Initial Goals
I am looking into getting/building a set of relatively small stand speakers to fill a room that is around 25square meters or 270 square feet.
The amplifier for this system is a Marantz 2216B giving around 16W into 8ohms.
I have found locally a pair of Yamaha HS7 monitors sold for parts. The amps are working, but the woofers are torn and the boxes have a few scratches (that I can live with). I am looking into options and deciding how much sense does it make to use these as a basis
The boxes are made out of 20mm MDF, and are 210x332x284mm giving ~12.8L (internal).
The woofer's center is 6.5" and the tweeter's is 1". And they have a port behind the tweeter that is tuned at 50Hz.
The woofer is at around 120mm from the bottom. The tweeter is at around 65mm from the top. Both speakers leave around 10mm from their own edge to the speaker's edge (end of tweeter waveguide and woofer plastic bezel)
Thoughts
1) I guess the simplest would be to get their own woofers (40 bucks a piece). The problem is that the 2216 does not have a pre out, so I would have to use the tape out and control volume through their own controls. Plus, the woofers are not really a well known quantity, and they do need some EQ to fix some issues. Plus, they are 4ohms, so more difficult to drive in case I decide to experiment with them any further.
Here is a link to detailed measurements
https://www.audiosciencereview.com/forum/index.php?threads/yamaha-hs7-review-studio-monitor.19761/
2) Get some other speakers to use with the integrated amps and active crossover. I understand that finding a complete match that sounds well is a long shot. And I would still have the same issue with the pre-out.
3) Get rid of the integrated amps and use some full range speaker in them , leaving the tweeter and some electronics in place to just fill the holes.
This probably makes the more sense. Especially since the monitor electronics are not really built for fidelity. I would still have to at least remove the limiter.
An issue with this would be that to fit a round woofer I would have to modify the tweeter's waveguide.
Using my mediocre experience with speakers, I was thinking perhaps something like the alpair 11MS that seems to work ok with even smaller boxes, or the Fostex FF 165 WK (the bass reflex boxes suggested are quite larger though). The fostex has the extra pro that it would fit without having to modify the tweeter.
Can you please suggest me some drivers that make sense for these boxes? Or maybe just call me an idiot and point me to the correct direction?
Thanks in advance
I am looking into getting/building a set of relatively small stand speakers to fill a room that is around 25square meters or 270 square feet.
The amplifier for this system is a Marantz 2216B giving around 16W into 8ohms.
I have found locally a pair of Yamaha HS7 monitors sold for parts. The amps are working, but the woofers are torn and the boxes have a few scratches (that I can live with). I am looking into options and deciding how much sense does it make to use these as a basis
The boxes are made out of 20mm MDF, and are 210x332x284mm giving ~12.8L (internal).
The woofer's center is 6.5" and the tweeter's is 1". And they have a port behind the tweeter that is tuned at 50Hz.
The woofer is at around 120mm from the bottom. The tweeter is at around 65mm from the top. Both speakers leave around 10mm from their own edge to the speaker's edge (end of tweeter waveguide and woofer plastic bezel)
Thoughts
1) I guess the simplest would be to get their own woofers (40 bucks a piece). The problem is that the 2216 does not have a pre out, so I would have to use the tape out and control volume through their own controls. Plus, the woofers are not really a well known quantity, and they do need some EQ to fix some issues. Plus, they are 4ohms, so more difficult to drive in case I decide to experiment with them any further.
Here is a link to detailed measurements
https://www.audiosciencereview.com/forum/index.php?threads/yamaha-hs7-review-studio-monitor.19761/
2) Get some other speakers to use with the integrated amps and active crossover. I understand that finding a complete match that sounds well is a long shot. And I would still have the same issue with the pre-out.
3) Get rid of the integrated amps and use some full range speaker in them , leaving the tweeter and some electronics in place to just fill the holes.
This probably makes the more sense. Especially since the monitor electronics are not really built for fidelity. I would still have to at least remove the limiter.
An issue with this would be that to fit a round woofer I would have to modify the tweeter's waveguide.
Using my mediocre experience with speakers, I was thinking perhaps something like the alpair 11MS that seems to work ok with even smaller boxes, or the Fostex FF 165 WK (the bass reflex boxes suggested are quite larger though). The fostex has the extra pro that it would fit without having to modify the tweeter.
Can you please suggest me some drivers that make sense for these boxes? Or maybe just call me an idiot and point me to the correct direction?
Thanks in advance
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You should be aware that Yamaha's ported box is designed specifically to suit the T/S parameters of the original woofer.
You would have to find a replacement woofer with exactly the same T/S parameters as the original in order for it to work in harmony with that box.
Replacement of like for like would obviate that problem.
12 litre.
a little big for A11ms (i max out at 9 litres).
A10.3 would fit (big bezel might save you from having to do a new front baffle. A10p can also be fitted.
Just looked at CHN 110 in 12 litres, looks like a nice alignment (bit you might need to add some resistance material to the vent. You’d need to push the tuning a bit lower. How big is the existing vent?
Note that even more resitance int he vent might let 50 Hz tunign work.
CHN-110 is not much more than the replacement woofers.
dave
a little big for A11ms (i max out at 9 litres).
A10.3 would fit (big bezel might save you from having to do a new front baffle. A10p can also be fitted.
Just looked at CHN 110 in 12 litres, looks like a nice alignment (bit you might need to add some resistance material to the vent. You’d need to push the tuning a bit lower. How big is the existing vent?
Note that even more resitance int he vent might let 50 Hz tunign work.
CHN-110 is not much more than the replacement woofers.
dave
Thanks a lot for taking the time Dave
I did some more measurements and recalculations. The volume is actually closer to 12.8L since the back is a metal plate and not a full sized mdf panel.
The woofer's center is at around 120mm from the external bottom. The tweeter's center is at around 65mm from the top. Both speakers leave around 10mm from their own edge to the speaker's edge (end of tweeter 4.5" waveguide and woofer plastic bezel). And the tweeter's waveguide goes a bit into the diameter of the woofer. The woofer itself is slightly cut to accommodate for this. That's why I was looking at the Fostex
The easiest way to modify the box is probably the back plate.
I guess I could reduce the volume by adding some thick plywood to it. With a quick calculation, a 80mm plug at the backplate would reduce the volume down to 8.88 liters. This would reduce the inner depth to a bit less than 200mm. Could this work?
The woofer hole is around 145mm, I don't think there is enough bezel to hold the smaller woofers properly
The vent is around 40mm in diameter and 170mm in length. I understand that it's thinner than most vents, and has a weird resonance at around 600-900Hz. But I guess the backplate and the vent are probably the easier things to replace and redesign. And I would definitely prefer it over replacing the front baffle which would probably be a no-go since it would also require a refinishing of the entire speaker
I did some more measurements and recalculations. The volume is actually closer to 12.8L since the back is a metal plate and not a full sized mdf panel.
The woofer's center is at around 120mm from the external bottom. The tweeter's center is at around 65mm from the top. Both speakers leave around 10mm from their own edge to the speaker's edge (end of tweeter 4.5" waveguide and woofer plastic bezel). And the tweeter's waveguide goes a bit into the diameter of the woofer. The woofer itself is slightly cut to accommodate for this. That's why I was looking at the Fostex
The easiest way to modify the box is probably the back plate.
I guess I could reduce the volume by adding some thick plywood to it. With a quick calculation, a 80mm plug at the backplate would reduce the volume down to 8.88 liters. This would reduce the inner depth to a bit less than 200mm. Could this work?
The woofer hole is around 145mm, I don't think there is enough bezel to hold the smaller woofers properly
The vent is around 40mm in diameter and 170mm in length. I understand that it's thinner than most vents, and has a weird resonance at around 600-900Hz. But I guess the backplate and the vent are probably the easier things to replace and redesign. And I would definitely prefer it over replacing the front baffle which would probably be a no-go since it would also require a refinishing of the entire speaker
https://frugal-phile.com/boxlib/markaudio/Alpair10x-dimensions-160616.pdf
Outer bezel diameter=164mm, cutout is 139.
dave
Outer bezel diameter=164mm, cutout is 139.
dave
I got the speakers and did some more precise measurements. The woofer screws are at a 169mm circle. The outer woofer bezel diameter is 183mm and the cutout is at 149mm on the HS7.
Are there any tricks to properly attach an A10 to such a large cutout?
Here are a few from the front, showing the woofer cutout. I don' think the other sides are very interesting. And I just noticed that the depth dimension I had included the heasink and front plastic bezel. The external depth is actually 250mm or 225mm internal, giving 11.17 liters
You can also have a better look on how the cab is constructed in this vid
You can also have a better look on how the cab is constructed in this vid
CHN-110 is a bit small for that cutout.
https://frugal-phile.com/boxlib/MA-dim/CHN110-dim.pdf
Fostex FF165wk has a bigger bolt circle, not as large a cutout, and a non-round bezel.
This thing has a metal back? You’ll want to replace that likely. Either a new baffle there or on the front is likley going to be done of you want some choice.
dave
https://frugal-phile.com/boxlib/MA-dim/CHN110-dim.pdf
Fostex FF165wk has a bigger bolt circle, not as large a cutout, and a non-round bezel.
This thing has a metal back? You’ll want to replace that likely. Either a new baffle there or on the front is likley going to be done of you want some choice.
dave
The pdf gives a cutout of 146mm. Does it have to be precisely the defined diameter or to be that close to the body of the speaker?
The bolt circle is 174mm so it falls on the existing routed slot. The non round bezel is 166mm on the small dimension, so it will cover the cutout. Unfortunately the pdf does not give the diagonal, so I don't know if it will fit inside the 183mm. What I can do is cut a ring that would bring the routed slot to be flush with the baffle, and then the speaker can just sit on top of everything.
Yep. And that's probably the easiest place to do any tuning changes. Like reducing internal volume with extra internal mdf, or fitting a different vent.
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