Help about 685 and 686 comparison when bass is cut at 90 HZ

[vagyver]

Hi all!!!
This is my first post and the main reason (the only one) is because there is a B&W Fan club!

I am a great fan of B&Ws too (my first one was a pair of 602 S2).


Well, i am about to set up my new system in the new (smaller) house.
Since i want to use B&W's speaker too, i am thinking of buying either 686 or 685 (for main speakers).

Living room is about 18m2 so i need something small. I am thinking also the option of using a sub, so (in this case) i will cut the main's low freqs to 90 HZ.

So, the question:

If i do so, the 685 will play significant louder that 686 or not? Because if not, there is no reason of extra money and (more important) the extra wooden volume.


Thank you in advance!

[Aldo]

The 686 has a sensitivity of 88dBs with one watt and the 685, 84 dBs.
So the 686 is more efficient if you are using the same amp.
Are you only looking for more volume?

[vagyver]

Hi Aldo!

I am mostly looking for better quality!

Of course, when watching movies, system must have an acceptable sound volume, but i am not crazy about very high sound levels.

My current AV amplifier is Yamaha RXV-630 (i think it is 6x75W with 0.01% distortion).

What i am asking is:

If i cut the low bass, then the 686 and 685 speaker will be more or less equal in sound level and quality, or what i am asking is stupid?

Of course, the most logical is that the 685 might be a little better. But the issue is how better, because (if i cut the low freqs below 90 HZ) if the difference is small, then the 686 becomes the value for money.

Thanks again!

[vagyver]

oups!

I think Aldo, you wrote it upside down.

686 has 84 db and the 685 has 88 db.

[Aldo]

oups!

I think Aldo, you wrote it upside down.

686 has 84 db and the 685 has 88 db.

Sorry :frypan: You understand!

[hifiguymi]

The 686 and the 685 sound very similar to one another but not the same. The 685's midrange is more robust and it has a smoother transition to the treble IMO. You should listen to them on the same system, and try to level match them when you do, and see what you think. I bet you'd like the 685 better.

Eric

[vagyver]

Eric thank you for your reply!

Yes, you are right, the 685 should sound better (as you said its midrange is better).

Andm of course, our ears is the best to decide.


I will try to find a store to listen. But until then, i am tring to understand some issues (not known to me).

By the way, if i close the bass reflex hole. will the speaker sound less loud?

Best regards

[Allegiance]

Eric thank you for your reply!

Yes, you are right, the 685 should sound better (as you said its midrange is better).

Andm of course, our ears is the best to decide.


I will try to find a store to listen. But until then, i am tring to understand some issues (not known to me).

By the way, if i close the bass reflex hole. will the speaker sound less loud?

Best regards

The bass won't be as deep, but it will not affect how loud the speaker goes.

[markov]

686 has 84 db and the 685 has 88 db.

Are B&W's measurements in-room or anechoic?

[dan87951]

The 686's IMO are to small for upfront duty, go with a 685 much more of a full range speaker when compared to the 686.

[hifiguymi]

By the way, if i close the bass reflex hole. will the speaker sound less loud?

No it won't affect how loud they play. They are meant for tuning the bass if the speakers are near a wall. If the speakers are going up against the rear wall the plugs tune the speakers to act more like an acoustic suspension speaker. The bass roll off happens higher up in the audio band but it's a smoother roll off. When a speaker is placed near a rear wall the bass gets boomy, and in a two way speaker like the 686 and 685 the midrange can sound thick and heavy. You have to listen to them in the room and try it both ways. I had a customer that was using them (on a pair of 803D's) and when he upgraded his amp, they were better without the plugs. It all comes down to system matching in your room and your tastes.

Eric

[vagyver]

Thank you all for your replies!

Eric, thank you for the nice explanation about back bass reflex.



I don't know if the sensitivity is measured in anechioc or in room.

Does these 4 db is large enough, so our ears can understand the difference?


What about the room's size that is good for 686 and for 685? My living room is 18 sq meter (193 sq feet).


Does anyone has heard or compared the 686 with the M1 ?

Is there a large difference in the quality or how loud they play, if they play starting at 90 HZ and above (by using amp's setting)? I think they both have almost the same tweteer.

Thank you in advance, once again!

[hifiguymi]

The 4 dB difference in sensitivity is quite a bit. It takes twice the amplifier power to play 3 dB more. With that being the case, the 686 requires more than twice the amp power to play at the same volume as the 685.

The M1 is a wonderful sounding little speaker. It's not as big sounding as the 686 or 685 however. I'd still opt for one of the them if it were me.

All three of the speakers you mention will work in your room but I'd still opt for the 685. It's a wonderful speaker for it's size and price.

Eric

[vagyver]

Since you are saying that M1 is wonderful speaker but not as big as 685 & 686, then i will surely go for one of those (685 or 686).

The issue here (which is the final one) is that the 685 is quite large for the space i have. The 686 is only a little bigger than would fit nicely (it is also big).


So the final question is: do you believe that the sound quality difference that the 685 has in comparison to 686, worths the extra size problem that i will have? (i will still place a subwoofer in both cases).

[Briz vegas]

What exactly is your size problem? ops:

If you are putting the speakers in an entertainment unit or bookshelf the sound will be compromised. If it is free on an open shelf then it will sound better and the size issue will be mostly its bulk. If you love your music I would put up with this and go for the 685. Dedicated stands (even home made) would be the best choice.

If it is a movie 90% system then the quality of the speakers is less important and you might live happily with the 686.

Coming from 602s I suspect you will prefer the 685. You will know which one is for you when you hear them.

[vagyver]

I used to have (in previous house) dedicated stands with my 602s. Also 602s were placed in positions as instruction manual described and i was very happy. I really liked this sound quality feeling (some people say that this is the English' type of sound)!


Now, (in new house) the limitation is the room' space and the position of speakers.

I have a long bookshelf on which i have the Sony Lcd tv and i will place the new speakers.
An other small issue (i will it is negative) is that the back of the speakers will be very very close to back wall (less than 10 cm).

My current amplifier is Yamaha RX-V630. (i think it is 6x75W).
It has only 90 HZ filter selection for selecting large or small speakers.

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