Sound damping material

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Wolfgang
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Re: Sound damping material

Post by Wolfgang » Mon Mar 16, 2020 11:16 pm

Simon, I listen with active (TS 300B PP/Burmester clone) modified Klipsch La Scala horns. The photo shows what I did.
KH_sub.jpg
The original sound has changed a lot, more open and relaxed than the typical KH sound. The midrange horn/300B PP needed some EQ for sounding lush and full rather than anemic but when it's all done in it's a wonderful combination. The tweeter is connected via passive x-over with an L-Pad for fine tuning.

simon
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Re: Sound damping material

Post by simon » Mon Mar 16, 2020 11:39 pm

And the OB subs?

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Re: Sound damping material

Post by Wolfgang » Tue Mar 17, 2020 3:50 pm

And the OB subs?
The subs come with a 370W RMS into 4 ohm amp (linear psu) per channel with the servo control board built in.
A370XLR3 (2).jpg
All controls are analog which is not my favorite way of doing this kind of stuff so I bypass them (LFE input ) and use my digital x-over for controlling Klipsch/sub(except the servo control settings of course). Absolutely no group delay! If this is done right the music almost explodes in the room with incredible precision and "speed". Couldn't sound more satisfying, sorry, but I need to say it again: It's almost too good to be true. I know my excitement will calm down again after some time. :wink:
The Behringer Ultradrive is not expensive and some people who use(d) it and are not satisfied have made a mistake at the connection side. They think it's the Behringer, maybe some "cheap" digital or analog parts etc, but it's not. It has been made for studio/PA use and needs a strong signal at its XLR analog input. If the audio system has only RCA IN/OUT one should use it either with active RCA to XLR/XLR to RCA conversion or one should use a powerful pre together with a XLR to RCA adapter. I use a single EF86 buffer with 15dB gain and it drives the Behringer flawlessly. I have used some Texas Instrument ICs in the past for doing the RCA/XLR/XLR/RCA which also sounded very good.

One last word regarding subs: I have used a Velodyne sub for many years and was quite happy with the results. It also has servo control (something that looks little a tiny little mic glued on to the back side of the cone while the 12" woofers use a second coil for delivering the information). It could control the Xmax but didn't deliver those details about the bass and the acoustics of the recording situation (that's at least how it sounds to my ears) and the servo control couldn't be fine tuned with different settings. It also sounded more "boxy" and added some smearing in combination with my room acoustics. OB subs with servo seems to be the best way.

simon
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Re: Sound damping material

Post by simon » Tue Mar 17, 2020 7:28 pm

This is the fourth time I've asked this question so I'm thinking I've missed details elsewhere, or it's something you can't discuss, (in which case my apologies) but what are the drivers and the cabinet design?

To put it another way, if I wanted to build these sub OBs which drivers would I need and which baffles would I need to build?

Wolfgang
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Re: Sound damping material

Post by Wolfgang » Wed Mar 18, 2020 1:55 am

Obviously a misunderstanding.
The drivers are the SW-12-08
http://www.rythmikaudio.com/GR_drivers.html
can be ordered here: http://gr-research.com/drivers.aspx

Couldn't find the link for the H-frame plans so I attached the pdf.
H-frame 2.pdf
(81.11 KiB) Downloaded 40 times

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Ray P
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Re: Sound damping material

Post by Ray P » Wed Mar 18, 2020 7:07 am

I've been looking at the websites Wolfgang linked to - interesting bass speaker products and not as expensive as I thought they might be.

I wonder how they would perform with a full range unit, like the Lii Audio ones, run open on a small baffle?

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Re: Sound damping material

Post by simon » Wed Mar 18, 2020 1:39 pm

No problem Wolfgang, I can't have been clear enough, sorry. Danke schoen, I'll have a read up later.

I do recall reading something, or watching a youtube video, a while back about GR Audio servo drivers but had completely forgotten.

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Re: Sound damping material

Post by simon » Fri Mar 20, 2020 11:51 pm

Well I'm quite tempted to have a go, though a pair of subs isn't cheap. Especially since the pound took a hammering against the dollar. Not the right time now anyway. But I'd look to use them as Ray suggests with a smallish baffle on top for the Fostex 208EZ and T90A.

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Ray P
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Re: Sound damping material

Post by Ray P » Sat Mar 21, 2020 6:13 am

simon wrote:
Fri Mar 20, 2020 11:51 pm
Well I'm quite tempted to have a go...
Likewise Simon, not cheap as you say at around $800US per channel but also not outrageous given the bundle includes two bass units and an amplifier (per channel).

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Re: Sound damping material

Post by Wolfgang » Thu Mar 26, 2020 6:08 pm

I wonder how they would perform with a full range unit, like the Lii Audio ones, run open on a small baffle?
They subs are limited to 120Hz max with the internal x-over because of servo control precision. The higher the frequency the harder for the servo to react precisely enough. Using the LFE input (bypassing all analog controls) and external active x-over might work for using them at higher frequencies for single driver OB (150-170Hz?). My plan was anyway to try at some point the PM6A OB but with the Klipsch bass unit for bridging the gap down to 70Hz.

Stereo OB subs open a completely new perspective into music (mostly with classical music/Jazz music). It's worth the money.

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Ray P
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Re: Sound damping material

Post by Ray P » Sat Mar 28, 2020 7:50 am

Wolfgang wrote:
Thu Mar 26, 2020 6:08 pm
They subs are limited to 120Hz max with the internal x-over because of servo control precision.
The Lii driver datasheet shows it extending down below 120Hz so maybe there are some opportunites there...
Capture 2.jpg

Wolfgang
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Re: Sound damping material

Post by Wolfgang » Sat Mar 28, 2020 1:31 pm

If that's the frequency response of the driver in a baffle then it will work even at lower frequecnies. Must be a hell of driver!

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Ray P
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Re: Sound damping material

Post by Ray P » Sun Mar 29, 2020 2:03 pm

I as hoping to get up to Mark (aka Island Pink) sometime in the springtime so he could measure my actual drive units but it looks like that'll be on the shelf for the forseeable future. That would help to shape my plans on how to use them.

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Nick
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Re: Sound damping material

Post by Nick » Sun Mar 29, 2020 3:39 pm

Colin has my pair now. It may be that at some point he can measure them, but not sure,
Resistance isn't futile it's V / I.

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Re: Sound damping material

Post by IslandPink » Sun Mar 29, 2020 3:52 pm

Yes it's shame, I was definitely looking forward to hearing them as well as testing, but like with everything we'll just have to be patient.
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