Carver Amazing Platinums - Update -

[OldiesButGoodies]

By baffles I mean the piece of wood where the woofers and ribbons are mounted. The grills are what I have been working on this afternoon - while listening to them,  so I was multitasking.  I like the bass.  Interesting design in that there is no enclosure holding back pressure for these woofs,  it is an infinite baffle design  (I can check infinite baffle speaker off my bucket list,  woot).   

I just finished the grills.  Looking good,  thank you Rev for donating the fabric!  The plate amp recap is done,  ordered the Dynamat Extreme tape from Amazon,  and still have time to replace the op amps in the Onkyo.  Some pics of the grill process:

[Sir Thrift-a-Lot]

Really nice work, Pepe.

[treos33]

Interesting design in that there is no enclosure holding back pressure for these woofs,  it is an infinite baffle design  (I can check infinite baffle speaker off my bucket list,  woot).   

Those are actually open baffle, not infinite. Just want to make sure you get you're bucket list right because some real infinite baffle sub woofers should be on every ones bucket list.

Great work with the restoration!

[Sir Thrift-a-Lot]

Since it is open baffle (I didn't notice that the rear cover is fabric, I initially thought it was a box), why put felt on the rear of the ribbon?   

[AdamG]

Really good job with the new fabric! I hate working with that stuff!

I've never seen an OB speaker get much below 40hz in-room, but 4 12s is a lot of air moving. With an active system helping boost the low end I can see how it may be possible.

An IB Subwoofer would be a great addition to this rig, then you could have the IB sub take over the low bass, which would free up the 12"s for better mid clarity without the extra excursion required for low bass, help get rid of some doppler effect.

4  long throw 18"s in a manifold is my dream. Effortless bass into the ultra low frequency. I can only reach 19hz f3 in my setup as it is.

[mbskeam]

why put felt on the rear of the ribbon? 

it helps with ribbon slap

[OldiesButGoodies]

Apparently uncle Bob designed it to have some back-pressure created by the felt.  And/or to keep dust away.

[schwarcw]

I had a piece of felt that came with my AL-III+'s.  I thought the felt was to be used when the speaker placement was close to the rear wall.  I believe the intent of the ribbons was to be dipole so you could have reflections from the rear wall.  Since you have the speakers 4 feet or more from the rear wall I don't see a need for the felt.  I am no Carver guru so maybe some of the more experienced and knowledgeable Carver folks will chime in here.  The magic of the Amazings really comes to life when these big speaker have a lot of space around them to breathe.  Four to six feet from the rear and side walls allow the speakers to image and sound their best.

[schwarcw]

Nice work on the grill cloth!

[schwarcw]

4  long throw 18"s in a manifold is my dream. Effortless bass into the ultra low frequency. I can only reach 19hz f3 in my setup as it is.

I have heard the Plat MK IVs with an 18" sub.  I agree it can really add to the very deep low bass.  I would place a big SW on the side wall if Pepe's space permits.

[MasterBlaster]

Bass horn!!!!! Pepe!!!

[MacGeek]

Lookin good!

[F1nut]

I had a piece of felt that came with my AL-III+'s.  I thought the felt was to be used when the speaker placement was close to the rear wall.  I believe the intent of the ribbons was to be dipole so you could have reflections from the rear wall.  Since you have the speakers 4 feet or more from the rear wall I don't see a need for the felt.  I am no Carver guru so maybe some of the more experienced and knowledgeable Carver folks will chime in here.  The magic of the Amazings really comes to life when these big speaker have a lot of space around them to breathe.  Four to six feet from the rear and side walls allow the speakers to image and sound their best.

The felt was an addition from the factory on later Plat's and Plat IV's. As you thought it allowed the panels to be placed closer to the back wall without issues, but I believe it was discovered to help overall.

[OldiesButGoodies]

Carl, F1:

(I am off to day,  so still playing around with the equipment)

I noticed that something changed about the musicality of the speakers yesterday.  One cause that I am addressing today is that I put the new grill on top of the old,  assuming the difference in transparence would be minimal.  I think the acoustical transparence diminished significantly,  and  some of the critical 80-150 hz info is getting muddled.  That is an easy fix. 

The other is the felt.  When I got the speakers from Tom, one ribbon had felt backing the other did not.  Covering the one may have hurt the dipole effect a bit (an effect I like). Since I bought triple the amount of felt I needed at Michael's,  I am going to take off the felt and see if the sound improves or how it changes. If the felt's purpose if to make them sound better against the back wall, I may leave it off,  as I have them 2.5 feet away anyway.  My concern was that it was meant to protect the ribbon in some way from dust.

I have been testing the ECS-U box in and out of the loop to see if the benefits are worth the cost of having it in the loop.  It is a very quiet device,  probably quieter than my Carver C-9.  The bass Q trim is useful.  The holography is ok,  not as strong as the C-9,  which may be a good thing if the speakers already image well.  The Gundry dip control I am still testing.  Will continue testing.

Regards,

OBG

[Reverend]

I didn't realize you put the new grill material over the existing ones.  I bought that from PE to redo my Amazing Silvers.  The reason I bought so much is I didn't know if I would have to double up or not.  One layer works perfect, sounds like you should go this route.

My silvers had the felt backing on the ribbons as well.  I experimented with this when I put the ribbons in my DIY speakers.  The felt seems to take away some of the tintiness.