Need at least the driver's Fs, Vas, Qts to help and of course ideally your's measured.........
Check out the TH18, SS15, and THAM15 threads in this forum.
Is there anybody here fluent enough in Hornresp or Akabak to simulate 2pcs of the SB Acoustics SB23MFCL45 8 in the MLTL 10 cabinet?
I'm contemplainting modifying my speakers, making a separate midrange cabinet and placing it on top of the speakers and put dual SB23MFCL's in the MLTL 10.
https://www.diyaudio.com/community/threads/an-improved-transmission-line-alignment.243483/page-27
I'm contemplainting modifying my speakers, making a separate midrange cabinet and placing it on top of the speakers and put dual SB23MFCL's in the MLTL 10.
https://www.diyaudio.com/community/threads/an-improved-transmission-line-alignment.243483/page-27
Only used mdf internally. All outer panels are made of 3/4" baltic birch ply. The magnet isn't supported though.
It is what @NeilBlanchard called the cabinet in post 380 on page 19 in this thread.
It is what @NeilBlanchard called the cabinet in post 380 on page 19 in this thread.
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It will work better if the woofer is connected to more of the box.
MDF is not a great brace material. What you had?
You said 2 woofers per box? Cabinet in picture seems to have just 1.
2 woofers, push-push can make a big difference.
dave
MDF is not a great brace material. What you had?
You said 2 woofers per box? Cabinet in picture seems to have just 1.
2 woofers, push-push can make a big difference.
dave
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Yes they are now fitted with a single Scanspeak P21WO 20 08. They sound great at low to moderate listening levels with incredibly deep bass. But what I notice is that the woofers seem to loose a little bit control as the volume goes up compared to cabinet I had them in before (55 liters BR).
If these SB Acoustics woofers simulate nicely in the MLTL's my plan is to build a separate cabinet with the same width an put a Seas CA22RNY or Jantzen JA8008 HMQ in it and use a Hypex amp to drive the woofers up to around 100hz.
If these SB Acoustics woofers simulate nicely in the MLTL's my plan is to build a separate cabinet with the same width an put a Seas CA22RNY or Jantzen JA8008 HMQ in it and use a Hypex amp to drive the woofers up to around 100hz.
I would not be surprised if that is caused by panel resonances. According to the drawing the back panel is not braced at all. And the MDF structure does not do much. MDF is dense cardboard but it does not have any structural strength.
Ideal line length is too short (1/4 WL) or too long (1/8 WL) based on a 28 Hz Fs = ~13543/4/28 = ~121", ~13543/2/28 = ~60.5", though fine tuning the vent solves this type of 'problem', but this means maybe enlarging it, so might want to try 'critically' damping it.
Attachments
All very true, though 3/4" thick at such a narrow width, high aspect ratio isn't a problem IME. Easy enough to add a ~1.5" x 24" vertical riser from scrap, offset at an odd harmonic in both planes to guarantee it doesn't. 😉
It's not shown in the picture but I have 3 bracings running down the backwall. The issue I'm describing is not due to cabinet resonance. The 55 liter speaker I had the woofer in before had just a single brace and the cabinets was made out of 18mm mdf. In those speakers I could hear cabinet resonance when I played loud.
In the MLTL it's like the cabinet is to big. Like the volume is too large to support the woofer. The woofer will bottom out much sooner in the MLTL's compared to the 55l BR. But the volume in the MLTL's are close to 90 liters.
I dont hava Akabak, I just simulated 2 SB23MFLS in Winisd with about the same volume and tuning as the MLTL 10 and it looked nice. That was why I was interested in how they would simulate in Akabak. Playing only up to about 100hz they will work only as subwoofers more or less, so I dont have to worry to much about dips and peaks higher up in the frequency range.
In the MLTL it's like the cabinet is to big. Like the volume is too large to support the woofer. The woofer will bottom out much sooner in the MLTL's compared to the 55l BR. But the volume in the MLTL's are close to 90 liters.
I dont hava Akabak, I just simulated 2 SB23MFLS in Winisd with about the same volume and tuning as the MLTL 10 and it looked nice. That was why I was interested in how they would simulate in Akabak. Playing only up to about 100hz they will work only as subwoofers more or less, so I dont have to worry to much about dips and peaks higher up in the frequency range.
For sure! Like 2.361x Vs a max flat BR by the way I design MLTLs, though again, can be dealt with via vent and/or damping same as Scott's Pensil designs.
SB23MFLS ? Specs?
SB23MFLS ? Specs?
MLTL? The line in Post 529 is not ann ML-TL.
It could well be too large, you put the driver in a line that wasn’t designed for it.
dave
The Scanspeak P21 has TS-parameters very close to the drivers Neil used to simulate rhe MLTL so it shouldn't be way off.
Dibirama measured the SB Acoustics woofers here: https://www.dibirama.it/home-page/sub-woofer/822-sb-acoustics-sb23mfcl45-8.html
Don't get me wrong, I love the bass these speakers produce. Very articulate and refined, you can very easily follow bass notes going very low. In that regard they remind me somewhat of the Bill Fitzmaurice horn subwoofers I used to have.
Dibirama measured the SB Acoustics woofers here: https://www.dibirama.it/home-page/sub-woofer/822-sb-acoustics-sb23mfcl45-8.html
Don't get me wrong, I love the bass these speakers produce. Very articulate and refined, you can very easily follow bass notes going very low. In that regard they remind me somewhat of the Bill Fitzmaurice horn subwoofers I used to have.
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Resonance is the same, Q is fairly different, Equivalent Volume is dramatically different. idoubt the small difference in Q will equal out the huge V[subas[/sub] difference.
My guess is that the driver is choked for volume. D’Appolito had the same probelm with Thor. No bass.
Fs // 28 // 28.5
Q[subts[/sub] // 0.33 // 0.43
V[subas[/sub] // 115 // 37
dave
My guess is that the driver is choked for volume. D’Appolito had the same probelm with Thor. No bass.
Fs // 28 // 28.5
Q[subts[/sub] // 0.33 // 0.43
V[subas[/sub] // 115 // 37
dave