rel acoustics live subwoofer demo

[sigbergaudio]

Ok I’m going to display my ignorance here. The “high level input” thing is a very common criticism levelled at REL, but what is actually wrong with doing it that way?

The signal has a longer signal path and has gone through the amplification stage of a power amplifier. This is certain to degrade the signal / add distortion. Whether the difference is audible (especially if you are crossing the sub at 30-40hz) is another matter.

That you get the sound signature of the amplifier is simply not a thing when the sub is barely playing an octave.

 

[Sir Sanders Zingmore]

The signal has a longer signal path and has gone through the amplification stage of a power amplifier. This is certain to degrade the signal / add distortion. Whether the difference is audible (especially if you are crossing the sub at 30-40hz) is another matter.

That you get the sound signature of the amplifier is simply not a thing when the sub is barely playing an octave.

So from what I can gather, on one hand there is a bunch of marketing nonsense from REL claiming superiority. But on the other hand, if you are not actively bass-managing your mains, running high level doesn’t seem anywhere near as disastrous as I’ve been led to believe.

 

[goat76]

So from what I can gather, on one hand there is a bunch of marketing nonsense from REL claiming superiority. But on the other hand, if you are not actively bass-managing your mains, running high level doesn’t seem anywhere near as disastrous as I’ve been led to believe.

There’s no problem using the high-level connection, it's just that the subwoofer get the same full-range signal as the main speakers, and the subwoofer's low-pass filter is set somewhere between 30-120 Hz depending on where the main speakers naturally roll off.

An additional cable besides to high-level cable is used for the LFE signal if your system also is a home theatre system, and the two signals work in tandem in that case with separate volume knobs where the low-pass filter for the LFE signal is managed in the AV receiver. The nice thing about this is that the REL subwoofers works both as a bass extension for the main speakers, and at the same time used for the LFE signal when watching movies.

If you for some reason want to use a low-level signal instead of a high-level connection, there is a connection for that as well in the REL subwoofers.

 

[sigbergaudio]

So from what I can gather, on one hand there is a bunch of marketing nonsense from REL claiming superiority. But on the other hand, if you are not actively bass-managing your mains, running high level doesn’t seem anywhere near as disastrous as I’ve been led to believe.

It's not disastrous. But not high passing the mains severely limits the positive benefits from having subwoofers. And RCA/XLR is both easier and cleaner, imo of course.

But RELs advice is right on the money for what is likely the intended audience, traditional audiophiles with no bass management and no desire to high pass the mains, because they have pride of ownership in their speakers and don't want to cut them by the knees, so to speak.

I have this discussion many times with potential customers, and a surprising amount of people do not want to high pass, often because adding that capacity to their system requires them to purchase new things and potentially replacing preamps etc. And that is a valid choice of course.

 

[Purité Audio]

I have some speakers here and they are pre-configured you just plug the subs into the mains and press play, they even have built in eq in the mains and in the subs.
Sound good too.
Keith

 

[goat76]

It's not disastrous. But not high passing the mains severely limits the positive benefits from having subwoofers. And RCA/XLR is both easier and cleaner, imo of course.

But RELs advice is right on the money for what is likely the intended audience, traditional audiophiles with no bass management and no desire to high pass the mains, because they have pride of ownership in their speakers and don't want to cut them by the knees, so to speak.

I have this discussion many times with potential customers, and a surprising amount of people do not want to high pass, often because adding that capacity to their system requires them to purchase new things and potentially replacing preamps etc. And that is a valid choice of course.

There are many small unnecessary things in your post that make it come out as if you put yourself above others, making everyone who doesn't share your ideas "traditional audiophiles" (less technical knowledgeable people) with "pride of ownership" (stubborn enough not to see the truth) and with the unwillingness to "cut the knees" of their loudspeakers out of that same "pride of ownership".

Let me help you with the ladder.

Many people who choose to use REL subwoofers in their systems are not all the type of "traditional audiophiles" you describe. The high-level connection will work greatly for anyone happy with the full performance of their main speakers that remain at low distortion at the maximum volume level they use their system at and just miss that last bit of bass extension making their speaker system a full-range system. It works greatly for anyone who has managed to position their main speakers optimally in the listening room, and one of the most important aspects of finding that good position is to position the main speakers where the bass frequency range sounds balanced with as few problems as possible.

I expect that most people here at ASR who still don't have subwoofers have managed to find that optimal position for their main loudspeakers already, and for the ones that are also satisfied with the full performance with hopefully low-distortion loudspeakers (speakers that don't try to play deeper in the bass than what the physical size allows), for them adding REL subwoofers connecting them with high-level signals will not change the way their main speakers already satisfyingly performs, but will act as bass extension making their sound systems full-range without having to find an additional solution for bass management.

 

[sigbergaudio]

There are many small unnecessary things in your post that make it come out as if you put yourself above others, making everyone who doesn't share your ideas "traditional audiophiles" (less technical knowledgeable people) with "pride of ownership" (stubborn enough not to see the truth) and with the unwillingness to "cut the knees" of their loudspeakers out of that same "pride of ownership".

Let me help you with the ladder.

View attachment 412114

Many people who choose to use REL subwoofers in their systems are not all the type of "traditional audiophiles" you describe. The high-level connection will work greatly for anyone happy with the full performance of their main speakers that remain at low distortion at the maximum volume level they use their system at and just miss that last bit of bass extension making their speaker system a full-range system. It works greatly for anyone who has managed to position their main speakers optimally in the listening room, and one of the most important aspects of finding that good position is to position the main speakers where the bass frequency range sounds balanced with as few problems as possible.

I expect that most people here at ASR who still don't have subwoofers have managed to find that optimal position for their main loudspeakers already, and for the ones that are also satisfied with the full performance with hopefully low-distortion loudspeakers (speakers that don't try to play deeper in the bass than what the physical size allows), for them adding REL subwoofers connecting them with high-level signals will not change the way their main speakers already satisfyingly performs, but will act as bass extension making their sound systems full-range without having to find an additional solution for bass management.

Thank you for the ladder, it can be helpful both for high horses and other things!

While everything you write above is technically true, let me be even more direct than in my previous post: In my opinon, anyone who don't high pass their mains, are leaving performance on the table. To the extent that when people with pretty large, expensive floorstanders contact me to purchase subs that they aim to just "fill in" the bottom octave, I usually warn them that the difference will be small. Depending on how the conversation goes, I may even try to dissuade them from the purchase. They will not get much more extension, and their bass response will not improve.

Why do people still want this configuration? I can think of a few reasons:

• They've never experienced how much better the alternative is
• They have a preference to more puristic systems (as alluded to in my previous post). Which again, is perfectly reasonable.
• They own subwoofers that either are not up to par with their speakers, or they think they're not. They think the speakers will do a better job. Sometimes they're right. Most of the time they're not.

I would also like to clarify that while I indeed think not highpassing the speakers is objectively the wrong choice for optimal sound performance, I can certainly understand reasons for not doing so. I don't think pride of ownership is a bad thing, or something wrong. It's perfectly fair. While I may be on my high horse, I understand and accept that this is a complicated hobby, and it's not all about sound quality. And/or the experienced sound quality is determined by more things than just the actual sound. If you for instance have a beautiful Accuphase preamp, I have no problem understanding the reluctance to replace it with something like a MiniDSP or DSPeaker product that looks neutral at best, feels cheap and plastic, and generally doesn't give a lot of pride of ownership in comparison. I like nice things too.

 

[Hear Here]

Isn’t this is the case with any system that doesn’t high-pass the mains? If you can’t high-pass the mains, sending a line level signal to the sub isn’t going to help “relieve” the mains.



I understand this, but isn’t it also precisely REL’s marketing too? That is, high level connections ensure the “sound” of your amp is passed on to the subs. If your amp does have a “sound” it’s almost certainly because of non-linear behaviour cause by clipping or possibly issues handling back emf. Assuming you like the “sound” of your amp (that is you like the way it distorts) it makes sense that you’d want the same sound from your sub.

I'd put it slightly differently as the main amp (as long as it's a good one) has very little effect on the sound compared with the speakers.

I'd suggest the main reason for not using high (speaker) level compared with low level (from the preamp) is that the signal received by the drivers in the sub has been through 2 power amplifiers whereas the signal to the drivers in the main has been through one amp. The less processing the signal receives, the better. Whether the millisecond or two delay in the sub's response resulting from the extra amp is audible I seriously doubt. However any reductions in processing or cabling must be preferable, so an XLR cable from the preamp to the sub is probably ideal. Unfortunately the REL S812 doesn't provide an XLR socket, but surprisingly its Airship wireless adaptor does!

 

[Hear Here]

That is great for you, but not generally applicable. The vast majority of people do not have speakers that can play down to 20hz in-room without compression at loud levels. And even fewer have both that, and are so lucky that they get an even frequency response in the bass from just two speakers.

I won't say it's one in a million situation, but it's certainly one in a hundred.

You have highlighted a trend in loudspeaker sales that I find counter-sensible!

In the good old days before anyone thought of subs, we bought a speaker (in mono days) or 2 (stereo) and chose these to suit our pocket and often our room size. If we wanted decent bass, we'd buy speakers with grown-up bass drivers and that was that.

In more recent times, we seem to be persuaded to spend initially less on speakers (easier for dealers to get us to part with our cash) and we buy ones that are really not up to the job of delivering the full frequency range. Our justification for this is often that these speakers with their 6 or 7" bass drivers sound remarkably convincing in the showroom, but after a while we realise there is something lacking, or that the bass is "strained" rather than natural. Back to the dealer who says "what you need is a subwoofer" and he sells us one, perhaps 2. We get them home, realise they look pretty ugly, take up floor space, need extra cables and, try as we might, the sound is muddled and we blame the room for this. The "solution" we read on forums, etc is "chuck room correction DSP at it and all your problems will disappear and your bass will be wonderful".

Call me old-fashioned, but I have always believed that speakers should have grown-up drivers and a that single pair of well-chosen speakers is usually all one needs for first-class 2-channel music. The thought of extra cabinets, extra amps, extra drivers, extra cables and the need for DSP, fills me with bewilderment! Why even think about this when a single pair of genuinely full-range speakers, well set up is all you really need in most well-arranged rooms. Sadly there are not so many about now, but they certainly can be found, both new and used.

My speaker history started with a home-built concrete enclosure with single 10" driver, then home-built Wharfedale Airedales (15", later changed to 13 x 9), Westrex studio monitors (15") and others including KEF Reference 107 (twin 10"), ATC Active (single 9" - a big disappointment though), Martin Logan (twin 10") and 3 Avantgardes (twin 10" or twin 12"). Many were bought used at remarkably reasonable cost. I worry less about measured bass accuracy if the excitement of a live performance is recreated in a pretty convincing way in my living room. Some of these speakers have mighty new prices, but the sound quality is exceptional and I'd suggest better than smaller speakers plus subs, cables, etc and their associated inconvenience - and cheaper probably all told.

Am I one in a million? I'd like to think so, but probably not!

 

[sigbergaudio]

You have highlighted a trend in loudspeaker sales that I find counter-sensible!

In the good old days before anyone thought of subs, we bought a speaker (in mono days) or 2 (stereo) and chose these to suit our pocket and often our room size. If we wanted decent bass, we'd buy speakers with grown-up bass drivers and that was that.

In more recent times, we seem to be persuaded to spend initially less on speakers (easier for dealers to get us to part with our cash) and we buy speakers that are really not up to the job of delivering the full frequency range. Our justification for this is often that these speakers with their 6 or 7" bass drivers sound remarkably convincing in the showroom, but after a while we realise there is something lacking, or that the bass is "strained" rather than natural. Back to the dealer who says "what you need is a subwoofer" and he sells us one, perhaps 2. We get them home, realise they look pretty ugly, take up floor space, need extra cables and try as we might, the sound is muddled and we blame the room for this. The "solution" we read on forums, etc is "chuck room correction DSP at it and all your problems will disappear and your bass will be wonderful".

Call me old-fashioned, but I have always believed that speakers should have grown-up drivers and a that single pair of well-chosen speakers is all one needs for first-class 2-channel music. The thought of extra cabinets, extra amps, extra drivers, extra cables, the need for DSP, fills me with bewilderment! Why even think about this when a single pair of genuinely full-range speakers well set up is all you really need in most well-arranged rooms. Sadly there are not so many about now, but they certainly can be found, both new and used.

My speaker history started with a home-built concrete enclosure with single 10" driver, then home-built Wharfedale Airedales (15", later changed to 13 x 9), Westrex studio monitors (15") and others including KEF Reference 107 (twin 10"), ATC Active (single 9" - a big disappointment though), Martin logan (twin 10"), and 3 Avantgardes (twin 10" or twin 12"). Many bought used at remarkably reasonable cost. I worry less about measured bass accuracy if the excitement of a live performance is recreated in a pretty convincing way in my living room. Some of these speakers have mighty new prices but the sound quality is exceptional and I'd suggest better than smaller speakers plus subs, cables, etc and their associated inconvenience - and cheaper probably all told.

I am currently developing a pair of fullrange floorstanders, so I can certainly see the appeal and simplicty. I also agree that if you are to have only speakers and no subs, it's a good idea to have proper capacity. The fact however remains that a system with subwoofers and EQ in the bass will almost always be superior to a system with just two speakers, both with regards to bass extension, bass capacity and accuracy in bass response.

Am I one in a million? I'd like to think so, but probably not!

Please refrain from strawman arguments. First of all I did not say it was one in a million, second of all I was not referring to people who had two speakers and were happy with their sound. I am sure there are many of those.

 

[dan_uk]

I think they are way over hyped. But in the end some people like them, so if they like them and want them, it is fine by me. I just think there are a lot better subs for the money. But in many situations such as music only listening, you often times don't need a great sub. For music AND home theater you will never be disappointed with a large powerful sub vibrating your walls and cracking the ceiling paint when a dinosaur stomps on the screen! I love high output subs myself. But they are kind of expensive!

What brands of sub would u suggest? I'm looking for a sub just for stereo music and I have bookshelf speakers.

 

[goat76]

While everything you write above is technically true, let me be even more direct than in my previous post: In my opinon, anyone who don't high pass their mains, are leaving performance on the table. To the extent that when people with pretty large, expensive floorstanders contact me to purchase subs that they aim to just "fill in" the bottom octave, I usually warn them that the difference will be small. Depending on how the conversation goes, I may even try to dissuade them from the purchase. They will not get much more extension, and their bass response will not improve.

The "fill-in" of the last bottom octaves works great and makes a huge difference with most loudspeakers that don't reach that low on their own. If you want to be honest with your customers I think you should stop saying that "the difference will be small" and that "their bass response will not improve", that is up to the bass capability of their loudspeakers and how well they manage to integrate the subwoofers with the main speakers.

Go back and listen to the demo that started this thread, and come back and tell me whether you heard a huge difference in the amount of bass output when the REL subwoofer was on or off. I'm pretty sure you will hear a significant difference in bass output with the subwoofer on, and if you do, I think you should stop saying to your customers that the difference will just be small.

 

[sigbergaudio]

The "fill-in" of the last bottom octaves works great and makes a huge difference with most loudspeakers that don't reach that low on their own. If you want to be honest with your customers I think you should stop saying that "the difference will be small" and that "their bass response will not improve", that is up to the bass capability of their loudspeakers and how well they manage to integrate the subwoofers with the main speakers.

It would be helpful for the discussion if you read everything I write, and try to assume good intent. I referred specifically to conversations with potential customers who had "pretty large, expensive floorstanders". Implied, speakers that do reach low on their own.

You are saying "last bottom octaves" (plural). If the sub is crossed over at 30-40hz, you're only covering one octave.

Go back and listen to the demo that started this thread, and come back and tell me whether you heard a huge difference in the amount of bass output when the REL subwoofer was on or off. I'm pretty sure you will hear a significant difference in bass output with the subwoofer on, and if you do, I think you should stop saying to your customers that the difference will just be small.

@goat76 I heard a significant difference, I even said so on page #1 of this thread. But those speakers have limited bass capacity on their own, so that is not so surprising.

 

[Sir Sanders Zingmore]

I'd put it slightly differently as the main amp (as long as it's a good one) has very little effect on the sound compared with the speakers.

I'd suggest the main reason for not using high (speaker) level compared with low level (from the preamp) is that the signal received by the drivers in the sub has been through 2 power amplifiers whereas the signal to the drivers in the main has been through one amp. The less processing the signal receives, the better. Whether the millisecond or two delay in the sub's response resulting from the extra amp is audible I seriously doubt. However any reductions in processing or cabling must be preferable, so an XLR cable from the preamp to the sub is probably ideal. Unfortunately the REL S812 doesn't provide an XLR socket, but surprisingly its Airship wireless adaptor does!

Surely “less processed” is only “better” if there is an audible difference. Same for cabling (btw my SVS subs don’t have an XLR socket either).

EDIT: I honestly can’t believe I’m coming across as a REL fan. I think they are very overpriced for what they do. There’s no way I’m a fan of them but I’m struggling to understand why they are considered “bad” (as opposed to bad value)

 

[goat76]

It would be helpful for the discussion if you read everything I write, and try to assume good intent. I referred specifically to conversations with potential customers who had "pretty large, expensive floorstanders". Implied, speakers that do reach low on their own.

You are saying "last bottom octaves" (plural). If the sub is crossed over at 30-40hz, you're only covering one octave.

I wrote in the plural to cover more speakers that are commonly used, but even if we keep the discussion to large speakers that only need help with the last octave it makes a significant difference in bass output. I would like to remind you that I use two REL subwoofers with a crossover in the range under 40 Hz, and it makes a large difference in sound with the subwoofers turned ON.

@goat76 I heard a significant difference, I even said so on page #1 of this thread. But those speakers have limited bass capacity on their own, so that is not so surprising.

And I can tell you that you would also hear a significant difference with larger speakers than the ones in the video. Adding the missing last octave makes a significant difference to the perceived overall sound, it makes things sound larger and adds envelopment.

 

[sigbergaudio]

I wrote in the plural to cover more speakers that are commonly used, but even if we keep the discussion to large speakers that only need help with the last octave it makes a significant difference in bass output. I would like to remind you that I use two REL subwoofers with a crossover in the range under 40 Hz, and it makes a large difference in sound with the subwoofers turned ON.



And I can tell you that you would also hear a significant difference with larger speakers than the ones in the video. Adding the missing last octave makes a significant difference to the perceived overall sound, it makes things sound larger and adds envelopment.

Personally I would not consider a speaker that roll off at 40hz to be full range or large, unless one is very unlucky with the room. But that is somewhat besides the point. The point, or at least additional point, is that you're missing out on EQ ability below 100hz, which is a vast improvement in almost all rooms.

 

[sigbergaudio]

@goat76 To nuance my answer a bit, I typically don't say to customers "Don't purchase our subwoofers unless you have high pass".

But in a situation where they have speakers and a room where it is likely they already have pretty significant output at least down to 30hz, they are missing out on a lot if they purchase our subs just to cross them over at 40hz and not employ the built-in EQ. Crossing them over at 80-100hz, and enabling EQ in that same range, would be a vast improvement, and lost opportunity if they don't. I try to explain this, and also say that just adding them for the very lowest octave might work well, but they will not be fully utilizing the potential of the subs or their purchase.

I've seen and listened to many systems with floorstanders that already extended basically down to 20hz, where there was little to no difference with and without sub.

 

[goat76]

Personally I would not consider a speaker that roll off at 40hz to be full range or large, unless one is very unlucky with the room. But that is somewhat besides the point. The point, or at least additional point, is that you're missing out on EQ ability below 100hz, which is a vast improvement in almost all rooms.

I'm not sure I would go with any subwoofer if my main speakers had a full-range capacity, I would just position them optimally in the room and call it a day.

Why would I be missing the ability to EQ below 100 Hz, that is perfectly doable no matter the crossover point and should preferably be done at the source. It is a bad idea to have the EQ built into the subwoofers as that would limit the EQ-able range severely, it's way better to do that externally so that you can use the EQ full range or at least up to 500 Hz.

 

[Purité Audio]

Eq built into the mains and the subs.
Keith

 

[CapMan]

I have some speakers here and they are pre-configured you just plug the subs into the mains and press play, they even have built in eq in the mains and in the subs.
Sound good too.
Keith

The new Harbeth Nelson uses the speaker level input of the P3s to drive it. It's been DSPd to integrate natively with the P3 rolloff.

Whether a 5" woofer can be called a sub - well just don't get me started

It does seems to appeal to the plug and play folks who want to plonk their P3s on a stand and get a bit more bottom end ...