[Bill Baker]

Don't kid yourself. This new model retails for 3 times what you paid for the AV-2's. And the AV-2 is probably 75-80% of their performance. If you change the crossover parts sometime in the future, you're probably talking 85% then - which is cheap and easy for you to do yourself

 He is correct ooheadsoo. As we spoke about privately, these designs have a lot of potential. You are already starting out with an exceptional design and with a bit of thought, you can voice these to your liking.

 Pay close attention to the internal arrangement as this also has a great effect on the signature of these speakers. When building the crossover, use your choice of quality components to get just the sound you desire.

 When your done, you will have a system that is happy with various means of amplification. Being a tube freak myself, I have a few hundred hours on them with a 70 watt tube amp (Reference Jolida 801) but also spent quite a bit of time using some of the EXtreme Hurricanes. Even a 3.2 watt 2A3 amp I was working on provided good dynamics (not that I would go this low in power).

 Depending on what you use for crossover componets, you will probably not have to go through the 300 hour burn-in as the Bellas require but I would give them a good pounding for a week or so before critical evaluation. Then in the end, YOU be the judge. I think you will find you have yourself a very nice system that represents exceptional value.

 Just remember one thing when choosing components:

"Build your system for yourself, not the critics"

[Watson]

I'm still having trouble understanding SP Pres' comments.  (I've also read the fight club thread, and his comments there seem to have confused the issue more for me.)

So far, SP Pres seems to have made the following comments:
1) baffle step compensation doesn't lower a loudspeaker's quoted sensitivity
2) baffle step compensation does lower a loudspeaker's sensitivity, but these speakers are designed for 2pi radiation so it doesn't matter (i.e. presumably they don't have BSC, or have very little)
3) these speakers have baffle step compensation (otherwise, they'd "sound like ass" in his words)
4) the Peerless HDS exclusive is, practically, rated at 90dB sensitivity and the AV-2s are rated at 93dB @ 1W/1M and 96dB @ 2.83V/1M.

Almost every pair of those statements is mutually exclusive.  They can't all be true.  Could you clarify this, SP Pres?  I would appreciate no personal attacks and a non-condescending tone, since I'm genuinely curious and I have a good understanding of this issue.

Also, if these speakers are designed for 2pi space, I'm assuming the quoted frequency response numbers are not measured in an anechoic chamber.  What environment were they measured in?

[_scotty_]

4) the Peerless HDS exclusive is, practically, rated at 90dB sensitivity and the AV-2s are rated at 93dB @ 1W/1M and 96dB @ 2.83V/1M.

This one I can explain. The AV-2 is a 4ohm loudspeaker,therefore it will
draw twice the amperage and if the amplifier can supply the the current it will
be [email protected]/1M.  It will behave just like an 8ohm loudspeaker that is 96dB@1W/1M  as long as the amplifier can double it's power into a 4ohm load.
Scotty

[ooheadsoo]

From what I understand, I think Bob is referring to two different aspects of baffle "loss."  One is the boost gained from a baffle as it is reinforced by the baffle.  In this case, like a waveguide, sensitivity is gained for "free" as Bob states.  Then there's the loss on the bottom end as the radiation change from 2pi to 4pi.  When placed close to the wall, this can be mitigated to some extent, as full 4pi radiation is prevented by the wall's proximity.  So there are two different baffle related aspects to compensate for in this case.

[diy_freak]

There were some comments made from a first-time poster against Bob that I moved here: http://www.audiocircle.com/index.php?topic=27335

I didn't find that necessary, but that's not my call... I think we settled that fast enough to move on now.

I'd like to see a reply to Watson's post, where he makes a few fair points.

[JohnR]

Hans (and Watson), perhaps you are familiar with the phrase "flogging a dead horse"?

 

[diy_freak]

Hans (and Watson), perhaps you are familiar with the phrase "flogging a dead horse"?

It seems to me you are creating a dead horse out of thin air.

Can we PLEASE focus on the content now. Thank you!

[JohnR]

Hans, the content is in big letters at the top of the page. The big letters say "Bella SP/AV-1 compared to VMPS ribbons." If you have something to say on that topic, go for it. Otherwise, put it away.

(Since the two-channel moderator is on vacation, I am acting on his behalf.)

[Aether Audio]

Watson, et.al.,

I hope I can clear things up.  This better do as I don't have time for further discussion.  I work a minimum of 70 hours per week at the shop so my time at home is at a premium.  My family likes to see me occasionally too and I'm writing this from home.  Again, taking time away from them to essentially satisfy what amounts to a handful of people that probably don't really care what the answers are all that much, one way or the other.  Not compared to the price I'm paying to provide them anyway.  I don't mean to be a snob though, it's just the facts.  I'll explain further below.

1)baffle step compensation doesn't lower a loudspeaker's quoted sensitivity
2) baffle step compensation does lower a loudspeaker's sensitivity, but these speakers are designed for 2pi radiation so it doesn't matter (i.e. presumably they don't have BSC, or have very little)
3) these speakers have baffle step compensation (otherwise, they'd "sound like ass" in his words)
4) the Peerless HDS exclusive is, practically, rated at 90dB sensitivity and the AV-2s are rated at 93dB @ 1W/1M and 96dB @ 2.83V/1M.

Almost every pair of those statements is mutually exclusive. They can't all be true. Could you clarify this, SP Pres?

(1)  BSC does lower on-axis sensitivity.  I mis-spoke.  I meant to say that the baffle step downward in frequency is not a lowering of broadband sensitivity.  The power response remains the same.  The energy is just radiated over a space twice the size of the 2pi field so the axial pressure drops.  Sometimes I think backwards of conventional thinking.  That’s my fault – sorry.

(2)  Correct.  Whenever we build something for 2-channel/4pi use, we compensate them.  Otherwise…YUK!  But with most of the AV stuff I haven’t gotten around to posting specs or even worried about them.  Besides Bill Baker, I’ve had two orders for the things.  One was ooheadsoo’s kit.  We make peanuts on them in onesy-twosey sales such as this, so it’s not been a top priority.  Regardless of the actual sensitivity, they’re an easy load to drive and most folks around AC don’t care much about specs anyway.

(3)  The ones I’ve done for Bill and others that are using them for two-channel use are compensated.  The AV Series was designed for 2pi radiation in their original concept.  Then Bill Baker came along and wanted to use them for 2-channel so I compensated them for him.  Then a couple of others bought them for 2-channel use so I did the same.  We’re a small company (that appears to be changing though) so we sell what people want on a per-use basis.  Our original intent was to sell them for AV use only and that’s where the spec came from.  If you’ll note, there’s almost no info on them on our website.  Why? - Haven’t had time to get it all up there.  You’ll notice that there are almost no pictures either – none of the AV-2s at all.  The product hasn’t sold much and so the squeaky wheel gets the grease.

(4)  Correct – in a 2pi field.


Sorry folks, the confusion has been my fault.  To be honest, as much as I enjoy answering questions here on AC and appreciate everyone here, the sales that result from all my efforts can hardly justify the time (John R, I still believe something could be done about this at minimal cost).  I have a 13,000 sq.ft. facility and a minimum of $10K/month overhead to worry about.  That’s why all the confusion in this case.  I should have taken the time to spell everything out better but my level of interest in anything AC is waning fast.  In the case of the AV product, it never got much in the way of my attention in the first place.  Don’t get me wrong, technically I’ve always seen to it that they have a flat response for their intended use.  I just haven’t concerned myself with documentation, is all.  In the coming weeks you’ll find my presence becoming even more scarce.  I have much bigger fish to fry in the coming weeks and months.  It won’t be long and you’ll be hearing all about it, I’m sure.

Take care,
-Bob

[Bill Baker]

Besides Bill Baker, I’ve had two orders for the things.

 I think it is only a matter of time till the word gets out about their sonic merits. I have only done small production runs so far to get some feedback and to date, the feedback has been much better than I had even hoped for. And this was all the Bella I's.

 I will shortly be doing a run of Bella II's as I have not yet focused my energy on this model in regard to promotion but after spending the last several weeks with tweaking these and a few hundred hours of listening.......well, it's time. They're ready. I think those who have heard and enjoy the Bella I's are in for a big surprise with the II's. I have a few customers that will end up with one pair of each. They must be doing something right

the Peerless HDS exclusive is, practically, rated at 90dB sensitivity and the AV-2s are rated at 93dB @ 1W/1M and 96dB @ 2.83V/1M.

 Okay, let's go with 89.3dB just for arggument sake. That brings us to 95.3dB @ 2.83V. Still a very effecient design which was my goal in the very beginning when this project was discussed with Bob. You see, I'm a tube guy and I wanted a design that was very versatile and could be used with various amplification. The Bella II's are suitable with anything from 8 watt 300Bs to 200 watt power houses. A pair of ASL Monsoons and/or Hurricanes have already proven themselves with these speakers (or is it the other way around? oh well, doesn't matter)

 You will notice I do not get too involved in these "debate" as I have learned over the years in many discussion forums that these things are NEVER resolved and only turn in to ongoing flame wars. Really not worth my time and I am sure others who visist these types of threads also find it a bit ridiculous to the point where they don't even want to keep up with it.

 I think the whole focus of this thread has been totally lost.

 This is the first issue that I have encountered with AC post as the past has always been an extreme pleasure. There are so many enjoyable people here. I appreciate the efforts, feedback and honest opinions submited by AC'ers over the past few years. I'm not going anywhere. I guess as a forum continues to grow, the family atmosphere goes by the wayside. That's too bad.

[diy_freak]

Thank you Bob for that informative reply. Much appreciated!    

Hans.

[woodsyi]

Gentlemen, I am taking this thread back to the intended topic since I still have some findings I would like to share.    

Now I go back to the RM40 and listen to the same stuff for a week.  Most obvious quality difference is the size and depth of soundstage.  Mind you, I am not really a soundstage guy, but the impact of an 80 pc orchestra is much better portrayed by the 40s than the Bella 1s.  Since the CDWG, the sound depth has improved very much with the RM40s to the extent that strings, wood winds and brass can clearly be separated on the stage.  Yes, you get a holographic sound stage -- a big one at that.  Macrodynamic difference, too, is obviously expected with speakers of such different size and driver configuration.  I think I should bring in my 626Rs from my wife's office for a more even size comparison later.

What about the tonality and microdynamics of RM40s compared to the Bellas?  RM 40 ribbons are as quick and nimble as any speakers I have heard including a pair of Sound Lab Stats and Carver's Amazing speakers.  There is a difference between the two and it's the timbre -- more specifically the texture or viscosity of the sound.  RM40 ribbons are creamier or richer than the cones in AV/SP1s.  Some of it could be the difference between TRT and V caps or the driver material.  I don't know, but RM40s are different from the Bella AV/SP1s like Pavarotti is different from Domingo, Caballe from Tibaldi, Norah Jones from Alison Krauss, clarinet from pan pipe, electric guitar to acoustic guitar, steel strings to nylon strings.  I am dramatizing the difference a little to point out a difference but the difference is subtle.  They both are excellent at what they do and I am glad I am keeping both of them.  I do wonder how AV/SP2s with matching subs would fare but the 1s are just right for my bedroom.  I hope this helps someone out there and bear in mind it's just one man's impression and you may get a totally different impression with different synergistic gear/room effect.