Active sub yes or no?

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rimljan99

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Active sub yes or no?
« on: 12 May 2006, 09:14 pm »
During some time I have listened few small speaker design with small woofer cones and I found some sounded extremely spacious, relaxing and fatigue free. And of course they are actually invisible in room.

Some use small bass cone (13 cm) and of course there is limited low bass, but anything above 80 Hz was fabulous.

I try also with some floorstanders, but in my room of 24m2 at first bass lines are better, solid but all the magic, spacious image suddenly gone from room.


I was thinking get one of those naughty small boxes and then add a quality active subwoofer like REL or B&W.

The question is, could sub destroy all the good things that came  from small boxes?:?

Some folks say that such small driver of 5" lack of midrange weight? Do you agree?

Thanks

rabbitz

Re: Active sub yes or no?
« Reply #1 on: 13 May 2006, 11:31 am »
Quote from: rimljan99
Some folks say that such small driver of 5" lack of midrange weight? Do you agree?


Phooey I say as a 5" is great in the right application. If you want absurd SPL's then it's not going to do the job but for sensible listening levels in a medium size room they are great. Small drivers such as these can still get down resonably low and I can get F3 of 55Hz out of the discontinued Peerless 850488 which carries the rhythm line well and maintains a beautiful mid.

A well designed floorstander with say 6.5" drivers still should still be able to give you great mids as well as good bass, but so often the bass dominates due to the design and /or room loading. I still prefer a floorstander to a standmounted / sub combination as it seems to integrate better and to do it properly for music, you need 2 subs. In one system I have a small sub to go with some 5" (2-way) and 4.5" (fullrange) standmounters and the sub is rarely turned on.

Too much bass can ruin music to these old ears.

Geoff-AU

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Active sub yes or no?
« Reply #2 on: 14 May 2006, 03:03 am »
I'm not a fan of subs in general, as they often don't blend seamlessly with the other speakers.  That said, if you like a really full sound then 5" midranges might not play low enough for you.  As rabbitz says an f3 of 55Hz is achievable.  The lowest notes on instrumental stuff (bass guitar, piano, double-bass) is around 40Hz, except for a 5-string double-bass which can hit 30Hz.

I designed my speakers with an f3 of around 50Hz and they sound great.  I wouldn't bother trying to integrate a sub with them.

I'm not really convinced that a sub would preserve the spaciousness of your music, if floor standers also killed it.

Tinker

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Active sub yes or no?
« Reply #3 on: 14 May 2006, 05:54 am »
These first posts really suggest that there is a large matter of taste involved. Perhaps you could borrow an active sub off a friend to get some idea what a sub would do for you?

I personally like subs. It is simply impossible to get good bass (i.e. low overhang below say 50Hz) out of a small speaker (unless you have a lot of small speakers), but single panels with multiple large drivers can suffer from imaging, diffraction, baffle step, re-radiation etc problems which tend to favour smaller units for nearly every factor except tight, powerful and phase-accurate bass.

A true sub needs to have a fairly low cutoff, otherwise it will be hard to blend an add-on sub with an existing set of speakers, and too high a cutoff will begin to interfere with the imaging unless you go with two subs close (i.e. < 1/4-1/3 wavelength at crossover frequency) to the main panels. I suspect these kinda of issues are at least partly responsible for the dissatisfaction some have with subs vs full-range speakers.

Bottom line is how low and loud do you want to go? For smallish live rooms you don't need a lot of bass below 50Hz.

T.

Geoff-AU

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Active sub yes or no?
« Reply #4 on: 14 May 2006, 06:34 am »
You're right Tinker, mixing large woofers and tweeters has its own compromises.  It's exceedinly difficult to make a speaker that covers most of the audible frequency range with few sonic penalties.

Quote from: Tinker
For smallish live rooms you don't need a lot of bass below 50Hz.


Yep.  Enclosed spaces get room/cabin gain.  This is an increase in response as frequency decreases.  In a car, it's the reason why you don't want to have a sub that's flat to 20Hz, because coupled with cabin gain you will end up with a HUGE amount of LF information.  Likewise for a modest listening room, big woofers will overpower the room.

stvnharr

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Active sub yes or no?
« Reply #5 on: 14 May 2006, 08:35 am »
Hello,
I personally find a good subwoofer can add a real low end dimension to the music unless one is already using a large speaker with a 12" or larger woofer.
Much of the difficulty with integrating subs to speakers is the 12 decibel rolloff of most subwoofer amp crossovers.  This gets the sub too much into the lower midrange.  All one really needs is just the stuff below 50-60 hz.  The trick is to find a sub with a 24 db rolloff.  Here is a link to one: http://www.customanalogue.com/sub_index.htm.  I have constructed this sub and can verify that is performs as advertised.  Hugh has heard this in my system as well.  The crossover is fixed at about 100hz. and has a 24 db. rolloff.  It only adds the low low bass, and give no integration difficulties at all for me.

andyr

Active sub yes or no?
« Reply #6 on: 14 May 2006, 09:25 am »
Wow, we certainly have a spectrum of opinion here ... so Im happy to throw the cat amongst the pidgeons!!  :D

1.  Rabbitz says he can get an f3 of 55Hz  Mate, you obviously don't listen to much organ music or string bass.  As you don't ... you'll be happy with the 5" drivers which you've got; me, I want an appreciable amount of signal at 30Hz (and lower if I can get it!  :)  I wanna hear that 16Hz organ pipe bellowing forth in all its majesty!!   :D

I've measured my Maggie IIIAs; their -3dB point is 40Hz ... but an Orion dual 10" Peerless woofer delivers far more bass than what I have!   :)   Strangely enough, the Maggies deliver the same output level at 30Hz - but the Orions have more more more!!  :D

2.  Same with Geoff-AU.  He's shown us the mathematical basis for the notes - but he's not interested in hearing all that a string bass can deliver live!   :?   Amaazing??   :?

And the statement "I'm not really convinced that a sub would preserve the spaciousness of your music, if floor standers also killed it" is idiosyncratic, to say the least.  Perhaps it was the fault of those particular floor-standers?  Or mebbe they weren't set up in the room-space correctly?

My floorstanding (well, actually they're 6' high by 2' wide) Maggies deliver spaciousness than few box speakers approach - but they don't have that Peerless-woofer bass!  :(

So if I want to maintain the spaciousness and the magic ribbon top end ... I gotta have me some cone subs!

3.  Back to rimljan99 ... I would suggest that for good music reproduction (ie. not dinosaur footfalls) he needs to add TWO active subs, one near each little speaker.  Using only one sub is simply a cost decision - but it compromises your sound.

Tinker agrees with me.   :)

4.  As stvnharr has commented, you need a sub with a 24dB LF rolloff AND you need to have this set at a low-enough frequency where the bass voice does not come from the subs.  This means a -3dB point of 80Hz, max ... and preferably the -6dB point should be 80Hz or even lower.

Rythmik Audio have such a sub; I've listened to it at DSK's place (mated with his Ambience ribbons) and I liked it so much I ordered one straight away (but I couldn't afford to buy the company!  :D  ).  

Regards,

Andy

Geoff-AU

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Active sub yes or no?
« Reply #7 on: 14 May 2006, 10:55 am »
Quote from: andyr
but he's not interested in hearing all that a string bass can deliver live! Amaazing??


Oh I'm definitely interested..  but can I afford it...  :mrgreen:

Actually the reason is my extremely small listening room (3x4m or so).  6.5" woofers are already too large for this room, I did design the box for an f3 of 50Hz but coupled with room gain I get some pretty low notes out of this setup.  And plenty of them :rock:

you could be right about the floor standers vs subs comment I made.  All other things being equal I'd say having 2 woofers closely integrated with the mids and tweeters sharing the same box would be more consistent than an active sub and simple filtering.  As you go on to say, maybe 2 subs are needed.  Then you're paying more attention to your setup, and approaching a true 3-way setup (except the subs are isolated from the main cabinets).

I haven't heard a really well done sub setup, but I did audition some very large speakers with a response of 30Hz-20kHz... and they sounded fantastic.

rabbitz

Active sub yes or no?
« Reply #8 on: 14 May 2006, 12:32 pm »
Quote from: andyr
Wow, we certainly have a spectrum of opinion here ... so Im happy to throw the cat amongst the pidgeons!!  :D

1.  Rabbitz says he can get an f3 of 55Hz  Mate, you obviously don't listen to much organ music or string bass.  As you don't ... you'll be happy with the 5" drivers which you've got; me, I want an appreciable amount of signal at 30Hz (and lower if I can get it!  :)  I wanna hear that 16Hz organ pipe bellowing forth in all its majesty!!   :D


What an arrogant and offensive post.... how do you know what I have and listen to?

My mains reach into the 30's easy but don't need it for organ music, yuk, as is not my taste, but others love it and good luck to them. The 5" comment was to show what can be achieved by a 5" driver and I can enjoy a speaker that goes down to 30hz as well as a Fostex fullrange that goes to 60Hz... I just enjoy the tunes.

A lot of what you say is valid and the stringing of words together could have been better. There is however other points of view, tastes, applications, budgets etc.

Man, what's the deal with commercial speakers on a DIY forum... get out and make some MDF dust. Yeah I know what the Peerless 830452 can do as I've got some.

andyr

Active sub yes or no?
« Reply #9 on: 14 May 2006, 12:53 pm »
Hi rabbitz,

As I enjoyed the Orions I listened to back in Feb so much, I'm currently planning on building some ... weeell, not Orions exactly but NaOs.

Trouble is, in spite of being able to afford "commercial" speakers (my 18 year old Maggies - e.i.g.h.t.e.e.n years old, mate .... not exactly a million $ worth!!), I can't afford to put up for approx $3,000 worth of parts until I sell my Maggies.  Unfortunately, not too many people seem to be interested in buying them ... or maybe it's just the age-old problem of finding those that ARE interested!  :)

And BTW, if I can take issue with what you said ... "what's the deal with commercial speakers on a DIY forum?"

This is not just any old DIY forum ... this is the Forum for people who have built - or are planning to build - AKSAs, sport.  As you can see from the date against my name - and the number of posts I've done - I probably actually HAVE done some DIY.  In fact my 4 AKSAs, my GK-1, my active crossovers and my phono stage are ALL diy ... so don't dump on me just because I haven't built my speakers.

In fact, my Maggies are so heavily modified they almost are DIY, too!   :D

Happy listening,

Regards,

Andy

PS: I said I was going to throw the cat amongst the pidgeons!   :D

Geoff-AU

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Active sub yes or no?
« Reply #10 on: 14 May 2006, 01:35 pm »
I'm sure you could find someone to take a pair of 18 year olds off your hands andy ;)


I built my own P17WJ/D25AG speakers about 3-4 years ago, and have been tweaking them ever since (although recently I made up some grilles for them and redid the crossovers and tweaked the amount of damping material and said THAT'S IT...  next mod will be new speakers.  heh).

rabbitz

Active sub yes or no?
« Reply #11 on: 14 May 2006, 01:40 pm »
Hi andyr

What's NaOs?

Yeah... it gets difficult selling older stuff even though it can be much better than new stuff. I keep going back to an old CD player I've had for 15 years with the newer ones not doing it for me, so age is of little importance in the end.

I had to get that dig in on the commercial speakers... allow me some points. You haven't lived until you've built some speakers.  :wink:

A question.... your GK-1.... are you running the sub from after the solid state stage or after the tube stage?

Keep that friggin cat away from us pidgeons.  :lol:

rimljan99

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Active sub yes or no?
« Reply #12 on: 14 May 2006, 02:09 pm »
Thanks for replies :D

I build AKSA 100N some time ago and I am still searcing for right speakers for my room.

I have tested and owned some speakers. The previous set of speaker I sold, becouse they sound thin and lack of deep bass . But now I got some floorstanders with really deep bass I was looking for, but this bass of course make some troubles in my room with resonances and masking other sonic parameters: space, air, midrange fluidness.  

I listened some diy speakers at my friend with Excel 4.5" midbass. Small box but speakers virtually and sonically dissapear.

I questioned myself is it worth ? Do I really need some real deep bass?

And more I thinking and experimenting, more I  feel  that small speaker works better in small to moderate sized room.

But to get or not to get some help from subwoofer friend this is the question now 8)

andyr

Active sub yes or no?
« Reply #13 on: 14 May 2006, 09:30 pm »
Hi Geoff,

Yes I'm sure someone who wants "Maggie-sound" will come across them eventually!   :)

Hi rabbitz,

NaOs are a design and crossover PCB put out by John Kreskovsy - see here:
http://www.musicanddesign.com/naomain.html

They use the same dual Peerless 10" woofers as the Orion but in a U-frame rather than an H-frame.  And the mid-tweeter crossover is at 2500Hz which, to my way of thinking, is preferable to the 1450Hz of the Orion.

You can construct them in an all-active version (which needs 4 AKSA channels per side) or a hybrid ... for which you could get away with 2 AKSAs.

When I get the subs (if I keep my Maggies), yes, I'll run them off the ss output of the GK-1.

Hi rimljan99,

Yes you should get a pair of subs - not necessarily to give you loud bass ... but to fill in the 3 octaves which those 4.5" drivers probably aren't delivering.

Regards,

Andy

stvnharr

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Active sub yes or no?
« Reply #14 on: 15 May 2006, 12:26 am »
AFAIK, Rythmik Audio is only other subwoofer that can be set up for 24db. rolloff.  I looked into them, but my budget was more diy friendly.  I think Joe R. is only one who publishes frequency response of his actual sub, and it's quite accurate, as per my listening experiences.
I only use 1 subwoofer.  If set up properly, and only supplying the low low frequencies, 1 sub is enough.  Of course if space and other things allow, 2 subs work nice.

For a speaker with only a 4.5 woofer, some bass reinforcement is really necessary unless one only listens to music with no bass.

Also, I run my sub out of my GK-1 direct off the attenuator and bypass the output stage.