Thank you,
I'm getting ready to order xo parts and Ive managed to source caps and inductors of the correct values...
Can I confirm the following parts for one xo;
Caps; 6uF x 1, 3.9uF x 1, 18uF x 1
Inductors; 0.47mH x 2, 0.20mH x 1
Are there any resistors or is that just the inductor R?
Also, you mentioned a 25L box. Can I alter the box size and if so by how much for all this to work as designed?
I'm getting ready to order xo parts and Ive managed to source caps and inductors of the correct values...
Can I confirm the following parts for one xo;
Caps; 6uF x 1, 3.9uF x 1, 18uF x 1
Inductors; 0.47mH x 2, 0.20mH x 1
Are there any resistors or is that just the inductor R?
Also, you mentioned a 25L box. Can I alter the box size and if so by how much for all this to work as designed?
Looks like one xover for one speaker to me.
6uf is not a 'preferred' value so will be very hard to find.
I'd use a 6.2uf.
No resistors, Coil DCR.
Why ? do you have a specific need for a certain volume ?
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Thanks for the reply.
Values I found fairly easily TBH. But does it matter if coil DCR is lower?
eg, 0.3 for 0.47mH
0.2 for 0.20mH
Re box volume, I initially started out with a plan of 7.5l or thereabouts.
Then the xo came with this comment;
I could go 15L or so max but not sure of the implications if any...
Values I found fairly easily TBH. But does it matter if coil DCR is lower?
eg, 0.3 for 0.47mH
0.2 for 0.20mH
Re box volume, I initially started out with a plan of 7.5l or thereabouts.
Then the xo came with this comment;
RajkoM said:
I could go 15L or so max but not sure of the implications if any...
Coil DCR wont really matter that much as its (I believe) a simulation and not based on actual measurements.
The smaller the box, the less bass you will get.
And no it won't affect the crossover, mainly as the crossover is to blend the bass driver to the tweeter.
As others have stated.
It's purely a starting point.
Without proper measurements of the drivers, in their finished cabinet, it's a (educated) guessing game.
The smaller the box, the less bass you will get.
And no it won't affect the crossover, mainly as the crossover is to blend the bass driver to the tweeter.
As others have stated.
It's purely a starting point.
Without proper measurements of the drivers, in their finished cabinet, it's a (educated) guessing game.
25 litre vented is way too large for the RS125-4. PE has it at 3.4 litres and Dayton 7.6 litres so your initial plan sounds reasonable but a tad smaller may be better in power handling etc.
Have a look at the Soprano PDF as a guide to designing a small speaker.
https://meniscusaudio.com/wp-content/uploads/2016/02/Sopranos-Write-up.pdf
Take a note of this paragraph when tuning small vented speakers:
"One of the things I have learned over the years concerns the relationship between the room, the speaker’s F3, bass tuning, and our perception of the bass response. I have found that when speaker rolloff in the 100 – 70Hz range a small hump of 2-3db just above the roll-off frequency can make the speaker sound more balanced and even more extend. This is the same thing Harwood did at the BBC in designing the LS3/5a. But if a speaker extends into the 50Hz range then a little hump works best, one of only 1-2dB. If a speaker extends to 40 Hz or so then it sounds the most balanced if it is as flat as possible. And finally, if a speaker extends below 30hz, and especially if it reaches 20Hz, then an over damped response with a gentle drooping at the bottom end sounds the most balanced in most rooms due toroom pressurization gain."
Wise words from JB.
Have a look at the Soprano PDF as a guide to designing a small speaker.
https://meniscusaudio.com/wp-content/uploads/2016/02/Sopranos-Write-up.pdf
Take a note of this paragraph when tuning small vented speakers:
"One of the things I have learned over the years concerns the relationship between the room, the speaker’s F3, bass tuning, and our perception of the bass response. I have found that when speaker rolloff in the 100 – 70Hz range a small hump of 2-3db just above the roll-off frequency can make the speaker sound more balanced and even more extend. This is the same thing Harwood did at the BBC in designing the LS3/5a. But if a speaker extends into the 50Hz range then a little hump works best, one of only 1-2dB. If a speaker extends to 40 Hz or so then it sounds the most balanced if it is as flat as possible. And finally, if a speaker extends below 30hz, and especially if it reaches 20Hz, then an over damped response with a gentle drooping at the bottom end sounds the most balanced in most rooms due toroom pressurization gain."
Wise words from JB.
Some use a series crossover as the impedance tends to err in the right direction (sort of). I'm thinking that if you work on the impedances you wouldn't necessarily be in a worse situation than with a parallel crossover.
I'd assume most rooms are lossy. Is there an indication that these words aren't based on his personal set of room modes?
"Some use a series crossover as the impedance tends to err in the right direction (sort of)." I'm not sure what you mean by that.
A flat impedance is one of the reasons I use AR series xo's (with CR on woofer) where above the woofer's Fs, the impedance sits within a 2-3 ohm envelope unlike some that look like a roller coaster ride.
I assume JB is talking about boundary gain whether 1, 2 or 3 surfaces as that's my experience and I've always done a similar method when tuning ports.
A flat impedance is one of the reasons I use AR series xo's (with CR on woofer) where above the woofer's Fs, the impedance sits within a 2-3 ohm envelope unlike some that look like a roller coaster ride.
I assume JB is talking about boundary gain whether 1, 2 or 3 surfaces as that's my experience and I've always done a similar method when tuning ports.
My Stances are in a 10 ltr box, and I would NOT advise going larger. You don't gain anything going larger in terms of extension, and the Xmax used is higher the larger you get, and definitely enters unsafe territory.
Later,
Wolf
Later,
Wolf
@ rabbitz & AllenB,
Champions both of you. Thank you for having this little discussion here as it answers a couple more questions I had as well 🙂
About port tuning, that paragraph seems to sum up my preference perfectly. I have heard examples where small ported speakers sound like they have something to prove with exaggerated bass, while others seem to concentrate on what they do best with a little augmentation in the lower regions. My calc's;
4.7 litres
Fb 59.4
Peak 0
-3dB 60.7
So yes agree with your comment rabbitz...
but a smidge over 9L seems ok too;
48.1
0
43.7
Strange but volumes between 5-9L result in neg peaks? Is this what's termed 'suckout'?
eg,
8 litres
50.1
-0.38
46.5
Thanks too wolf... very timely. Would someone be kind enough to check my volume calc's re the 'sudden' neg peaks and 9 litres suitability.
Series/parallel xo? Decision made for this build... no going back now. Again it's a learning experience for me, only starting on the other side of the fence so to speak.
cheers and thanks
Champions both of you. Thank you for having this little discussion here as it answers a couple more questions I had as well 🙂
About port tuning, that paragraph seems to sum up my preference perfectly. I have heard examples where small ported speakers sound like they have something to prove with exaggerated bass, while others seem to concentrate on what they do best with a little augmentation in the lower regions. My calc's;
4.7 litres
Fb 59.4
Peak 0
-3dB 60.7
So yes agree with your comment rabbitz...
but a smidge over 9L seems ok too;
48.1
0
43.7
Strange but volumes between 5-9L result in neg peaks? Is this what's termed 'suckout'?
eg,
8 litres
50.1
-0.38
46.5
Thanks too wolf... very timely. Would someone be kind enough to check my volume calc's re the 'sudden' neg peaks and 9 litres suitability.
Series/parallel xo? Decision made for this build... no going back now. Again it's a learning experience for me, only starting on the other side of the fence so to speak.
cheers and thanks
Another question... 😱
I presume the wise thing to do to start with is use inexpensive caps until the final circuit is decided on. That way when it sounds it's best there *might* be even more surprises left in store with better quality caps.
I presume the wise thing to do to start with is use inexpensive caps until the final circuit is decided on. That way when it sounds it's best there *might* be even more surprises left in store with better quality caps.
An underdamped response is not what you should be looking for.
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I've had excellent sound from inexpensive caps, even (certain) electrolytics feeding tweeters. Where many seem to go wrong is in assuming that the more you spend the better it will sound. Most caps are 'almost' perfect. Some seem to be faulty. Even with very careful acoustic design and crossover design (which are much more important) there is relatively little difference in brands.
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Thank you. By the looks of that graph then I seem to have things *** about...
So I'm actually looking for 0 - 1-2 dB peak for only a little bass extension?
Re caps, yes, yes a whole other argument I know... I guess I just want to be 'fair' to someone else's circuit in this case (within reasonable limits of course). That may still sound like I'm clearly on one particular side of that fence but it might as well be yet another exercise for my ears at a later point in time.
Dennis,
you can use some box volume which you want. Personally, I would not go below 10L with these drivers.
25L I used because I just had it in my software base.
And I'm almost sure you'll want a better bass soon. For a larger bass-driver you will need much larger box 😉
you can use some box volume which you want. Personally, I would not go below 10L with these drivers.
25L I used because I just had it in my software base.
And I'm almost sure you'll want a better bass soon. For a larger bass-driver you will need much larger box 😉
If I bumped the volume to 15L (double) would this driver work instead of the RS-125?
830883 Peerless 61/2" Mid-Woofer Hds-Ex, Speaker Drivers | Wagner Online Store
Thanks
830883 Peerless 61/2" Mid-Woofer Hds-Ex, Speaker Drivers | Wagner Online Store
Thanks
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Yes. See Lou C's Veepers.(almost the same hds, only with a dustcap, similar TSP)
And the rs125 would make a nice mid, if you already have them and would like a little more sensitivity after bsc.
And the rs125 would make a nice mid, if you already have them and would like a little more sensitivity after bsc.
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