Hi all,
I have built a small pair of open baffles with Wild Burro Betsy's and like them a lot. But I would love to wind down the top end a little. The 'too much' area is about 2.5kHz to 11kHz. Down by a couple of dB would likely do it at a guess. But in reality with one notch it would be more like a bell shaped dig into the area? Basically looking to flatten the response out by taking down 2.5 - 11 but that would take a flat top notch filter. Is that a thing achievable with some passive parts?
I am completely ape-like when it comes to passive parts values knowledge, by it seems the right size air coil plus the right size resistor could help here, even without a cap? Or with a cap?
Any help very appreciated indeed.
I have built a small pair of open baffles with Wild Burro Betsy's and like them a lot. But I would love to wind down the top end a little. The 'too much' area is about 2.5kHz to 11kHz. Down by a couple of dB would likely do it at a guess. But in reality with one notch it would be more like a bell shaped dig into the area? Basically looking to flatten the response out by taking down 2.5 - 11 but that would take a flat top notch filter. Is that a thing achievable with some passive parts?
I am completely ape-like when it comes to passive parts values knowledge, by it seems the right size air coil plus the right size resistor could help here, even without a cap? Or with a cap?
Any help very appreciated indeed.
You could do it passively before the amp by experimenting with this Baffle Step Compensation It's easily adjustable and scalable.
Greets!
'Sounds' like CD horn EQ is what you're wanting, if so, then a parallel notch filter: Parallel]DIY Audio & Video Notch Filter Designer / Calculator Help
GM
'Sounds' like CD horn EQ is what you're wanting, if so, then a parallel notch filter: Parallel]DIY Audio & Video Notch Filter Designer / Calculator Help
GM
I think you may be looking for something called a 'speaker passive shelving filter' - it's included in the modern passive xover design packages but called response profiling or equalization, or something like that.
I haven't been able to find the old books on this but the Vance Dickason's "Loudspeaker Design Cookbook" will most probably have it - it's a pretty simple technique, once you get the idea.
I haven't been able to find the old books on this but the Vance Dickason's "Loudspeaker Design Cookbook" will most probably have it - it's a pretty simple technique, once you get the idea.
Another one is the old book by G A Briggs (Wharfedale) - it's quite old now but just as relevant and explains the idea quite well - I think you can get it from Amazon, believe it or not!
Somewhere there's a site devoted exclusively to the Betsy driver and I think Caintuck Audio have done lots of work on this
Somewhere there's a site devoted exclusively to the Betsy driver and I think Caintuck Audio have done lots of work on this
Well, I am trying to use them as monitoring alternatives in a recording studio environment, and whilst they are already very useful as they are, the top is a bit clangy and that is after painfully optimising exact positioning and toe in. I am sitting close, too close for the Betsy's design goals no doubt, hence the issue. Once a bit further away things change, but I need to be that distance.
About a square foot of air, open to one side, with a fat mattress on the back wall. Body wise they're good and useful.
But I have only driven them with a modded Adcom GFA-545 as yet, which is far to much juice, waiting for my gain clone to arrive and then perhaps they will be less stressed sounding already. Not touching them until heard on the gain clone.
Douglas said the 3kHz area peak was due to the dust cap and I could remove it, and I have. It helped a little. Already asked him about shaving the whizzer down some, but he squirms about it.
Did you completely lose it? Or how much did you cut off? What happens? All treble down? From about where?
See, I don't necessarily need a snotload of open air on these, that is not what I use them for. The fact they have no crossovers makes for mixing information that you just don't get with 2 way or more, so tweeters are definitely out.
I started professionally sound engineering in 1993, so no, what is useful in a studio setting does not 'escape me'. lol And I already have Amphion one15's for that.
But if you were to describe what the Bestys without whizzers (or with less?) and running without tweeters would sound like, that would be really helpful to me.
But if you were to describe what the Bestys without whizzers (or with less?) and running without tweeters would sound like, that would be really helpful to me.
The shelving network is just 2 resistors and a capacitor - one resistor + caps sets the freq, and the other sets the amount of attenuation - the rolloff is less than 3db/oct, I think, so would be just fine for your requirement and easy to change to suit your taste.
It's maybe possible that some of that extra treble is the driver when new and might settle down with longer use - the other thing to consider when listening closely is to maybe add a light layer of dampening material across the back of the baffle - not too much - this will tend to increase the control of the cone without sacrificing any of the detail, transients, etc and produce a slightly 'softer' sound.
Also,as Scott mentioned, the driver produces nearly as much mid/treble energy behind the baffles as in front and a close backwall could be producing this altered freq response so perhaps add some damping material near/on surfaces behind - easy to try anyway …
I'm using the same driver in the Decware Tombstone baffle but is about 5 ft from the wall behind and this is covered by styrene version of Tim Perry's "leanfused" diffusors' (the modern equivalent of the Schroeder 1D diffusors) and has no extra treble lift - it did take awhile for the drivers to settle down too. I'm using Canare Star Quad 4S8 speaker cable from the First watt F6 amp.
An absolute bargain of a speaker, especially if using a bass driver to do all the 'hard work' as a FAST arrangement.
It's maybe possible that some of that extra treble is the driver when new and might settle down with longer use - the other thing to consider when listening closely is to maybe add a light layer of dampening material across the back of the baffle - not too much - this will tend to increase the control of the cone without sacrificing any of the detail, transients, etc and produce a slightly 'softer' sound.
Also,as Scott mentioned, the driver produces nearly as much mid/treble energy behind the baffles as in front and a close backwall could be producing this altered freq response so perhaps add some damping material near/on surfaces behind - easy to try anyway …
I'm using the same driver in the Decware Tombstone baffle but is about 5 ft from the wall behind and this is covered by styrene version of Tim Perry's "leanfused" diffusors' (the modern equivalent of the Schroeder 1D diffusors) and has no extra treble lift - it did take awhile for the drivers to settle down too. I'm using Canare Star Quad 4S8 speaker cable from the First watt F6 amp.
An absolute bargain of a speaker, especially if using a bass driver to do all the 'hard work' as a FAST arrangement.
Hey thanks!
Yes, they are great drivers, make a great little 3D world option to work inside. I am not going to do anything else to them that is irreversible until they indeed have played in some more, likely that will help a lot. Do feel a bit stiff and tangy because of new. And until they have made friends with the gain clone. Possibility is that at that point this will all be moot and I'll just think leave it as is. But good to have options to tweak in case that is not how it lands.
Yes, they are great drivers, make a great little 3D world option to work inside. I am not going to do anything else to them that is irreversible until they indeed have played in some more, likely that will help a lot. Do feel a bit stiff and tangy because of new. And until they have made friends with the gain clone. Possibility is that at that point this will all be moot and I'll just think leave it as is. But good to have options to tweak in case that is not how it lands.
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