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stpierre76's picture
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Mix and match subwoofers

Hi all,

I am after some info in regards to mix and match of multiple subwoofer for my dedicated HT room.
I know it s a big no no to mix different subs,different models.... But what about mix and match in this scenario:
Having one smaller sub like a BK XLS200 for the fronts connected via the high level and another sub like the monoliths plus for LFE.
Would that be a problem? Could I even do 2 monoliths plus for LFE and one XLS200 for each front?
All advice will be greatly appreciated.
Associated equipment is 3 in ceilings speakercraft Profile aim 8 five and profile aim Surround dipole, with a yamaha rxa3020., panasonic 7000 and a 130inch anamorphic screen. Room is 6.5m long by 4m wide and as already been accoustically treated by a professional ( cost me $3000AU.) and to be honest it sounds great already. I can t believe the difference between Pre treatment and after. In ceiling does not sound like in ceiling no more.WOW.
Sincerely yours
John

ric71's picture
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RE: Mix and match subwoofers

I personally am not sure if it would work but what I would say is if you are considering spending that much on four subs I would just buy one really  good sub which will play louder and deeper and should fulfill all of your needs. Consider the KK DXD 12012.  Will eat the BK's for breakfast.  

ellisdj's picture
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RE: Mix and match subwoofers

If you wired high level to the XLS200 and wired low level to the Monolith it would work ok - however you will be doubling up some of the bass there and that would probably cause cancellation so you would end up with less bass beleive it or not.  Unless they were out of phase with each other which I dont think they could be unless the low level wired sub was at the back of the room - might work?

 

Why not just buy an XLS400 and have the best of both worlds.  fantastic fast bass for music over low level and is a 400w 12" Peerless Driver based sub - it goes deep and strong, enough to rumble 90% of standard domestic rooms, you could double them up.

 

I have not tried it high level but I would expect the exact same performance

 

Anyone who wants 2 monoliths must live in a detached house and bit a bit bass mental Smile

Chewy's picture
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RE: Mix and match subwoofers

This issue crops up so frequently with so much misinformation offered as advice that I'm surprised WhatHifi haven't done a feature on it yet?! (Or maybe they have and I missed it!)

AFAIK there are three reasons for having more than one sub:

A: To help even the in room frequency response in the bass region and help combat room modes.

B: To add more SPL where the existing sub is not powerful enough to pressurise the room sufficiently

C: To allow subs to be used in a stereo configuration to supplement the bass output of the FR and FL channels in a stereo set-up. (This latter use is up for debate as bass is non-directional in nature below the cut-off frequencies used in the majority of cases, so one sub should suffice).

Where the reason for adding an extra sub is scenario B, you'd be better placed just getting a more capable sub. Where adding an extra sub is for reason A, two subs will perform better than one (of the identical model), and four will perform best of all.

Two subs, correctly placed in the room will help flatten peaks and troughs in the frequency response caused by modes in the room, i.e. where one sub creates a mode the other creates a null and visa versa - hopefully to the point where the summed output results in a flatter frequency response. Incorrect placement may make the in room response worse though.

You (the OP) state that your room has been professionally acoustically treated? If this is the case, your room modes should have been dealt with to an extent. In addition your room size is small enough that one sub should provide sufficient SPL alone. Running two in stereo with the FR and FL is frankly a waste of time and will likely make the in room response worse. For option A above to work correctly ALL subs should be sent the SAME signal, that being LFE and all bass frequencies below the cut-off frequency. Only then will their interaction correctly flatten the in room response.

To summarise then; either get four identical subs of good quality, or get get two identical subs of excellent quality - and send them all the identical signal. Placement and proper response measurement will be critical to ensure they are set up correctly.

martin morecroft's picture
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RE: Mix and match subwoofers

I agree with Chewy. I would go so far as to say that in many cases two seemingly inferior subs should outperform one good sub. I have not see a feature on two subs vs one in recent times and it should be covered. 

stpierre76's picture
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RE: Mix and match subwoofers

Hi all,
thanks for all your advice and input.
i think i will indeed go for 2 xls 400 as it will give me the best of both world at a reasonable price.
i am a little short on cash as i spent a few dollars on the rest of the equipment and room accoustics and can t really afford a big well known sub brand. keep in mind that the ht room was not the focus of my attention but my living room was where my martin logan are.
I also treated this room but to a much higher quality in order to keep wife happy and blend with the decor,where as the ht room it was about getting right, not looks.
i will try and evaluate if the BK xls400 is musical and fast enough for the ML theos and if i can pair them with success.ML subs are way out of my league at this stage.
i used vicoustic to treat the room. they worked off my floor plan, pictures and furniture to determined what was best suited.
for my ht room , m looking after something with a bit of slam for movie watching and in the living room, m looking for fast and musicallity to pair with ML theos with a tiny bit of HT slam when watching miovies when kids are in the HT room.
regards
jean

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