New Full-Range Ribbon Speaker Line Debuting in Munich

[dr k]

The question is just that these panels are dipoles and as such need 6 dB/oct dipole slope correction, something that is feasible in an active servo controlled system, although it limits maximum loudness. I have built such dipole subwoofer long ago, using the famous 24" Hartley speaker - the main speakers were Quad ESL, dynamic range was not a problem! I can not see how this can be passively implemented is such a limited area panel, 22 Hz is really low.

Yea, I agree 22 Hz is really freakishly low for a panel design of this size, but not impossible. But we have know idea if that is -3dB point or -10dB point.

 

[Zero000]

Yea, I had a brain fart on the 5 12 inch woofers. I was thinking more like two 12 inch woofers similar to my active dipole dynamic subwoofers. According to specs, the Botticelli bass panel area is 4544 cm2 or 705 square inches which is similar to two 12 inch subwoofers...I’ve found no 12 inch cone subwoofer actually has effective radiating area as indicated by the published radius. But it is a push pull design using much more effient magnets, unlike the single ended Duetta bass panel which I found its bass to become soft below 40 Hz. I’m getting a little resentment vibe from you. Why? I have no personal stake in the Botticelli or the Apogee because I own neither currently. Just both intrigued and skeptical at the design.

The only resentment is the posting of incorrect information. People search these threads and try to use what information they can to understand things. So posting incorrect stuff is baadddd...

It's not personal. It is just a pet hate. I have no clue who you are

According to the Hi-Fi News Malcolm Colloms Duetta review, the Duetta panel area is equivalent to three 12 inch woofers.

 

[Zero000]

Yes, there is 2 cm space to move in, but how do you know the membrane can’t move close to that? Do you have inside knowledge we don’t? Why would a designer put that much space if the membrane only moves a small fraction? It would be better to have smaller space to improve linearity, no?

I know because I watched a YouTube video where the main man expressively states that that is the case. If I get the time I will try and find it again and post it.

He does not state what it actually is. I honestly expect he doesn't actually know precisely, since he probably doesn't own Kilowatt power amps that will take them to the max. That said, the film/glue and conductor panel used will have excursion limits and the last half a Kilowatt will probably only move them very fractionally more. I suspect it gets very close to the limit at way below 100 Watts in this particular case, though.

This is what happens with Apogees and Maggies, once you're close to that limit, no amount of power can realistically give you much more.

 

[microstrip]

5 12 inch woofers? Really? Are you referring to the bass panel in Botticelli? Also, much of the radiating area is obscured in this design.

My Duetta Signature based speakers measure +/- 0DB at 21 Hz in room according to my test mic. Above that, bass output is excessive at the 32Hz point, say.

My Soundlab's measure around 0 dB at around 19 Hz - but it is a fake value due to the main resonance of the long room. It does not allow me to claim I have response down to 19 Hz in my room. When a designer claims response down to 20Hz I am admitting a nice regular graph, not a roller coaster.

IMHO panel bass is subjectively different from box bass and we can not directly compare data from panels and boxes.

 

[Zero000]

My Soundlab's measure around 0 dB at around 19 Hz - but it is a fake value due to the main resonance of the long room. It does not allow me to claim I have response down to 19 Hz in my room. When a designer claims response down to 20Hz I am admitting a nice regular graph, not a roller coaster.

IMHO panel bass is subjectively different from box bass and we can not directly compare data from panels and boxes.

It is.

I am really not a fan of long throw, small diameter dynamic woofers, that essentially punch small holes in the air and consequently produce a very thuddy type of bass. My Martin Logan Descent was completely guilty of that, and consequently unpairable with a large surface area Apogee bass panel.

I'd much rather have bass from a dynamic driver of large surface area. The Bohne modified 18 inch JBL drivers that were used at Munich this year were fabulous, for instance. Fantastic sense of bass 'weight' with those.

 

[bonzo75]

A couple of my favorite horns have two 18 inches in each speaker front loaded that move fast and produce a similar vertical plane bass

 

[damic]

For info, if something helps. Just measured left bass panel of Apogee Duetta Signatures, near filed, app 1cm from the net, at 4 heights, 120, 100, 85 and 64cm from the floor. Measured range from 10Hz to 200Hz.

Measuring mike height limited due to tripod stand.

 

[spiritofmusic]

dr k, if these go down to low 20's, then what do the flagship models with one and two additional subs panels per side get to?

Btw, what amps are you planning to use?

 

[PeterA]

I didn't suggest I was buying it. I am just reporting.

Any new planar speaker is of some interest to our many planar-loving members.

Your humble reporter, reporting. Keep up the good work, Ron.

 

[PeterA]

http://leonardospseakers.it

I heard these Leonardo speakers at the NYC Audio show in about 2012 driven by some 14 watt tube amps. They were the rage of the show. I really liked the sound and the host even played two of my LPs. I wonder why one doesn't hear more about them.

 

[Rob181]

Neodymium magnets are not miraculous - if just replacing magnet type all speakers could get an 8 dB improvement in efficiency all old JBLs would have gone in the 100 db/W zone! I think that typically magnetization is up to two times higher than other magnets.

Can show you where Ambience Speakers here in AUS did exactly that...
His Standard ribbon speakers run at 89 db - his Reference ribbon speakers run at 96 db...
The difference in the ribbon section is replacing the magnets with neodymium magnets...
I own both the 1600 standards & the 1800 Reference..
http://ambiencespeakers.com.au/standard-series/

 

[Zero000]

For info, if something helps. Just measured left bass panel of Apogee Duetta Signatures, near filed, app 1cm from the net, at 4 heights, 120, 100, 85 and 64cm from the floor. Measured range from 10Hz to 200Hz.

Measuring mike height limited due to tripod stand.

That looks very similar to my original Duetta refurbishments. My current Interstella Duetta variants hugely tame that 32 Hz bass peak and go lower.

 

[Zero000]

Actually getting high excursion on the panel with 15Hz test input signals or even lower is a good way to approximate maximum excursion capability. Within reason. At these low frequencies with very high power it might be possible to do some damage.

Mine literally go visually bats at 15Hz with quite modest power come to think of it.

 

[microstrip]

That looks very similar to my original Duetta refurbishments. My current Interstella Duetta variants hugely tame that 32 Hz bass peak and go lower.

Near field 1cm from the net? Can I ask what is the purpose of showing such measurements?

 

[dr k]

dr k, if these go down to low 20's, then what do the flagship models with one and two additional subs panels per side get to?

Btw, what amps are you planning to use?

The multi panel speakers don’t go down that much lower, somewhere between 18 and 20 Hz if I remember correctly. They’re really efficient so I can try many different amps on hand from 25 watts to 900 watts.

 

[Zero000]

Near field 1cm from the net? Can I ask what is the purpose of showing such measurements?

It wasn't me.

1m is more usual. But for dipoles I think it's mad. 3 metres makes far more sense.

I guess he was trying to rule out room effects at 1cm.

 

[damic]

The purpose of near field measurements were to avoid room influence as much as possible and show what only bass panel does at low freq.

 

[dr k]

The purpose of near field measurements were to avoid room influence as much as possible and show what only bass panel does at low freq.

There lies the conundrum. Near measurement doesn’t tell you what the speaker’s response is at the listening position, measurement at 3 meters is closer to what we actually hear at the listening position but is room dependent. I prefer the latter.

 

[damic]

....At very low frequencies, where the acoustical wavelength is much larger than the radiator, far field response is identical with the attenuated near field response considering the distance of the measurement points ...

https://www.klippel.de/know-how/mea...n-and-propagation/near-field-measurement.html

 

[dr k]

....At very low frequencies, where the acoustical wavelength is much larger than the radiator, far field response is identical with the attenuated near field response considering the distance of the measurement points ...

https://www.klippel.de/know-how/mea...n-and-propagation/near-field-measurement.html

That makes sense, but I wasn't specifically referring to just the very low bass response, rather the entire frequency response.