I am a sound engineer. I have very little knowledge but some little success building speakers - designs usually found online. I’m building these speakers because comparably specified “branded” studio monitors cost 3X as much as my build. As is, being only moderately successful in third world India, it has taken me a long time to save up and procure components for this current build.
“It's better to ask for forgiveness than permission” - Grace Hopper.
Every time I seek advice on driver selection and such, I get well meaning but strong, contrasting an opinions. I end up getting confused and doing nothing. This time, following my gut, for better or worse, I went ahead and bought the following drivers (per speaker):
Subwoofer - SB Acoustics SB Acoustics SB42FHCL75-6
Woofer - Purifi PTT8.0X04
Mid-Range - Volt VM752
Tweeter - Satori TW29RN-4
Four way design powered by QSC PLD 4.2 - 4x 400W w/ onboard DSP
The listening position will be a mere 5’ from the speakers. Most of the space between the speakers and listener will be occupied by a console table.I know this could be a problem… positioning large speakers in the near-field position… but there are plenty of reputed 3 way near-field monitors, mine just add the subs. My room is very highly damped, down to about 40 Hz…
I’ve come up with two cabinet layout designs, I seek your opinions on these, and suggestions for alternatives.
Option 1: Woofer to the side of mid-range/tweeter
Advantages:
A. Driver to driver proximity should lead to a more cohesive sound?...
B. More space for subwoofer cabinet (3-way "satellite" speakers will be in a separate enclosure, placed on top of the subwoofer).
Disadvantage: path length differences will significantly affect integrity in the horizontal plane?
Option 2: Woofer below mid-range/tweeter.
Advantage: Better Integrity in the horizontal plane?
Disadvantages:
A. Woofer lip is just above the console table top, possibly leading to a reflected, comb filtered sound dominating the direct sound.
B. Less space for the subwoofer enclosure.
C. Too much driver to driver distance?
Looking forward to inputs. Thank you.
“It's better to ask for forgiveness than permission” - Grace Hopper.
Every time I seek advice on driver selection and such, I get well meaning but strong, contrasting an opinions. I end up getting confused and doing nothing. This time, following my gut, for better or worse, I went ahead and bought the following drivers (per speaker):
Subwoofer - SB Acoustics SB Acoustics SB42FHCL75-6
Woofer - Purifi PTT8.0X04
Mid-Range - Volt VM752
Tweeter - Satori TW29RN-4
Four way design powered by QSC PLD 4.2 - 4x 400W w/ onboard DSP
The listening position will be a mere 5’ from the speakers. Most of the space between the speakers and listener will be occupied by a console table.I know this could be a problem… positioning large speakers in the near-field position… but there are plenty of reputed 3 way near-field monitors, mine just add the subs. My room is very highly damped, down to about 40 Hz…
I’ve come up with two cabinet layout designs, I seek your opinions on these, and suggestions for alternatives.
Option 1: Woofer to the side of mid-range/tweeter
Advantages:
A. Driver to driver proximity should lead to a more cohesive sound?...
B. More space for subwoofer cabinet (3-way "satellite" speakers will be in a separate enclosure, placed on top of the subwoofer).
Disadvantage: path length differences will significantly affect integrity in the horizontal plane?
Option 2: Woofer below mid-range/tweeter.
Advantage: Better Integrity in the horizontal plane?
Disadvantages:
A. Woofer lip is just above the console table top, possibly leading to a reflected, comb filtered sound dominating the direct sound.
B. Less space for the subwoofer enclosure.
C. Too much driver to driver distance?
Looking forward to inputs. Thank you.
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Good.
This isn't usually the problem people tend to think it would be.
Can you flip them and suspend, soffit or shelf? I am partial to a symmetrical polar response so in line works better for me personally. Your other driver grouping reminds of the JBL midfields 4311 as an example or 4343 which had a rotatable baffle for the upper drivers for soffit mounting. You could try both baffles to see which works best in your room,
Rob 🙂
https://www.lansingheritage.org/html/jbl/specs/pro-speakers/1977-4343.htm
Rob 🙂
https://www.lansingheritage.org/html/jbl/specs/pro-speakers/1977-4343.htm
You think of dual cabinets subs separate? Where are you planning to crossover to the woofer? 80 hz of JBL style 250-300Hz? You do seperate boxes you optimize sub placement and do any configuration of the upper drivers you want.
Rob 🙂
Rob 🙂
Since I didn’t read about it: what measurement setup you have available?
First step would be making mock-ups for the baffle (cheap wood or XPS foam) based on initial simulations in VituixCad (VCad) or The Edge. You will have to vary driver positions, distances, baffle sizes and corner shapes (facets, roundovers). And measure the dummies at least from 0-90 degrees in 10 degree steps.
After evaluation, pick your baffle size, shape and unit placement and build an enclosure. I take it that tuning the low end for the SB and Purifi are just peanuts for you. Since you have DSP at your disposal it actually is a right assumption. I also take it you know about enclosure building and performing adequate internal damping. These are not that hard.
Next: measure everything again and import in VCad. Fool around with the crossover section until you find an acceptable response, both on and off-axis. Import it in the DSP and: Presto! I would use passive C’s for the Satori and the Volt for protection BTW, as well as a waveguide for the tweeter. Check out the OSMC to be found on this forum.
First step would be making mock-ups for the baffle (cheap wood or XPS foam) based on initial simulations in VituixCad (VCad) or The Edge. You will have to vary driver positions, distances, baffle sizes and corner shapes (facets, roundovers). And measure the dummies at least from 0-90 degrees in 10 degree steps.
After evaluation, pick your baffle size, shape and unit placement and build an enclosure. I take it that tuning the low end for the SB and Purifi are just peanuts for you. Since you have DSP at your disposal it actually is a right assumption. I also take it you know about enclosure building and performing adequate internal damping. These are not that hard.
Next: measure everything again and import in VCad. Fool around with the crossover section until you find an acceptable response, both on and off-axis. Import it in the DSP and: Presto! I would use passive C’s for the Satori and the Volt for protection BTW, as well as a waveguide for the tweeter. Check out the OSMC to be found on this forum.
What a nice project. Congratulations to your awesome selection of chassis.
Please let me give you some of my thoughts on your project:
Keep the purifi for your next (2 way) project and replace it with a pro 8" or 10"
Would double sd in the LF and now you have the possibility to realize a cb enclosure with all its advantages if active driven.
If space is no problem, I would increase the baffle width to maximum for more directivity in the lower mids.
Please let me give you some of my thoughts on your project:
Keep the purifi for your next (2 way) project and replace it with a pro 8" or 10"
Would double sd in the LF and now you have the possibility to realize a cb enclosure with all its advantages if active driven.
If space is no problem, I would increase the baffle width to maximum for more directivity in the lower mids.
If I recall correctly, @audiothings you are in a non-environment control room, so monitors will be flush-mounted, right ?
There are no reputable monitors designed for listening at 5' with a 15" woofer and 2"+1.25" drivers on a flat baffle. Reputable monitors also rarely use fashionable boutique drivers but ones chosen to best fit the speaker configuration in this case one for listening at 5' in the presence of a desk/console.
If you have the option to return the drivers, settle on a speaker configuration appropriate for your use and then choose drivers appropriate for the configuration that might be the best way forward. If you cannot return the drivers then it becomes a question of how to make the best of a less than ideal situation.
One option might be to go for midfield monitors and ignore their inadequacies for close listening.
What to do with a 2" and 1.25" driver? The 2" driver could be a filler but it seems a bit of a waste given the extremely high price. The close listening distance and the large size of the 2" driver is a problem w.r.t. lobing and degrading the imaging with two distinguishable sources. A low crossover frequency would help in this respect.
What to do with the 15" driver? A seperate cabinet which can be placed above or to the side could help with future changes of use and driver configurations. The smaller cabinet for the mid and high frequencies could then be better optimised for close work perhaps with the midwoofer to the side of the filler and tweeter. It could also be replaced for less cost if the current choice of 2"+1.25" drivers cannot be made to perform sufficiently well.
It is hard to give many suggestions without a better understanding of your options, constraints and objectives.
It's a 3" dome with short WG, no worries there. Many main monitors often are developed like that (3"+1.25")
Will revert soon with a detailed response, meanwhile, here are a couple of very well regarded studio monitors with 3" mid-range drivers.
ATC SCM25 Pro
Neumann KH-310
ATC SCM25 Pro
Neumann KH-310
Thanks for the correction. The 3" is a obviously a better match for the 1.25" and 8" drivers.
The monitors shown are indeed well regarded for listening close at 5' but note the absence of 15" woofers.
Hello @audiothings !
I more or less followed your path about the idea of a 4-ways monitor in the near field situation of my little auditorium...
View from the listening positiion... The distance from my head to the speakers is 2.50m (circa 8.2 ft) :
As you can see, I went for your option 2 matched offset vertical inline speakers if I can say so, since I was more concerned by horizontal directivity than vertical, due to the disposition of the room.
Even if I am in a small, near-field area like you, I do not have to manage with the presence of a mixing console and a listening distance at 5 ft (1.50m) ! This makes a significant difference...
I have the same advice as @Robh3606 :
And I would also increase the listening distance for a better sound integration...
But if it's not doable, then your option 1 is probably better suited then, having in mind this kind of compact 3-way studio monitor image you posted, notably if the FC of the subwoofer is low (60 to 80Hz) :
The subwoofer section position can possibly be lowered enough in position, in order to not to interfere with the mixing console size, since infra bass frequencies are rather omnidirectional. The rest of the monitor located upper is compact enough to offer your a convenient sound integration then.
Well... Less easy to deal with than it seems ! 😕😉
T
I more or less followed your path about the idea of a 4-ways monitor in the near field situation of my little auditorium...
View from the listening positiion... The distance from my head to the speakers is 2.50m (circa 8.2 ft) :
As you can see, I went for your option 2 matched offset vertical inline speakers if I can say so, since I was more concerned by horizontal directivity than vertical, due to the disposition of the room.
Even if I am in a small, near-field area like you, I do not have to manage with the presence of a mixing console and a listening distance at 5 ft (1.50m) ! This makes a significant difference...
I have the same advice as @Robh3606 :
And I would also increase the listening distance for a better sound integration...
But if it's not doable, then your option 1 is probably better suited then, having in mind this kind of compact 3-way studio monitor image you posted, notably if the FC of the subwoofer is low (60 to 80Hz) :
The subwoofer section position can possibly be lowered enough in position, in order to not to interfere with the mixing console size, since infra bass frequencies are rather omnidirectional. The rest of the monitor located upper is compact enough to offer your a convenient sound integration then.
Well... Less easy to deal with than it seems ! 😕😉
T
I bought a pair of those Volt midranges. Fortunately I was able to sell them on eBay at a small loss a few months later. I wasn't a fan of the sound. I'm now using Bliesma 3" midranges instead. The Volt drivers look like the ATC drivers, but they don't have the flat response that the ATC drivers have. Maybe you will like them.
I recommend you use one of the free design software programs to determine the baffle locations and crossover design. Look at Visaton Boxsim and VituixCadII. These have baffle modeling in them as well as crossover design. The software can help you get a good match on the radiation angle at the crossover points.
I recommend you use one of the free design software programs to determine the baffle locations and crossover design. Look at Visaton Boxsim and VituixCadII. These have baffle modeling in them as well as crossover design. The software can help you get a good match on the radiation angle at the crossover points.
Ok, How about Option 3: Separate boxes for Sub and the rest of the speaker? This would open up some other options.
This isn't that unheard of... think Linkwitz for example. There are other speakers that do this too.
You've got some good choices... But isn't there a bit of overlap between the Purify and your SB Sub.
Purifi gets down to what? 27Hz or so per their data sheet.
The SB Sub gets you down to 20Hz or so?
This is why I thought about separating the Woofer/Sub in separate box would give you a shot to redesign a smaller main cabinet based on the internal volume you'd need. Also it seems that there's a bit of overlap between Purifi and the tweeter where you probably don't need the Volt and go 3 way?
(I saw the comment about the Volt... I have no experience with them so I don't know anything.)
But hey! Its your speaker, and your dream.
I'm just guess. Like I said, you've got some good drivers in the SB and Purify.
Just let us know what you think.
BTW... I think option 2 makes more sense than option 1 if you go that route.
Purifi gets down to what? 27Hz or so per their data sheet.
The SB Sub gets you down to 20Hz or so?
This is why I thought about separating the Woofer/Sub in separate box would give you a shot to redesign a smaller main cabinet based on the internal volume you'd need. Also it seems that there's a bit of overlap between Purifi and the tweeter where you probably don't need the Volt and go 3 way?
(I saw the comment about the Volt... I have no experience with them so I don't know anything.)
But hey! Its your speaker, and your dream.
I'm just guess. Like I said, you've got some good drivers in the SB and Purify.
Just let us know what you think.
BTW... I think option 2 makes more sense than option 1 if you go that route.
Thank you for the replies. Taking into mind various considerations, here is where I'm at today. There is no possibility of change in the driver selection because of near non-existent buyer's market and paucity of funds to stretch anything further. The following is my going to be my new room. (@Storm Mastering - you're right, honoured that you remember - I build and work out of Non-Environment rooms, for the most part.) For various reasons, I will not be flush mounting the speakers in this build case.The subwoofers will be firing to the side walls for reasons explained around 2.35 mins into this video. At this time, in my mind, I'm thinking about the following driver layout.
The 3 way "top" speakers are sealed and angled to just behind the listening position.
The starting point of above driver layout is that the tweeters are at 48" height from floor level.
Thoughts about this layout..?
.
The 3 way "top" speakers are sealed and angled to just behind the listening position.
The starting point of above driver layout is that the tweeters are at 48" height from floor level.
Thoughts about this layout..?
.
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I think you should be able to position the Subwoofer in any direction without too much difference although facing the wall in the corner may increase the bass.
Not sure why your woofer has such a large cabinet. 48" for the tweeter height? Kinda tall for most listening positions. YMMV but yes. I think this is better than a single cabinet. You could also have some isolation between the two cabinets... you may already have that planned but not shown and it would be optional. The nice thing too... if you wanted you could put the sub elsewhere and invert the top speaker and put it on a stand.
Good luck w the build.
Not sure why your woofer has such a large cabinet. 48" for the tweeter height? Kinda tall for most listening positions. YMMV but yes. I think this is better than a single cabinet. You could also have some isolation between the two cabinets... you may already have that planned but not shown and it would be optional. The nice thing too... if you wanted you could put the sub elsewhere and invert the top speaker and put it on a stand.
Good luck w the build.
WinISD recommends 130L+ for a ported cabinet, which is par for course with a driver like this, AFAIK... hence provision for the large cabinet, exact dimensions TBD. Seating is "workstation" height, not couch height. I'm pretty short and my ear is @ about 41"... I'm going by the general studio standard of of 46"-50", but your suggestion is well taken, I will definitely take it into account when going further with plans...
@AllenB I'm no tech expert, but what I can make out from the video link I pointed to, is that subwoofers facing opposite walls will arrive out of phase at the listening position, and reversing the phase of one speaker brings them back in phase... somebody who understands this better is welcome to chime in...