AudioCircle
Industry Circles => GR Research => Topic started by: gguy on 14 Dec 2019, 11:07 pm
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Hi all,
Looking for a little advice. I want to upgrade my current speakers/sub setup, and my research has led me to this forum. I am intrigued by the prospect of going DIY and I like what GR has to offer, also, what I have read through all threads here has been motivating. My desire to move toward OB was sparked by hearing a pair of Spatial Audio M3's a while back, and I couldn't quite shake what I heard (in a positive way). I had originally looked at the NX-Otica exclusively, but after reading up, I am not sure if they are ideal for my space. I have reached out to get GR and have spoken with Danny and he reassured me they would be great. I want to make sure I am going in the right direction before embarking on this journey.
My current setup: Tekton Impact Loudspeakers, 2 SVS SB13 Ultra Sub, Parasound P6/A21 combo, Marchand XM9 crossover. My listening room is a 12x15 untreated (WAF issues) living room, negatives about the space is that the ceiling is cathedral and half of the room opens to the rest of the house, getting the subs to energize the space has proven difficult.
Before taking the dive, I would like to get some user feedback from those who have worked with the NX-Oticas in a similarly dimensioned space. I have read that some prefer the smaller speakers (wedgies/MTM's) in a smaller space, and I know my dimensions are on the edge of this. I can pull the speakers out 3ft from the front wall to the baffle, but not much more. I almost feel like the Otica's would be too close to the listing position, and have a hard time disappearing. Additionally, I know I will eventually move to OB subs, and their positioning would be right next to the wall (at least on one side). Below is a picture of the listening space, the subs are now next to the mains and the listening seats are pulled farther away from the back wall, I was experimenting when I took this photo. Any feedback is appreciated.
(https://i.imgur.com/LgN2Ffv.jpg)
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If you put the speakers on the 14ft wall you have enough room for the full size NX-Oticas and sub towers without sitting on top of the Oticas. I have the Otica MTM monitors on top of dual servo subs on the 12ft wall of a 12 x 14 room and am not on top of the speakers.
The OB subs have nulls to the sides so you can put the up next to the walls if need be.
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If you put the speakers on the 14ft wall you have enough room for the full size NX-Oticas and sub towers without sitting on top of the Oticas. I have the Otica MTM monitors on top of dual servo subs on the 12ft wall of a 12 x 14 room and am not on top of the speakers.
The OB subs have nulls to the sides so you can put the up next to the walls if need be.
Mike, what front wall to back wall arrangement (speakers from front wall, listening pos, etc) ended up working for you?
J
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I think i got an idea looking at your open baffle gallery mike, assuming whats shown is the same space to which you refer...
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Mike, what front wall to back wall arrangement (speakers from front wall, listening pos, etc) ended up working for you?
J
The room is 12' x 14' x 8'. The speakers are set up on the 12' wall opposite the door. The front baffle of the NX-Otica monitors is about 4' off the wall. The outside of the dual H-Frames are 18" from the side walls. The speakers are about 8' apart, center to center, and about 9' from the listening position which is about 1' from the back wall.
(https://www.audiocircle.com/image.php?id=202042)
The TV is no longer in this position. I took down the ceiling mount, framed in the window, and installed an over the fireplace mount. When in the up position, the TV is almost to the ceiling and much closer to the window. I can easily pull it down to the position in the picture when watching a movie or push it up to listen to music. I have also removed the two outboard diffuser panels and placed them at the first reflection points.
In this room, the 4' position off the front wall has a dip in the response between 125Hz-175Hz. Moving them farther off the wall didn't help but moving them closer did. If the speakers were 3' off the front wall, the dip went away but the soundstage shrunk a little. I couldn't really hear the dip so I chose to keep the larger soundstage.
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Got it. With subs in locations other than collocated with the oticas, sounds like that frequency dip might be alleviated. Close the open baffles are to the front wall, the soundstage is reduced; further away and it expands (subject to a limit I’m sure). But the same is largely true also with box designs, isn’t it? Out of your experience, what do you find to be the fundamental differences between box and OB? In similar room positions?
Thanks for your detailed responses. Only so much to be learned given limited in person auditions, so your amazingly detailed responses are always appreciated!
J
The room is 12' x 14' x 8'. The speakers are set up on the 12' wall opposite the door. The front baffle of the NX-Otica monitors is about 4' off the wall. The outside of the dual H-Frames are 18" from the side walls. The speakers are about 8' apart, center to center, and about 9' from the listening position which is about 1' from the back wall.
(https://www.audiocircle.com/image.php?id=202042)
The TV is no longer in this position. I took down the ceiling mount, framed in the window, and installed an over the fireplace mount. When in the up position, the TV is almost to the ceiling and much closer to the window. I can easily pull it down to the position in the picture when watching a movie or push it up to listen to music. I have also removed the two outboard diffuser panels and placed them at the first reflection points.
In this room, the 4' position off the front wall has a dip in the response between 125Hz-175Hz. Moving them farther off the wall didn't help but moving them closer did. If the speakers were 3' off the front wall, the dip went away but the soundstage shrunk a little. I couldn't really hear the dip so I chose to keep the larger soundstage.
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Thanks for the feedback. On the subject of OB subs, would duals or triples be better for my space?
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It looks like Mike has answered your questions, I would add that both the NX Otica and the Wedgie will give you great sound, but if choosing one today it would be the NX Otica for me unless my room was very small, like my first room, see below:
This was the room where I preferred the Wedgies over the NX Oticas, although to be fair I was moving to a larger room so I didn’t go to great pains to get the Otica dialed in.
(https://www.audiocircle.com/image.php?id=51258)
This is the room where am currently running the NX Oticas, I am tweaking the placement but this is close. They sound fantastic in this room:
(https://www.audiocircle.com/image.php?id=167525)
Best,
Ed
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Got it. With subs in locations other than collocated with the oticas, sounds like that frequency dip might be alleviated. Close the open baffles are to the front wall, the soundstage is reduced; further away and it expands (subject to a limit I’m sure). But the same is largely true also with box designs, isn’t it? Out of your experience, what do you find to be the fundamental differences between box and OB? In similar room positions?
Thanks for your detailed responses. Only so much to be learned given limited in person auditions, so your amazingly detailed responses are always appreciated!
J
It's true most speakers perform better the farther into the room they are, it is especially true of OB speakers. With box speakers, the sound comes out the front then some of it wraps around the speaker and travel to the front wall where it is reflected back. OB speakers fire direct sound from the rear of the baffle towards the front wall which then reflects into the room. What you are shooting for is at least 6msec delay between the time the direct waves from the front of the speaker and the reflected waves from the front wall reach your ears. If there is at least 6msec between the waves reaching your ears, your brain perceives them as two different signals which results in a sense of spaciousness and the illusion of a wide and deep soundstage. The more time between the waves, the larger the soundstage seems. However, if there is less than 6msec between the waves, your brain perceives them as one somewhat muddied signal and a diminished soundstage.
From my perspective, the fundamental differences between boxed and OB speakers has to do with the character and spaciousness of the sound. OB speakers have an open airy quality to the sound that box speakers don't. Also, OB speakers don't load/pressurize the room like box speakers do. This allows them to play loud but they don't shout at you. The difference in pressurization is especially apparent with bass. OB bass is full, deep, and strong but it doesn't punch you in the gut. My dual 12s are -3dB around 14Hz.
I can sum it up by saying the first time I heard OB was at the Lone Star Audio Fest and knew immediately I had to get me some of that. I was putting the final touches on a pair of Danny's N3 transmission line towers and was wondering how I was going to talk my wife into letting me build another pair of speakers. I got lucky. When I finished the N3s and hooked them up, my wife said "Those are mine. Go build yourself something else" :thumb:
I'm not the best at describing things. Maybe someone else will chime in with their description of the differences.
Mike
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Thanks for the feedback. On the subject of OB subs, would duals or triples be better for my space?
Triples unless you go with the MTMs.
If you go with the MTM you will need duals since the MTMs need to sit on top of the subs. The crossover point to the subs is too high. It's better to think of them as a two piece full range floorstander.
You will get the most out of the combination of full size NX-Oticas with triple subs backing them up. With triples you get 50% more displacement for the cost of an extra driver and a larger cabinet. This gives the bass more weight, dynamics, and is more effortless since each driver has less work to do.
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From my perspective, the fundamental differences between boxed and OB speakers has to do with the character and spaciousness of the sound. OB speakers have an open airy quality to the sound that box speakers don't. Also, OB speakers don't load/pressurize the room like box speakers do. This allows them to play loud but they don't shout at you. The difference in pressurization is especially apparent with bass. OB bass is full, deep, and strong but it doesn't punch you in the gut. My dual 12s are -3dB around 14Hz.
I'm not the best at describing things. Maybe someone else will chime in with their description of the differences.
Well, that description pretty much nails it. Hard to describe until you hear it for yourself.
IMO, OB speakers generally sound more natural. It's really apparent in subwoofers because you can literally hear the constraints of the box (we call it, "boominess").
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Thanks you all. Placing my orders for the NX-Otica kit and 3 Sub kit.
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You will be very pleased. Be sure to get the copper by-pass caps.
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Just finished my set (NX-Oticas with triple subs) and am loving them. Still waiting on a bunch of treatments from GIK for the room, but they sound great already. Have fun with yours.
(https://www.audiocircle.com/image.php?id=202115)
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Just finished my set (NX-Oticas with triple subs) and am loving them. Still waiting on a bunch of treatments from GIK for the room, but they sound great already. Have fun with yours.
(https://www.audiocircle.com/image.php?id=202115)
Wow, looks awesome. I see your running Parasound gear too (JC-2, A-21?). Did the new speakers expose any uglies hiding in the electronics?
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Bryston BDP-2 -> Schiit Yggdrasil -> JC-2BP -> JC-5. Front end components all plug into a PS Audio Power Plant 3. The JC-5 has way more power than I need for the NX-Oticas, but are probably operating in their class A region all the time.
The room is too live right now (travertine over concrete floor, cinder block walls, and lots of glass on the front wall, but even with this, they sound great. I am planning some absorption panels for the ceiling, some larger diffusor/bass traps behind the speakers, and some art panels above the fire place and on the opposite wall at the first reflection points.
I had a party at the house this weekend and everyone was amazed at how good they sounded. Of course I'm always looking for ways to improve the sound, but I don't think I'll replace the parasound gear any time soon.
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Jaytor, nicely done!
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Bryston BDP-2 -> Schiit Yggdrasil -> JC-2BP -> JC-5. Front end components all plug into a PS Audio Power Plant 3. The JC-5 has way more power than I need for the NX-Oticas, but are probably operating in their class A region all the time.
The room is too live right now (travertine over concrete floor, cinder block walls, and lots of glass on the front wall, but even with this, they sound great. I am planning some absorption panels for the ceiling, some larger diffusor/bass traps behind the speakers, and some art panels above the fire place and on the opposite wall at the first reflection points.
I had a party at the house this weekend and everyone was amazed at how good they sounded. Of course I'm always looking for ways to improve the sound, but I don't think I'll replace the parasound gear any time soon.
What kind of diffusion panels do you have on the floor behind the speakers? Very nice looking room!
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These are GIK 2'x2' 6A Alpha Pro Series Bass Trap Diffusor/Absorbers (6" thick). I have 2'x4' versions on order that I'm going to use in more-or-less the same position, and I'm going to move these to the side wall behind the speakers.
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These are GIK 2'x2' 6A Alpha Pro Series Bass Trap Diffusor/Absorbers (6" thick). I have 2'x4' versions on order that I'm going to use in more-or-less the same position, and I'm going to move these to the side wall behind the speakers.
Very nice, I’ve been contemplating some of those myself from GIK. I have nothing but their absorption panels at the moment so would like to experiment with their diffuser products. Like that you have majority of your components to the side. I noticed a nice improvement in the soundstage when my stack got out of the way.
Those speakers look incredible in your room and I’m sure sound even better. Congrats!
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Thanks guys. I can't wait to get the room treatments installed. Dec 30 ship date according to GIK. I'm also going to do some curtains on the windows to soften up the look a bit and absorb a little bit of the high frequency reflections. These will probably have minimal affect on the acoustics though.
The subwoofers have only been done for a few days, so I'm sure there is some more break-in required. I haven't spent a lot of time trying to dial them in yet since I figured that break-in and room treatments would likely affect the settings at least a bit.
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That's a killer looking setup, Jaytor!
About to order some GIK panels myself.
Keep us posted on the sound please.
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Just placed my order for the NX-Oticas and 3-sub H-Frames.
Are you guys crossing over the Oticas to the subs, or are you running them full range? I’m wondering if I still need my Marchand crossover.
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Just placed my order for the NX-Oticas and 3-sub H-Frames.
Are you guys crossing over the Oticas to the subs, or are you running them full range? I’m wondering if I still need my Marchand crossover.
I would keep stuff like that out of the signal path and just use a single inline cap to roll off the bottom end.
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I am using an inline cap (actually two per channel since I'm running balanced). I spliced these into the cable and hid everything in a small bakelite box that snaps around the cable.
I ran the NX-Oticas full range for the first couple of weeks and I do think they sound a bit better with the inline caps - particularly bass notes like double-bass and tympani drums.
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I am using an inline cap (actually two per channel since I'm running balanced). I spliced these into the cable and hid everything in a small bakelite box that snaps around the cable.
I ran the NX-Oticas full range for the first couple of weeks and I do think they sound a bit better with the inline caps - particularly bass notes like double-bass and tympani drums.
I would keep stuff like that out of the signal path and just use a single inline cap to roll off the bottom end.
Thanks. Jaytor, how did you establish what’ value capacitor to use and what frequency to target?
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Jaytor, how did you establish what’ value capacitor to use and what frequency to target?
First, you need to find out the input impedance of your power amp. My JC5 has 33K ohm per leg for the balanced inputs. Then find a capacitor value that will have a -3db point around 70Hz or so. The specific frequency isn't that important, but I think somewhere between 65Hz and 80Hz is probably a good range for these speakers. Danny can correct me if I'm wrong.
The f-3db point is calculated as 1/(6.28*R*C). Here's a link to an online calculator.
http://www.learningaboutelectronics.com/Articles/High-pass-filter-calculator.php (http://www.learningaboutelectronics.com/Articles/High-pass-filter-calculator.php)
I went with 0.068uF caps which results in a -3db point of 71Hz. I used Gen II Sonicaps that I got from Sonic Craft.
There are probably better caps (such as Miflex copper caps) if you can find them in a size that will work for you. The Sonicaps were the only high quality caps I could find that were easily found in a value that would give me a cutoff frequency in the range I was looking for.
If you have a Parasound amp, they list the input impedance of all their amps on their website.
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First, you need to find out the input impedance of your power amp. My JC5 has 33K ohm per leg for the balanced inputs. Then find a capacitor value that will have a -3db point around 70Hz or so. The specific frequency isn't that important, but I think somewhere between 65Hz and 80Hz is probably a good range for these speakers. Danny can correct me if I'm wrong.
The f-3db point is calculated as 1/(6.28*R*C). Here's a link to an online calculator.
http://www.learningaboutelectronics.com/Articles/High-pass-filter-calculator.php (http://www.learningaboutelectronics.com/Articles/High-pass-filter-calculator.php)
I went with 0.068uF caps which results in a -3db point of 71Hz. I used Gen II Sonicaps that I got from Sonic Craft.
There are probably better caps (such as Miflex copper caps) if you can find them in a size that will work for you. The Sonicaps were the only high quality caps I could find that were easily found in a value that would give me a cutoff frequency in the range I was looking for.
If you have a Parasound amp, they list the input impedance of all their amps on their website.
Got it. I have an A21, I believe the input impedance is the same. Are you running the subs off of the loop outs from the back of the JC-5
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I'm using the RCA outputs from the preamp for the subs and the balanced (XLR) outputs for the JC5. Yes, the input impedance of the A21 is the same as the JC5. So 0.068uF or a little smaller (which will raise the cutoff frequency) should work fine.
You don't want to use the loop outs from the power amp since the amp won't be getting the lowest frequencies after you add the inline filter caps.
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Everything should be arriving here in the next week or two. I do have a few questions.
- Due to time and space restriction to do a good quality paint job, I am planning to use Duratex for both the speaker and sub cabs. Has anyone used the white Duratex and can comment on any issues?
- Should I paint on the Duratex prior to gluing up everything?
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I haven’t used the white DuraTex so can’t comment on that but glue everything up and do all filling, sanding, edge profiling (if any) before applying the Duratex. The DuraTex is the last thing you do.
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@gguy - One issue I ran into was mounting the tweeter in the waveguide. This is a very tight fit. I made the mistake of painting the routed out area where the tweeter fits into the back of the baffle and the thickness of the paint prevented the tweeter from seating correctly. I had to use a dremel with a router bit to clean out all the paint so that it would fit in correctly. So...I'd recommend masking this area off before painting (back side only) so that the tweeter fits snugly against the back of the waveguide.
- Jay
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@gguy - One issue I ran into was mounting the tweeter in the waveguide. This is a very tight fit. I made the mistake of painting the routed out area where the tweeter fits into the back of the baffle and the thickness of the paint prevented the tweeter from seating correctly. I had to use a dremel with a router bit to clean out all the paint so that it would fit in correctly. So...I'd recommend masking this area off before painting (back side only) so that the tweeter fits snugly against the back of the waveguide.
- Jay
Thanks for the heads up. What kind of paint did you end up using?
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I used Zinsser BIN Shellac primer (light sanding after each or two coats) and Benjamin Moore Advance Satin. The BM Advance is a latex paint but flows like an oil paint. I used a roller and brush. Not quite as smooth as spraying, but this paint works quite well at hiding brush strokes.