Boom Boom Bass Bass Boom

[Wozy68]

Hi all,

Moved house and renovating. I've got my new 'AV' room wired up and so dug out my Arcam A85 Amp and CD72 CD Player (Believe it or not 10 years old and just about never used) installed them in their new cabinet, wired up my Mission 750s on their Atacama stands (again not used for probs 10 years) and switched it all on, let the Amp warm up and inserted a CD.

Sat back for some top quality tunes .................... and boom boom bass bass boom.

Gutted. The floor is a suspended wood floor with a 600MM or so gap to the ground beneath, and obviously the speakers are on stands, just surprised its so boomy..

Previously for the very short time I had it wired up years ago it was on a (non suspended) wood floor and was fine. I'm assuming its the floor, thing is what can I do about it?

Any ideas appreciated.

[BlueMR2]

They are definitely wired correctly?

Not just half of a bi wired setup?

[Wozy68]

BlueMR2 said:

They are definitely wired correctly?

Not just half of a bi wired setup?

Hmmm, well they were bi-wired years back at the speaker end, but they are not now at either the speaker or Amp. I couldn't find the bridging plates to have them wired in the normal manner so for now connect the top red and black speaker terminals to the btm red and black speaker terminals using small amounts of speaker cable.

Have I done a bad thing?

Edited by Wozy68 on Monday 24th June 21:55

[clived]

No, that's fine so long as you are sure the tweeters are actually connected - have you got up close for a listen?

Do you have the speakers in good free air or against the wall or in the corners?

[Crackie]

Wozy68 said:

Hi all,

Moved house and renovating. I've got my new 'AV' room wired up and so dug out my Arcam A85 Amp and CD72 CD Player (Believe it or not 10 years old and just about never used) installed them in their new cabinet, wired up my Mission 750s on their Atacama stands (again not used for probs 10 years) and switched it all on, let the Amp warm up and inserted a CD.

Sat back for some top quality tunes .................... and boom boom bass bass boom.

Gutted. The floor is a suspended wood floor with a 600MM or so gap to the ground beneath, and obviously the speakers are on stands, just surprised its so boomy..

Previously for the very short time I had it wired up years ago it was on a (non suspended) wood floor and was fine. I'm assuming its the floor, thing is what can I do about it?

Any ideas appreciated.

What are the room's dimensions ?

[OldSkoolRS]

Might be worth trying the speakers stood on heavy stone slabs as a test (garden patio slabs for example). If this solves it (though probably repositioning will help too) then you could buy something more elegant like a couple of granite plinths perhaps.

[Wozy68]

Crackie said:

What are the room's dimensions ?

The rooms is about 3.7 metres by 3.7 metres, with bookcases on three walls and an open fire place, the ceiling is around 2.7 metres.

The speakers are either side of the hearth of the fireplace, 1.2 metres away from a corner and about 350MM from the wall.

Good point about tweeters from another post. I'll check they are working. I assumed they are .........

[Wozy68]

OldSkoolRS said:

Might be worth trying the speakers stood on heavy stone slabs as a test (garden patio slabs for example). If this solves it (though probably repositioning will help too) then you could buy something more elegant like a couple of granite plinths perhaps.

Good point.

[outnumbered]

Wozy68 said:

The rooms is about 3.7 metres by 3.7 metres, with bookcases on three walls and an open fire place, the ceiling is around 2.7 metres.

The speakers are either side of the hearth of the fireplace, 1.2 metres away from a corner and about 350MM from the wall.

Good point about tweeters from another post. I'll check they are working. I assumed they are .........

Square rooms are notoriously bad for bass resonances. Once you're sure the tweeters are working, try some different positions for the speakers, there are lots of different setup guides on the web if you google it.

[Crackie]

Wozy68 said:

Crackie said:

What are the room's dimensions ?

The rooms is about 3.7 metres by 3.7 metres, with bookcases on three walls and an open fire place, the ceiling is around 2.7 metres.

The speakers are either side of the hearth of the fireplace, 1.2 metres away from a corner and about 350MM from the wall.

Good point about tweeters from another post. I'll check they are working. I assumed they are .........

There are some helpful freeware calculators http://www.mh-audio.nl/SG.asp which will explain which frequencies are giving you room mode problems; your room dims give big issues at 46.5Hz and 93Hz. These calculators will tell you what's wrong but won't fix it; this software costs buttons and should help a lot. http://www.hometheatershack.com/roomeq/

Good luck.

Edited by Crackie on Wednesday 26th June 06:42

[Wozy68]

Crackie said:

There are some helpful freeware calculators http://www.mh-audio.nl/SG.asp which will explain which frequencies are giving you room mode problems; your room dims give big issues at 46.5Hz and 93Hz. These calculators will tell you what's wrong but won't fix it; this software costs buttons and should help a lot. http://www.hometheatershack.com/roomeq/

Good luck.

Edited by Crackie on Wednesday 26th June 06:42

Cheers for that Crackie.. Very Interesting, thanks.

[Crackie]

Wozy68 said:

Crackie said:

There are some helpful freeware calculators http://www.mh-audio.nl/SG.asp which will explain which frequencies are giving you room mode problems; your room dims give big issues at 46.5Hz and 93Hz. These calculators will tell you what's wrong but won't fix it; this software costs buttons and should help a lot. http://www.hometheatershack.com/roomeq/

Good luck.

Edited by Crackie on Wednesday 26th June 06:42

Cheers for that Crackie.. Very Interesting, thanks.

REW will also be able to measure real time so you can optimise speaker position manually rather than using DSP processing; either way you'll need a mic and pre-amp / interface to measure the room. An ECM8000 mic http://www.gak.co.uk/en/behringer-ecm-8000/1059?gc... and audio interface like the Tascam US-122 http://www.gak.co.uk/en/tascam-us122-mkii/29799?gc... work well for this.

ARTA is an alternative free measurement software which extremely easy to use and very effective if you want use the manual positioning option rather than have complex DSP in the signal path. http://www.artalabs.hr/ .