Hi,

there's no filtering for the mono speaker. It's just adding the left and the right channel to the sum ( =mono).

It will work with two BL 7.4 as steero speakers, if you feed them with a special powerlink cable: the one cable should only feed the left channel while the other one feeds only the right channel signal.

Normal powerlink cables feed both channels !!! Using a normal powerlink cable would give you a great sound in double mono!  😉

Simple way is to ask Steve from Sounds Heavenly ( tripple link at the end of the side) to make such a cable for you 🙂. or you fiddle around yourself 😕

RaMaBo wrote:

Hi,

 

there's no filtering for the mono speaker. It's just adding the left and the right channel to the sum ( =mono).

It will work with two BL 7.4 as steero speakers, if you feed them with a special powerlink cable: the one cable should only feed the left channel while the other one feeds only the right channel signal.

Normal powerlink cables feed both channels !!! Using a normal powerlink cable would give you a great sound in double mono!  😉

Simple way is to ask Steve from Sounds Heavenly ( tripple link at the end of the side) to make such a cable for you 🙂. or you fiddle around yourself 😕

 

Hi 

Thanks for that! Glad to hear that there isn't any special filtering, 

Hi Bensa

The good news, there is absolutely NO need for special cables, just two regular powerlink will do!

The 7-4 sums the L-R signal and thus creates a mono signal from stereo. In you case simply assign L and R correctly. make sure to use the NONE option for the unused channel in the powerlink set.

The bad news, You will be disappointment, listening to music. The 7-4 is tuned towards dialog, at which it truly excels,. Expect for the BL10 it might just be the supreme king of center speakers, but not for music!

They can be used as surround or rear speaker in a 5.1 / 7.1 setup, since those channels are limited anyway.

A suggestion for upgrading the BL4000 would be the 7-1,2 or 6, which I run in several stereo setups!

Truly awesome, secondhand they run as little as 500-1000dkk in Denmark. Proving that the world really is messed up. 6 drivers. 750w Icepower, cast aluminum chassis, and people still prefer a plastic mono BT box they can talk to. A mono configuration will require a custom cable though.

Best of luck with the upgrade 🙂

Thanks RaMaBo!

Yes, I can provide specially wired Powerlink cables to send left audio to the left speaker and right audio to the right speaker (ie. audio summed to both channels) so that 2 x Beolab 7-4 speakers will work correctly as a stereo pair.  Please feel free to get in touch via my sponsor link below if you would like more details.

Kind regards, Steve.

Hi Steve

Please elaborate, the 7-4 is already summing the left and right signal, and provided you interface to a B&O...

...and this is where I dawns on me!

I am doing this on a Beosystem/Beovision where i can assign my way out of what does need to be a special cable if its an audio product.

That cable would work with the rest of the Beolab 7 series as well. Thanks for making me rethink 🙂

Still not a good proposal using a 7-4 as a music speaker though.

Input summing on BL7-4

Hi Beovox141,

I make a cable that sends left audio to both the left and right pins in the cable that goes to the left speaker.  This means that when the left speaker sums the two input signals, it plays the correct left channel audio, instead of combining the left and right audio sounds.

The same process is used to send only the right channel sound to the right speaker.  This way, the two speakers can be used as a stereo pair, with excellent results.

Hope this helps.

Kind regards, Steve.

BEOVOX141 wrote:

 

The bad news, You will be disappointment, listening to music. The 7-4 is tuned towards dialog, at which it truly excels,. Expect for the BL10 it might just be the supreme king of center speakers, but not for music!

 

What difference is there with a BL7.4, BL10 & the speaker in a BV9? Same tweeter and driver. the BV9 would use the same volume of air as the 7.4, does the BL10 use the volume in the cabinet for better sound?

Rob - Danish AV wrote:

does the BL10 use the volume in the cabinet for better sound?

Good question, short answer,- YES! 

The BL 10 does go significantly deeper than the BL7-4. It has more than twice the volume and the lower bound is specified at 45Hz vs. 50 for the BL 7-4.

And those 5Hz makes quite a difference. Where the BL7-4 has virtually no bass output, the BL-10 does. Besides the BL-10 carries the triangular signature design of the AV9000, and its built like a tank. The mount is the most complex, insane design I have ever seen and must have cost a fortune to manufacture. I am not sure whether or not it was intentional, but it does fit on a BV 7-40 or 55 stand with only 18 mm to spare if you want to be able to open the DVD tray, pretty cool.

Much to my surprise it turns out that a lot of BV7 setups was sold and operated with the BL7-4 as the only speaker,- go figure.

Another oddity with the BL7-4 is the fact that the sensitivity at least with the BS3, clearly is way off, its simply to loud, and the fact that the centre channel cannot be adjusted is slightly annoying.

Both speakers are outstanding as centres and the lens allows for the entire audience to hear every single detail in the dialog, which in most other setups are muffled. I cant help considering the claims that the Avant or Eclipse carries: "The world best TV sound". Simply not true since they absolutely lack in the centre department. I dont care what anybody says, the centre channel cannot be emulated or substituted, it has to be a single point speaker!  

As to the BV-9, it has the specifications of the BL-10 in a BL7-4 sized box, which clearly indicates that the BL7-4 was very much tuned as midrange, dialog speaker. On top of that all three are closed box systems, again leaning towards the properties of a centre speaker. Usually B&O prefers a 2 way bass reflex system, in a 4-5 liter box.

Why B&O decided to abandon the line of what I consider the best centre speaker ever made, is simply beyond me.

Hi Steve.

Same way I did the "Stereo/Mono" cables for the BL7-1 and 2. If we really want to go into the nerdy territory, the summing should be done with a couple of small resistors i.e. 100 ohms, but for at least one of my cables I was lazy and just did a short. 👍