DIY Flat Panel Speaker Love

[rmeinke]

Re: DIY Flat Panel Speaker Love

The cardboard must sound better, I fell asleep while listening. Couldn't relax and listen long enough to the xps panels to do that.


This may be where I'm heading next. http://www.ebay.com/itm/4-ft-x-25-50...8yxIzgX5NQl_Yw

Hey KB,
XPS is certainly not the ultimate DML panel material, but I'd say that with your panels are not optimized:

1.) For such a large panel, they need some damping. The spline mounting helped to give it some stability. I'm sure there are still resonances that need to be dealt with. My 2'x4' XPS panels needed more damping and mine would have more damping then yours currently do. This is probably the biggest area of improvement.

2.) Rounding the corners (true rounded) which are not terminated at the edges should improve the SQ.

3.) Round the edges too. This takes makes the mid-range sound less edgy to me. Doesn't seem to change the frequency response much other that the last octave as the rounded corners and edges make the panel less rigid.

XPS, being so light and rigid, seems to respond well to EQ in regards to improving the SQ.


Has the cardboard dried/hardened yet? I compared the PVA treated to the old shellaced boards and the shellac is harder AND less damped.

Really looking forward to getting the shellaced panels up and running. Hard time deciding on exciters for this material...

[rmeinke]

Re: DIY Flat Panel Speaker Love

One more thing...

As you might know, I am in the minority, but I don't favor big panels... just too many resonances to deal with and have never been happy with the low frequency sound quality. Smaller panels matted with OB bass bins or quality sub will give you the best results KB.

I have not built a set yet myself but an array of small panels should be cleaner and more dynamic and I really like listening to line arrays. Have some time off over Xmas and hoping to build a small line array!! Man, looking forward!!!

[rmeinke]

Re: DIY Flat Panel Speaker Love

Hey FShow... if you are listening in...

Do you have any advice on mounting an exciter via a spline... how did you ensure that the exciter/voice coil was aligned to the panel? I am considering a semi rigid mounting... something to support the exciter but not hold it completely rigid. Provide some slight damping. Possibly sorbothane between the spline and the exciter...

Curious as to what you have done or tried already.

Thanks!

[Unbiasedsound]

Re: DIY Flat Panel Speaker Love

Hey Rich I listen to your dml panels on utube they sound pretty similar to my bertagnis speakers.......I found this vid of some Bertagni speakers on youtube so you can "sort of" get the feel of how they sound.

https://www.youtube.com/watch?v=r5eqcmHW3Vs

[rmeinke]

Re: DIY Flat Panel Speaker Love

Hey UBS! Thanks for the link ma man. I had a pair of Bertagni speakers 90 miles from my house that came up for sale but unfortunately missed them... vetoed by the significant other... I've accumulated to much equipment, parts, panels... I have no place to go with them any more... even I had to come to my senses. It was a shame... they were in perfect condition.

I'm am planning on implementing a Bertagni like design element in my next panel. Implementing a small panel with a 19cm voice coil for better high freq. extension. I don't find them lacking as is today in most instances but want to hear how this sounds to have a dedicated HF panel and how they will integrate with the full-range panel(s).

Anyway... thanks again for the links... I've been reading and studying the Bertagni designs. More to come fairly soon...

[rmeinke]

Re: DIY Flat Panel Speaker Love

ALERT!!! PE Flash Sale - The Dayton Audio DAEX30HESF-4 High Efficiency Steered Flux Exciter with Shielding 30 mm Exciter 40W 4 Ohm is on sale for $15!!!

I JUST ordered a set for $45... this is BIG savings guys and while I have not listened to a set yet, I've heard good things over at AC... more detailed than the Thruster and looks robust.

Will be able to report on how it sounds and measures soon! Stay tuned!

[Fshow]

Re: DIY Flat Panel Speaker Love

Hey FShow... if you are listening in...

Do you have any advice on mounting an exciter via a spline... how did you ensure that the exciter/voice coil was aligned to the panel? I am considering a semi rigid mounting... something to support the exciter but not hold it completely rigid. Provide some slight damping. Possibly sorbothane between the spline and the exciter...

Curious as to what you have done or tried already.

Thanks!

Hi Rich

My wife has been in and out of the hospital lately but I still had some time to work on the panels
Some improvements:
- stiffened the spline. I had a weak point which I improved. Gave better bass.
- secured the exciter to the spline with Epoxy. Previously secured only with silicon. I am not totally finished with this yet, but so far so good.
- supported the panel in the middle with 2 legs so that the panel no longer sits on the floor but is supported by the middle of the panel. This greatly reduced a dip in responce around a 100 hz.
- changed speaker wire from DIY cat 5 wire to more standard 16 gauge. This was a huge improvement, everything was better. I changed to the cat 5 wire early on and it was a big mistake.
- turned the panels around so the back of the panels face forward. Gives better detail.
- replaced the Tamp with a pair of DIY 5 watt mono blocks. Also tried a pair of Nelson Pass's DIY Zen amps. The 5 watt amp was the winner with better bass and detail. I now need less equalization. I plan on tryinga pair of Cary 572-3 triode amps in the future.

Things I tried that didn't work:

- placed painters tape in a pattern of 20 or so pieces on the panel surfaces. This gave reduced high and detail.

--------

To answer your question

A placed several extra coats of PVA just where the exciters would be placed on the panels and sanded it smooth. I then mounted the exciter to the panel. I then installed the spline leaving a small place for silicon adhesive. I gobbled in some silicon installed the spline and then waited. I now recommend using a hard epoxy.

The panels have never sounded better, vocals are amazing, with good detail and surprising bass, (not window shaking bass).

I am beginning to get discouraged though. I keep thinking of the panels inherent mass and I wonder if the panels will ever compete with audios elete, like large ribbon speakers or horn etc.
But who knows....they have completely surprised me so far...I guess I will keep trying.

Thanks
Fred

[Gary.M]

Re: DIY Flat Panel Speaker Love

Hi Rich

My wife has been in and out of the hospital lately but I still had some time to work on the panels
Some improvements:
- stiffened the spline. I had a weak point which I improved. Gave better bass.
- secured the exciter to the spline with Epoxy. Previously secured only with silicon. I am not totally finished with this yet, but so far so good.
- supported the panel in the middle with 2 legs so that the panel no longer sits on the floor but is supported by the middle of the panel. This greatly reduced a dip in responce around a 100 hz.
- changed speaker wire from DIY cat 5 wire to more standard 16 gauge. This was a huge improvement, everything was better. I changed to the cat 5 wire early on and it was a big mistake.
- turned the panels around so the back of the panels face forward. Gives better detail.
- replaced the Tamp with a pair of DIY 5 watt mono blocks. Also tried a pair of Nelson Pass's DIY Zen amps. The 5 watt amp was the winner with better bass and detail. I now need less equalization. I plan on tryinga pair of Cary 572-3 triode amps in the future.

Things I tried that didn't work:

- placed painters tape in a pattern of 20 or so pieces on the panel surfaces. This gave reduced high and detail.

--------

To answer your question

A placed several extra coats of PVA just where the exciters would be placed on the panels and sanded it smooth. I then mounted the exciter to the panel. I then installed the spline leaving a small place for silicon adhesive. I gobbled in some silicon installed the spline and then waited. I now recommend using a hard epoxy.

The panels have never sounded better, vocals are amazing, with good detail and surprising bass, (not window shaking bass).

I am beginning to get discouraged though. I keep thinking of the panels inherent mass and I wonder if the panels will ever compete with audios elete, like large ribbon speakers or horn etc.
But who knows....they have completely surprised me so far...I guess I will keep trying.

Thanks
Fred

Can you clarify the two legs supporting the panel in the middle? Do I understand you have nothing touching anywhere on the panel edges?

[Kornbread]

Re: DIY Flat Panel Speaker Love

Trimmed the treated cardboard panel away from the foam mounted edges with an exacto knife (as you can see I was no so exact ... o in my cuts) leaving only 4 tabs holding the panel at the points the 'pen test' said were less active.




Measurements, treated cardboard w/tabs, no exciter brace.


Treated cardboard with only tabs holding panel, no exciter brace vs solid treated cardboard panel.


Treated cardboard with tabs, blue vs xps panel with tabs, exciter brace and corners rounded, green.


At this point it looks like a HUGE difference in panel material but this latest exciter on cardboard didn't last long enough to be mounted on a brace. That will surely change the freq response yet again.


rmeinke, what was the actual spl level at which you took your measurements? My levels are way below what REW wants to see but if I turn up the volume any more the exciters self destruct.

Due to reliability concerns, at this time I can not recommend the Dayton DAEX32EP-4 Thruster 32mm Exciter 40w 4ohm. I originally purchased 2, both originals quit, the first within minutes, the second one after a ~few hours of easy listening, both went open circuit. PE replaced both. The first replacement exciter just quit within ~2 hours after being played at low levels and one REW measurement that was way below the level REW wanted. The fourth exciter is sitting here on the desk and I'm thinking about chunking it in the trash right now ... chances are it's going to wind up there anyway.

I asked PE if they had an expert that could comment on this tread reguarding the reliability issue or the manner it which we're using these exciters. PE replied, 'it was impossible to have a meaningful hands on relationship for all 15000 items we carry... Dayton is aware of the issue.' I understand PE's position.

To this point, PE has been good about replacing the exciters but I'm tired of wasting my time and effort.

[Fshow]

Re: DIY Flat Panel Speaker Love

Hi Gary

The panels are glued solidly to a reinforced wood frame. I just support the panel on the right and left frame in the middle. The panels and frame are suspended by these two legs. There is a picture of the panels without the legs on page 9.

Fred

[rmeinke]

Re: DIY Flat Panel Speaker Love

Hi Rich

My wife has been in and out of the hospital lately but I still had some time to work on the panels
Some improvements:
- stiffened the spline. I had a weak point which I improved. Gave better bass.
- secured the exciter to the spline with Epoxy. Previously secured only with silicon. I am not totally finished with this yet, but so far so good.
- supported the panel in the middle with 2 legs so that the panel no longer sits on the floor but is supported by the middle of the panel. This greatly reduced a dip in responce around a 100 hz.
- changed speaker wire from DIY cat 5 wire to more standard 16 gauge. This was a huge improvement, everything was better. I changed to the cat 5 wire early on and it was a big mistake.
- turned the panels around so the back of the panels face forward. Gives better detail.
- replaced the Tamp with a pair of DIY 5 watt mono blocks. Also tried a pair of Nelson Pass's DIY Zen amps. The 5 watt amp was the winner with better bass and detail. I now need less equalization. I plan on tryinga pair of Cary 572-3 triode amps in the future.

Things I tried that didn't work:

- placed painters tape in a pattern of 20 or so pieces on the panel surfaces. This gave reduced high and detail.

--------

To answer your question

A placed several extra coats of PVA just where the exciters would be placed on the panels and sanded it smooth. I then mounted the exciter to the panel. I then installed the spline leaving a small place for silicon adhesive. I gobbled in some silicon installed the spline and then waited. I now recommend using a hard epoxy.

The panels have never sounded better, vocals are amazing, with good detail and surprising bass, (not window shaking bass).

I am beginning to get discouraged though. I keep thinking of the panels inherent mass and I wonder if the panels will ever compete with audios elete, like large ribbon speakers or horn etc.
But who knows....they have completely surprised me so far...I guess I will keep trying.

Thanks
Fred

Sorry to hear about your wife Fred. Hope she will be back to good health soon... surely she is needed to keep you in line and on the straight and narrow. :D

Was thinking a very similar approach... exciter, glob of silicon then mount the spline to the frame. I'm starting with a light mounting. A thin, not entirely rigid wood spline. I just want to lightly damp the exciter. A start for me. I have noticed that distortion improved when the panel is allowed to move more freely but this may not translate into a light spline mounting also having better distortion characteristics... but we shall see. I can always strengthen the spline as needed for testing purposes.

I put together a treated cardboard panel and have to say it has promise. Didn't get much of a chance to listen much but hope to do over the next few days. Seemed to measure smoother than both ply and XPS. Want to give the exciter more time to break in before really commenting but positive so far.

Don't know if they will ever topple a ribbon or ES but there are some advantages to these panels... and while they are not technically better and have some coloration to deal with with there is something special about them. I really like listening to these... they are fun to listen to... just a joy to listen to!

[rmeinke]

Re: DIY Flat Panel Speaker Love

Trimmed the treated cardboard panel away from the foam mounted edges with an exacto knife (as you can see I was no so exact ... o in my cuts) leaving only 4 tabs holding the panel at the points the 'pen test' said were less active.




Measurements, treated cardboard w/tabs, no exciter brace.
[ATTACH=CONFIG]62376[/ATTACH]

Treated cardboard with only tabs holding panel, no exciter brace vs solid treated cardboard panel.
[ATTACH=CONFIG]62377[/ATTACH]

Treated cardboard with tabs, blue vs xps panel with tabs, exciter brace and corners rounded, green.
[ATTACH=CONFIG]62378[/ATTACH]

At this point it looks like a HUGE difference in panel material but this latest exciter on cardboard didn't last long enough to be mounted on a brace. That will surely change the freq response yet again.

rmeinke, what was the actual spl level at which you took your measurements? My levels are way below what REW wants to see but if I turn up the volume any more the exciters self destruct.

My measurements are not accurate. They were not consistent with my Omnimic measurements in the HF range and I saw a few nights ago that the mic/soundcard settings in the REW Preference tab were back to the default settings. The soundcard calibration also does not look correct so have some troubleshooting to do to verify the measurements. So consider the measurements that I posted for comparisons only for the different panel materials and sizes.

Due to reliability concerns, at this time I can not recommend the Dayton DAEX32EP-4 Thruster 32mm Exciter 40w 4ohm. I originally purchased 2, both originals quit, the first within minutes, the second one after a ~few hours of easy listening, both went open circuit. PE replaced both. The first replacement exciter just quit within ~2 hours after being played at low levels and one REW measurement that was way below the level REW wanted. The fourth exciter is sitting here on the desk and I'm thinking about chunking it in the trash right now ... chances are it's going to wind up there anyway.

I asked PE if they had an expert that could comment on this tread reguarding the reliability issue or the manner it which we're using these exciters. PE replied, 'it was impossible to have a meaningful hands on relationship for all 15000 items we carry... Dayton is aware of the issue.' I understand PE's position.

To this point, PE has been good about replacing the exciters but I'm tired of wasting my time and effort.

Man, sorry to hear the troubles continuing... the manufacture has to get that quality straightened out. Between the leads and adhesion between the VC and mounting flange I'm not ordering more Ultra's or Thrusters. I believe the exciters with the exposed tinsel leads and the one piece VC/mounting flange are reliable.

Are they failing when you are measuring them? Your rate of failure seems higher than normal but may just be some bad luck!?!?

PE has always been fantastic from a support perspective. I really like doing business with them... feel confident with everything I buy knowing they will take care of you should something happen with a product. Well... and I just really like buying speaker parts... just what I need more of :p

You ought to try the 24 watt high efficiency exciter. That thing is smooth... especially on cardboard... more to come soon on that guy...

[Fshow]

Re: DIY Flat Panel Speaker Love

Sorry to hear about your wife Fred. Hope she will be back to good health soon... surely she is needed to keep you in line and on the straight and narrow. :D

Was thinking a very similar approach... exciter, glob of silicon then mount the spline to the frame. I'm starting with a light mounting. A thin, not entirely rigid wood spline. I just want to lightly damp the exciter. A start for me. I have noticed that distortion improved when the panel is allowed to move more freely but this may not translate into a light spline mounting also having better distortion characteristics... but we shall see. I can always strengthen the spline as needed for testing purposes.

I put together a treated cardboard panel and have to say it has promise. Didn't get much of a chance to listen much but hope to do over the next few days. Seemed to measure smoother than both ply and XPS. Want to give the exciter more time to break in before really commenting but positive so far.

Don't know if they will ever topple a ribbon or ES but there are some advantages to these panels... and while they are not technically better and have some coloration to deal with with there is something special about them. I really like listening to these... they are fun to listen to... just a joy to listen to!

Thanks Rich
I agree with you about the value of these speakers. I downloaded several audiophile recordings and took a listen. With all the changes I have made, things have really improved, micro dynamics and bass are much better. I was impressed, my daughter thought it sounded as if the musicians were in the room with us. I have slow down for a while and just listen. I did a quick compare to my double stacked Advents, and the panels were much better. But it was an unfair test because I had those same dumb cat 5 cables on the Advents. Is there some way to make a recording that could be put out for evaluation?

Fred

[Gary.M]

Re: DIY Flat Panel Speaker Love

Hi Gary

The panels are glued solidly to a reinforced wood frame. I just support the panel on the right and left frame in the middle. The panels and frame are suspended by these two legs. There is a picture of the panels without the legs on page 9.

Fred

This is interesting as you have broken all the "rules" :-) ie, hard mounted the panel into a frame, used non NXT panel dimensions etc. Your reports sound like it is working well. One question... how did you decide the location you attached the exciter to the panel?

[Unbiasedsound]

Re: DIY Flat Panel Speaker Love

Hey UBS! Thanks for the link ma man. I had a pair of Bertagni speakers 90 miles from my house that came up for sale but unfortunately missed them... vetoed by the significant other... I've accumulated to much equipment, parts, panels... I have no place to go with them any more... even I had to come to my senses. It was a shame... they were in perfect condition.

I'm am planning on implementing a Bertagni like design element in my next panel. Implementing a small panel with a 19cm voice coil for better high freq. extension. I don't find them lacking as is today in most instances but want to hear how this sounds to have a dedicated HF panel and how they will integrate with the full-range panel(s).

Anyway... thanks again for the links... I've been reading and studying the Bertagni designs. More to come fairly soon...

Your welcome, I just ordered some some DAEX30HESF-4 and will be using 2 exciters per panel just like my bertagni sm100 speakers and wiring them for a 8ohm load. I am going to try and mimic the bertagnis as closely as I possibly can and see how they compare with each other if they are equal or better then my bertanis I will be very very happy. I just love the sound of the Bertagni's I can listen to them for hours and hours on end with NO ear fatigue at all which makes me want to listen to them all day and night long, in fact I am listening to them right now as I type LOL.