Adding a subwoofer

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sts9fan

Adding a subwoofer
« on: 27 Feb 2008, 07:53 pm »
Hi

I am strongly considering adding a subwoofer to my system.  My question is what is the best way to go about this. 
Do I
A) Just add it and do not worry about the signal going to my Druids?
or
B) Do something to attenuate the signal to the Druids say over 60-70Hz? 

I was thinking one of those Behriger DCX jobbys would do the trick nice but I am adding some processing to my nice simple system.  Is this worth it?  I am very interested in the approach people have taken to add subs successfully to your systems.

Kris

Loftprojection

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Re: Adding a subwoofer
« Reply #1 on: 27 Feb 2008, 08:17 pm »
Like you I was a bit afraid of subs and I thought it was not really needed for music since my speakers have great transmission line bass and go down to 40.  Well when I added the sub I thought I was going to faint!!!  Wow, a really nice improvement.  I did not change anything to the signal going to my main speakers but I played quite a bit with the various adjustments my sub plate amp has to fine tune the integration with my main speakers.  Have fun with the new project, subs rule but make sure you buy a real good one!  :icon_lol:

doug s.

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Re: Adding a subwoofer
« Reply #2 on: 27 Feb 2008, 08:24 pm »
imo, the best way to go is a separate x-over so your druids can be crossed as you suggest.  the druids  will then definitely sound better above the x-over point, imo, if they do not have to see any frequencies below that point.  this should be more true for most speakers, & more true for the druids than other speakers, as these drivers have to do all the music up past 10khz...

i would also definitely recommend stereo subs.  for an excellent crossover that will not break the bank, marchand is a great choice, imo.  i have not heard the less expensive pro-audio x-overs, but i suspect they would still offer an overall improvement to your druids if used in an active x-over subwoofer set-up...

doug s.

DSK

Re: Adding a subwoofer
« Reply #3 on: 27 Feb 2008, 08:44 pm »
Depending on the size of your room and how loud you listen etc etc, you may find that you do not need to add a HPF/XO to your main speakers.

I believe that when we really want to fool ourselves into believing that we are "in the room" with the performers, we turn the volume up until we "feel" it. IMHO it is the bass that we "feel" the most. When you add a sub you will not need to turn the volume up as high to get to the point where you and the room are energised by the bass and your main speakers will be less stressed as a result .... ie. the same result you are trying to get by adding a HPF.

sts9fan

Re: Adding a subwoofer
« Reply #4 on: 27 Feb 2008, 09:58 pm »
Quote
believe that when we really want to fool ourselves into believing that we are "in the room" with the performers, we turn the volume up until we "feel" it. IMHO it is the bass that we "feel" the most. When you add a sub you will not need to turn the volume up as high to get to the point where you and the room are energised by the bass and your main speakers will be less stressed as a result .... ie. the same result you are trying to get by adding a HPF.

Nice part about this is I can try it first and if I don't like it I can try a filter. 

doug s.

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Re: Adding a subwoofer
« Reply #5 on: 27 Feb 2008, 10:18 pm »
Quote
believe that when we really want to fool ourselves into believing that we are "in the room" with the performers, we turn the volume up until we "feel" it. IMHO it is the bass that we "feel" the most. When you add a sub you will not need to turn the volume up as high to get to the point where you and the room are energised by the bass and your main speakers will be less stressed as a result .... ie. the same result you are trying to get by adding a HPF.

Nice part about this is I can try it first and if I don't like it I can try a filter. 
you will probably like it.  get two subs & an active x-over, & you will like it more.    8)   easier to integrate into your room/system, as well...

doug s.

sts9fan

Re: Adding a subwoofer
« Reply #6 on: 28 Feb 2008, 07:22 pm »
ok so what active crossovers do people use/suggest?
I have been looking at
-Marchand XM9
-NHT X-2
http://nhthifi.com/current/manuals/current/X2_Manual.pdf

what else should I look at?

Kris

doug s.

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Re: Adding a subwoofer
« Reply #7 on: 28 Feb 2008, 08:25 pm »
ok so what active crossovers do people use/suggest?
I have been looking at
-Marchand XM9
-NHT X-2
http://nhthifi.com/current/manuals/current/X2_Manual.pdf

what else should I look at?

Kris
the nht looks nice, but i have never used one.  i'd query them about what the x-over slope is, tho - i would want at least 24db/octave x-over slope...

i have an xm9 - it's really nice, wery transparent.  tho i have never tried it, a few folk said it's better than the spendy bryston x-over...  the xm44 is also supposed to be excellent, even a hair better than the xm9. woodsyi recently upgraded his xm44 (i believe) to a marchand tube x-over (wery spendy), & he said it took his system to another place...   :wink:  i haven't heard the system since woodsyi made the change, but it's hard to imagine it sounding much better than it awreddy did.   :thumb:

also, as i mentioned before, pro-audio x-overs are supposed to be good for the money, (& not too difficult/expensive to get modded), but i have no direct experience.  brands to look for include, but are not limited to dbx, art, behringer, rane...  there are some pro audio x-overs that are quite expensive, w/a lot of dsp built in.  but, still relatively cheap compared to the audiophile-type dsp x-overs from tact & deqx.  i am presently using a deqx that i got a decent deal on, by purchasing used...

doug s.

sts9fan

Re: Adding a subwoofer
« Reply #8 on: 28 Feb 2008, 08:54 pm »
How easy is it to change the crossover point on the Marchand?

woodsyi

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Re: Adding a subwoofer
« Reply #9 on: 28 Feb 2008, 09:00 pm »
Kris,

I have a xm-9 2 way out on loan on west coast.  PM me if you want to try it with your sub.  I think there is only 70 Hz module and you'd have to get more from Phil if you want to try different poles.  I also have a XM44 you can try but it's 3-way. 

Edit:  You change frequency by changing the frequency module which were $12 a pair (hp and lp would be $24).
« Last Edit: 28 Feb 2008, 09:12 pm by woodsyi »

MaxCast

Re: Adding a subwoofer
« Reply #10 on: 28 Feb 2008, 09:01 pm »
How easy is it to change the crossover point on the Marchand?
It's pretty easy.  You yust have to replace two little black chips.
I have a mx-9 and xo'd at 40, 50 and 80.  I liked it best at 80 with norh 6.9's and a pair of Rava subs.

doug s.

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Re: Adding a subwoofer
« Reply #11 on: 28 Feb 2008, 09:02 pm »
How easy is it to change the crossover point on the Marchand?
extremely easy - you yust have to remove the cover, & plug in these li'l 8-pin mini-boards that have 4 resistors on 'em - two mini-boards per x-over point; 1 each per channel.  i think phil marchand charges something like $12/pair for each x-over point.

doug s.

sts9fan

Re: Adding a subwoofer
« Reply #12 on: 28 Feb 2008, 09:05 pm »
Thats a great offer thanks!  I am gonna build the subs so it is awhile off.  Just trying to plan things.  I will shoot you a PM later

Thanks again
Kris

opnly bafld

Re: Adding a subwoofer
« Reply #13 on: 28 Feb 2008, 10:03 pm »
ok so what active crossovers do people use/suggest?
I have been looking at
-Marchand XM9
-NHT X-2
http://nhthifi.com/current/manuals/current/X2_Manual.pdf


Kris

NHT X-2   even though it is 12dB/oct.

miklorsmith

Re: Adding a subwoofer
« Reply #14 on: 28 Feb 2008, 10:44 pm »
I'm going to cut across the grain here.  While I agree with the theory that lightening the burden on the main speakers can reduce amplifier and driver loads (See John Potis Bryston XO review), the Druids are really efficient and don't have the same ground to make up as other speakers.  Further, their drivers are wickedly burly and don't exhibit the strain with bass heavy stuff that other speaker/amp pairings do.

Further, the Druids' bass quality is excellent.  I don't see the utility in eliminating it.

Bear in mind, whatever sub you get will have its own low-pass XO.  If you do go the XO route, you really only need a high-pass filter for the mains.  When I had my Definition Pros I used these, high pass at 70 hz:

http://www.hlabs.com/technical/crossovers/

These won't mess up your sound and run about $30 a pair.  I'd start here if you want to dip your toe in the waters.

When I had the TacT units I played with all manner of XO settings with the Pros, I determined a steep setting at 65 hz was best.  Whenever there was overlap between the mains and subs, a muddiness would set in that would disappear once the overlap was removed.  I thought it was a phase issue but now that I have the Def. 2s with much better bass bin tuning, I can run the subs to 125 hz where the mains go down to 40 hz and they blend very well.

In fact, this creates a bipole at those frequencies in my room which adds space and depth to the aural illusion.

With the TacT units, I was running a $4k DAC that fed straight off the native TacT frequency.  All told, it was $10k of processor.  I came to a point where I believed the processing itself was holding me back and I abandoned it.  I would be wary of Digital XOs though I know they are gaining popularity.

For analog XOs, my sense is dealing with it at line-level is better than high/speaker level but if you can avoid it altogether I think that's best.  I don't think there's such a thing as a transparent circuit, just ones that are less bad.  IMO, of course.

If you want to get a sense of what's actually going on in your room, a quick sweep with the Room EQ Wizard is invaluable.  If you want to truly integrate a sub I would think it or something similar would be essential.

At the end of the day, I would try hard to get it to work without additional stuff.  You know for a fact adding components won't help transparency, at best they'll do nothing but split signal.  Spending money to add complexity should be a last resort if you absolutely need additional functions.

If you DO decide to go full-bore XO, the ability to run a parametric EQ off the bass output would be THE reason to do it.  If you go that way, don't half-ass it.

IMO, grain of salt, disclaimer, YMMV
« Last Edit: 28 Feb 2008, 10:55 pm by miklorsmith »

sts9fan

Re: Adding a subwoofer
« Reply #15 on: 29 Feb 2008, 01:07 pm »
Thanks for the thorough as usual answer Mike.  I will be building the subs first so I will try them first without and extra processing.  I have never been unhappy with the bass I am getting (actualy now with the Pass amps I LOVE it) just curious.  We shall see.  Thanks

Kris

doug s.

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Re: Adding a subwoofer
« Reply #16 on: 29 Feb 2008, 01:17 pm »
while the druid woofers are efficient, because they cover so many octaves, they will benefit more than normal woofers from being crossed over electronically, imo.  whatever 'veiling" an active x-over may add to the party, (extremely minute, imo, when done actively before the amp), it will be far outweighed by the drivers' output not having to see the lowest octave.  re: the harrison labs passive line x-overs, while i have never tried them myself, this is because i have heard more less-than favorable things about them than positive things.  but, they're so cheap, it might be worth trying.

i have tried active x-over between subs & main speakers w/many different speakers, & it always has resulted in across-the-board improvements.

ymmv,

doug s.

miklorsmith

Re: Adding a subwoofer
« Reply #17 on: 29 Feb 2008, 03:42 pm »
Possibly, I won't discount the possibility.  Zu heartily recommends against in-line XOs though as said before I was using one for some time.

My Def. 2s' main array covers the same band as the Druids and they don't need any assistance.  In fact when I had the TacT and ability to EQ the mains, I cranked the snot out of the 40 - 100 hz range to see what they could handle.  Answer - a ton.  It was surprising considering the miniscule subenclosure volume and sealed alignment.  Set up this way, it did interfere with midrange tonality but so does an overblown subwoofer that skews tonal balance - without any network interference with the mains.  The point here is the drivers are probably underutilized in standard alignment, not overworked.

Even so, the sub array can put out a LOT more juice down there.  The Druids are strong enough in the midbass that you could run into problems if there is frequency overlap.  Moreover, their bass isn't tuneable like a sub would be.  If you have to choose between the mains and subs from 40 - 100 hz or whatever there is definitely some advantage to that capacity.

On the Harrison Labs Fmods - they seem to lose a few dB of overall gain but once volume is compensated they're surprisingly good.  What frequency value you choose would depend on how tuneable the bass system is.  With a full parametric EQ I'd probably go for 120 hz, with "normal" sub controls I'd probably go for 70 hz.