Hello, looking for help. I have no technical knowledge of building speakers... at all, first time. But I do know wood working. I have heard that there is a larger enclosure for the Zaph ST 71 but I can not find the drawings.
Also, would it change the sound quality of the shape of the box is changed but the volume remains the same??
I wanted to change the shape to a tapered rectangle. The sides would slope downward but the front and back would still remain straight and parallel.
any help is appreciated.... I have no clue.
Also, would it change the sound quality of the shape of the box is changed but the volume remains the same??
I wanted to change the shape to a tapered rectangle. The sides would slope downward but the front and back would still remain straight and parallel.
any help is appreciated.... I have no clue.
Hi,
I can't see much advantage to a far more complicated cabinet.
It can be converted to a floorstander with the same baffle width and
reduced depth, a section in the base for sand loading is a good idea.
You can increase box volume from the 14L to say 21L.
(Designed for a 0.5 cuft box, will work well in 0.75cuft.)
You'll need to shorten the port to minimum length for 21L / 40Hz.
rgds, sreten.
I can't see much advantage to a far more complicated cabinet.
It can be converted to a floorstander with the same baffle width and
reduced depth, a section in the base for sand loading is a good idea.
You can increase box volume from the 14L to say 21L.
(Designed for a 0.5 cuft box, will work well in 0.75cuft.)
You'll need to shorten the port to minimum length for 21L / 40Hz.
rgds, sreten.
Last edited:
@ sreten, thanks. I probably wasnt too clear. I wanted to build the .75 cu/ ft version as I hear it sounds better. Deeper bass etc. i also wanted to change the shape a small amount purely for aesthetics.
Are you saying that as long as the volume remains the same the sound quality wont change?
Are you saying that as long as the volume remains the same the sound quality wont change?
I built the SR71 as a floorstander a few years ago and increased the volume to 17 litres. I would agree with all the previous comments and add that any changes you make will have an effect on the sound. Fortunately Zaph gives a number of options to change but I think the less you change it the better.
He does recommend a larger box size. See this link - first post last sentence
http://www.htguide.com/forum/showthread.php?28179-Seas-ER18-design-thread
Also this review of the SR71 recommends an 18 litre size.
http://www.diyaudio.com/forums/multi-way/213397-zaph-audio-za-sr71-review.html
As a floorstander the longer baffle does make a small but noticeable difference. I changed the size of the big inductor from 3.3mH to 3.0mH to reduce the BSC a bit. Also changed the tweeter resistor from 4 ohms to 3.5 ohms. Even small changes to the crossover will be audible.
If you do unwind an existing inductor to lower the value you must make sure the coils are securely held otherwise they resonate and distort the sound. Cable ties and insulation tape will not really do. I used epoxy adhesive but I guess hot glue might work as well. There is some debate as to whether it sounds better to mount the crossover outside of the main enclosure (which is easy to do with a floorstander) but it certainly makes it easier to make adjustments.
You will also find that after you build them they will need to be used for about 100 hours or so to break them in. Much like a new car feels tight for the first few thousand miles. It may not make a big difference but again you will hear some change. Also, tighten the driver mounting screws and the screws holding the back or baffle if they are removable after this initial period.
I found using an adjustable reflex port made it easier to get the bass tuning just right. There is some element of personal opinion when it comes to bass, and it varies depending on room size and speaker placement.
He does recommend a larger box size. See this link - first post last sentence
http://www.htguide.com/forum/showthread.php?28179-Seas-ER18-design-thread
Also this review of the SR71 recommends an 18 litre size.
http://www.diyaudio.com/forums/multi-way/213397-zaph-audio-za-sr71-review.html
As a floorstander the longer baffle does make a small but noticeable difference. I changed the size of the big inductor from 3.3mH to 3.0mH to reduce the BSC a bit. Also changed the tweeter resistor from 4 ohms to 3.5 ohms. Even small changes to the crossover will be audible.
If you do unwind an existing inductor to lower the value you must make sure the coils are securely held otherwise they resonate and distort the sound. Cable ties and insulation tape will not really do. I used epoxy adhesive but I guess hot glue might work as well. There is some debate as to whether it sounds better to mount the crossover outside of the main enclosure (which is easy to do with a floorstander) but it certainly makes it easier to make adjustments.
You will also find that after you build them they will need to be used for about 100 hours or so to break them in. Much like a new car feels tight for the first few thousand miles. It may not make a big difference but again you will hear some change. Also, tighten the driver mounting screws and the screws holding the back or baffle if they are removable after this initial period.
I found using an adjustable reflex port made it easier to get the bass tuning just right. There is some element of personal opinion when it comes to bass, and it varies depending on room size and speaker placement.
Just noticed my clumsy phrasing may be a bit misleading. Here is the first paragraph again
I built the SR71 as a floorstander a few years ago and increased the volume to 17 litres. I would agree with all the previous comments and add that any changes you make will have an effect on the sound. Fortunately Zaph gives a number of options to tweak the crossover but even so the less changes you make to the original design the better.
I built the SR71 as a floorstander a few years ago and increased the volume to 17 litres. I would agree with all the previous comments and add that any changes you make will have an effect on the sound. Fortunately Zaph gives a number of options to tweak the crossover but even so the less changes you make to the original design the better.
Thanks Richard 10. As I mentioned , I am clueless. I can build the cabinet but I need the crossovers to come fully assembled. Do you know if madisound could make the changes to the cross over for the larger cabinet? Also, I have the drawing for the smaller box but can not find the larger drawing. Should I simply add to the over all length (height) of the box?
The overall width of the front baffle will stay the same, though the shape would change slightly to a trapezoid (tapered) rectangle. Very slight slope.
The 14 litre baffle measure 9.1" wide x 15.4 tall. I am guessing that the 18 liter baffle will measure 9." x 19" (?)
Sorry for the amateurish questions. I want this too look great and sound great.
The overall width of the front baffle will stay the same, though the shape would change slightly to a trapezoid (tapered) rectangle. Very slight slope.
The 14 litre baffle measure 9.1" wide x 15.4 tall. I am guessing that the 18 liter baffle will measure 9." x 19" (?)
Sorry for the amateurish questions. I want this too look great and sound great.
Hi,
A bit taller cabinet for a bit more volume will not effect the x/o.
Increasing the depth makes more sense for a standmounter.
A floorstander will a little, and if your really keen you can repeat
the baffle diffraction sims using free software and slightly reduce
the baffle width to compensate, rather than inductor tweaking.
rgds, sreten.
A bit taller cabinet for a bit more volume will not effect the x/o.
Increasing the depth makes more sense for a standmounter.
A floorstander will a little, and if your really keen you can repeat
the baffle diffraction sims using free software and slightly reduce
the baffle width to compensate, rather than inductor tweaking.
rgds, sreten.
I think sreten has some given some good advice.
There are a number of different tools on the internet to help you calculate enclosure volume. This is a simple one but there are others
Subwoofer Enclosure Calculators, Parallel, Series, Port Length and Volume
Zaph says on his website that with the port and tuning he used there is only just enough clearance. So don't reduce the depth.
There are a number of different tools on the internet to help you calculate enclosure volume. This is a simple one but there are others
Subwoofer Enclosure Calculators, Parallel, Series, Port Length and Volume
Zaph says on his website that with the port and tuning he used there is only just enough clearance. So don't reduce the depth.
Guy, thank you both for the help and info. It looks like I am sticking with a normal rectangle box rather than the tapered (trapezoid) design. The exterior dims will be 9" wide, 10.5" deep and 18" tall to give me about 18 Liters volume. Plan is the paint with metallic automotive coatings. I will post pics when done.
A tall cabinet must be divided vertically, to prevent standing waves, perhaps max 30"?
The lower compartment of a floorstander can easily nest a subwoofer on the sidewall!
The lower compartment of a floorstander can easily nest a subwoofer on the sidewall!
New here but not new to audio. I thought I would share my experience on these here. I built these twice, first in the same size baffle design with 1/2" round over but just a little bit deeper 18 liter and tuned to 38HZ. They sounded truly exceptional and would agree that they sound way more expensive than they were. I had half a sheet of MDF left over and some free time and decided I wanted to do something different and had an idea and then found a photo on the internet of another SR71 build and decided to copy the front baffle. So I built these.
I have not tuning equipment, or ran any software, I just got one done and switched the drivers over and tuned by ear. To me overall the new design sounded better more relaxed and a bit bigger sound stage. The only thing I noticed was the tweeter was overpowering. So I added 2 ohms to the resistance and now there is no fatigue, I can hear every minute detail in the high end still and these sound spectacular with everything. Yes the drivers are broke in with well over 100 hrs on them. So far I am really happy with the results.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
I have not tuning equipment, or ran any software, I just got one done and switched the drivers over and tuned by ear. To me overall the new design sounded better more relaxed and a bit bigger sound stage. The only thing I noticed was the tweeter was overpowering. So I added 2 ohms to the resistance and now there is no fatigue, I can hear every minute detail in the high end still and these sound spectacular with everything. Yes the drivers are broke in with well over 100 hrs on them. So far I am really happy with the results.
Often the crossover won't change with cabinet volume in a two way. The reason is the cabinet affects the bottom end of the response, but as you go upwards the driver's characteristics, instead of the box, predominate. This is why a sealed and vented enclosure with the same driver will have the same response and voltage efficiency at the top of it's range.
I do note that Zaph includes notes on adjusting the overall tweeter level by replacing or adding a resistor if needed. With a little luck that's all you'll need.
Best,
Erik
Ports
Appreciate this is an old thread but can anyone confirm the port diameter for this build and calculate the port length needed for the 18 litre cabinets tuned to 38Hz?
Cheers
Appreciate this is an old thread but can anyone confirm the port diameter for this build and calculate the port length needed for the 18 litre cabinets tuned to 38Hz?
Cheers