Not easy to see... Yes, it seems there is a kind of frame all around the membrane with a small gap. The rear bracing is bolted to it.
I am wondering about the role of the screw visible on the rear views.
This is for me an open topic. In a previous post I shown a solution which is to have a capacitor in parallel to one of the exciter so only one will work in HF. Here the panel is too small to hide a film capacitor. A non polarized chemical... maybe
Christian.
Have you measured the panel response with and without the HF roll off on one of the exciters ?
Steve.
Have you measured the panel response with and without the HF roll off on one of the exciters ?
Steve.
Eucy.
by screw I mean the mounting screws that bolt the exciter spine to the frame on the sides and maybe to the panel ?
it is not clear, there might be notches cut out in the panel ?
Without taking the panel apart or seeing drawings, it is difficult to see or know what is going on ,similar to the tectonic panels.
steve.
by screw I mean the mounting screws that bolt the exciter spine to the frame on the sides and maybe to the panel ?
it is not clear, there might be notches cut out in the panel ?
Without taking the panel apart or seeing drawings, it is difficult to see or know what is going on ,similar to the tectonic panels.
steve.
Hi Eric
How do you think the Rev Ply would do as a free hanging panel not mounted on a frame?
Pete
Christian, Eucy.
Sorry , it's me not paying attention.
That looks like a wall or bracket mounting thread ?
Steve.
Sorry , it's me not paying attention.
That looks like a wall or bracket mounting thread ?
Steve.
Separate sub-topic:
Given the relatively high price of exciters here, I've been considering buying a suitable speaker and chopping it to make a DIY version...
Has anyone tried this, and if so, how did it turn out?
Given the relatively high price of exciters here, I've been considering buying a suitable speaker and chopping it to make a DIY version...
Has anyone tried this, and if so, how did it turn out?
I did it with a few speaker types. Started with a few pairs of 10 to 15v tv speakers and chopped up a 3" pair. Do an advanced search for toddincabo posts and have a look, they will be the earliest posts. They worked, I'll give em' that, but man what a lot of work to get them right, nothing like true exciters you can just stick and forget. The sound dynamics aren't there as well compared to my true exciters, not even close.
The ones i built needed to be mounted in a spine to where they could be manipulated in all manner while I ran a sweep to get them to perform properly. Check out the posts, you'll see what I'm talking about. I learned a ton from building those cheapies that I still use today, don't regret any of it.
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Hello Steve
Just got a chance to listen on headphones. I must say your recordings are very impressive. What is the variable crossover you use?
Pete
Toddincabo.
I had pretty much the same experience making exciters out of cone drivers, and gave up.
Steve.
I had pretty much the same experience making exciters out of cone drivers, and gave up.
Steve.
hi Pete.
Glad you liked the recordings.
They give a good idea of how the panels sound , but not the whole picture.
You cannot hear how it presents the sound in the room.
I use the Behringer ultra drive pro in the digital domain , it's getting pretty old now , but they are still selling them.
The best thing I ever bought, I could not have done all this testing without it !
Just a quick push of some buttons and a turn of a dial and you have reset to another XO or full range speakers 😁
It is a joy.
Seve.
Glad you liked the recordings.
They give a good idea of how the panels sound , but not the whole picture.
You cannot hear how it presents the sound in the room.
I use the Behringer ultra drive pro in the digital domain , it's getting pretty old now , but they are still selling them.
The best thing I ever bought, I could not have done all this testing without it !
Just a quick push of some buttons and a turn of a dial and you have reset to another XO or full range speakers 😁
It is a joy.
Seve.
i found this video amusing, turning a dry wall into a speaker, he makes a lot of excited burbling , because he IS so excited about the sound.
it does sound good , but he is playing that, royalty free musak 🙄
steve.
it does sound good , but he is playing that, royalty free musak 🙄
steve.
this is also interesting if you are interested in bracing ,clear panels , and all in one sub and panel speakers.
he does not seem to worry about the rising treble though ?
he has made quite a few videos of his panel projects.
steve.
he does not seem to worry about the rising treble though ?
he has made quite a few videos of his panel projects.
steve.
Pete,
I'm not a fan of free hanging panels of any material. I have never found a way with free hanging panels to get a smooth frequency response at the low end of the frequency range with hanging panels. Of course, if you use a sub and cross over at a high enough frequency it's less of an issue.
That said, the Revply should be pretty good as a free hanging panel. It has decent efficiency and is capable of doing high frequency better than many materials. The biggest drawback might be the risk of warping, even if you can find a nice flat piece to start with. A frame helps counter that, but as a free hanging panel, the plywood will do whatever it wants to do!
Eric
Hello Steve,
Have a look on post #5270 for tests and comment.
To be more clear, I made a quick simulation on LTspice.
Here is the schematics that models the circuit of the test above:
R1 is one exciter with a capacitor C1 across its connections
R2 is the second exciter
Below V(Exc1) is the voltage (so the level) across R1, V(Exc2) the voltage across R2. I show also the sum which is constant.
Sorry for the dark background. I didn't find how to change it
The impedance for the amplifier is not constant : 8 Ohms to fall to 4 Ohms (not shown here)
The R2 (Exc2) will work full tension in HF.
As the power is mainly in the low to mid frequency, the power handling might be improve also.
Christian
Hello Toddincabo
+ @Eucyblues99
The idea to make exciter with a speaker is interesting. It could be a way to get higher force factor (BL) and maybe lower inductance in a 8 ohm impedance... which I think a way to get better HF.
From your pictures Toddincabo (#3076), I see the membrane was may be not completely removed so that the voice coil pushes the membrane through a flexible remaining part of cone.
See below how I dismount a speaker for an application close to that (at this time i didn't know the DML). I think I glued a disk (which material?) on top of the voice coil). With care, a small cylinder might be added.
I think there are 2 difficulties at least:
- the voice coil end is close to the spider. Some very rigid interface part might be needed
- an exciter is designed to accept an angle between the voice coil axis and the magnetic circuit, a speaker not. So it needs more precise position.
And of course a spine.
So not easy... but why not.
Christian
I asked him that very question back when he released that video (subscribed) and he replied that coming up next was a crossover to hopefully take care of that skyrocket high end.
The left over cone acted as a cup that I filled with epoxy achieving the same thing as in your picture. I just don't see a homemade coming close to a true exciter in any fashion, you will always be leaving a lot on the table.
You can buy 8 Ohm exciters all the way down to 2w.
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