Perhaps just a novelty then .
If the expert old guys who repair or build Cello / Double Bass or Guitars ever got into the industry of speaker building one day we might see some nice innovations.
It doesn't hurt to dream lol.
If the expert old guys who repair or build Cello / Double Bass or Guitars ever got into the industry of speaker building one day we might see some nice innovations.
It doesn't hurt to dream lol.
Those look a bit like my MLTLs with the same (or very similar) driver. Apparently the Sibelius is an ML-TQWT, rather than an MLTL like mine, which accounts for why his drivers are at the top, and mine offset down from the top. But the MLTL and ML-TQWT are very close cousins.
Eric
Eric
Yesterday my wife popped out for a short while( leaving me to do jobs around the house) 🤫
I took this opportunity to screw the hdn8 exciter to the floorboards in the kitchen where I have a surround sound with sub.
I wired the sub to the hdn8.
This was a very strange experience.
Standing or sitting I felt that I was getting seismic activity running up my spine, and everything standing on the floor was vibrating, plates in the cupboard were vibrating.
Walls seem a better option as long as you do not have anything that can vibrate attached to the wall !
I always thought that a shaker attached to my seating position would be a good idea, but have now changed my mind.
Some notes felt like electric shocks going up my spine 😱 🤣
It was too distracting and felt uncomfortable, some might like this for movie soundtracks, but I will give it a miss.
Steve.
I took this opportunity to screw the hdn8 exciter to the floorboards in the kitchen where I have a surround sound with sub.
I wired the sub to the hdn8.
This was a very strange experience.
Standing or sitting I felt that I was getting seismic activity running up my spine, and everything standing on the floor was vibrating, plates in the cupboard were vibrating.
Walls seem a better option as long as you do not have anything that can vibrate attached to the wall !
I always thought that a shaker attached to my seating position would be a good idea, but have now changed my mind.
Some notes felt like electric shocks going up my spine 😱 🤣
It was too distracting and felt uncomfortable, some might like this for movie soundtracks, but I will give it a miss.
Steve.
Technically that is what a Bass Shaker is made for to be felt rather then heard when attached to very hard/solid objects.
I've pinned down the earlier trouble I reported with respect to my center channel.
As some will remember, I had previously attached a Thruster to the back of my LG OLED TV to use it as a center channel in my home theater system.
The TV as DML has less efficiency than my aluminum honeycomb main DMLs, so I had boosted the trim on the center channel to align their sound output.
It worked and sounded great until some 30 minutes into watching Dune at higher volumes than my neighbors would appreciate. Great fun, but it blew up the center channel exciter.
To address the issue, I've decided to mount two Thrusters on the TV as DML and drive each of them with separate amplifiers (I have a spare NCore stereo module). I'll feed both amps with the same center channel signal from my AV pre/processor.
This should better level the output of the center and main channels.
The attached image, shows the LG TV from the side and back (the red line defines the DML panel area). You'll note that the TV's design has the thin acrylic upper panel fixed to the thicker unit at the lower end of the TV that holds the electronics and connections.
Previously, I had placed a single exciter in the middle of the upper panel.
I'd appreciate suggestions and explanations for where to place the 2 exciters I plan to use now.
Working on my own so I don't have someone to hold the exciters while I listen ;-(
As some will remember, I had previously attached a Thruster to the back of my LG OLED TV to use it as a center channel in my home theater system.
The TV as DML has less efficiency than my aluminum honeycomb main DMLs, so I had boosted the trim on the center channel to align their sound output.
It worked and sounded great until some 30 minutes into watching Dune at higher volumes than my neighbors would appreciate. Great fun, but it blew up the center channel exciter.
To address the issue, I've decided to mount two Thrusters on the TV as DML and drive each of them with separate amplifiers (I have a spare NCore stereo module). I'll feed both amps with the same center channel signal from my AV pre/processor.
This should better level the output of the center and main channels.
The attached image, shows the LG TV from the side and back (the red line defines the DML panel area). You'll note that the TV's design has the thin acrylic upper panel fixed to the thicker unit at the lower end of the TV that holds the electronics and connections.
Previously, I had placed a single exciter in the middle of the upper panel.
I'd appreciate suggestions and explanations for where to place the 2 exciters I plan to use now.
Working on my own so I don't have someone to hold the exciters while I listen ;-(
Attachments
Hello Earborne,
I don't know about this exciter but I already shared links to DML sub (not tried). Have a look to #7432 (content below). The keyword are infraflex/infraplanar. The pages are in French, shouldn't be a problem with the translator tools. Many pictures. The basis is a large EPS clamped membrane moved by a modified subwoofer.
Technically the hdn8 isn't a bass shaker , but a full range exciter, but it does have a very large and heavy magnet which can drive walls and floors full range.
It is one thing to listen to a wall producing sound but another thing to actually be part of the vibrating surface on the floor.
I previously said it might be a good idea to use the floor as a sub, but now that I have tried it ,I would not recommend it.
But that might just be me, but some might like it for films?
Steve.
@Earborne 963Hz
I have a couple of these, which I think is likely one of the better exciters to use for bass duties:
https://www.alibaba.com/product-det...8.html?spm=a2756.review-list-buyer.0.0.hBRPv9
It is also a billionsound product: https://www.billionsound.com/product/209.html
Overall it seems like a really good exciter that can handle loads of power, but will slope off the high end a lot due the the impedance of the large coil.
Haven't explored to make a DML sub though, it just seems unpractical with little advantages to me...but I'm mostly in to electronic music and do want that somewhat unreal oomph you can get with a traditional sub.
I have a couple of these, which I think is likely one of the better exciters to use for bass duties:
https://www.alibaba.com/product-det...8.html?spm=a2756.review-list-buyer.0.0.hBRPv9
It is also a billionsound product: https://www.billionsound.com/product/209.html
Overall it seems like a really good exciter that can handle loads of power, but will slope off the high end a lot due the the impedance of the large coil.
Haven't explored to make a DML sub though, it just seems unpractical with little advantages to me...but I'm mostly in to electronic music and do want that somewhat unreal oomph you can get with a traditional sub.
First off I would never place an exciter on a TV as at high volume levels it could damage the tv in the long run, combined with the fact that the tv is not an ideal DML diaphragm, hence the low efficiency.
You place the exciters side by side with at least a 2 inch gap between them in the middle of the diaphragm. When the exciters are closer together they will tend to act and sound like the sound it coming from a single point source with the midrange/vocals being more prominent. The further away each exciter is placed from each other the less prominent the midrange/vocals will become being harder to localize the exact source. Its personal preference BUT for center channel use I recommend closer together as the center channels main function is dialogue.
Instead of placing the exciters on the TV I would build a dedicated DML center channel speaker using EPS then you wont have to worry about destroying another exciter and you will only need to use one exciter as EPS is very efficient.
Technically the hdn8 is a hybrid of a exciter and bass shaker which is the reason it was made to be attached to hard (wood) surfaces, no other exciter is built like it thats why its designed to be screwed into the hard surface.
Bass shakers were designed to be attached to solid surfaces (with mounting screws) so one can feel the vibrations rather then hear it. But with any transducer the sound is dependant on the material used. If you place a bass shaker on EPS without any crossover/filtering it will sound like a full range driver.
In this video he uses the same type of "PUCK" bass shakers that I have used for one of my DML sub panel. With this type of application you never mount it with screws but instead a adhesive or double sided tape.
Hello Jaxboy,
Some vacations, topics on going without results for now, posting on the other threads but still here!
Christian
For any US based DML people, what is a convenient source of EPS? anything from the home stores you use?
+ @Andre Bellwood
Hello André,
To give a follow-up to your impedance measurement, I did some impedance measurements today with REW and the sound card I have (an old Audigy2NX). Not too bad. I did it with one DAEX25FHE-4. It confirms the data sheet (voice coil mass, inductance, compliance). What is unexpected it is the spikes on the measurements. To be investigated. If somebody has a clue..?
Hello André,
To give a follow-up to your impedance measurement, I did some impedance measurements today with REW and the sound card I have (an old Audigy2NX). Not too bad. I did it with one DAEX25FHE-4. It confirms the data sheet (voice coil mass, inductance, compliance). What is unexpected it is the spikes on the measurements. To be investigated. If somebody has a clue..?
I haven't tried this but it might be a place to start
https://www.homedepot.com/p/3-4-in-...-Insulation-Sheathing-6-Pack-150705/202090272
Pete
Hello Pete
Seems Homedepot doesn't like my foreign IP adress (access denied). Which EPS density is it? I have in mind a minimum of 25kg/m³. I have found for now not more than 15kg/m³ in local DIY store.
Christian
I've looked at Home Depot and Lowes often for EPS. Most PS foam insulation in the US seems to be XPS. The only EPS I've found in those stores seemed to be very low density, and very soft. I couldn't convince myself to spend the money to be certain, because it seemed so obviously bad. But it could be that the stuff Alaska mentioned is different from what I've found there.
The only source I've found in the US for high density EPS sheets is The Foam Factory. They have EPS in 1 inch (and thicker but not thinner) and with density of 1, 2, or 3 pcf (16, 32, 48 kg/m3). I bought three 24x48 sheets of the 3 pcf density. Generally, I would say the quality appears to be good. The only issue I had quality-wise is that the surface has ridges in it, which must be from their molding process.
That said, I have to say I was not impressed with its performance as a DML. Frankly, for me it was no different from the pink or green XPS that you can get much cheaper and faster from HD and Lowes. It is has great efficiency, for sure, but has the same weird echo that XPS has, to my ears. But do be honest, I don't know if it's just me, or it's PS, but we don't seem to get along!
I would be interested to hear if anyone finds any PS (XPS or EPS) that anyone finds in the US that sounds as good as the UK EPS sounds.
Eric
The only source I've found in the US for high density EPS sheets is The Foam Factory. They have EPS in 1 inch (and thicker but not thinner) and with density of 1, 2, or 3 pcf (16, 32, 48 kg/m3). I bought three 24x48 sheets of the 3 pcf density. Generally, I would say the quality appears to be good. The only issue I had quality-wise is that the surface has ridges in it, which must be from their molding process.
That said, I have to say I was not impressed with its performance as a DML. Frankly, for me it was no different from the pink or green XPS that you can get much cheaper and faster from HD and Lowes. It is has great efficiency, for sure, but has the same weird echo that XPS has, to my ears. But do be honest, I don't know if it's just me, or it's PS, but we don't seem to get along!
I would be interested to hear if anyone finds any PS (XPS or EPS) that anyone finds in the US that sounds as good as the UK EPS sounds.
Eric
@ Spedge/Steve, Homeswinghome / Christian, Veleric /Eric and all the others who have given guidance.
First the Home Depot esp doesn’t list much info. The product is ¾ x 14 in. x 4 ft. Sells in a pack of 6 for just under $13 usd. R-value is
R2.65. Product weight is 2 lbs.
Just like you Eric I could not find the materials that I “thought” I wanted to work with. At first from Burnts posts I leaned toward Birch ply, with none to be found. Everywhere I tried to find EPS I came up short. I wasn’t really impressed with the XPS clips I’d listened to. Then out of sheer luck I found a local mfg. of EPS. When I called them I was told they only sold wholesale. SOL again. Twenty min. later the gal I had spoken with called me back and said they were doing a run that afternoon of their grade II ( 24 kg/m3 ) . They would be happy to add my few sheets to the order, cut to thickness. See post #6168.
Eric the ridges in the surface are from the hot wire cutting the sheets to thickness.
For my first set of panels I made ¾ in x 24 in x 24 in. Rounded the corners and sanded the entire panel. Followed by a full cote of 50/50 PVA. When dry I used a silicone ring for cooking eggs and poured a 50/50 PVA pad for the EAEX25FHE-4 exciters. It dries down very tight and makes an excellent mounting surface.
After 7 months of listening I just pulled them down to remove the DBL sided tape on the exciters and replace with epoxy.
Mean while I’m listening to a pair of 4mm birch ply panels 18 in. x 12 in. with DAEX32EP-4 exciters. And while they are good …. The EPS are “heaven” and well worth the effort and time.
Thank you for the design tips and patience Steve !! and everyone.
Pete
First the Home Depot esp doesn’t list much info. The product is ¾ x 14 in. x 4 ft. Sells in a pack of 6 for just under $13 usd. R-value is
R2.65. Product weight is 2 lbs.
Just like you Eric I could not find the materials that I “thought” I wanted to work with. At first from Burnts posts I leaned toward Birch ply, with none to be found. Everywhere I tried to find EPS I came up short. I wasn’t really impressed with the XPS clips I’d listened to. Then out of sheer luck I found a local mfg. of EPS. When I called them I was told they only sold wholesale. SOL again. Twenty min. later the gal I had spoken with called me back and said they were doing a run that afternoon of their grade II ( 24 kg/m3 ) . They would be happy to add my few sheets to the order, cut to thickness. See post #6168.
Eric the ridges in the surface are from the hot wire cutting the sheets to thickness.
For my first set of panels I made ¾ in x 24 in x 24 in. Rounded the corners and sanded the entire panel. Followed by a full cote of 50/50 PVA. When dry I used a silicone ring for cooking eggs and poured a 50/50 PVA pad for the EAEX25FHE-4 exciters. It dries down very tight and makes an excellent mounting surface.
After 7 months of listening I just pulled them down to remove the DBL sided tape on the exciters and replace with epoxy.
Mean while I’m listening to a pair of 4mm birch ply panels 18 in. x 12 in. with DAEX32EP-4 exciters. And while they are good …. The EPS are “heaven” and well worth the effort and time.
Thank you for the design tips and patience Steve !! and everyone.
Pete
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