tagis -
They don’t seem to have had much luck with the solenoids. See: preview of article
What do we need in an exciter?
They don’t seem to have had much luck with the solenoids. See: preview of article
What do we need in an exciter?
Steve
The plot thickens. The attached shows the difference between the 396mm x 565mm panel (pink) and a cut down 396mm x 350mm panel, measured from about the same distance - 30cm or so. The small panel sees the large 15db trough moved out to 12khz or so. I've also tried to use as little double sided sticky stuff as possible. The smaller panel looks easier to EQ.
What I will say though is that having the panel flapping about as it's merely attached to the exciter and nothing else is a little disconcerting.
Simon
The plot thickens. The attached shows the difference between the 396mm x 565mm panel (pink) and a cut down 396mm x 350mm panel, measured from about the same distance - 30cm or so. The small panel sees the large 15db trough moved out to 12khz or so. I've also tried to use as little double sided sticky stuff as possible. The smaller panel looks easier to EQ.
What I will say though is that having the panel flapping about as it's merely attached to the exciter and nothing else is a little disconcerting.
Simon
Attachments
Lordtarquin.
That is a much better response curve, starting to get near the 10k mark.
I usually use a very steep roll off to make sure no LF gets through to the exciter.
Steve.
That is a much better response curve, starting to get near the 10k mark.
I usually use a very steep roll off to make sure no LF gets through to the exciter.
Steve.
Thanks Steve.
Two additional plots as requested.
The pink plot is taken 2 inches from the panel half way between the exciter and the long edge.
The dirty green/blue plot is taken 2 inches from the panel directly in front of where the exciter is with the blutak on the panel. Very little difference!
But in both cases, there's a pretty smooth rolloff with no deep troughs.
(I can never get REW to use nice claret and blue colours - long time Villa fan).
Perhaps I should try a plot from a meter away too, although as the mic moves further from the panel, the more room effects come into play.
Two additional plots as requested.
The pink plot is taken 2 inches from the panel half way between the exciter and the long edge.
The dirty green/blue plot is taken 2 inches from the panel directly in front of where the exciter is with the blutak on the panel. Very little difference!
But in both cases, there's a pretty smooth rolloff with no deep troughs.
(I can never get REW to use nice claret and blue colours - long time Villa fan).
Perhaps I should try a plot from a meter away too, although as the mic moves further from the panel, the more room effects come into play.
Attachments
Steve
Yes, I use an LR 24 db/oct curve set at around the 200 to 300 hz mark. I've experimented with 48db/oct too. The miniDSP HD makes changing things on the fly very easy.
Yes, I use an LR 24 db/oct curve set at around the 200 to 300 hz mark. I've experimented with 48db/oct too. The miniDSP HD makes changing things on the fly very easy.
lordtarquin.
im getting a little confused now ,the plot at 2inches is showing a drop from just below 2k to just below 8k of about 25db ?
in the meantime i came across my old hifi news test cd ,i thought why not try it out on the surround sound panels and amp.
these are loud so listen at a low volume to start with.
big ben and fenny poppers were recorded at half volume but the second fenny popper was recorded at full volume with no problem.
the panel on the left was distorting badly on the big ben recording , there is something wrong with the exciter, not the panel.
when you have the levels sorted out try to listen to them as loud as possible.
enjoy .
steve.
im getting a little confused now ,the plot at 2inches is showing a drop from just below 2k to just below 8k of about 25db ?
in the meantime i came across my old hifi news test cd ,i thought why not try it out on the surround sound panels and amp.
these are loud so listen at a low volume to start with.
big ben and fenny poppers were recorded at half volume but the second fenny popper was recorded at full volume with no problem.
the panel on the left was distorting badly on the big ben recording , there is something wrong with the exciter, not the panel.
when you have the levels sorted out try to listen to them as loud as possible.
enjoy .
steve.
Thanks Steve
I don't pretend to understand what's going on either. I just know that the system was sounding very good indeed before I blew up an exciter. That was with the 3mm poplar ply panels. There's no way I could get the ply panels reaching 20khz, hence playing with EPS ones. With EQ, they reach 20khz easily.
The smaller panels seem like they are going to work well and be a good fit for my redesigned winged OB speakers. With some EQ, these are flat - near field - from 40hz until I roll them off. They are only 4db down at 30hz. However, one I move the mic to the listening position, I get all sorts of suckouts. Some room treatment may be needed after all...
I don't pretend to understand what's going on either. I just know that the system was sounding very good indeed before I blew up an exciter. That was with the 3mm poplar ply panels. There's no way I could get the ply panels reaching 20khz, hence playing with EPS ones. With EQ, they reach 20khz easily.
The smaller panels seem like they are going to work well and be a good fit for my redesigned winged OB speakers. With some EQ, these are flat - near field - from 40hz until I roll them off. They are only 4db down at 30hz. However, one I move the mic to the listening position, I get all sorts of suckouts. Some room treatment may be needed after all...
Attachments
I went ahead and ordered those Aiyima exciters. I got 2 20W 8 ohm exciters per channel that I will run in parallel. They will be low passed and I will high pass my 4 ohm Dayton Audio exciter, I'm thinking around 600 or so hz. Hopefully they will be enough to at least go down to 60 or so Hz on a 2x2' XPS panel. If not I will start over with some canvas panels.
I'd be very interested to hear how those exciters work out. They are inexpensive - and available. They are also heavy, so I suspect they will definitely need support.
I'm mounting them facing down on a ceiling hung panel, so all they need to do for me is suspend themselves. Their design does make it easy to make braces though
Lordtarquin.
I just mounted two old test panels one was a 16 inch square vh grade panel until I re shaped it,coated in vinyl silk.
The other is about 23inche's by 16inches low grade eps coated in tissue .
All measurements done from 3 metres distance.
The first picture is the low grade eps panel only with tls.
The second is the vh grade eps only with tls.
The third is both running with the tls turned off.
The fourth is the tls with the eps panels turned off.
This audiocircle link is the same 40cm square vh grade panel with just the pva coating ,which I measured way back , can't remember when , notice the high frequency continues on up to 20k with only a small dip.
this is 40cm 10mm thick panel response after mods
NO EQ USED.
Steve.
I just mounted two old test panels one was a 16 inch square vh grade panel until I re shaped it,coated in vinyl silk.
The other is about 23inche's by 16inches low grade eps coated in tissue .
All measurements done from 3 metres distance.
The first picture is the low grade eps panel only with tls.
The second is the vh grade eps only with tls.
The third is both running with the tls turned off.
The fourth is the tls with the eps panels turned off.
This audiocircle link is the same 40cm square vh grade panel with just the pva coating ,which I measured way back , can't remember when , notice the high frequency continues on up to 20k with only a small dip.
this is 40cm 10mm thick panel response after mods
NO EQ USED.
Steve.
Attachments
Last edited:
Frieda,
Thanks for posting this link. It's a very interesting article, plus the same author has several other great papers!
Another DML (distributed mode loudspeaker) / NXT project by inception. - YouTube
Any idea about DML speaker shown in this youtube video, where they are saying that they are using some cabinet (black loaded horn) for getting more bass from the DML with relatively smaller size
Any idea about DML speaker shown in this youtube video, where they are saying that they are using some cabinet (black loaded horn) for getting more bass from the DML with relatively smaller size
Sarath.
This is basically an exciter on a wooden box with a port or horn?
Maybe he should have used a bass shaker ? It didn't sound that great and there wasn't that much low end 😕 .
I think he is missing the point of dml.
I'm sure he could do better with a larger box and a port , but it would still sound like a speaker in a box?
Steve.
This is basically an exciter on a wooden box with a port or horn?
Maybe he should have used a bass shaker ? It didn't sound that great and there wasn't that much low end 😕 .
I think he is missing the point of dml.
I'm sure he could do better with a larger box and a port , but it would still sound like a speaker in a box?
Steve.
Lordtarquin.
In the pictures top third from the left and second down from the left, shows the response of a very large eps panel.
The top one shows the room dip in the 80hz to 300hz and the other the response that happened when the TLS and panel cover the same 80hz to 300hz together (overlapping )
The room dip has practically gone.
Normally I have the panels in front of my TLS and use time delay to match them , I also when using small panels , i place them higher up in the room ,above my head level when seated ,this( I think) gives a more natural presentation in the room .
No need to have the tweeter beaming into your ears for that sweet spot.
I prefer to listen to the singers standing in my room not kneeling on the floor.
Some floor standing speakers make it sound like the singers head is poking out of the floor😀
Steve.
Uploaded Pictures
In the pictures top third from the left and second down from the left, shows the response of a very large eps panel.
The top one shows the room dip in the 80hz to 300hz and the other the response that happened when the TLS and panel cover the same 80hz to 300hz together (overlapping )
The room dip has practically gone.
Normally I have the panels in front of my TLS and use time delay to match them , I also when using small panels , i place them higher up in the room ,above my head level when seated ,this( I think) gives a more natural presentation in the room .
No need to have the tweeter beaming into your ears for that sweet spot.
I prefer to listen to the singers standing in my room not kneeling on the floor.
Some floor standing speakers make it sound like the singers head is poking out of the floor😀
Steve.
Uploaded Pictures
Hi Steve,
Could you please share some info on how does DML speakers compare with conventional full range speakers. Looking at DML speakers, it looks to be very simple and easy to build, and will not take much space (only a flat piece of material). But from the various frequency responses, it looks like its top end (treble) is little weak and looks to be mostly a mid range response rather than a regular normal full range speaker with "mid-bass + mids + treble".
How does it sound in practice, compared with normal full rage speakers.
What is the preferred material for building the DML speakers, plywood / foam board / ceiling tiles made of rockwool,mineral wool, synthetic poly etc ..
Steve
I took a series of measurements yesterday from 1m out to my listening position. Broadly speaking, the curves were identical, with just lower SPL as the distance was increased. The attached image is an average of three readings. I'm increasingly convinced it's the double sided sticky stuff I'm using.
Therefore, yesterday I glued the DA exciter to the smaller 10mm EPS panel. I may get the chance to do some measuring later today.
It may be my system, but I get vocalists above the speakers regardless of speaker height. I do pay a lot of attention to cables - all DIY including mains.
I took a series of measurements yesterday from 1m out to my listening position. Broadly speaking, the curves were identical, with just lower SPL as the distance was increased. The attached image is an average of three readings. I'm increasingly convinced it's the double sided sticky stuff I'm using.
Therefore, yesterday I glued the DA exciter to the smaller 10mm EPS panel. I may get the chance to do some measuring later today.
It may be my system, but I get vocalists above the speakers regardless of speaker height. I do pay a lot of attention to cables - all DIY including mains.
Attachments
hi sarath.
here is a recording of these old bashed about panels .
i reduced the volume on the panels because i usually find the panels sound louder than the plots seem to show?
i end up using the TLS as a sort of tone control to blend the sounds together.
Lordtarquin.
you have got the hf up to nearly 8k again?
lets hope it is the tape, harder materials such as ply ,veneer , vh grade eps, should have no problem reaching 20k
the softer grades need a little more help.
steve.
here is a recording of these old bashed about panels .
i reduced the volume on the panels because i usually find the panels sound louder than the plots seem to show?
i end up using the TLS as a sort of tone control to blend the sounds together.
Lordtarquin.
you have got the hf up to nearly 8k again?
lets hope it is the tape, harder materials such as ply ,veneer , vh grade eps, should have no problem reaching 20k
the softer grades need a little more help.
steve.
Lordtarquin.
To show the problems I'm having at the moment with my room .here is a photo of the phone sitting on a rolled up rug ,used as a microphone stand, surrounded by boxes and a washing machine.
I can hardly move around the room !
The microphone is picking a lot up from all this junk in the room but hopefully it still sounds good.
Trumpets come across very well on dml panels ,they can go from very quiet to extremely loud, but the dml panels have no problem with this.
No compression, it just let's it out with ease ,
Steve.
steve.
To show the problems I'm having at the moment with my room .here is a photo of the phone sitting on a rolled up rug ,used as a microphone stand, surrounded by boxes and a washing machine.
I can hardly move around the room !
The microphone is picking a lot up from all this junk in the room but hopefully it still sounds good.
Trumpets come across very well on dml panels ,they can go from very quiet to extremely loud, but the dml panels have no problem with this.
No compression, it just let's it out with ease ,
Steve.
steve.
