Many helpful responses. Thanks to all, especially to Zaph for even providing the design and for being more helpful and resourceful than we could all ask for.
The owner of the BAMTM (good friend) is in the process of installing L-pads on the tweeter for attenuation. While the speaker is in pieces, we will shoot some photos of the x-over so you can view and check for correctness. Probably will not be until mid week (sorry). The only listening equipment I have is an md player and a modest stereo mic. I can do an A/B comparisson I suppose with some Diana Krall. First played through a two-way AR.COM bookshelf (very detailed and open vocals) and then through the BAMTM; then I will post in mp3 format to a site all can listen to. I will do this test without any tweeter attenuation.
BTW, what is everyone's favorite speaker for vocals? -- it can be a DIY or Commercial offering.
Thanks
The owner of the BAMTM (good friend) is in the process of installing L-pads on the tweeter for attenuation. While the speaker is in pieces, we will shoot some photos of the x-over so you can view and check for correctness. Probably will not be until mid week (sorry). The only listening equipment I have is an md player and a modest stereo mic. I can do an A/B comparisson I suppose with some Diana Krall. First played through a two-way AR.COM bookshelf (very detailed and open vocals) and then through the BAMTM; then I will post in mp3 format to a site all can listen to. I will do this test without any tweeter attenuation.
BTW, what is everyone's favorite speaker for vocals? -- it can be a DIY or Commercial offering.
Thanks
augerpro said:
One of our fellow forum members has shown that it works quite well to do simulations without having actual measurements that you've taken yourself, he posted some examples showing no significant difference in the measured response based on his simulation method compared to an actual measurement.
Was it Jay, I think?
It would be fun and educational to be able to load up the simulation for every interesting DIY speaker design that we see.
Let's say I want to build a speaker like a design that you posted, but, I have a different model of tweeter.
If I could load up your design, then surely, [if I had the driver file for the different tweeter that I had] I could swap that in and:
1) see how much tweaking might be needed
2) see if it is a decent candidate to use as a substitute
3) see how the design would look if I switched from vented to sealed, because I think I would like to use some "bass bins" with the cheap (but good) 8" drivers I got on a buyout would let me have higher maximum output, less overall distortion, and more extended bass
4) etc. etc. etc. - without myself being skilled enough using the software yet to be able to get the design input properly and working starting from scratch, or, not having my own measurement capability
SoundQuest said:
Don't do that. It will change the impedance of the circuit and the function of the crossover. Zaph has listed tweeter level options and BSC options that you should use. I hope you haven't done any other "mods" to improve the sound outside of Zaph's suggestions?
critofur said:
But that's not what you are doing, and you still don't seem to understand why although myself and others have tried to explain.
critofur said:
But you don't have SE so how can you "load up" my design or my drivers? And you have no idea what my measurement conditions are, mic placement, baffle size and layout, gating, etc. What everyone has been trying to tell is because of all these things my measurements are worthless to you.
I know what you want, but what you want is useless, and I just don't know how to explain that so you will understand. Consider: if there is a thing that a lot of people want, some one will make it for them. But if no one wants this (except you), what does that tell you? I wish what you were asking for was possible, because it would be incredibly useful.
I hope this doesn't offend, I don't mean to. But you keep asking for this and I keep trying to explain why it just isn't useful. If you don't understand why, then you will never understand how to do Jay's method properly.
SoundQuest said...
"Thanks to those that have responded reasonably and kindly."
It occurs to me that in post #6 that my tone was downright rude. My intention was to chide or poke a little fun, not to be disrespectful to a poster who was simply seeking help. It is compounded by the fact that I have never heard the design and therefore have not a leg to stand on defending it or criticizing his observations. I sentence myself to build at least one more dismal failure of my own design and post no pictures.
"Thanks to those that have responded reasonably and kindly."
It occurs to me that in post #6 that my tone was downright rude. My intention was to chide or poke a little fun, not to be disrespectful to a poster who was simply seeking help. It is compounded by the fact that I have never heard the design and therefore have not a leg to stand on defending it or criticizing his observations. I sentence myself to build at least one more dismal failure of my own design and post no pictures.
SoundQuest said:
Hi,
You cannot have your cake and eat it at the same time. The details
of the AR.com are no longer available but from what I remember it
is not an accurate design in terms of tonal balance.
GR Research measured it :
I do not seem to be able to access the original GR article either.
It seems you are comparing chalk and cheese.
🙂/sreten.
tinitus said:
I've never heard any model other than Maggie MMGs; therefore, they are the only model I can render an opinon. They are excellent for vocal presentation.
All Maggies have similar charateristics though.
JimOfOakCreek said:
Its the projection of the particular sound source geometry and its low mass that gives a spectacular presence and airiness to vocals. Listen more carefully and you may find that the focal accuracy isn't that correct, and that the vocalists sizes are larger than life. Very beguiling though.
I have built and measured the AR.com DIYs.
As sreten said - the crossover had problems and the Peerless tweeter has a rise above 8KHz giving impression of false "air". At a 1m measuring distance the crossover has a dip making vocals RECESSED from my A/B comparisons to a Kef C30.
However - at a 4 metre measuring distance (roughly 15 degrees off axis) including room reflections, the AR.com measures nearly flat in my room.
I have measured and compared a Kef C30 with the AR.com DIYs. The KEFs definitely have clearer vocals.
The BAMTM should have much better vocals than the AR.com DIYs.
I will post some measurements of the AR.com if you are interested.
David.
Haha, funnily this thread begins to touch the so often paradoxal things of listening impressions !Dave Bullet said:
SoundQuest, do you use the closed or BR version? Besides vocals, do you feel lacks in other ranges?
And what about stuffing? Have you tested different amounts/sorts?
Sealed version. To answer your other questions, the BAMTM reproduces lower frequencies with great ease and speed. They are very tight with no hints of muddy floppy lazy bass. They do very well off axis, instruments sound great, especially the high sample-rate electronic variety used by Depeche Mode in their two most recent works. The SEAS tweeter reproduces such inhumane and caustic sounds so effortlessly -- making them sound sweet and hypnotic. Voice...well...that's what this thread is all about initially. It sounds as if Dave Gahan is stuck behind the stage curtain and like Diana Krall is singing into a mic wrapped in an afghan. Hopefully it's something we did wrong with the crossover.crazyhub said:Haha, funnily this thread begins to touch the so often paradoxal things of listening impressions !
SoundQuest, do you use the closed or BR version? Besides vocals, do you feel lacks in other ranges?
And what about stuffing? Have you tested different amounts/sorts?
Is it possible to post photos of the crossover? if not already firmly fixed within the cabinets) Might be easier to troubleshoot.
The other really useful thing would be a frequency/impedance plot, but suppose you can't do that.
David.
SoundQuest said:
Hi,
It is certainly not "spot on" as the inductor layout does not minimise
the considerable interactions between (two air cored) inductor fields.
The fields, i.e. coil placements, need to be orthogonal, 90 degrees.
Stand the 0.3mH inductor on its edge, held with a tiewrap.
http://www.troelsgravesen.dk/coils.htm see 6 and 7.
🙂/sreten.
(EEE - soldering could be better ....)
As far as the earlier posts about the AR.COM DIY, I find it comical that we rely on graphs, peaks, valleys, plateaus, computers, and software, to dictate to the ear, and the brain, what sounds excellent and what does not.
Is it possible that the ear picks something up that the equipment and software cannot? I should think so. But more and more I am seeing the philosophy; a bump here, a dip there, some breakup over here -- and all of a sudden..."screw the listening tests, this thing is no good." Or even, "wow, that speaker sounds incredibly accurate with incredibly transparent and airy vocals and life-like dynamics." But then, after putting it up on the screen and plotting a graph..."oh, my ears have been deceived, that was false accuracy I heard, false airiness, that speaker was dead, not alive and dynamic, I was fooled and this graph right here shows my dupability. Like I said... comical.
But...being fair and true to our species, taste is certainly not uniform and we all have our own preference -- it just seems to border on absurdity when we use a machine and a machine only, and not our own ears and the unmatched biochemical supercomputer that is between them, to make the conclusion "this sounds right."
Are computers and software useful? Sure, of course they are, but only to a certain extent. I believe a computer can point us in the direction of mediocrity and at least give us a starting point; it's then a human must take over and turn mediocrity into a masterpiece through fine-tuning and tweaking as dictated by his own two human ears.
Is it possible that the ear picks something up that the equipment and software cannot? I should think so. But more and more I am seeing the philosophy; a bump here, a dip there, some breakup over here -- and all of a sudden..."screw the listening tests, this thing is no good." Or even, "wow, that speaker sounds incredibly accurate with incredibly transparent and airy vocals and life-like dynamics." But then, after putting it up on the screen and plotting a graph..."oh, my ears have been deceived, that was false accuracy I heard, false airiness, that speaker was dead, not alive and dynamic, I was fooled and this graph right here shows my dupability. Like I said... comical.
But...being fair and true to our species, taste is certainly not uniform and we all have our own preference -- it just seems to border on absurdity when we use a machine and a machine only, and not our own ears and the unmatched biochemical supercomputer that is between them, to make the conclusion "this sounds right."
Are computers and software useful? Sure, of course they are, but only to a certain extent. I believe a computer can point us in the direction of mediocrity and at least give us a starting point; it's then a human must take over and turn mediocrity into a masterpiece through fine-tuning and tweaking as dictated by his own two human ears.
Hi,
The reason the BAMTM does not sound good is because something
is messed up and measurements would find what that mess up is.
The rest of your post is pureconjecture and uniformed. What is
comical is people who do not know they are doing thinking that
they can do better than someone who proficiently does.
You cannot, you are stumbling around in the dark.
No amount of fine-tuning and tweaking will ever turn something
that is wrong into a "masterpiece". Getting all the fundamentals
correct is measurement, engineering and sensible compromise.
FWIW the AR.com as I recall is simply an ill-thought out poor design.
🙂/sreten.
The reason the BAMTM does not sound good is because something
is messed up and measurements would find what that mess up is.
The rest of your post is pureconjecture and uniformed. What is
comical is people who do not know they are doing thinking that
they can do better than someone who proficiently does.
You cannot, you are stumbling around in the dark.
No amount of fine-tuning and tweaking will ever turn something
that is wrong into a "masterpiece". Getting all the fundamentals
correct is measurement, engineering and sensible compromise.
FWIW the AR.com as I recall is simply an ill-thought out poor design.
🙂/sreten.
SoundQuest said:
As someone mentioned, the coils should be perpendicular to each other. Also very hard to tell what is connected to what from that picture. Some people post such pictures with connections drawn on top of the image using a photo editing software. Paint.net is free and works actually really well for ANY most types of photo editing.
Another option is to just reverse the polarity on the tweeter. Allot of people mentioned that as a possible source for your problem so you could just reverse and give it a listen.
Peter
- Status
- Not open for further replies.