AudioCircle
Industry Circles => GR Research => Topic started by: birkbott on 16 Dec 2019, 06:38 pm
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I'm currently building X-LS Encores and considering putting dual subs under them. Due to my lack of space I'm thinking sealed (the servo sub kit 2) with the amp mounted externally and forward facing so I can adjust the settings easily.
Has anyone ever tried a setup like this and if so how was it?
Would look something like this with the sub amps on the bottom, using the built in 80hz crossover to split the duty between the subs and the X-LSs.
(https://www.audiocircle.com/image.php?id=202099)
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Build open baffle servo subs, even though you may not have the space. Why? because it will still sound much better than dual box subs. Besides, it will be less expensive to build.
A forward facing amp???? Naw, dude. That's wrong on so many levels.
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I'm currently building X-LS Encores and considering putting dual subs under them. Due to my lack of space I'm thinking sealed (the servo sub kit 2) with the amp mounted externally and forward facing so I can adjust the settings easily.
Has anyone ever tried a setup like this and if so how was it?
Would look something like this with the sub amps on the bottom, using the built in 80hz crossover to split the duty between the subs and the X-LSs.
(https://www.audiocircle.com/image.php?id=202099)
Personally I'd put the Encores on speaker stands.
You can build the subs with the amps in the same cabinet as the driver and just turn them around so the amps face out. With subwoofers, it doesn't really matter which way the drivers face. I used to have Danny's N1X bookshelves on stands with a sealed sub behind the stand. When I built the N3 towers I had to move the sub. I ended up moving it to the back of the room behind the couch with the driver facing sideways. It sounds much better in this location then on the front wall. It also sounds like the bass is coming from the main speakers. You don't realize the sub is actually behind you.
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Build open baffle servo subs, even though you may not have the space. Why? because it will still sound much better than dual box subs. Besides, it will be less expensive to build.
A forward facing amp???? Naw, dude. That's wrong on so many levels.
You're saying to build one OB sub instead of dual sealed subs, correct? And even if it's up against a wall it will sound better than the dual sealed?
RE: the forward facing amp, what's wrong about it? It would be recessed into that enclosure with grill cloth covering it most of the time so you wouldn't see it.
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Personally I'd put the Encores on speaker stands.
You can build the subs with the amps in the same cabinet as the driver and just turn them around so the amps face out. With subwoofers, it doesn't really matter which way the drivers face. I used to have Danny's N1X bookshelves on stands with a sealed sub behind the stand. When I built the N3 towers I had to move the sub. I ended up moving it to the back of the room behind the couch with the driver facing sideways. It sounds much better in this location then on the front wall. It also sounds like the bass is coming from the main speakers. You don't realize the sub is actually behind you.
That's interesting, what do you have the crossover set to?
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Build open baffle servo subs, even though you may not have the space. Why? because it will still sound much better than dual box subs. Besides, it will be less expensive to build.
A forward facing amp???? Naw, dude. That's wrong on so many levels.
I'm the oddball that prefers like with like. By that I mean I prefer the overall sound of the sealed servo sub with the N3 towers and open baffle subs with open baffle speakers.
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RE: external servo sub amps in general, 4 pin SpeakON connectors would work to connect the amp enclosure to the speaker enclosure, right?
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That's interesting, what do you have the crossover set to?
With the N3s 40Hz. With the encores it would be somewhere around 50-60Hz
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RE: external servo sub amps in general, 4 pin SpeakON connectors would work to connect the amp enclosure to the speaker enclosure, right?
Yes
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You're saying to build one OB sub instead of dual sealed subs, correct? And even if it's up against a wall it will sound better than the dual sealed?
RE: the forward facing amp, what's wrong about it? It would be recessed into that enclosure with grill cloth covering it most of the time so you wouldn't see it.
I'm saying build TWO OB servo subs.
Remember, you're gonna have cables attached to the amp. Do you want cables running in front of your speakers. Besides, an amp facing forward is gonna look ridiculous.
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I'm saying build TWO OB servo subs.
Remember, you're gonna have cables attached to the amp. Do you want cables running in front of your speakers. Besides, an amp facing forward is gonna look ridiculous.
I'm not really sure I follow this logic as the OB sub kits are more expensive than the sealed kits.
Yes I'm aware of cables, etc. There will be an exit in the back of the amp enclosure for them and it will be concealed behind grill cloth 99% of the time.
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I'm the oddball that prefers like with like. By that I mean I prefer the overall sound of the sealed servo sub with the N3 towers and open baffle subs with open baffle speakers.
My position is to always go with what sounds better.
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With the N3s 40Hz. With the encores it would be somewhere around 50-60Hz
Do you always prefer to run your mains full range and integrate the sub at the natural roll off? I was thinking I would use the 80hz crossover on the sub amp to better integrate and reduce the load of the mains. The directionality of the higher crossover is why I was also thinking they should be forward facing and directly under each main speaker.
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I'm not really sure I follow this logic as the OB sub kits are more expensive than the sealed kits.
Yes I'm aware of cables, etc. There will be an exit in the back of the amp enclosure for them and it will be concealed behind grill cloth 99% of the time.
I started with a single OB sub, then eventually two, now I have three. I don't know your budget, so I recommended two.
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Do you always prefer to run your mains full range and integrate the sub at the natural roll off? I was thinking I would use the 80hz crossover on the sub amp to better integrate and reduce the load of the mains. The directionality of the higher crossover is why I was also thinking they should be forward facing and directly under each main speaker.
Even at 80Hz the signal is still omnidirectional so driver direction doesn't matter. As an aside, 80Hz is the THX standard crossover point.
The numbers on the crossover dial of the sub amp don't actually correlate to a specific frequency so you can't just set the dial to 80Hz and actually have an 80Hz crossover point to subs. Having some way of measuring the signal is a lot easier than doing it by ear. I use REW.
If you are going to let your speakers roll off naturally, you want to crossover where the speakers are -6dB. With the X-LS Encores that's around 51Hz but could differ due to room gain. If you want to roll them off higher and you have a separate preamp and power amp, you can use an inline filter between the pre and power amp to change the rolloff and thereby the -6 point. If you are using a receiver with bass management, like an AVR, you can use it's bass management to set the crossover point. In this case you would connect to the LFE input on the sub amp. This by-passes the sub's crossover controls.
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Go with dual OB subs, you will be very happy you did. IMO true stereo bass that integrates perfectly at the speaker position is one of the main reasons for going with an OB speaker in the first place.
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Even at 80Hz the signal is still omnidirectional so driver direction doesn't matter. As an aside, 80Hz is the THX standard crossover point.
The numbers on the crossover dial of the sub amp don't actually correlate to a specific frequency so you can't just set the dial to 80Hz and actually have an 80Hz crossover point to subs. Having some way of measuring the signal is a lot easier than doing it by ear. I use REW.
If you are going to let your speakers roll off naturally, you want to crossover where the speakers are -6dB. With the X-LS Encores that's around 51Hz but could differ due to room gain. If you want to roll them off higher and you have a separate preamp and power amp, you can use an inline filter between the pre and power amp to change the rolloff and thereby the -6 point. If you are using a receiver with bass management, like an AVR, you can use it's bass management to set the crossover point. In this case you would connect to the LFE input on the sub amp. This by-passes the sub's crossover controls.
As I understand it the A370PEQ amp that comes with the Servo Sub Kit 2 has a built in fixed 80hz crossover if you're using the low level inputs between your pre and power amps.
The only thing I dislike about this setup is that you have to run interconnects from the preamp to the sub amp and then back to the power amp and then speaker wire back to the speakers so it's a lot of back and forth.
I'm considering building some Hypex NC400 monoblocks that can easily fit in the sub amp enclosures or on top of the Encores to get everything closer together. I love the sound of my Schiit Aegir but I'm afraid it will be underpowered for the Encores and I don't think I have room for 2 of them.
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Go with dual OB subs, you will be very happy you did. IMO true stereo bass that integrates perfectly at the speaker position is one of the main reasons for going with an OB speaker in the first place.
What do most people do with the amps on those OB designs?
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What do most people do with the amps on those OB designs?
Set them on the floor a few inches behind the subs. They're not visible from the front of the room.
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Birkbott,
You mentioned space concerns. In which way?
OB subs require the ability to pull your main speakers out at least 3' from the wall. Is that possible in your case?
If not, the sealed servos would be the way to go. You can use them as speaker stands, but most likely your speakers and room will sound better if the subs are located elsewhere in the room.
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Birkbott,
You mentioned space concerns. In which way?
OB subs require the ability to pull your main speakers out at least 3' from the wall. Is that possible in your case?
If not, the sealed servos would be the way to go. You can use them as speaker stands, but most likely your speakers and room will sound better if the subs are located elsewhere in the room.
Well it's a typical small-to-medium sized living room type setup so we have the TV mounted on the wall with an entertainment center under it. On either side of that I have about 16"W x 18"D to fit speakers. I had a pair of Spatial Audio M4s in there and as much as I loved them I always felt like the low frequencies were hindered by not having enough room to breathe. When I first got them I thought I could live with it but I found myself missing the low end.
In a previous incarnation I had some sealed bookshelf speakers from Selah and a single sealed SVS sub but I never felt like I could integrate them well and the (perhaps psychological) imbalance of having only one sub bothered me, so I've been thinking about a 2.2 system for a while.
As for locating them elsewhere in the room I doubt that would be possible. My spouse is already at "eye-roll" stage with this project as it is I don't think I could rearrange the living room to accommodate subs in other locations. Also we have small kids so I need to keep things as contained/hidden as possible.
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As I understand it the A370PEQ amp that comes with the Servo Sub Kit 2 has a built in fixed 80hz crossover if you're using the low level inputs between your pre and power amps.
The only thing I dislike about this setup is that you have to run interconnects from the preamp to the sub amp and then back to the power amp and then speaker wire back to the speakers so it's a lot of back and forth.
I'm considering building some Hypex NC400 monoblocks that can easily fit in the sub amp enclosures or on top of the Encores to get everything closer together. I love the sound of my Schiit Aegir but I'm afraid it will be underpowered for the Encores and I don't think I have room for 2 of them.
The consensus is that built-in high pass filter isn’t any good, dont use it. The A370PEQ3 amps I have been using don’t even have the high pass out. They have two pairs of inputs. One line in and one LFE in. From now on when I build subs for myself I’m going to use the A370XLR3 amps since my preamp has balanced outputs. You can get the other versions of the A370 amps. Just call Danny and let him know what you want.
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Well it's a typical small-to-medium sized living room type setup so we have the TV mounted on the wall with an entertainment center under it. On either side of that I have about 16"W x 18"D to fit speakers. I had a pair of Spatial Audio M4s in there and as much as I loved them I always felt like the low frequencies were hindered by not having enough room to breathe. When I first got them I thought I could live with it but I found myself missing the low end.
In a previous incarnation I had some sealed bookshelf speakers from Selah and a single sealed SVS sub but I never felt like I could integrate them well and the (perhaps psychological) imbalance of having only one sub bothered me, so I've been thinking about a 2.2 system for a while.
As for locating them elsewhere in the room I doubt that would be possible. My spouse is already at "eye-roll" stage with this project as it is I don't think I could rearrange the living room to accommodate subs in other locations. Also we have small kids so I need to keep things as contained/hidden as possible.
The M4's are nice speakers, but they are nowhere near capable of the bass that dual OB Rythmik subs can put out. I'd use dual OB subs as stands for the speakers and a nice grill cloth front and back to keep the drivers hidden.
If your spouse is decor conscious, you could paint the speakers white and use some nice colorful grills to make the more room friendly. I've got my speakers in white with a maroon set of grills, but I think navy blue might also be nice in my setup.
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The M4's are nice speakers, but they are nowhere near capable of the bass that dual OB Rythmik subs can put out. I'd use dual OB subs as stands for the speakers and a nice grill cloth front and back to keep the drivers hidden.
If your spouse is decor conscious, you could paint the speakers white and use some nice colorful grills to make the more room friendly. I've got my speakers in white with a maroon set of grills, but I think navy blue might also be nice in my setup.
I'm into the OB thing, I just don't think I have the space. These would be just about up against the rear wall.
I'm way ahead of you on the white paint thing. I'm planning to use Duratex with a fine roller. My spouse is on board with that part. I have white, grey, and black grill cloth samples but navy or maroon might be cool too.
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The consensus is that built-in high pass filter isn’t any good, dont use it. The A370PEQ3 amps I have been using don’t even have the high pass out. They have two pairs of inputs. One line in and one LFE in. From now on when I build subs for myself I’m going to use the A370XLR3 amps since my preamp has balanced outputs. You can get the other versions of the A370 amps. Just call Danny and let him know what you want.
That's interesting, that was my main reason for going with the A370PEQ over the HX300.
It's too bad that high quality crossovers for dual subs are so hard to find and/or expensive.
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The A370 amps are much more versatile and adjustable then the HX300s. The versatility makes the A370s compatible with more preamps/amps and the adjustability makes them easier to dial in.
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Even at 80Hz the signal is still omnidirectional so driver direction doesn't matter. As an aside, 80Hz is the THX standard crossover point.
The numbers on the crossover dial of the sub amp don't actually correlate to a specific frequency so you can't just set the dial to 80Hz and actually have an 80Hz crossover point to subs. Having some way of measuring the signal is a lot easier than doing it by ear. I use REW.
If you are going to let your speakers roll off naturally, you want to crossover where the speakers are -6dB. With the X-LS Encores that's around 51Hz but could differ due to room gain. If you want to roll them off higher and you have a separate preamp and power amp, you can use an inline filter between the pre and power amp to change the rolloff and thereby the -6 point. If you are using a receiver with bass management, like an AVR, you can use it's bass management to set the crossover point. In this case you would connect to the LFE input on the
sub amp. This by-passes the sub's crossover controls.
Just re-reading this, is there a high pass filter that you think is good quality for raising the roll off point of the main speakers?
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Just re-reading this, is there a high pass filter that you think is good quality for raising the roll off point of the main speakers?
You build it yourself. It consists of one small cap inline between the preamp and power amp. The size of the cap depends on the input impedance of your power amp and the frequency you want to be 3dB down at. Danny has a link to a calculator in this forum. I’m on my phone so I can’t cut and paste the link here. From the GR Research main page search inline filter. Since the cap size is small a really good cap is not that expensive. For single ended (RCA) connections you need one cap per channel.
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You build it yourself. It consists of one small cap inline between the preamp and power amp. The size of the cap depends on the input impedance of your power amp and the frequency you want to be 3dB down at. Danny has a link to a calculator in this forum. I’m on my phone so I can’t cut and paste the link here. From the GR Research main page search inline filter. Since the cap size is small a really good cap is not that expensive. For single ended (RCA) connections you need one cap per channel.
And get a pair of matched value caps if you do to keep both channels the same.
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Here's the link to the post about the in-line filter calculator. It's at reply 12
https://www.audiocircle.com/index.php?topic=126480.msg1334315#msg1334315
Here's the link to the calculator
https://www.v-cap.com/coupling-capacitor-calculator.php
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Here's the link to the post about the in-line filter calculator. It's at reply 12
https://www.audiocircle.com/index.php?topic=126480.msg1334315#msg1334315
Here's the link to the calculator
https://www.v-cap.com/coupling-capacitor-calculator.php
Well this just keeps getting more and more interesting.
So this additional cap would be between the preamp and power amp, correct?
The input impedance on my amp is 22k so in order to have -3db at 80hz I would need a cap value of 0.09 according to the calculator. But where does that put the -6db point? An octave lower?
It seems like a pretty gradual slope I wonder about integrating it with the sub slope which is I believe is 12 db/ocatve at it's most gradual setting.
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Here is a single pole RC high pass at 120Hz response plot.
The -6dB down point is about 68Hz. You can use the fraction Fc*(68/120) to find the -6dB point for a different cut off frequency for the power amp high pass. Depends on the servo amp setting. As long as both HP and LP -6dB points match, they should be close.
(https://www.audiocircle.com/image.php?id=202123)
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Here is a single pole RC high pass at 120Hz response plot.
The -6dB down point is about 68Hz. You can use the fraction Fc*(68/120) to find the -6dB point for a different cut off frequency for the power amp high pass. Depends on the servo amp setting. As long as both HP and LP -6dB points match, they should be close.
(https://www.audiocircle.com/image.php?id=202123)
So if I want my -6db at 80hz I would need to start the high pass at around 140hz.
I'm trying to square this with the cap calculator linked above. That calculator solves for the -3db value. Would that be half way between the two? So 110hz?
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1. Do you think dual sealed subs would integrate well with the Encores in this configuration given the space limitation?
A sealed servo sub will work great.
And yes, while open baffle is awesome, and kind of the hill around here, you don't have the space for it.
2. Do you agree that the built in 80hz crossover on the A370PEQ should not be used?
Again, don't use that. It is not a high quality cap.
3. If so do you agree that an in-line passive capacitor would be helpful in filtering some of the low-end out of the mains and would this improve sound quality?
Yes. Here is an example of one with a by-pass for the servo sub.
(http://gr-research.com/pics/yconnector.jpg)
I would go with a .1uF for your amp. That will get you a -3db of 72Hz and allow a crossover somewhere in the 60Hz range or lower. that will be more ideal with these speakers.
4. Do you think one Schiit Aegir will be powerful enough to run the Encores (max 20W per channel into 8 ohms) or should I consider switching to something like the Vidar with more power? Or is there another power amp that you personally recommend for the encores?
It may be fine if you are not far away from them and you don't clip it on them.
5. Do you agree that a 4-pin speakon connection would be a good choice to connect the sub driver to the amp if it's in an external enclosure?
Yes, we use them for that all the time and stock them for it.
We just don't use that type of connector for anything above 200Hz.
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Danny thanks for the great responses as usual. :thumb:
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Has anyone ever tried just splicing the cap into the RCA cable?
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I did this with my cables. I using balanced cables and I cut the cable about 8" from the preamp connection end and spliced in two caps on the + and - leads. I used these little ABS boxes which just snap together around two cable ends to enclose the caps and shield connection.
https://www.amazon.com/gp/product/B07MMMN2JD
- Jay
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This is the box I made. I realized after I had it soldered that I had it backwards so my white rcas feed the right channel an red rcas feed the left. I put a big arrow on top to remind myself which way it goes.
(https://www.audiocircle.com/image.php?id=202575)
(https://www.audiocircle.com/image.php?id=202576)
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Well, my plan has been executed:
(https://www.audiocircle.com/image.php?id=203979)
This is the left channel, there’s an identical set up on the right channel. Didn’t get to listen to them very much but very impressed with the bass extension and evenness of the sound.
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Just need to finish the grills to cover everything up and we’re good to go.
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I like your approach of putting a sealed servo sub under the X-LS Encore. I also don't think I have the space for OB subs. I'm considering putting sealed servo subs under NX Studio Monitors. Are you still happy with your results? Would you recommend anything anything different?
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Birkbot very nice job! I hope it sounds as good as it looks. Seems like you made the best out of the space you had to work with.
Some day you will likely have a room better suited to audio. I think most of us that have been at this a while have been in your position. I finally have a (mostly) dedicated listening room, and that has probably been the biggest improvement to my listening enjoyment that I have made. I can now set up the room as needed for best performance and not worrying about decor and multi use functionality so much.
Again great job!
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DThor
I like your approach of putting a sealed servo sub under the X-LS Encore. I also don't think I have the space for OB subs. I'm considering putting sealed servo subs under NX Studio Monitors. Are you still happy with your results? Would you recommend anything anything different?
Unless you really don't have the space I would not put the subs under the Studio's. It's best if subs can be moved around the room to find the location that sounds the best. With that being said I have found that in my room and system that I do prefer the subs next to the speakers. Keeping them separate allows you more options for fine tuning the bass because quite often the best location for the speakers is not the best for the subs. Just something to think about.
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Thanks Sonicjoy. Very good point. I will plan on putting the Studios on stands. That way I can experiment with placement of the subs.