Has anyone heard these nice looking dipoles?

Only at last years Bristol show (I think) I thought they were rather promising given the environment.

Only at last years Bristol show (I think) I thought they were rather promising given the environment.

Same here. It's a shame it was only an AV demo so we were unable to judge their musical abilities. The room was also a bit small and this is not good for dipoles if you want to hear deep bass - even with two 15 inch woofers.

A dipole speaker cannot produce bass below the lowest room mode because it cannot pressurise the room like a box speaker can. If you want to hear 40 Hz bass you will need a roughly 4.25m room (just over 14 feet).

Having said that, the AV sounded fine. I hope that this year we might get to hear some music.

I don't think that is anymore true than saying a sealed speaker can't produce any sound over 40Hz because it is a pressure transducer. The main problem with open baffle is simply that the wavelengths are so large the bass from the back cancels out the bass from the front very effectively so you need to boost a hell of a lot down that low.

type in 'Orion dipole speakers' in Google and take a look at what comes up... I have heard these active speakers and if I was a motivated individual I would reply my active SBL's with them... very good. R909 I assume would be similar with the style attached :D

Has anyone heard these nice looking dipoles?

Haven't heard them myself, but they have been reviewed by REG in the US magazine "The Absolute Sound". The review is on the web and can be downloaded here:

http://avguide.com/products/product-3802/?download=%2Ffile-download%3Freview%3D2314

REG has posted a supplement to his review here:

http://www.regonaudio.com/Jamo909Measurements.html

If you are looking for a dipole why not consider the much cheaper Orion here:

http://linkwitzlab.com/orion_challenge.htm

Reviews of the Orion have been uniformly positive. See the Linkwitz site for reprints of reviews.


Hope this helps.

I heard them at their inaugaration. One of the best loudspeakers that I've ever heard - they sounded like a band was playing live. If I had the space, they would be on my short list along with 15" horn loudspeakers.

http://www.audiostyl.pl/Obrazki/Kolumny/Jamo/jamo_R909.jpg

Given the simplicity of the cabinet.... why are the Jamo R909s speakers so expensive?

Would love to hear them, I am toying with the idea of making my own Open Baffle speakers.

Given the simplicity of the cabinet.... why are the Jamo R909s speakers so expensive?

With the usual 20% remise, they are about 10K EUR in France. I just love their monolithesque looks. The quality of construction is exemplary. The base is a metal casting, the front baffle is multi-ply and the rear supporting structure is aluminium:

http://www.jamo.com/Files/Billeder/R%2090/R909_detail_3_med.jpg

Given the simplicity of the cabinet.... why are the Jamo R909s speakers so expensive?


Not to mention they use a SEAS Excel midrange and a Scanspeak Revelator tweeter and those 15" high efficiency bass drivers are from a pro-audio source and not cheap.

They are fab speakers.

BTW, they are quite different from the Orions. The Jamo is a flat dipole and is a pure passive design. The Orion is a flat dipole at the top but uses an H frame in the bass and is an active design so you'll need three times the amplification and then it doesn't look quite so cheap but a good speaker of its type nonetheless.

I've seen it written many places now that once you hear the sound of a boxless speaker, you'll hate going back to anything with a box. I liked the R909 when I heard them at Bristol.

I did find a place on line that did them for £3750... Hopefully that is for a pair :)

BTW, they are quite different from the Orions. The Jamo is a flat dipole and is a pure passive design. The Orion is a flat dipole at the top but uses an H frame in the bass and is an active design so you'll need three times the amplification and then it doesn't look quite so cheap but a good speaker of its type nonetheless.


My original post didn't say they were the the same, only that those interested in dipoles might also want to have a look at the Orions.

Passive dipoles are a bit of a mixed bag because the mid and high frequency drivers have to be padded down quite a bit to account for the dipole roll off of the bass units and consequent eq. See Linkwitz' crossover details for the eq applied. The Gradient Revolution, another commercial speaker using a passive dipole woofer section, has a net sensitivity of around 81 dB/W. This is about 7dB/W less than the intrinsic sensitivity of the coaxial SEAS mid-treble unit used in the Gradient. There is no merit in throwing away all this power in a passive crossover. Gradient already offer an active upgrade option to the Revolution and it would not surprise me to see an active option from Jamo in the future.

Regarding prices, in the US a DIY Orion can be built for ca. US $ 2500. As for amplifiers, the position here in the US is that there is a glut of good stereo amps on the second hand market - hard core constructors can always take the DIY route - and 8 identical channels of amplification should not add more than 1k to the final price of the Orion. This brings the total to ca. US $ 3.5k, a fraction of the price of a pair of Jamos. Even if you buy the Orions ready made, the final cost will still be substantially less than that of a 909 plus amp.

http://img123.imageshack.us/img123/2208/orionzl0.jpg

:D

http://img123.imageshack.us/img123/2208/orionzl0.jpg

:D

Nice!! Are you going to use the rear tweeter too?

Nice!! Are you going to use the rear tweeter too?

Eventually, and the subs as well, ie. the full +++ setup, for which I now have all the parts.

However, I want to get the basic speakers up and running as a first step and I'm almost there.

I don't think that is anymore true than saying a sealed speaker can't produce any sound over 40Hz because it is a pressure transducer. The main problem with open baffle is simply that the wavelengths are so large the bass from the back cancels out the bass from the front very effectively so you need to boost a hell of a lot down that low.

I believe it is true; for the same reason you can't drive a small room/car with a ported speaker.

it would not surprise me to see an active option from Jamo in the future.


Given that Jamo has been wound up, I'd be very surprised to see further developments. The assets were mostly bought by Peter Lyngdorf IIRC; his new dipole (for use with his digital room correction system) seems partially based on the work done by Jamo.

Given that Jamo has been wound up, I'd be very surprised to see further developments. The assets were mostly bought by Peter Lyngdorf IIRC; his new dipole (for use with his digital room correction system) seems partially based on the work done by Jamo.

This is news to me. A shame really, another quality manufacturer bites the dust.

I believe it is true; for the same reason you can't drive a small room/car with a ported speaker.

You can't hear a ported sub in a small room? News to me.

The idea that a room can't be driven below its lowest mode is misinformation, the room simply stops acting in a modal fashion and you don't get the modal boost. A closed or ported speaker will start to pressurise the room at this stage, which an open baffle can't do so easily, but that is why its known as a velocity transducer and it can still set the air particles in motion. However, with open baffle loss, as well as the loss of modal gain the level does drop very rapidly. It acts as though the speaker is outside, where neither modal behavior nor pressurisation can easily occur.

At least thats what I understand of it.

You can't pressurise a space if the pressurising element is open to the space on both sides.

I heard the Orions at the DIY show upt north... Someone forgot to tell the speakers about that as they sounded superb.

AFAIK this is not a high sensitivity speaker. don't know the figures but i remember - when considered a shortlist of interesting speakers to demo - i remove 909s from the list for not being able to be driven with a first watt type of the amps (i generally prefer these days).

AFAIK this is not a high sensitivity speaker. don't know the figures but i remember - when considered a shortlist of interesting speakers to demo - i remove 909s from the list for not being able to be driven with a first watt type of the amps (i generally prefer these days).

The official spec is 89dB/1w/1m...which is quite reasonable.

still you need looooots of power for these...... OBs suck it up

still you need looooots of power for these...... OBs suck it up

So that is not a sensitive/efficient specification?