Announcement

Collapse
No announcement yet.

DIY Flat Panel Speaker Love

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • allenb
    replied
    I'll start experimenting with the 9 1/2 x 14 and see where it starts rolling off on the low end and will try slightly larger if needed.

    Something I've been considering instead of the weather strip pressed in between the frame and edge of the panel as in the bertagni, is to use a custom milled wooden frame with a channel that is lined in felt. The frame would be made of two complete halves to where I can line the two halves of a 1/4" x 5/8" channel with 1/16" felt and when the two faces are screwed together, it could be shimmed to where there is just enough pressure to allow the panel to be slid around with moderate force but hopefully allow the perimeter edge to not be so forcefully captive. Hopefully allow a slight increase in low frequency extension. A lot of work but I've got the time and the wood shop facilities to fabricate them for experimentation. I'm sure it's like most neat ideas, a lot of work and sounds good on paper but produces no real advantage.

    Leave a comment:


  • Unbiasedsound
    commented on 's reply
    No, thats the only problem is that they dont list the density but it seems to be of higher grade then the standard densities found if local hardware stores. I use to buy all my EPS from Mr.Polystyrene on ebay but he is in the UK and seems to no longer ship to USA.

  • Unbiasedsound
    commented on 's reply
    It would be safer to go with the 9-1/2 for 150hz. If you look at most DML panels they are rectangle in shape including Bertagni speakers. It seems to increase the high frequency response. Also the longer the height from the width the more the panel will flex bend which in theory should produce more bass but there is a limit to how tall you can make it which is why I say at max double the width. I prefer 4-6inches taller then the width.

  • allenb
    replied
    Have you been able to find the density of the eps from these ebay sources?

    Leave a comment:


  • allenb
    replied
    I'll be experimenting with variations of the smaller panel but have a couple of questions related to the frequency range I'm shooting for. I'm looking for a crossover point of 150 hz. In your estimation, will the 6" width allow going that low? Or, would the 9 1/2" you posted have a better chance making it down that low? I'm also ok shooting for 200 hz if neither panel is large enough.

    Second question is what benefit is it to make the panel taller than it's width?

    Thanks,
    Allen

    Leave a comment:


  • Unbiasedsound
    commented on 's reply
    Also I am not saying that you cant make your panel 12X12 as larger panels will sound fuller and play lower but some highs will suffer the larger the panel becomes.

    This EPS is 9-1/2inch width X 14inch height X 1/2 thick.

    https://www.ebay.com/itm/29355118553...Cclp%3A2563228

  • Unbiasedsound
    replied
    Originally posted by allenb View Post

    Thanks so much for the quick replies. The reason I had settled on the 12 x 12 in the 1/4" thickness is from advice you had given Listencarefully a few pages back when he had built a pair. So, it appears you have done additional testing and found the 1/2" thickness in a narrower width is advantageous over a 12 x 12? One would think such a small panel in that thickness would have zero flex and would instead act as a solid piston up until wavelength became shorter than it's width but maybe that provides an improved acoustic performance.

    Have you built a few of these and is definitely your preference for a mid that can reach down to 150 hz up through the normal upper mid frequencies?

    It will be so much easier to access the 1/2" EPS compared to the 1/4!

    Are you still advising the 2lb density with a thicker, smaller panel? Or will a lesser density suffice?

    Last question. Are you still suggesting the TEAX19C01-8 exciter for these small panels?

    My apology for the multiple questions but want to get this right!

    Thanks,
    Allen
    I explained on post #1392 and 1394 in more detail of why I changed my panels design. Its because you cant defy physics as DML's are very similar to conventional cone drivers. Less flex (stiffer)=better highs while more flex= better bass so you have to find a balance.

    3 major factors that effect the frequency response of DML panels.

    1. Type and size of exciter used as larger exciters have more bass while smaller exciters have better highs but less bass. This is physics and was explained in earlier post.

    2. Density of panel as the higher the density the better the high frequencies while lower densities will produce more bass but less highs.

    3. Size of panel as larger panels will produce more bass but the higher frequencies will suffer while smaller panels will produce less bass but better high frequency response.

    There are usually compromises when using a full range driver and you have to find the right balance for your application.

    2-3lbs of density with 1/2 thickness. Higher (4-5lbs) the density the better the high frequencies BUT the higher the density the less efficient they become due to being to dense. Again you have to make compromises. What works for my design might not work for your design.

    Oh yes most def. the TEAX19C01-8 is the best when it comes to balance of highs, mids and bass as this is my go to exciter for all my designs. I dont like to mention this because P.E will raise the price. LOL

    Leave a comment:


  • allenb
    replied
    Originally posted by Unbiasedsound View Post
    There are 1/4 thickness on ebay but I prefer the 1/2 over 1/4 as the 1/2 sounds more full while the 1/4 sounds more thin. As for the width of the panel 12 inches is too wide/large..... A small panels ideal width should be around 5-8 inches give or take a few inches, while the height can be the same and or at max double the width. This is the reason I recommended the 6X10X1/2 EPS.

    Also ideal DML panel height placement when you are sitting down is below ear level. DML's have very wide dispersion patterns so if the panel is to tall the high frequencies tend to go over your head.

    To many people watch Tech Ingredients vids and think that there panels should be placed higher up above ear level which is not the ideal height placement.
    Thanks so much for the quick replies. The reason I had settled on the 12 x 12 in the 1/4" thickness is from advice you had given Listencarefully a few pages back when he had built a pair. So, it appears you have done additional testing and found the 1/2" thickness in a narrower width is advantageous over a 12 x 12? One would think such a small panel in that thickness would have zero flex and would instead act as a solid piston up until wavelength became shorter than it's width but maybe that provides an improved acoustic performance.

    Have you built a few of these and is definitely your preference for a mid that can reach down to 150 hz up through the normal upper mid frequencies?

    It will be so much easier to access the 1/2" EPS compared to the 1/4!

    Are you still advising the 2lb density with a thicker, smaller panel? Or will a lesser density suffice?

    Last question. Are you still suggesting the TEAX19C01-8 exciter for these small panels?

    My apology for the multiple questions but want to get this right!

    Thanks,
    Allen

    Leave a comment:


  • Unbiasedsound
    replied
    There are 1/4 thickness on ebay but I prefer the 1/2 over 1/4 as the 1/2 sounds more full while the 1/4 sounds more thin. As for the width of the panel 12 inches is too wide/large..... A small panels ideal width should be around 5-8 inches give or take a few inches, while the height can be the same and or at max double the width. This is the reason I recommended the 6X10X1/2 EPS.

    Also ideal DML panel height placement when you are sitting down is below ear level. DML's have very wide dispersion patterns so if the panel is to tall the high frequencies tend to go over your head.

    To many people watch Tech Ingredients vids and think that there panels should be placed higher up above ear level which is not the ideal height placement.

    Leave a comment:


  • allenb
    replied
    Originally posted by Unbiasedsound View Post
    Styrofoam Sheets (6" X 10" X 1/2") - Craft Quality Sheets | eBay

    Smaller panels are better suited for mids and highs and since you are using a pair of 8inch woofers you dont have to worry about the low end.

    Although there will be a difference the benefits are subjective to your personal preference. Its basically about dispersion.
    I agree entirely on small versus large panels. I'm looking for the 150 hz - 8K range. I'm shooting for a 12" x 12" x 1/4" panel and can cut larger panels down to the 12x12 but can't hot wire cut the thickness down which would be needed if using the source you linked to. Do you know of any sources who can sell small quantities of the 1/4" thickness in the higher densities?

    Leave a comment:


  • Unbiasedsound
    replied
    Styrofoam Sheets (6" X 10" X 1/2") - Craft Quality Sheets | eBay

    Smaller panels are better suited for mids and highs and since you are using a pair of 8inch woofers you dont have to worry about the low end.

    Although there will be a difference the benefits are subjective to your personal preference. Its basically about dispersion.

    Leave a comment:


  • allenb
    replied
    Hi everyone. New member here. I've read all of the thread and lots of great info here.
    I'm building a pair of open baffle using a pair of 8" woofers for low end and want to build something similar to the Bertagni SM80's in a 12x12 for mid-hi. Will experiment with adding extended hi range after giving a listen.

    A couple of questions. I've had no luck finding a source for the 1/4" eps in 2lb or anything in that range but did see a reference to a UK source. Can someone shoot me some possibilities for higher density eps here in the states? Ebay turned up nothing either but maybe was not searching with correct wording.

    The open baffle wings will be 8" deep from floor to top of enclosure. Do you see any huge benefit in stopping the wings where the 12x12s will reside?

    Thanks,
    Allen

    Leave a comment:


  • Unbiasedsound
    commented on 's reply
    The Z standard cap on the 2nd order low pass made a difference as its now smoother and more neutral then the dayton cap.

  • DeZZar
    commented on 's reply
    I've used the Jantzen cross cap on the woofer circuit before and can't complain. I'm going to try the Standard Z next time.

  • Unbiasedsound
    replied
    For my DML panels the best capacitor is the Jantzen Z standard over the Theta and Dayton film and foil caps.

    Theta is clear and detailed but gives out ear fatigue. Maybe a boosted top end?

    Dayton film and foil is sounds very open but has a lot of sibilance and or what some might call air? DML's have a lot of sibilance to begin with so more is not needed especially for my taste.

    The Jantzen Z standard is more neutral/smooth sounding with way less sibilance then both caps mentioned above. I guess it comes down to personal taste as some people like sibilance.

    Also some people mentioned that ones speakers must be very revealing in order to hear differences in capacitors and DML's are very revealing to begin with and even more so if built/designed right.

    Leave a comment:

Working...
X