Cremona Auditor Ms

[Fanaticalism]

Originally Posted by miner

Any comments on set up appreciated - I think I may need to space the Auditor Ms father apart and move the REL between them. My listenin position is about13' from the current M location.

REL sub bass systems need the added boundary reinforcement as they all have a response that begins to slope around 40hz. This is the main reason why they recommend their subs be placed in a corner. If you are in a null with the existing placement I would try one of the other three corners or moving the listening position closer to the back wall. The only problem with getting closer to the back wall is that your mains will need to be moved up as well so that you still have an equilateral triangle.

[metaphacts]

Quote:
Originally Posted by miner
Any comments on set up appreciated - I think I may need to space the Auditor Ms father apart and move the REL between them. My listening position is about 13' from the current M location.

Originally Posted by Fanaticalism

REL sub bass systems need the added boundary reinforcement as they all have a response that begins to slope around 40hz. This is the main reason why they recommend their subs be placed in a corner. If you are in a null with the existing placement I would try one of the other three corners or moving the listening position closer to the back wall. The only problem with getting closer to the back wall is that your mains will need to be moved up as well so that you still have an equilateral triangle.

RELs go in a corner for the same exact reasons any sub that is working below a pair of reasonably extended speakers goes in the corner - extension (longest axial) and output down very low. Why would one give up the additional 3dB of gain if there was nothing detrimental about it? The whole point is to get below most common room issues and pressurize the low bass evenly throughout the room. REL makes no bones about crossing over low and using very high gain to avoid the exact resonance problems one gets when positioning a sub away from the corner and using higher crossover points.

The B2 port slot loads as you move into the corner. Alignment of that port to the corner/walls determines the port's contribution and whether it is negative or positive. The trick is to get maximum extension,output, and linearity. It's certainly easy to hear and set up takes a matter of minutes.

The sub is there to improve the performance of the mains - not the other way around. I can count on 1 hand with no fingers the number of times in my life I have had to compromise the mains to allow a sub to work in a room - and I started playing with subs back in the Hartley 24" and Janus W1 days. You set up the mains in the room and make the sub align (sonically) to the room and to them. I also can't emphasize enough that the two mains need to be pressurizing the room evenly together in the bass before adjusting any sub. If this is not done, you might as well be herding mercury. At most audio shows I attend, typically less than 5% of the systems I hear are actually aligned in the bass speaker to speaker.

miner if your listening chair is not in a null with your mains placed where they are (or where you reposition them), the B2 should easily go in the right front corner (unless there is some physical room anomaly I cannot see in the pics). Just reposition it for lowest extension and highest output. As stated before, your crossover will likely end up in the A3 to A5 range.

Don't know if you will be at RMAF miner but if you are, I would be happy to show you what happens in a room when the mains are properly aligned in the bass versus when they are not.

[Fanaticalism]

Originally Posted by metaphacts

Quote:
Originally Posted by miner
Any comments on set up appreciated - I think I may need to space the Auditor Ms father apart and move the REL between them. My listening position is about 13' from the current M location.



RELs go in a corner for the same exact reasons any sub that is working below a pair of reasonably extended speakers goes in the corner - extension (longest axial) and output down very low. Why would one give up the additional 3dB of gain if there was nothing detrimental about it? The whole point is to get below most common room issues and pressurize the low bass evenly throughout the room. REL makes no bones about crossing over low and using very high gain to avoid the exact resonance problems one gets when positioning a sub away from the corner and using higher crossover points.

Yes, placing a sub does give you the most boundary reinforcement but there is no such thing as a clear and cut rule when it comes to sub placement. Placing the sub in a corner also excites more room nodes which will exasperate peaks and nulls (the latter being virtually impossible to correct without room treatments). You take a sub with relatively flat frequency/power response and it will give you more flexibility and greater linearity within its passband not to mention greater overall output at its tuning point with lower overall distortion.

The RELS are notorious for falling off radically below 40hz with overall THD well above the threshold of audibility and coloration. Like I mentioned above, you take a REL out of the corner and your output below 40hz drops off like a rock so what you will be forced to do is you try and apply tilt the bottom octave which will raise distortion immensely. You take another sub, like a JL, Velodyne or one of the popular ID brands and these will not suffer the same effect. In fact, most will place these away from the corner to reduce boominess.

The B2 port slot loads as you move into the corner. Alignment of that port to the corner/walls determines the port's contribution and whether it is negative or positive. The trick is to get maximum extension,output, and linearity. It's certainly easy to hear and set up takes a matter of minutes.

The sub is there to improve the performance of the mains - not the other way around. I can count on 1 hand with no fingers the number of times in my life I have had to compromise the mains to allow a sub to work in a room - and I started playing with subs back in the Hartley 24" and Janus W1 days. You set up the mains in the room and make the sub align (sonically) to the room and to them. I also can't emphasize enough that the two mains need to be pressurizing the room evenly together in the bass before adjusting any sub. If this is not done, you might as well be herding mercury. At most audio shows I attend, typically less than 5% of the systems I hear are actually aligned in the bass speaker to speaker.

I know this is RELS philosophy and while it may make sense to most, from a scientific standpoint it has many holes. It also argues against many other philosophies such as Floyd Toole, Sean Olive, Barry Ober, Miller and Kreisel etc. There are many benefits to a floor standing speaker one of which is inter modulation distortion. By adding a sub and applying a filter your are also maximizing the dynamic range and transients of your mains by alleviating the load from your amplifiers; not to mention flexibility of placement of the lower frequencies will allow one to focus on soundstaging and imaging of your mains.

As far as alignment (phase) goes, this isn't too hard to acquire using a sinewave at the crossover frequency with an inverted polarity of your mains one at a time sitting equidistant from each one while phase and time domain alignment are corrected.

Now, with all that said, I do feel that the distortion the RELS provide is not unpleasing and are excellent subwoofers.

[metaphacts]

Originally Posted by Fanaticalism

REL sub bass systems need the added boundary reinforcement as they all have a response that begins to slope around 40hz. This is the main reason why they recommend their subs be placed in a corner. If you are in a null with the existing placement I would try one of the other three corners or moving the listening position closer to the back wall. The only problem with getting closer to the back wall is that your mains will need to be moved up as well so that you still have an equilateral triangle.

Originally Posted by Fanaticalism

Yes, placing a sub does give you the most boundary reinforcement but there is no such thing as a clear and cut rule when it comes to sub placement. Placing the sub in a corner also excites more room nodes which will exasperate peaks and nulls (the latter being virtually impossible to correct without room treatments). You take a sub with relatively flat frequency/power response and it will give you more flexibility and greater linearity within its passband not to mention greater overall output at its tuning point with lower overall distortion.

The RELS are notorious for falling off radically below 40hz with overall THD well above the threshold of audibility and coloration. Like I mentioned above, you take a REL out of the corner and your output below 40hz drops off like a rock so what you will be forced to do is you try and apply tilt the bottom octave which will raise distortion immensely. You take another sub, like a JL, Velodyne or one of the popular ID brands and these will not suffer the same effect. In fact, most will place these away from the corner to reduce boominess.

I know this is RELS philosophy and while it may make sense to most, from a scientific standpoint it has many holes. It also argues against many other philosophies such as Floyd Toole, Sean Olive, Barry Ober, Miller and Kreisel etc. There are many benefits to a floor standing speaker one of which is inter modulation distortion. By adding a sub and applying a filter your are also maximizing the dynamic range and transients of your mains by alleviating the load from your amplifiers; not to mention flexibility of placement of the lower frequencies will allow one to focus on soundstaging and imaging of your mains.

As far as alignment (phase) goes, this isn't too hard to acquire using a sinewave at the crossover frequency with an inverted polarity of your mains one at a time sitting equidistant from each one while phase and time domain alignment are corrected.

Now, with all that said, I do feel that the distortion the RELS provide is not unpleasing and are excellent subwoofers.[/QUOTE]


At this point I assume we are talking about the use of a sub in a 2 channel mode. And on the subject of clear cut rules, we are in agreement. They're more like guidelines as the the pirate in the movie once said. If one were to look at Toole's recommended reading, Todd Welti's "Subwoofers: Optimum Number and Locations," we would find that corner placement was just fine. There are the caveats that it is written based on the perfectly rectangular room and that we should have multiples subs anyway. Damned pirate again, "guidelines."

If you put a sub in the corner with the intention of crossing it over higher than the 35-40Hz range in a typical listening room then yes subs will boom there. In fact if you intend to cross a REL over higher than 40Hz then you would also move it out of the corner. Above 40 HZ, you're exciting what is typically the worst distribution of issues(peaks and nulls) based on the range of dimensions of most home listening rooms. Also very large objects in a room and large rebates (fireplace opening, alcoves, etc) do affect these things though not in the easily predictable way the sealed rectangular room dimensions do. Give me a JL or a Velodyne with a low enough crossover and I'll easily make them work in/near a corner as well. But they do need to be positioned carefully and properly, not just thrown down helter skelter.

Phase alignment with a sine wave is an interesting illusion. You might want to check alignment and phase with transients at multiple frequencies of overlap rather than just a sine wave at the crossover point. Your results might be a bit different than you expected, especially as you move outside of that tightly defined singular head position to other parts of the room.

There certainly can be a valid argument for rolling off the mains actively to reduce distortion. From an amplifier standpoint, it allows you to choose one whose power/drive capability might not have been sufficient to properly play the speaker full range. From a convenience standpoint, it eliminates the need to properly align full range speakers to the room/each other in the bass (easily the most critical part of speaker set up). The reason it's so easy to set up a very small speaker is precisely because it has no bass to speak of. Imaging is pinpoint because there is no misaligned bass (can't misalign what isn't there) to confuse the issue. However, the real question when given the option is: can the subwoofer add back the sound of the hall (recording acoustic or lack thereof), the dimension and body of the instruments/voices better than allowing a properly aligned set of more full range mains to roll off naturally with the sub brought up to blend underneath? Both can work well but for continuity, to have the whole acoustic system breathe as one throughout the room as life always does but hifi rarely does, I usually find the latter preferable. YMMV

The real issue for me is this: Why would I want to throw away the perfectly blended, tonally integrated bass Franco Serblin designed into my very expensive speakers? Isn't it difficult enough to make a sub sound like the mains without allowing a sub to take over what the speaker already does beautifully? Is the lowered IM worth this loss? Again, YMMV but for me this is usually an easy choice. All one need do is listen and choose the sound his listening prejudices dictate.

Now once we head off to the land of multiple subs and LFE, things do get even more interesting.

[Masterlu]

metaphacts, am I correct you work for Sumiko?

[metaphacts]

Originally Posted by Masterlu

metaphacts, am I correct you work for Sumiko?

I thought people could easily tell that, even if it's been only for 11 of the 35 years I've been in high end audio. (Insert old curmudgeon smiley here)

But also believe it's fair to say that you've had a few more clues than some others.

[metaphacts]

Originally Posted by KMC45

No, some probably couldn't, but it was obvious to me, and I asked Ivan to bring it to peoples attention.

If you work for a specific company the right thing to do is let people know your ties to that company.

fair enough

Sumiko 1999 - 2010
Manufacturer's Consultant 1997 - 1998
Metaphor Acoustic Designs Ltd. - 1993-1997
International Audio Technologies LTD (Goldmund) - 1986-1993
Sound Components - 1984 - 1986
Christopher Hansen Ltd - 1982-1984
Sound Components - 1978 - 1982
HiFi Hutch - 1975 - 1978

that should cover it.

[Fanaticalism]

Originally Posted by metaphacts

fair enough

Sumiko 1999 - 2010
Manufacturer's Consultant 1997 - 1998
Metaphor Acoustic Designs Ltd. - 1993-1997
International Audio Technologies LTD (Goldmund) - 1986-1993
Sound Components - 1984 - 1986
Christopher Hansen Ltd - 1982-1984
Sound Components - 1978 - 1982
HiFi Hutch - 1975 - 1978

that should cover it.

What part of the U.S. do you cover?

[metaphacts]

Originally Posted by Fanaticalism

What part of the U.S. do you cover?

At this moment, Eastern Canada south to Puerto Rico. (One of our regionals left to join the new Vienna Acoustics company.)

[1KW]

Metaphacts,

Do you make house call's ?