21" version of TRS-218
Printed From: Speakerplans.com
Category: General
Forum Name: General Forum
Forum Description: Open Discussion / Questions
URL: https://forum.speakerplans.com/forum_posts.asp?TID=107874
Printed Date: 20 April 2024 at 6:01am
Software Version: Web Wiz Forums 12.06 - https://www.webwizforums.com
Topic: 21" version of TRS-218
Posted By: snowflake
Subject: 21" version of TRS-218
Date Posted: 09 May 2023 at 10:00am
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I've modelled and drawn a double 21" that has a similar layout to the TRS-218. Does anyone have an approximate hornresp model for a TRS-218 or an F221 so I can check whether it is anywhere close to the performance of those?
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Replies:
Posted By: fatfreddiescat
Date Posted: 09 May 2023 at 10:24am
There is the Ohm measured data here: https://www.oldbarnaudio.co.uk/wp-content/uploads/2019/02/TRS-218_Datasheet_V2.0_09-02-2018.pdf |
Posted By: smitske96
Date Posted: 09 May 2023 at 11:22am
I would sim it like a simmed a cubo, TH, with throat chamber (which is large). S1=S2 L12 0,1cm. Tap part is very short, but could be seen as there. Otherwise i would see it just as a normal BR (which it mostly is for the working part if i see the layout correctly).
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snowflake wrote:Posted By: snowflake
Date Posted: 09 May 2023 at 12:44pm
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yep have modelled mine as a tapped horn with large throat volume. there is a plan for TRS218 on youtube but not sure if it's accurate. Ohm make the drivers and no idea of ts parameters.
https://www.youtube.com/watch?v=7c_gNBvdNTw" rel="nofollow - https://www.youtube.com/watch?v=7c_gNBvdNTw |
Posted By: smitske96
Date Posted: 09 May 2023 at 2:31pm
| That youtube channel is mostly bs. So would not trust it. |
Posted By: snowflake
Date Posted: 09 May 2023 at 3:29pm
yeah their TRS218 plan shows two paths that are 140mm wide connected to the central path which is only 200mm wide. There are people who say constricting a horn at a bend works but it's very unusual. agree probably BS |
Posted By: snowflake
Date Posted: 09 May 2023 at 4:03pm
that what I've got with 2W nominal input for direct comparison to TRS218 response. My box is 100L bigger than the TRS218 but sensitivity is 1-2dB better and a bit flatter. not sure what driver OHM use but expect peak output will be a lot greater with high excursion 21" drivers.
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Posted By: snowflake
Date Posted: 09 May 2023 at 7:54pm
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Posted By: FOO
Date Posted: 09 May 2023 at 10:25pm
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Have a look at TW Audio BSX. I guess it's probably what you are aiming for. https://www.twaudio.de/en/product/b-series/bsx-serious-low-throw/" rel="nofollow - https://www.twaudio.de/en/product/b-series/bsx-serious-low-throw/ And yes, they do what it says on the box
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Posted By: Lucasdude
Date Posted: 09 May 2023 at 10:33pm
Bit of a shame they choose to quote program power figures, and very vague frequency limits!
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Posted By: snowflake
Date Posted: 09 May 2023 at 11:15pm
that's 50% larger than the TRS-218. Look good but can't find any response plot for them... guess they are using something like an 18Sound 21id driver. |
Posted By: FOO
Date Posted: 10 May 2023 at 5:05am
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If I get the time this upcoming weekend, I can measure them. It will be outside on a grassy field. 6 each side in end firing setup, 3 layers of 2. But one box could be plugged in on its own for measurements. But they don't disappoint. 27hz is real. Not f3 real, but they do get down there. And can't see why it's a problem with the program power?
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Posted By: smitske96
Date Posted: 10 May 2023 at 8:34am
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@snowflake They probably use the 21NLW9601-04. |
Posted By: snowflake
Date Posted: 10 May 2023 at 10:05am
I suspect that there is a lot of EQ boost in the DSP settings to get significant 27Hz output - would be interesting to see raw response without DSP applied. |
Posted By: snowflake
Date Posted: 10 May 2023 at 10:06am
oh yes probably is. For some reason the -04 version isn't on loudspeakerdatabase.com |
Posted By: FOO
Date Posted: 10 May 2023 at 12:23pm
I can bypass the DSP if we got time for it. Could be fun to see raw vs processed.
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Posted By: snowflake
Date Posted: 14 May 2023 at 11:01am
did you get any data? |
Posted By: Pasi
Date Posted: 07 June 2023 at 9:11pm
Correct. And you shouldn't. I have some knowledge about TRS-218 and the drivers in it but with that video, I would end up having something different than the advertised product. |
Posted By: jazomir
Date Posted: 08 June 2023 at 7:09pm
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That Utoob channel is, as Pasi states, bullsh1t! Like so many emulators, without knowing the TS parameters of the drivers, it's almost impossible to simply copy the cabinet and stick a 'similar' driver in and expect to get similar results. Add to this that many of the cabs shown on this (and other channels) also have DSP applied to the original drivers and all bets are off as far as simply copying stuff is concerned. Even copying stuff like FIR processing onto another DSP enabled amp isn't going to work either - all this processing is unique to a certain brand of DSP so what works on 'brand A' won't necessarily work the same on 'brand B'. Speaker manufacturers such as Fulcrum have DSP designed for specific makes of amps and using a different combination of DSP/amp could have, at best, poor results and, at worst, catastrophic consequences. ------------- For sidefills, can we have two enormous things of a type that might be venerated as Gods by the inhabitants of Easter Island, capable of reaching volumes that would make Beelzebub soil his pants. |
Posted By: snowflake
Date Posted: 10 June 2023 at 11:04am
well this is the best I can get out of two sheets of ply. sensitivity doesn't look much better than a standard ported enclosure of same size but the max output is significantly higher.  |