Sub xover

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bonzo

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Is it better to:

1. Get a hybrid and a sub
2. Get a full range that goes deep, like Apogees, Audio Exklusivs, etc and xover into the sub at the bottom of the full-range
3. Get 2 but xover well before the bottom of the full range (around 100 or so)
4. Get something like the CLX which doesn't go that deep, and xover into the sub.

What should give a better integration, and sound for orchestral and rock music?

Here is room correction is applied to the sub only, that will leave the panels unmolested?

Jon, Ken?
 
First, let's get one thing out of the way, there is no such thing as a 'full-range' dipole. The physical laws of rear-wave cancellation are not repealable. Some models do better than others, but none can deliver the bass slam of a closed-box alignment.

So in my book, any ESL needs to be crossed over to a sub, and ideally, multiple subs to manage room modes. So all those systems with subs symmetrically placed next to the ESL towers are usually wrong in terms of maximizing the benefits of mode management.

From your list, I assume we're playing the cost-no-object game here, so my ideal setup from your list would be a pair of CLX, crossed over at around 80Hz with a 24 or 48dB/Octave slope to a pair of BalancedForce 212's. Run PBK individually on them, then use a Pre-pro with a good DRC and bass management (for the crossover). The DRC in the pre will ensure a smooth blend (time aligned and frequency balanced) of all the speakers and to the room.
 
Thanks. I want to keep the panel sound preference out of the consideration set here. So when you say CLX, is that because crossing it at 80 is better than crossing over at 80 another panel that actually goes down to 40 (That's what I am trying to understand)
 
What Jonathan said.

No panel (yes, I"ve heard the big Soundlabs many times) will provide IMHO adequate dynamics at low frequencies even in a music-only setup. And, as Jonathan and I have said many times, linear bass with good decay characteristics is best achieved by multiple subs invariably not collocated with the mains.

IME, mains/sub Xover should be at the highest frequency which avoids bass localization - typically around 80Hz. Not only are the subwoofers almost always better at reproducing < 80Hz than mains, the higher xover relieves the mains woofs from LF "heavy lifting", and results in lower distortion, cleaner bass from 80Hz and up.

Kedar, you know my views re: room correction i.e. full range can provide substantial improvement vs. bass only correction, provided the RC product is well-designed mixed-phase, and provides target curve adjustment. At the moment, that's Dirac or Trinnov, and I'm heavily biased toward the latter as it has far more flexibility.

The only area where Jonathan and I have diverged is in subwoofer type. He likes sealed and IB, possibly/probably because he's looking for chest-thumping bass in his movies+music room. In my music-only room, I'm happily exploring OB subs, because IME they have terrific decay characteristics and they don't pressurize the room. That exploration is still a work in progress.:music:
 
Thanks. What are OB and IB subs? I am not looking for chest-thumping. I am looking for better cellos in orchestral, for power chords/bass in rock, and I have seen sometimes subs can add certain thickness to the mid. I don't want to hear the sub.

Also, if you suggest x-over at 80, is it better to have a panel that goes down not too deep, like the CLX, in which case the xover naturally comes at the panel's low, or does it make any difference if I have a panel that goes down deeper but I forcibly cut it off at 80, much above it's bottom?

When it is not co-located with mains, the time-alignment of the two is important, correct?
 
Ken and Jonathan summed it up perfectly !!
 
Thanks. What are OB and IB subs? I am not looking for chest-thumping. I am looking for better cellos in orchestral, for power chords/bass in rock, and I have seen sometimes subs can add certain thickness to the mid. I don't want to hear the sub.
OB = Open Baffle i.e. no sealed cabinet and the drivers act as dipoles
IB = Infinite Baffle i.e. they're typically built into a false wall with a relatively large (many cubic feet) space behind the cone

Thickness could be many things, like one or more peaks in the FR, poor decay characteristics, or just plain poor setup.

Also, if you suggest x-over at 80, is it better to have a panel that goes down not too deep, like the CLX, in which case the xover naturally comes at the panel's low, or does it make any difference if I have a panel that goes down deeper but I forcibly cut it off at 80, much above it's bottom?
Because the high pass half of the xover means that the main is still reproducing content well below the nominal xover point, you need the main to provide adequate output well below that point. For example, a 4th order LR xover @ say 80Hz means that the main will be 24dB down at 40Hz - one octave below the xover point, and you need your main to be able to do that.

When it is not co-located with mains, the time-alignment of the two is important, correct?
Absolutely. Delays and gains must be set properly.
 
... The only area where Jonathan and I have diverged is in subwoofer type. He likes sealed and IB, possibly/probably because he's looking for chest-thumping bass in his movies+music room. In my music-only room, I'm happily exploring OB subs, because IME they have terrific decay characteristics and they don't pressurize the room. That exploration is still a work in progress.:music:

Hi Ken, one thing OB and IB's have in common is the lack of linear compression distortion that traditional box-based alignments have, as both an IB and OB drivers are essentially operating in 'free air'. So both offer very low THD. Much lower than sealed and big time better than ported ;-)

I'm very lucky that my IB back chamber is identical in volume to my room, so the symmetry in air-load is consistent at all volume levels.

However, the chest slam comes from the mid-bass (60 to 400hz) which is why I went with a line-array for the center channel and tuned the other woofers for that range.

What an IB does is deliver low distortion, high-SPL in-room pressure changes. My ears have popped, the door to the HT has been sprung open by the sheer intensity of the shaking and pressure change. You've not heard bass until you hear a big IB do it's thing. OMG, people run from the room (literally, I had someone freak out during a demo)

Yet it is incredibly clean, 'fast' (hate that word, but people use it) and measure very well. My center + IB measure in at 0.6% THD at 75dB SPL. That's in, room, through the whole audio chain including speakers, and better than some amps out there.
 
Thanks. What are OB and IB subs? I am not looking for chest-thumping. I am looking for better cellos in orchestral, for power chords/bass in rock, and I have seen sometimes subs can add certain thickness to the mid. I don't want to hear the sub.

Come hear my set up, you will not 'notice' the sub in music, there is just a wide frequency range covered and a dynamic range that is consistent up to 105dB SPL (the power envelope).
Thickness is typically room induced or bad sub/speaker design, or poor integration.

Also, if you suggest x-over at 80, is it better to have a panel that goes down not too deep, like the CLX, in which case the xover naturally comes at the panel's low, or does it make any difference if I have a panel that goes down deeper but I forcibly cut it off at 80, much above it's bottom?

What Ken said. + the CLX is rated only down to 60Hz F3, so I'd use a fourth-order (48dB/octave) slope in the xover. Even then, the DRC might have to push the sub to 'fill in' a bit near the xover.

When it is not co-located with mains, the time-alignment of the two is important, correct?

Absolutely. I've spent hours looking at impulse response measurements and tweaking delays in 0.1ms increment to get my system perfectly time-aligned. That's between woofer and panel and sub to woofer.

I'm adding one more sub this summer, so the fun will start all over again, as this new one will be at the opposite end of the room (mid back-wall)
 
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Come hear my set up, you will not 'notice' the sub in music, there is just a wide frequency range covered and a dynamic range that is consistent up to 105dB SPL (the power envelope).
Thickness is typically room induced or bad sub/speaker design, or poor integration.

Yes, my next stage will be experimenting with some pre and powers in my system and some room tweaks, after which I will go to subs and RC (speakers, cables, and dacs/cdps I have more or less scratched my curiosity itch) - so I guess I will have to check yours and Ken's system before that.
 
What Ken said. + the CLX is rated only down to 60Hz F3, so I'd use a fourth-order (48dB/octave) slope in the xover. Even then, the DRC might have to push the sub to 'fill in' a bit near the xover.

I seem to recall a comment that Martin Logan might have been slightly conservative in respect to their published 56Hz due in part to the methodology in which that figure was arrived at. I shall en devour to dig it up. In the meantime~

Noel K, from the HiFi World review,

"Below 700Hz output is on average 3dB up, right down to 55Hz no less, Our measurements show the CLXs go very low, down to 40Hz (-6dB), which is lower than most box loudspeakers, and their dipole radiation pattern little excited our listening room's main mode at 24Hz, something I also noticed in use."

James Tanner also made some interesting points regarding Sub's with CLX's, with the caviat, that he wasn't utilizing either ML sub's, ergo nor ML's CLX>Sub crossover module.

" Subs?:
I tried the CLX's with a pair of powered subs I had available and it was a frustrating experience to say the least. I felt I could 'flesh out' the sound a little on the bottom octaves (below 60Hz) but it seemed to throw off the coherency and speed of the panel on it's own. I ended up scrapping the sub idea and continued listening to the bare panels. Again if your looking at a home theatre setup or high sound pressure levels then the sub(s) will certainly provide a more robust sound then the panels can on their own. To some degree I think 'sub or no sub' will be the salient point for most people when it comes to the CLX's. The ability to use and integrate a subwoofer will be mandatory for some and irrelevant for others. Martin Logan has a sub dedicated to the CLX's so that may be my next move. One of the problems is that even though you insert a sub that helps add body to the very low frequencies (60 to 20Hz) integrating it with the power response of the panel between 60 and 300Hz is a problem not easily solved."
 
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Jonathan, having suffered the extreme stress of tinnitus for about a month (mercifully, it went away), I'm very careful of the SPLs to which I subject my ears. If in a listening session your ears have popped and a door has sprung open, you are listening at too high a level.
 
Hi Ken, one thing OB and IB's have in common is the lack of linear compression distortion that traditional box-based alignments have, as both an IB and OB drivers are essentially operating in 'free air'. So both offer very low THD. Much lower than sealed and big time better than ported ;-)

I'm very lucky that my IB back chamber is identical in volume to my room, so the symmetry in air-load is consistent at all volume levels.

However, the chest slam comes from the mid-bass (60 to 400hz) which is why I went with a line-array for the center channel and tuned the other woofers for that range.

What an IB does is deliver low distortion, high-SPL in-room pressure changes. My ears have popped, the door to the HT has been sprung open by the sheer intensity of the shaking and pressure change. You've not heard bass until you hear a big IB do it's thing. OMG, people run from the room (literally, I had someone freak out during a demo)

Yet it is incredibly clean, 'fast' (hate that word, but people use it) and measure very well. My center + IB measure in at 0.6% THD at 75dB SPL. That's in, room, through the whole audio chain including speakers, and better than some amps out there.
Hi Jonathan. You're very lucky to have the space required to implement IB. For good or ill, it's not practical within my space constraints, and I'm deliberately avoiding room pressurization - that's why I sold off my SubMersive and started exploring dipole subs. If I were showing movies in the room and looking for gobs of <25Hz response, certainly I'd need to go another direction.

...so I'd use a fourth-order (48dB/octave) slope in the xover....
You're typing too fast! I'm sure you meant to say 8th order, 48dB/octave.:) Wish I had an 8th order option on my Trinnov.....
 
In my experience, I'd recommend xover 2x subs (to help deal with room nodes as mentioned already) positioned wherever results in the most seamless, best integrated bass possible. There is no 1 best location; I've heard subs sound fantastic in 100K - 1M+ systems behind the mains. I have also heard phenomenal integration/quality bass from rear wall placement, it depends on your room dimensions and setup. Also, there is a direct relationship between integration and xover freq - the higher you go (e.g.: the closer to your main's freq range), the more difficult seamless integration becomes, not to mention issue with localization of sub sound. Once above 60 Hz or so, sub audible output becomes apparent, which may limit your placement locations. Last tip - Let your mains do as much of the work as they can, and use the sub only for the lowest of lows that your mains cannot. Doing otherwise can create muddy bass and can blur imaging, IMO. Sub choices - Rel subs (British made not Chinese made - Stentor's a great choice) or JL Audio.
 
I tried running a Descent with my diploes for quite a while. It just didn't work.

Why? The nature of bass radiation from a Descent is totally different to the Apogee bass panel. It tends to thud with it's long throw and lowish surface area. It also travels through walls with the "punch effect" it produces and made my wife pretty unhappy 1 floor up on the other side of the house. It was a good stab for a sub, though. I liked the philosophy behind it. And that's just it - you can theorise as to why something should be better, but when you hear it the theory doesn't necessarily line up with what you are experiencing.

The Duettas hits 25Hz in room no problem +/- 0DB - in fact they are well up at 30Hz if your ears are close to the rear wall. And as Bonzo knows they do sound very dynamic indeed. No ESL can match it. None I've heard anywhere get close to it in the bass department in terms of power, speed and slam.

So - been there, done the sub thing, and rejected it. Just my opinion though folks.

Also, many recordings contain stuff you just don't want to listen to at LF - pure crud and gunge in some cases. Even Dark Side Of The Moon contains some pretty odd LF in places. The Descent was fun with movies cranked to silly levels, though.
 
For music, I get the best integration by running my SL3s full range and crossing over my REL T1 sub at 30 Hz. This gives me sufficient three-dimensional sound stage and bass augmentation, but one cannot hear the sub per se. DRC is implemented through a DSPeaker AntiMode Dual Core which corrects mains and sub as a 2.1 system. It all works very well to preserve the transparency that is ML's hallmark while providing for a flatter response in the lowest octave. I was surprised to note how little bass augmentation the SL3s actually need.
 
For music, I get the best integration by running my SL3s full range and crossing over my REL T1 sub at 30 Hz. This gives me sufficient three-dimensional sound stage and bass augmentation, but one cannot hear the sub per se. DRC is implemented through a DSPeaker AntiMode Dual Core which corrects mains and sub as a 2.1 system. It all works very well to preserve the transparency that is ML's hallmark while providing for a flatter response in the lowest octave. I was surprised to note how little bass augmentation the SL3s actually need.

I agree. My Ascents didn't need much either. I think subs are best with AV stuff, when turning the sub's levels up for explosions really can be great fun.
 
I tried running a Descent with my diploes for quite a while. It just didn't work.....
Hi Justin, Can I ask you to clarify a few things?

  • When you say "thud", do you mean the drivers are hitting their stops? At what kind of volume is this happening?
  • Can you describe "punch effect" in general terms? Is the room sealed or open to other areas?
  • What were you using for a crossover, at what frequency and with what slopes?
  • How did you select the subwoofer location?
  • What process did you use to set gains and delays?
  • How did the combined response measure for FR and decay?

And in re: your Apogees, how loud will they play a 25Hz tone without audible distortion, or better still measured <10%?

Also, many recordings contain stuff you just don't want to listen to at LF - pure crud and gunge in some cases. Even Dark Side Of The Moon contains some pretty odd LF in places. The Descent was fun with movies cranked to silly levels, though.
I'm with you here. Dunno about DSOtM, but I have a number of albums where the mastering engineer apparently forgot to low-pass the bass, leaving non content related VLF "grunge", and forcing me to invoke a 25Hz low-pass to improve the SQ.
 
It was definitely sub-optimal, Ken, if you'll forgive the pun.

All I had was the Descent's controls at the time. I couldn't get it to kick in low enough. Also, only one Descent, placed off centre against the front wall - deliberately so, as in the middle caused weird sounding anomalies.

Phase was set by ear - 90 degrees if I remember.

With adequate power, and I mean a lot - 400 Watts plus (A21 territory), the 25Hz output will be quite substantial, and the panel movement extremely visible. They really do move with balls. I can't be any more accurate than that. Even with my tube amps I can play pink noise at 90DB and they still measure flat at 25Hz. That's pure hell, though, pink noise is annoying. I haven't tried more.

A 15 Hz test tone produces massive excursions but I'm sure output is well down below where it should be. Speaker damage with sufficient Watts is probably a certainty.

Distortion is low generally - less than many power amps. Getting 10% at 25Hz? Loud I expect.

The thud is simply caused by high excursion drivers with lowish surface area. Think cars with subs. You can hear them coming from a huge distance.

You could easily set the sub up better than I did Ken. Even if you did, I still don't feel it would be worthwhile. Others may not agree. Just down to personal taste.
 
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