design for a pair of enclosures that housed 2x of those 21LW1400s each a number of years ago.

They were rather large, 14 cu ft internal each, ported to 28hz. I used them for DJing. My friend helped me build the enclosures. They were nothing short of amazing. Definitely interested in the results.
Reply
Reply
post #21 of 37
7/19/12 at 5:24am
I liked the 21LW1400 when I had it. It is really sensitive due to the low MMS but it does give up some displacement to the 21SW152-4 and it definitely could not cope with high power as well. Distortion was higher too. Still it is cheaper. I would bet money that the RCF slots right in between the two.
Reply
Reply
post #22 of 37
7/19/12 at 7:41am
Thread Starter 
So far the RCF gives the B&C a serious run for the money. Not to mention it is ~$300 less.



For the cost of one RCF I can get one ZV3 18 and one FaitalPRO 18. It is double the pack space, but is looking quite attractive.







Anyone want the B&C and 18Sound?

B&C - $600 SHIPPED
18Sound - $350 SHIPPED
Reply
Reply
post #23 of 37
7/19/12 at 9:42am
You can get a Zv3 18 and a Faital 18 both new for $500? Which Faital? 18XL1600? The B&C can be had for about $650 if you look around. Yeah still expensive. RCF has a new big daddy. LF21n551 Found it for $580. 5.3" voice coil and slightly more excursion than the 451. Still planning to get my hands on one of the big 18Sound drives and the biggest B&C eventually but I just purchased the final 3 XXX's for my HT #'s 6, 7 and 8. wink.gif so I'm tapped out for awhile.
Edited by Ricci - 7/19/12 at 10:14am
Reply
Reply
post #24 of 37
7/19/12 at 11:04am
Thread Starter 
Quote:
Originally Posted by Ricci View Post

RCF has a new big daddy. LF21n551 Found it for $580.

I will be checking this one out.
Reply
Reply
post #25 of 37
7/19/12 at 11:36am
Quote:
Originally Posted by Ricci View Post

....but I just purchased the final 3 XXX's for my HT #'s 6, 7 and 8. wink.gif so I'm tapped out for awhile.

YES! Awesome! You gotta post up a new thread about the reconfigured system once you've got all that, Josh. smile.gif

On a related note, I just bought JBL 2226 #18. biggrin.gifcool.gif
Edited by Scott Simonian - 7/19/12 at 11:44am
Reply
Reply
post #26 of 37
7/19/12 at 1:02pm
Quote:
Originally Posted by WiSounds View Post

I will be checking this one out.

Just found it Googling today...First I'd seen of it. SavingLots had it for $579 I think. I ordered from them before and they were fine. FYI. Might be worth it if it is only an extra bill over the 451. Those super sized vc's really help to soak up the long term heat. Every little bit of excursion helps on these pro drives too.
Reply
Reply
post #27 of 37
7/19/12 at 1:05pm
Quote:
Originally Posted by Scott Simonian View Post

YES! Awesome! You gotta post up a new thread about the reconfigured system once you've got all that, Josh. smile.gif


Will do it's going to be awhile though gotta move,etc...Lot on my plate. I'm hungry though. There will be no issues of having enough displacement EVER. cool.gif


Quote:
Originally Posted by Scott Simonian View Post

On a related note, I just bought JBL 2226 #18. biggrin.gifcool.gif

Dude WTH are you doing out there!? confused.gifrolleyes.gif

Shoot we could almost open up a store with the amount of drivers between us three. Hell I own 16 18's, 2 21's, and 6 15's and that is not counting the 9 15's and 2 18's coming from the AE group buy, PR's, 12's,10's....I see a big sale in my future.
Reply
Reply
post #28 of 37
7/19/12 at 2:00pm
Josh, Justin and Scooter's Super Mega Woofer Store

biggrin.gif
Edited by Scott Simonian - 7/19/12 at 3:03pm
Reply
Reply
post #29 of 37
7/19/12 at 5:46pm
seriously scott, 18 x 2226?

that has to be some sort of record.

ricci, 8 xxx's?

that has to be some sort of record too.

just out of curiousity, what were you missing with "only" 4 re xxx's?

i'm not even asking scott what he was missing with 9 x 2226...

btw, what is required for "avs club" or "avs gold club"?
Edited by LTD02 - 7/19/12 at 6:39pm
Reply
Reply
post #30 of 37
7/19/12 at 7:01pm
Thread Starter 
Quote:
Originally Posted by Scott Simonian View Post

Josh, Justin and Scooter's Super Mega Woofer Store
biggrin.gif

Reply
Reply
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: DIY Speakers and Subs
AVS › AVS Forum › Audio › DIY Speakers and Subs › 21" Driver showdown, my RCF LF21N451 arrived today.