[Quiet Earth]

my direct experience is that the speaker level yields much better results than line level inputs on REL

That's basically all I was wondering. Have you compared the line vs. speaker level inputs with the same sub and do you have a preference? (while running the mains full range - no high pass crossover)

FWIW, I don't mind generalizing on the topic since it's a general question. The speaker level concept actually makes more sense to me (regardless of brand name), because the sub will see the exact same signal the main speakers see. Perhaps that is why the sub would integrate better?

I haven't used a sub in a long time, so I thought I would check in with you guys and see what you have experienced.

[mark funk]

Thats is how I run my sub. Speaker level input.



                                                                                                   

[Davey]

If you sample from speaker-level that means you can't high-pass your main speakers.  Your only option then is to high-pass the main speakers with large electrolytic capacitors downstream.

Do you fellas not see the basic problem with that?

Cheers,

Dave.

[roscoeiii]

That's basically all I was wondering. Have you compared the line vs. speaker level inputs with the same sub and do you have a preference? (while running the mains full range - no high pass crossover)

FWIW, I don't mind generalizing on the topic since it's a general question. The speaker level concept actually makes more sense to me (regardless of brand name), because the sub will see the exact same signal the main speakers see. Perhaps that is why the sub would integrate better?

Yes, for the REL Storm III, I compared line level with speaker level and had a clear preference for speaker level. IIRC, REL recommends line level for home theater applications where there may be an LFE output of a receiver. On many RELs there are separate crossover adjustments for each input, so you can tune the sub for different applications (music vs. HT mainly, I'd suppose).


I worry about generalizing because not all implementations of any design are created equal (be it crossover, amplifier topology, etc). At the very least I think it is important to point out when specific implementations are somehow unique, thus meaning that some generalizations may not apply.

[roscoeiii]

If you sample from speaker-level that means you can't high-pass your main speakers.  Your only option then is to high-pass the main speakers with large electrolytic capacitors downstream.

Do you fellas not see the basic problem with that?

Cheers,

Dave.

As I think I mentioned earlier in this thread, I find that speaker-level connections only make sense when you do not need to high pass your mains. If your amp and/or speakers would be best served by high passing then I wouldn't recommend a speaker level sub connection.

[DaveC113]

Do you fellas not see the basic problem with that?

Cheers,

Dave.

LOL, wut? 

[Quiet Earth]

If you sample from speaker-level that means you can't high-pass your main speakers.

Hi Davey,

Yes, that was the scenario I was constructing. If you already have two full range speakers and you just want to try the multi-sub scheme, or if you are just looking to add a little ultra-low frequency energy into the final mix,  then you may not want to cross over your mains. Is this a bad idea? It seems a lot simpler and a lot cleaner to leave the mains alone if they can already go below 30Hz. Maybe I am overlooking something?

I worry about generalizing because not all implementations of any design are created equal (be it crossover, amplifier topology, etc). At the very least I think it is important to point out when specific implementations are somehow unique, thus meaning that some generalizations may not apply.

No problem roscoeiii. I think we all agree with that. But we have to start the ball rolling somewhere don't we? We can always qualify the generalizations during the discussion. I think we did. Thanks!

[*Scotty*]

From Quiet Earth,

It seems a lot simpler and a lot cleaner to leave the mains alone if they can already go below 30Hz.

That is what I do in my system in as much as my front speakers already hit 20Hz. I use line level from my preamp to my supplemental subs in a CABS arrangement in my L shaped room. In my room this is the most convenient setup from a cabling standpoint. My preamp has 4 outputs and I use two of them for the subs at the rear and side of the room.
 I don't need to add bass, but I do need to try to eliminate the standing waves caused by the planer bass wave from the front speakers reflecting off of the wall behind me.
http://www.audiocircle.com/index.php?topic=106838.0
http://vbn.aau.dk/files/12831869/AC-phd.pdf
Scotty

[Davey]

If you high-pass the mains (preferrably at line-level) you will reduce cone/panel excursion (reduced distortion and higher SPL capability)....you could possibly use a lower powered amplifier....you can achieve a more symmetrical acoustic crossover....etc....etc.

If a person's only objective in using a sub-woofer is to augment an already existing "full-range" speaker then I understand the concept of not high-passing the main speakers.  But then you lose the (possible) advantages I just described.

I still don't see any inherent advantage in picking up the subwoofer signal after the amplifier vice before.  I know you fellas are asserting it's preferrable because the sub-amplifier then "sees the same thing as the main speakers."  However, I don't buy that's any inherent advantage because of what I outlined previously about the main amplifier being a voltage source.

Cheers,

Dave.

[*Scotty*]

If you high-pass the mains (preferrably at line-level) you will reduce cone/panel excursion (reduced distortion and higher SPL capability)....you could possibly use a lower powered amplifier....you can achieve a more symmetrical acoustic crossover....etc....etc.

The potential advantages outlined above are subject to how a particular loudspeaker is designed. If your mid-ranges are already crossed over at or above 150Hz and you have adequate low frequency capability then no advantages will accrue.
A full-range speaker such as the one pictured below will see no improvement.

Scotty

[chrisby]

Then again,  there are some folks that like playing with small (3-4")  "full range" drivers (name your flavor favorite), with which the advantages line level  HP in the upper bass to lower mid-bass region ( e.g. from 120 to as high as 300) can be substantial .

Even at the high end of this frequency range,  the cost of quality passive parts ( i.e. "audiophile grade " Film vs EL caps, and air core inductors etc) can be substantial -  whereas passive line level can be achieved  for a fraction of the cost (a tidy little project case and jacks can easily factor by several times the final expense).   

Since the application under discussion assumes use of some sort of plate amp including LF filter,  something as simple as a first order HP for the "mains" can be effective enough.

[roscoeiii]

If a person's only objective in using a sub-woofer is to augment an already existing "full-range" speaker then I understand the concept of not high-passing the main speakers.  But then you lose the

I still don't see any inherent advantage in picking up the subwoofer signal after the amplifier vice before.  I know you fellas are asserting it's preferrable because the sub-amplifier then "sees the same thing as the main speakers."  However, I don't buy that's any inherent advantage because of what I outlined previously about the main amplifier being a voltage source.

Cheers,

Dave.

It is all about trade offs. Davy mentions many excellent reasons to high pass. Speaker level for some systems will integrate better. But this is worth it only if he issues Davey mentions are not going to be big problems for your speaker and amp.

[Carl V]

Not being the expert as many of the others in this thread.
Back in the day (early 80's) I bought my 1st 'serious' system
PV-5 MV-50 & 2C speakers, Dennon TT, Nak Dragon. The
next big step was 2W, then another MV-50 then another
2WQ.  that same system has simply been updated. Better
PV-12,  MV-52 (MV60SE) 2Ce i then Sig etc. etc.  it still does well.
I've been on this merry go-round sine 1978. Trying this-n-that.

Mr Vandersteen's subs use a variation of Line/speaker level.
They work quite well.  I've used them in other audio systems
& HT systems.  That being said successful integration has also
been achieved with either Line Level & speaker level...when I have
used clean Active X-overs & EQ after measurements.  Takes some work.

I've owned Velodyne,Snell,MJA & REL  amongst others (DIY).
And when it comes to REL always used speaker level with a good deal of
XO adjustment & room placement. MJA with Speakon speaker level.
Successful implementation
is not always a result of a "specific gear/technology or theory---but set-up" imho.

That being said, I've been told that some tube amps EL-34 UL for instance
don't respond well to high voltages in the bass regions of the Freq Spectrum.
Something about Transformer Saturation etc., Many SE amp topologies are
are subject to some of the same problems.  Which explains why some of the Amps
I've owned have larger regulated PS or Better Transformers, which cost more & more often
perform better.

[Davey]

Speaker level for some systems will integrate better.

Speculation?    You jumped on me for speculating.

There's no technical reason for that to be the case.
A picked-off signal at the power amp output is the same (for this purpose) as the signal at the power amp input (except it's amplified in voltage.)  You can then reduce it via a voltage divider or some other means and use it to feed the subwoofer amplifier line-level circuitry.

Unless of course this is some horrible power amplifier with wild frequency response swings.....or some other wild inaccuracy.    And in that case, you would say that a line-level connection would be preferred.

Cheers,

Dave.

[roscoeiii]

Speculation?    You jumped on me for speculating.

Nope, not speculation. Direct experience and comparison. My REL Storm III with SP Tech Minis sounded far better via speaker level. This was comparing it to using the REL at line level (with high pass via an NHT X2). This single REL Storm III via speaker level was also preferable to my dual NHT subs with the X2 crossover providing high and low pass. This despite all of the advantages that dual subs can provide over a single sub. The REL via speaker level just sounded better.

Maybe look for some REL reviews or literature for details on why that may be. In most of those reviews you will find others who report better integration via speaker level. I have clearly stated above that there are certainly systems for which a speaker level connection will not work well. BUT there are some in which it is musically preferable. MY SYSTEM for example.

There are surely technical reasons for this (and no I don't have the time to research these for you). They just don't happen to be the technical aspects of subwoofer integration that you are focusing on (which I agree are very important, particularly for certain main speakers and certain main amps).

Any system and component design is going to have trade-offs. Nature of the beast.

[Davey]

Apples to oranges comparison with an extra variable.  Do you not see that?

The technical reasons are proprietary (at least for REL) are they not?  That's why I asked you about their "high-level circuitry" earlier in this thread.  (You had no information.)  You are as ignorant as I am on this magical REL high-level circuitry.  But you're not speculating. 

And why would I spend time researching proprietary technical reasons when, because it's proprietary, I would come up empty? 

Anyways, how does using a product become "direct experience" with it?  If I drive a Toyota Camry do have "direct experience" with how their engine management system works?

Cheers,

Dave.

[roscoeiii]

Look this is tiring. I have direct experience with a REL using speaker level which is what sounded best in my system. Not sure how these permutations that I used are all apples to oranges (though some are). I compared all the combos possible of what I had on hand. REL with line level and main speakers full range, REL with line level and speakers high passed, REL with speaker level and mains full range, and dual NHT subs, with speakers high passed and full range. REL with speaker level won that competition.

This is a thread in the Bass Place not the Lab, and the OP asked "do you prefer the sound." I am not interested in why a Camry drives better and a Corolla, only whether it does or not according to the driving criteria important to me. Similarly to my assessment of audio equipment. There are technical reasons as well as reviews that lead me to choose what I want to audition, but it comes down to the sound in my system, in my room, according to my preferences.

I have direct experience with the REL. LISTENING. Nope I don't know anything about the details of its speaker level integration. I don't even know enough about the REL speaker level integration to speculate on it. It is my impression from reading reviews and from REL literature that their speaker level circuitry is somehow unique. The fact that the REL was the first sub I have had for which I preferred the speaker level is supporting evidence.

For any reader of this thread: MY ADVICE IS TO AUDITION IN YOUR SYSTEM.

OK, I have said what I feel needed saying. Good bye.

[doug s.]

unless my main speakers already had their woofers crossed over to their midranges at ~100hz or lower, i would never run subs in my main system w/o an active outboard x-over, to high pass the mains, low-pass the sub's.  in act, when i first bought a sub set-up, my speakers were -2db at 20hz, and i still high passed them, as their woofers were crossed over at 400hz; quite a bit higher than 100hz...

ideally, i would have passive subs, and separate amps.  if i were using active subs, i would simply set their x-over at the highest setting, and come underneath that w/my active x-over's low-pass setting.  which means, yes, i would be using the active sub's line level inputs.  (i have doe this to good effect.)

if the rel's sound so much better w/their speaker inputs than their line level inputs, that simply means they would not be on my shopping list.     actually, based upon an in-home audition w/a ~$1500 rel several years back, (i don't recall the model name), they wouldn't be on my shopping list anyway - extremely disappointing performance for the price, imo...

doug s

[doug s.]

The potential advantages outlined above are subject to how a particular loudspeaker is designed. If your mid-ranges are already crossed over at or above 150Hz and you have adequate low frequency capability then no advantages will accrue.
A full-range speaker such as the one pictured below will see no improvement.

Scotty

don't you mean BELOW 150hz, not above?

doug s.

[satfrat]

Line level for me.

Ditto,,,, easy peasy. 

Cheers,
Robin