PDA

View Full Version : Floorstanders with built in Subwoofers



ninedecks
30-05-2012, 14:48
I happened to see an ad on ebay for some Mission 704A floorstanders with built in subwoofers.
There wasn't much to find when I did a search but I decided to take a punt and give them a try.
I notice that other manufacturers - B&W DM605 S2 and Audio Pro Avanti A100DC
supply similar products.
I've not had them for long but I am quite impressed with the results.
The sub can be connected via the pre out of my AV amp and the HF & MF can be connected from the standard front speaker outputs.
A little bit of fiddling with levels is needed but in AV mode the subs knock out some good LF. Having additional bass for music cd's is also impressive.
I think that these will be keepers. However they are big lumps and you need a reasonable sized room to hide them in.
David

Reid Malenfant
30-05-2012, 14:57
Similar speakers have been available for quite a few years, but with one exception ;)

Never heard of having the sub seperated from the speaker electrically :scratch:

The normal way of doing this would be to have what would be in effect a passive speaker, but with the sub active, though it'd still be connected to the line level speaker inputs & would simply go with the flow.


But having the sub seperate? Not something I have heard of, great for bass heads I guess, but I prefer things to be as natural as possible :eyebrows:

ninedecks
30-05-2012, 17:54
You had me scratching my head because I have seen another advert where the connections sound as if they are the same as these.

Extract from Mission instructions from the net. No instructions have turned up from my own searching on 704A but I did manage to find the Mission 705A manual.

User Instructions. Mission 700 Series Active Loudspeakers.

Connecting the 705a via line and high level inputs.

Connect a single phono cable from the left channel of your preamplifier output to the line input of the left 705a loudspeaker.
Repeat for the right channel.
You must not use the subwoofer output for this purpose.
Now connect a cable from the loudspeaker terminals of your amplifier to the high level MF and HF terminals of your 705a.
The manual goes on to mention polarity and also Relative Phase when connecting as above.
Instructions for connecting the high level inputs only are included (they actually recommend bi-wiring).

ninedecks
30-05-2012, 17:59
I should have added to my original post that I set my front speakers to accept the lf signal (Large?) from my AV amp.

Reid Malenfant
30-05-2012, 18:00
I really don't see the point in this in all honesty :D

I mean it's obvious that the bass section is active as they must have there own power amp & connect to the mains.

So why piss about with a seperate phono lead when it says you can't connect it to the sub output of an AV amp.

It would have been so much easier to do what others have done & simply use a resistor divider to get the high level inputs back down to line level from the main speaker inputs. Then process & squirt to the bass amp & driver :)

Dead easy, obviously just too easy for some manufacturers :lol:

ninedecks
30-05-2012, 18:38
The technical bits about electrickery tend to pass me by.
I've found a bit more info:
How the 705a works.
The Midrange (MF) and Treble (HF) units operate conventionally with regular crossovers. The two (one on the 704a) bass units are powered by a dedicated amplifier/crossover network.
High level signals fed in via the Bass loudspeaker terminals are are attenuated to reduce their output to line level before joining up with the Line Input.
The signal is then fed via the level control into the bass amplifier.

Does the above mean that the subwoofer output of the amp could in fact be used?.
David

Reid Malenfant
30-05-2012, 18:48
The two (one on the 704a) bass units are powered by a dedicated amplifier/crossover network.
High level signals fed in via the Bass loudspeaker terminals are are attenuated to reduce their output to line level before joining up with the Line Input.
The signal is then fed via the level control into the bass amplifier.
Thank gawd for that, that it the best way of doing it - an engineer with a brain :eyebrows: That is exactly the way I was describing to do it earlier!

Does the above mean that the subwoofer output of the amp could in fact be used?.
David
No, I don't think so as you'd create what would amount to a weird short circuit at line level ;)

However, as long as you were NOT feeding the midrange & treble speakers via an amplifier (it must be totally disconnected from the speaker cables) & just the line level to the subs, then yes you could :)

Reid Malenfant
30-05-2012, 20:44
I should have added to my original post that I set my front speakers to accept the lf signal (Large?) from my AV amp.
& I should add that that is how you should have them set so you feed maximum bass information to the speakers :) The powered sub side of things will then get full bass information & act accordingly :D