[OB_Newbie]

Hey Tom,
I saw your "exciter powered" guitar on YouTube... sounds good... for a resonant guitar!!  I was surprised, actually, how good it sounds!

If it can be done, like Ben said, making the cardboard larger (almost to the edge of the frame would improve low freq. output and probably sound quality overall.

IMHO... for damping, I would use batting material that you find at any craft/fabric store like this: http://www.amazon.com/Fairfield-Poly-Fil-Feather-Weight-Batting/dp/B00YNZ7V78/ref=sr_1_1?ie=UTF8&qid=1454528246&sr=8-1&keywords=quilting+poly+roll.  This batting would be within the frame and held in place with a piece of felt stapled or glued to the frame.  Someone earlier in this thread used this and even commented that, if the batting touches the panel lightly, it was useful for damping some of the panel resonances. If you can double up the felt backing, that would be better.

Look for batting made from cotton... that would be best in my opinion.  Recycled denim/cotton is often used to line speaker cabinets... good stuff but slightly more expensive. 

I've only tested with holding panels close to the wall and even in those cases, placing a heavy drape REALLY improved the bass response... sounded quite good...even without the frame.

Have the makings for panels like this and may be joining you... so many panel projects...   

[sweenz27]

Thank you Ben and OB_Newbie for your suggestions and comments! 
Looks like I have some more experimenting to do, and will be sure to report back! 
Have a fun day 

[sedge]

I have now purchased enough wood to build a 6x2ft x3mm rigidly framed panel , the price of the wood was 18 pounds sterling + the exciter, this included some wood to go around the front to see if the extra strength improved things .
If the performance is much the same as the 2x3ft panel I will cut the panel in half ,so I will have two panels for the same price .
I also hope to test my 14x21inch 3mm ply panels I have,just to see if the smaller panels can be improved by rigidly mounting the same as the larger panels ?

Sweenz 27
Not sure if sealing the back of the panel and then adding a port in the side might increase the lower end a little ,it's only a thought ,not sure if it would work with dml,might be getting a little over involved.
Steve

[mildperil]

I have spent the last few evenings optimising my Re-Board panels, and I have to say the results are just amazing .

Currently the Re-Board panels are simply hung from the ceiling, with one DAEX30HESF-4 and a DEAX25TP on each panel. I've been using 2 Breeze Audio TPA3116 amplifiers to power them, with a 2x4 MiniDSP handling the crossover duties (and a fair bit of EQ too). The crossover is set at 3kHz, and the combination is noticeably cleaner, smoother and more extended than a DAEX30HESF-4 on its own. The DAEX30HESF-4s also have a high pass filter at 80Hz, and are crossed over to a big tapped pipe subwoofer of my own design.

The whole thing just sounds so huge and effortless, detailed, clean and fast. It just doesn't seem to distort (I measured 120dB at the mouth of the sub before the neighbour guilt kicked in).

I'm sure it could be improved with a frame to support the back of the exciters, and I am wondering if I can add another DAEX30HESF-4 in series per panel for some more headroom and kick in the upper bass (hopefully there should not be any negative effect on the higher frequencies because of the 3Khz low pass filter). As the volume increased the DAEX30HESF-4s did get quite warm, but the DEAX25TPs stayed cool.

One thing I did notice is the the panel's low frequency response was reduced when hanging compared to having a corner clamped in a vice as I had had them before. I guess that makes sense as the bench would have been acting as a bit of a baffle, and they were a bit further away when hanging.

Also, with spoken word there is a tiny bit of sibilance, but that is getting very picky.

I kind of wish there were more (interested) people around to show it off to

[sedge]

Am now entering stage one of this project, I have glued the exciter to the 6x2ft panel and now await it to dry ,so as I can move it out of the kitchen, hopefully it won't get knocked about!
I have used the monacor position and will see how it compares to the solidly mounted 2x3ft panel.
I will probably have to stand the panel on some foam pads as I don't have anything tall enough to hang them from ,I can hold the panel for short tests .
Will let you know how it goes after a few days drying.
Steve

[OB_Newbie]

I have spent the last few evenings optimising my Re-Board panels, and I have to say the results are just amazing .

Currently the Re-Board panels are simply hung from the ceiling, with one DAEX30HESF-4 and a DEAX25TP on each panel. I've been using 2 Breeze Audio TPA3116 amplifiers to power them, with a 2x4 MiniDSP handling the crossover duties (and a fair bit of EQ too). The crossover is set at 3kHz, and the combination is noticeably cleaner, smoother and more extended than a DAEX30HESF-4 on its own. The DAEX30HESF-4s also have a high pass filter at 80Hz, and are crossed over to a big tapped pipe subwoofer of my own design.

The whole thing just sounds so huge and effortless, detailed, clean and fast. It just doesn't seem to distort (I measured 120dB at the mouth of the sub before the neighbour guilt kicked in).

I'm sure it could be improved with a frame to support the back of the exciters, and I am wondering if I can add another DAEX30HESF-4 in series per panel for some more headroom and kick in the upper bass (hopefully there should not be any negative effect on the higher frequencies because of the 3Khz low pass filter). As the volume increased the DAEX30HESF-4s did get quite warm, but the DEAX25TPs stayed cool.

One thing I did notice is the the panel's low frequency response was reduced when hanging compared to having a corner clamped in a vice as I had had them before. I guess that makes sense as the bench would have been acting as a bit of a baffle, and they were a bit further away when hanging.

Also, with spoken word there is a tiny bit of sibilance, but that is getting very picky.

I kind of wish there were more (interested) people around to show it off to

Hey Ben,
The DEAX25TP sounds very promising!!  I imagine the Re-Board panels are not nearly as light as a poly panel so that makes it even more impressive.  When you compared the different exciters, how did you mount them to the panel? 

Cheers!
Rich

[OB_Newbie]

Am now entering stage one of this project, I have glued the exciter to the 6x2ft panel and now await it to dry ,so as I can move it out of the kitchen, hopefully it won't get knocked about!
I have used the monacor position and will see how it compares to the solidly mounted 2x3ft panel.
I will probably have to stand the panel on some foam pads as I don't have anything tall enough to hang them from ,I can hold the panel for short tests .
Will let you know how it goes after a few days drying.
Steve

Hey Sedge!  Really looking forward to hearing how the bigger panel sounds.  It's been crazy busy the last few weeks and out of town for almost another 2 weeks but will be checking in to see how they are sounding!!

Keep us posted!!!

[mildperil]

Hello OB-Newbie,

When comparing the exciters they were all attached with super glue, except for the DEAX25TP, which I used the VHB double sided that came with it. The DEAX25TPs are now super glued as well. I use super glue because it sets hard and fast.

I have become convinced that good hf response is less about the weight of the material and more about its (lack of) compressibility, or to put it another way, how efficiently hf information is transmitted through the thickness of the material. I think that this is why corrugated cardboard lacks HF, because it is a structure designed to absorb energy, and protect whatever it is surrounding. Re-board certainly doesn't lack HF to my ears, although I know I can't hear above 15kHz. I must do some measurements.

[sedge]

OB_NEWBIE
I too am going to be all over the place for the next two or three weeks but hopefully I will get a chance here and there to do some more tests .
Steve

[sedge]

Had a quick listen today ,the first thing that was very obvious was the larger amounts of LF and the 4 to 5db or so louder volume ,this was from the smaller 3x2ft rigidly mounted panel,I had to turn down the volume on the smaller panel to get the stereo to give a central image 
This is very handy as the exciter only gets warm when playing loud ,instead of very hot.
To my ears the smaller panel also sounds livelier ,but this could just mean that the larger free edged panel needs a more powerful exciter?
I managed to hang the 6x2ft panel in the end,so no problems resting on or touching anything.
When I get time I'll do some more listening,but so far they both sound very good.
Steve

[Odal3]

To my ears the smaller panel also sounds livelier ,but this could just mean that the larger free edged panel needs a more powerful exciter?

That's my experience too, and yes, a more power full exciter will get the liveliness back (or alternatively using multiple low powered ones)

I'm having a great time with my 2.5 x 2.5 ply panels as well. The 25hesf exciters sound so good on them. The LF goes pretty low at low volumes but the problem is that when cranking it up, the exciters bottom out and rattle below 55hz. But that's OK with me since I'm using subs and can easily cross them over that point.

Adding a second exciter on the same panel in a biamp mode results in 10db pick up accross the spectrum and didn't really hurt hf much at all. When putting them in series with my low power amp and only using one channel, the output obviously is reduced some. Wish they would have 8 ohm versions as well so I could parallell them instead.

[Odal3]

Mildperil - while the material and how the exciter Is attached has a big impact on the HF, I have to say that which exciter used have even more of an impact. The HF for the heavier 40w exciters with large diameter mounting ring seems to fall off much sooner than the smaller 25 exciter I'm liking more and more for every day.

As an example, I had some panels with one of the larger 40 W exciter on. Using the VHB tape it took it up to maybe 7-8k and with some proper glue and panel treatment I could stretch it up to 10-12k. Once I removed the big exciter and put the smaller on, the HF spiked up to just under 20k and this was with the VHB tape it came with.

I have also noticed that HF drops a lot with distance (regardless of exciter or material used), but that may just be all the reflections in my room.

[sedge]

I have taken some measurements of the free floating ply panel ,they clearly show that the HF up to 20k holds its output even at distance,more so than the lower frequencies.
The output of HF up to 20k from a metre to the side the panel is also very strong.
This seems a strong point of the ply panel,radiating HF in all directions,without drop off at distances,I have only measured up to a maximum of just over 3metres.
My laptop is refusing to start-up at the moment so can't show the pics as yet 
Steve

[Odal3]

We believe you! Sounds like you're getting great results!

[sedge]

Odal3
Used my wife's computer to load these pics
The first pic shows the ff panel at 1metre (dotted line) and at 3metres( thick lower line )


This next pic shows the ffp ply panel at 1 metre in front again (dotted line) and 1metre from the side( lower thick line.)



The suckout in the 200 or so Hz is (I think ) a reflection from the side wall?
Will be adding more pics as I go along.
Steve

[Odal3]

OB_Newbie - congratulations on getting your panels featured in the latest Parts-Express catalogue! 

[sedge]

Looks like my wife is going out to London for the day on Wednesday,so looks like that will be a good time to fit the solid frame to the 6x2ft ply panel !
Up till three in the morning again last night listening to both ply panels ,very realistic when playing simple live recordings made in a church,very difficult to turn off and go to bed 
Looking forward to seeing what happens when I solidly mount the 6ft panel ,will it have the same db output as the 3ft solidly mounted panel ?
Will it have the more lively sound as well?  We shall see.
OB_NEWBIE
Maybe parts-express should be thinking of providing a kit with ready moulded high quality panel!
Steve

[sedge]

Thought I'd have a quick listen to the panels in the kitchen, a 6x5 metre room.
Set up the t-amp ,but forgot about the 5db channel imbalance  ,couldn't be bothered to rip everything apart again,had to listen one channel at a time,although playing both channels at the same time sounded OK

Must think harder before doing these things 
Steve

[sedge]

I finally got the panel Finished ,I haven't used glue yet as I was running out of time, you know who was coming back from London  the output has increased but not sure by how much,will have to wait till I get back to my room.

I have increased rigidity by adding wood to the front of the panel as well,not sure if this will make any difference.
Steve

[bigaudioscotto]

Hey guys,
Getting ready to take the plunge on these.
Just trying decide on the general consensus of best baffle material type and size to get true full range ?
Also which transducer to choose of the daytons sounds best ?

Regards
Scott