I build music studios and have integrated into them several speaker designs popular in these DIY circles... Big studio monitors are super expensive, and designs based around the SEOS waveguides and such can easily rival the SPL capabilities of studio monitors costing 5x as much...
However, I have come to believe that large woofers (>12") + horn loaded CDs crossed over @ ~1.2 KHz require a substantial listening distance in order to work well, else imaging is horrible.
Now I am looking for a design with a smaller mid-woofer and a dome tweeter, so that I can monitor from as close as 6' distance. I want it to be sealed, so that it is easy for me to adapt the design for different rooms, without having to recalculate ports etc. I also build rooms that have extremely low decay times down to below 40 Hz - and I simply do not want to compromise the "tightness" with a port... Yes, I know that a well designed port stays inaudible, but I just don't want to go there with this, unless I have to.
So this is my starting point - my goal is to end up with a sealed system which can do 110 dB continuous @ 1m. I want the mid-woofer to be as small as possible, but deliver the required SPL from 80 Hz - 2.2 KHz, and a HF unit that can take over from there, upwards... My initial idea is as follows:
Anarchy 708 Woofers +
Morel Titanium Supreme TSCT1104 +
Rythmik DS1510+ w/H600XL2 amplifier
In most cases the speakers will be flush mounted into a purpose built wall. Dimensions of the boxes will change, depending upon the room, but internal volume will remain constant, as modeled for optimal sound quality.
I'm not too worried about electronics at this stage... system will definitely be three way and crossed over with a MiniDSP or similar device. Class D amplifier power has become so cheap that it is also not a serious concern...
Much as I would like the most refined system I can get, I'm prioritising the SPL capability over finesse.
I'd appreciate any inputs on where I may have gone wrong with this design and how I can improve upon it.
However, I have come to believe that large woofers (>12") + horn loaded CDs crossed over @ ~1.2 KHz require a substantial listening distance in order to work well, else imaging is horrible.
Now I am looking for a design with a smaller mid-woofer and a dome tweeter, so that I can monitor from as close as 6' distance. I want it to be sealed, so that it is easy for me to adapt the design for different rooms, without having to recalculate ports etc. I also build rooms that have extremely low decay times down to below 40 Hz - and I simply do not want to compromise the "tightness" with a port... Yes, I know that a well designed port stays inaudible, but I just don't want to go there with this, unless I have to.
So this is my starting point - my goal is to end up with a sealed system which can do 110 dB continuous @ 1m. I want the mid-woofer to be as small as possible, but deliver the required SPL from 80 Hz - 2.2 KHz, and a HF unit that can take over from there, upwards... My initial idea is as follows:
Anarchy 708 Woofers +
Morel Titanium Supreme TSCT1104 +
Rythmik DS1510+ w/H600XL2 amplifier
In most cases the speakers will be flush mounted into a purpose built wall. Dimensions of the boxes will change, depending upon the room, but internal volume will remain constant, as modeled for optimal sound quality.
I'm not too worried about electronics at this stage... system will definitely be three way and crossed over with a MiniDSP or similar device. Class D amplifier power has become so cheap that it is also not a serious concern...
Much as I would like the most refined system I can get, I'm prioritising the SPL capability over finesse.
I'd appreciate any inputs on where I may have gone wrong with this design and how I can improve upon it.
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There's no practical advantage to using Anarchy woofers if you're high-passing them, and their low thermal limits and efficiency would prevent you from reaching the SPL you want. A single 6-8" prosound woofer would be much more suitable, and actually play louder than the pair of Anarchys. The Peerless FSL-0615R02-08 would work nicely, or (if that's not expensive enough for you) Beyma, 18Sound, B&C, FaitalPRO, Celestion, et al. make some nice parts.
If you're running a subwoofer on each channel, you could cross much higher than 80 Hz with no penalty, and it would relieve the mid(s) of a lot of intermodulation distortion and heat.
If you're running a subwoofer on each channel, you could cross much higher than 80 Hz with no penalty, and it would relieve the mid(s) of a lot of intermodulation distortion and heat.
Hi,
If your room is lossy (regarding low end, which seems to be the case from your statement) closed for low end may not be suited from my experience.
Closed for low end is great if your room is located into a concrete shell as it give possibility to lower qts ( thanks to an LT) to suit the long boomy decay the room create.
In a lossy room you'll need the higher efficiency of a BR ( you are more or less in the same situation as outdoor). And as you pointed you may not loose 'tightness' if you use an alignement which favor transient response.
For your spl target a Dayton 15" rss390 may produce up to 114db spl@1m with a bessel alignement ( in 80 liter box).
I agree with Lojzek and Scudinc for driver type: go for PA rather than fragile poor tiny hifi drivers.
I don't with Lojzek about mtm but a 'good' implementation is not as easy as it may seems and in the end it is a personal preference too.
I'm surprised by your comment about horrible imaging with horn. You hint 1,2k as xover freq so i suppose you used waveguide. Have you playec with toe in with them?
If your room is lossy (regarding low end, which seems to be the case from your statement) closed for low end may not be suited from my experience.
Closed for low end is great if your room is located into a concrete shell as it give possibility to lower qts ( thanks to an LT) to suit the long boomy decay the room create.
In a lossy room you'll need the higher efficiency of a BR ( you are more or less in the same situation as outdoor). And as you pointed you may not loose 'tightness' if you use an alignement which favor transient response.
For your spl target a Dayton 15" rss390 may produce up to 114db spl@1m with a bessel alignement ( in 80 liter box).
I agree with Lojzek and Scudinc for driver type: go for PA rather than fragile poor tiny hifi drivers.
I don't with Lojzek about mtm but a 'good' implementation is not as easy as it may seems and in the end it is a personal preference too.
I'm surprised by your comment about horrible imaging with horn. You hint 1,2k as xover freq so i suppose you used waveguide. Have you playec with toe in with them?
Not uncommon in pro world ( and much less crazy than some control rooms i've worked in, make a search for studio Mega in Suresnes, France to have an idea...120dbspl clean peaks at the desk...more than 4meters away from loudspeakers!): let's say you want to be able to use k-20* listening reference this is 'just enough' spl wise at 2 meters.
85dbspl +20db for dynamic within the musical program = 105dbspl +6db for distance= 110dbspl.
*: Google Image Result for https://upload.wikimedia.org/wikipedia/commons/thumb/8/82/Ksystem.svg/1200px-Ksystem.svg.png
Pro is different than domestic recreative use spl wise. And no we don't use it master wide open for 10hours sessions, but nevertheless from time to time you need this kind of high Spls.
85dbspl +20db for dynamic within the musical program = 105dbspl +6db for distance= 110dbspl.
*: Google Image Result for https://upload.wikimedia.org/wikipedia/commons/thumb/8/82/Ksystem.svg/1200px-Ksystem.svg.png
Pro is different than domestic recreative use spl wise. And no we don't use it master wide open for 10hours sessions, but nevertheless from time to time you need this kind of high Spls.
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Thanks for the responses.
Lojzek, scudinc - I will take your advice and look for a suitable pro driver.
krivium - thank you. Largely we are in agreement. My understanding is that the general spec for cinema mixing rooms is 85 dB average, with 20 dB headroom for peaks (this goes as low as 79 dB average for smaller mix rooms). This is with a reference of (RMS) pink noise generated @ -20 dB Fs.
While the listening position in my music rooms is typically 6' - 10', the client's couch is typically @ 12' - 20' away from the speakers. If I want "big" speaker performance at the client's position, 110 dB average @ 1m feels about right... This is also the typical spec for a medium-large studio monitor. I would like the system to have a comparable SPL capability to, say, the ATC SCM 150ASL Pro - these guys can put out 117 dB continuous @ 1m. I'll settle for 110 dB for a sealed system...
Of course one will not be monitoring continuously at that level... The system will be pushed when we are trying to replicate a "cinematic" or club based experience.
In my studio (pic attached), my main speakers are Tannoy DC12i (dual concentric, with a 1.4" CD), with custom AE 15" subs... Previously I had SEOS12 + 12" Eminence Definimax woofers + LAB12 subs... The problem is consistent... The speakers are about 9' apart, and my listening position is @ about 7'... At my position, the balance keeps changing even if I move by a few inches... At the rear of the room (@ about 11'), imaging is super wide and consistent.
All the rooms I build conform to the ITU775 spec... the L&R speakers are toed in by 30 degrees. Engineers expect to see this arrangement.
Lojzek, scudinc - I will take your advice and look for a suitable pro driver.
krivium - thank you. Largely we are in agreement. My understanding is that the general spec for cinema mixing rooms is 85 dB average, with 20 dB headroom for peaks (this goes as low as 79 dB average for smaller mix rooms). This is with a reference of (RMS) pink noise generated @ -20 dB Fs.
While the listening position in my music rooms is typically 6' - 10', the client's couch is typically @ 12' - 20' away from the speakers. If I want "big" speaker performance at the client's position, 110 dB average @ 1m feels about right... This is also the typical spec for a medium-large studio monitor. I would like the system to have a comparable SPL capability to, say, the ATC SCM 150ASL Pro - these guys can put out 117 dB continuous @ 1m. I'll settle for 110 dB for a sealed system...
Of course one will not be monitoring continuously at that level... The system will be pushed when we are trying to replicate a "cinematic" or club based experience.
In my studio (pic attached), my main speakers are Tannoy DC12i (dual concentric, with a 1.4" CD), with custom AE 15" subs... Previously I had SEOS12 + 12" Eminence Definimax woofers + LAB12 subs... The problem is consistent... The speakers are about 9' apart, and my listening position is @ about 7'... At my position, the balance keeps changing even if I move by a few inches... At the rear of the room (@ about 11'), imaging is super wide and consistent.
All the rooms I build conform to the ITU775 spec... the L&R speakers are toed in by 30 degrees. Engineers expect to see this arrangement.
Attachments
Hi Audiothings.
Yes 85db spl @ -20dbfs in theater/cinema is the norm. If my memory serve this is one of Dolby's constraints for the room to have the label.
Of course this is room dependent: in a typical cinema's room (which are big rooms) 85db is ok but if your room is smaller you may have to lower the reference level a bit ( down to 75db spl which is the 'lowest' spl Bob Katz recommend, but this is a recommendation and in the end one's have to adapt to his own preference as long as you keep the dynamic range).
The difference in level/ room volume is linked to early reflections and the way our brain interpret it: in large room as ER are longer and lower in level the overall spl can be higher, in smaller room it seems our brain tell us that overall spl is to high and potentialy dangerous so the need to lower the reference point in the scale.
So 85db spl was the norm from Aes/Ebu since the 80's but recently in France it was decided ( by the health agency ) to lower even further to 82db spl for public space. This include clubs, concert halls and most probably cinema's too ( it is allowed to have 102db spl peaks averaged over 15 minutes and this is now mandatory to have limiters and constant monitoring including visual feedback and permanent recording of all data...).
In my view you are absolutely right to conform to Aes/Ebu norms relative to control rooms and speaker position. As you stated engineers requires it anyway.
About your sweet spot issues: interesting you use Tannoy as i would have recommend to you to try coax! In my experience those are the most consistents performers to have same sound ( from low mid to high) everywhere in a room.
So i would be tempted to say your issue is room/furniture related. Your working desk/screens are probably the culprit and you experience comb filtering from them ( those are nice reflectors and given their size they will make the area of 1khz to 4khz troublesome).
If you can make an experiment in your room pulling everything back to the couch and listen at your usual sweet spot and hear if there is any change, i bet your issues will disapear or being much less obvious.
With large analog consoles the metering is used as a screen to mitigate the effect ( by shadowing) and in mastering facility's you will see some very small workspace/desk ( below 1m2 surface) to minimize this. I've seen a recent mastering control room where equipment have been located to the side of room and the engineer is listening standing up in the sweet spot...
Not convenient in your case but maybe you could find a way for your workflow thinking about this example.
Yes 85db spl @ -20dbfs in theater/cinema is the norm. If my memory serve this is one of Dolby's constraints for the room to have the label.
Of course this is room dependent: in a typical cinema's room (which are big rooms) 85db is ok but if your room is smaller you may have to lower the reference level a bit ( down to 75db spl which is the 'lowest' spl Bob Katz recommend, but this is a recommendation and in the end one's have to adapt to his own preference as long as you keep the dynamic range).
The difference in level/ room volume is linked to early reflections and the way our brain interpret it: in large room as ER are longer and lower in level the overall spl can be higher, in smaller room it seems our brain tell us that overall spl is to high and potentialy dangerous so the need to lower the reference point in the scale.
So 85db spl was the norm from Aes/Ebu since the 80's but recently in France it was decided ( by the health agency ) to lower even further to 82db spl for public space. This include clubs, concert halls and most probably cinema's too ( it is allowed to have 102db spl peaks averaged over 15 minutes and this is now mandatory to have limiters and constant monitoring including visual feedback and permanent recording of all data...).
In my view you are absolutely right to conform to Aes/Ebu norms relative to control rooms and speaker position. As you stated engineers requires it anyway.
About your sweet spot issues: interesting you use Tannoy as i would have recommend to you to try coax! In my experience those are the most consistents performers to have same sound ( from low mid to high) everywhere in a room.
So i would be tempted to say your issue is room/furniture related. Your working desk/screens are probably the culprit and you experience comb filtering from them ( those are nice reflectors and given their size they will make the area of 1khz to 4khz troublesome).
If you can make an experiment in your room pulling everything back to the couch and listen at your usual sweet spot and hear if there is any change, i bet your issues will disapear or being much less obvious.
With large analog consoles the metering is used as a screen to mitigate the effect ( by shadowing) and in mastering facility's you will see some very small workspace/desk ( below 1m2 surface) to minimize this. I've seen a recent mastering control room where equipment have been located to the side of room and the engineer is listening standing up in the sweet spot...
Not convenient in your case but maybe you could find a way for your workflow thinking about this example.
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Assuming same driver budget, I'd use a less expensive tweeter and add a good small midrange to make it a 3-way. That way you avoid the sound power problems inherent in the 7" 2-way with 180deg waveguide. And maybe bump the woofer up to 8". The B&C 8BG51 would do nicely...
If you want to stick with the MTM, 180deg tweeter waveguide use the smaller Anarchies.
Also, look at some of Augerpro's threads about small WGs for tweeters.
Overall, think "DIY Revel Gem II"
If you want to stick with the MTM, 180deg tweeter waveguide use the smaller Anarchies.
Also, look at some of Augerpro's threads about small WGs for tweeters.
Overall, think "DIY Revel Gem II"
In my studio (pic attached), my main speakers are Tannoy DC12i (dual concentric, with a 1.4" CD), with custom AE 15" subs... Previously I had SEOS12 + 12" Eminence Definimax woofers + LAB12 subs... The problem is consistent... The speakers are about 9' apart, and my listening position is @ about 7'... At my position, the balance keeps changing even if I move by a few inches... At the rear of the room (@ about 11'), imaging is super wide and consistent.
All the rooms I build conform to the ITU775 spec... the L&R speakers are toed in by 30 degrees. Engineers expect to see this arrangement.
With your CD speakers you could try the toe-in recommended by this article.
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