Solid 35hz in 4 cu ft
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URL: https://forum.speakerplans.com/forum_posts.asp?TID=81523
Printed Date: 27 March 2026 at 8:45am
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Topic: Solid 35hz in 4 cu ft
Posted By: SonicXtasy
Subject: Solid 35hz in 4 cu ft
Date Posted: 27 August 2013 at 1:00am
I am putting together a smallish system for gigs that don't need extreme volume and where big cabs aren't appropriate. What I want is a cabinet that plays as low as my 2 X 18 Yorkville TX9S, has more punch, and is less than half the size and preferably 1/3 the weight. I will build 2 and there will be a 2 X 10 +1" on top of them. I have modeled some 18" reflex and most don't go low enough in a smaller box and worried that if I tune a 15" low that it won't have a nice tight punch. any suggestions would be appreciated. Thanks ------------- The member formally known as vwbidder. |
Replies:
Posted By: all bass
Date Posted: 27 August 2013 at 8:58am
Are you familiar with http://sites.psu.edu/speakerdesign/2013/01/24/hoffmans-iron-laws-of-speaker-building/" rel="nofollow - Hoffman's iron Law ? Tony Wilkes designed a range of very compact subwoofers, but if i remember correct they don't go down to 35. |
SonicXtasy wrote:Posted By: Tony Wilkes
Date Posted: 27 August 2013 at 9:38am
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The Q15 has a similar response to a 18" cab tuned to 40hz and sounds very clean and fast (sic) Used 4 off this weekend for some live bands and they deffo did not sound like a small box :) Ask the neighbours 50M away  Grab a driver off Assistance Audio and give one a go. Speak to Jack Arnott http://www.assistanceaudio.com/" rel="nofollow - http://www.assistanceaudio.com/ Tony
------------- www.forteaudio.eu - BMS - db-Mark Processors - Lexon (SAE) |
Posted By: SonicXtasy
Date Posted: 27 August 2013 at 11:23am
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[QUOTE=all bass] Are you familiar with http://sites.psu.edu/speakerdesign/2013/01/24/hoffmans-iron-laws-of-speaker-building/" rel="nofollow - Hoffman's iron Law ? [QUOTE]Yes, sorry, I meant to add that I did not need the same output as a double 18. I do realize that the efficiency will be considerably lower and that the output will also be limited unless I am using a 2000 watt driver with 20mm xmax. I was going to use 2 12" Alpine car subs per box. They give me the response that I want (actually lower than I need) in the size I want but the efficiency is so low I am running the amp a little into clipping (1250 watts/4 ohm) to get the level I need. I am looking for something in between two extremes. I will sim some of the BMS drivers and see what I can come up with. I have been simming some of the Faital Pro drivers too which seem to take a small box but the extension isn't there either. 40hz just isn't low enough for most modern pop/dance music. If it was I would be building more THAM15's. ------------- The member formally known as vwbidder. |
Posted By: Elliot Thompson
Date Posted: 27 August 2013 at 11:47am
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You will need to step down in size in terms of drivers. Nothing larger than a 12-inch. Eminence Lab 12 can achieve 35 Hz (if not lower) in a reflex box, however you will need to scale it in a 4-cubic foot box to confirm if the box is big enough. Best Regards, ------------- Elliot Thompson |
Posted By: Tony Wilkes
Date Posted: 27 August 2013 at 11:55am
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The secret is B6 loading, the Q15 is only 50L :) Choose a driver that is well suited and you will be surprised at the results. I thought B6 loading was popular in the States? Tony ------------- www.forteaudio.eu - BMS - db-Mark Processors - Lexon (SAE) |
Posted By: SonicXtasy
Date Posted: 27 August 2013 at 12:06pm
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B6, is that the same as ESB6 in WinISD? Doesn't the driver loose a lot of punch and impact with that tuning? ------------- The member formally known as vwbidder. |
Posted By: _djk_
Date Posted: 27 August 2013 at 12:08pm
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" thought B6 loading was popular in the States?" Only thing I design. Driver Properties Name: 18 TBW 100 Type: Standard one-way driver Company: B&C Speakers No. of Drivers = 1 Fs = 35 Hz Qms = 8 Vas = 175 liters Cms = 0.0842 mm/N Mms = 245.7 g Rms = 6.754 kg/s Xmax = 12 mm Xmech = 25 mm P-Dia = 392.5 mm Sd = 1210 sq.cm P-Vd = 1.452 liters Qes = 0.41 Re = 5.3 ohms Le = 2.45 mH Z = 8 ohms BL = 26.43 Tm Pe = 1500 watts Qts = 0.39 no = 1.764 % 1-W SPL = 94.61 dB 2.83-V SPL = 96.4 dB ----------------------------------------- Box Properties Name: Type: Vented Box w/ Active HP Filter Shape: Prism, square Vb = 3.5 cu.ft Fb = 35 Hz QL = 6.414 F3 = 32.54 Hz Fill = minimal No. of Vents = 1 Vent shape = other Vent ends = one flush Av = 50 sq.in Lv = 24.71 in ----------------------------------------- Active 12 dB/oct. HP Filter Fx = 35 Hz Qx = 1.93 **************************************** F3 = 32.54 Hz, Should handle 3KW on program material without exceeding x-max! (129dB at 50hz) ------------- djk |
Posted By: Tony Wilkes
Date Posted: 27 August 2013 at 12:31pm
If it did there would be no way I could put up with it :) ------------- www.forteaudio.eu - BMS - db-Mark Processors - Lexon (SAE) |
Posted By: Tony Wilkes
Date Posted: 27 August 2013 at 12:33pm
I know you do mate, it is just that I read an article that said it was popular over your side of the pond but not over here. ------------- www.forteaudio.eu - BMS - db-Mark Processors - Lexon (SAE) |
Posted By: _djk_
Date Posted: 27 August 2013 at 1:02pm
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EV was the first company to do a commercial design, circa 1974. My first 6th order vented design (circa 1974) used dual 8's and a 15" PR, and was flat to 30hz in a tiny box. ------------- djk |
Posted By: Elliot Thompson
Date Posted: 27 August 2013 at 3:28pm
It really depends on what the aim is. Personally, none of my boxes uses the B6 alignment. I rather find a smaller driver to get the job done in a small box, which will appear large to a small driver than, using a large driver in a small box. Some people are willing to sacrifice size versus performance whereas others are not. Best Regards, ------------- Elliot Thompson |
Posted By: Tony Wilkes
Date Posted: 27 August 2013 at 3:36pm
But as you have never heard one of my boxes you have no idea if I am one of those. What characteristics of the B6 alignment do you think compromises performance ? Tony
------------- www.forteaudio.eu - BMS - db-Mark Processors - Lexon (SAE) |
Posted By: tomr_29
Date Posted: 27 August 2013 at 4:18pm
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If I can add my 2p as someone who has heard the Q15, and as a result owns a pair, there is no way I would say such a design has sacrificed performance. Four of them on Sunday was impressive and brought a big smile to the bassist's face when we turned it up a bit later in the day. They sound very deep and full with the B6 EQ applied on the LMS, more like 18" bins. The subs also retain a nice punchy sound unlike many low-tuned large reflex cabinets. I'll post some pics and a review on Tony's Q15 topic when I get a chance. ------------- Proper capitalisation is the difference between helping your Uncle Jack off a horse and helping your uncle jack off a horse. www.facebook.com/tremoracoustics |
Posted By: Elliot Thompson
Date Posted: 27 August 2013 at 4:34pm
I’ve had my experience listening to small bass reflex boxes using large drivers in addition to large bass reflex boxes using large drivers. My ears always sway to wards large reflex boxes with large drivers. This is due to my full range cabinets sitting on top of my bass reflex cabinets capable of offering 50 – 45 Hz on their own. I use EAW KF 750s. So my bass reflex cabinets needs to pick up where they leave off and move further down frequency scale. My goal is the fundamentals, which is easier achieved with a large driver in a large reflex box than a large driver in small reflex box that can manage multiple cabinets, which fall in the performance of the EAW KF 750. Best Regards, ------------- Elliot Thompson |
Posted By: SonicXtasy
Date Posted: 27 August 2013 at 4:36pm
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I would love to here your review of the Q15s. I am pretty sure they were not playing that gig with his double 8" though. As for the B6 alignment, I am currently at work so is it possible somebody can sim some drivers from Faital Pro? Primarily the 18HP1040 and18HP1060 because I have a local contact that I might be able to get them through pretty cheap. Thanks. ------------- The member formally known as vwbidder. |
Posted By: Tony Wilkes
Date Posted: 27 August 2013 at 4:41pm
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Elliot, I respect your views but if you read what you wrote there was a definite inference that if anyone goes for an assisted alignment type box then they do not care about performance just convenience.
------------- www.forteaudio.eu - BMS - db-Mark Processors - Lexon (SAE) |
Posted By: Tony Wilkes
Date Posted: 27 August 2013 at 4:47pm
There would have been no problem at all using my double 8" boxes at the gig, we would have just had to raise the X-over a bit higher that is all, from 120 to around 180. A double 8" box with decent drivers is a match for a 12" box except if you need extension. I have been to some large gigs with just 3 dv-Dosc a side crossing really low to meet SB28's, that is just 3 x double 8's and they ain't special. Tony ------------- www.forteaudio.eu - BMS - db-Mark Processors - Lexon (SAE) |
Posted By: SonicXtasy
Date Posted: 27 August 2013 at 5:00pm
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I am so used to thinking of low xover points that I did not take into account that you could simply raise the cutoff frequency and save the 8"s from over excursion. On top of these subs I was planning on using some 4 Eminence Deltalite 2510s that I have. 2 in a 1.6cuft box tuned to 62 seem to give me a reasonable amount of extension with out running out of xmax too quickly. Just ordered 2 RCF H100 horns for them. For the moment the comp will be a set of B&C DE-200s that I currently have but plan on replacing them with some better drivers such as some BMS' s. ------------- The member formally known as vwbidder. |
Posted By: Elliot Thompson
Date Posted: 27 August 2013 at 5:13pm
I never said there was anything wrong with the b6 alignment. In the United States many will choose a particular alignment based on other factors. Those factors usually take in account the other speakers used within the chain. This is why I said it really depends on what the aim is. There isn’t a standard on what is the most popular alignment in the United States for a Bass Reflex cabinet. The reason for choosing one over the other will vary from person to person based on his/her requirements in the United States. Best Regards, ------------- Elliot Thompson |
Posted By: SonicXtasy
Date Posted: 28 August 2013 at 12:21am
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I must be missing something. I entered the data from B&C's website for the 18TBW100 into WinISD and selected ESB6 alignment and it gave a cabinet size of 10.88 cuft tuned to 21.5hz. Is B6 different from WinISD's ESB6? ------------- The member formally known as vwbidder. |
Posted By: _djk_
Date Posted: 28 August 2013 at 2:31am
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"Is B6 different from WinISD's ESB6? "
Yes.
I picked that driver based on price and availability in the USA, and for your cut-off requirements and a small cabinet size.
A B6 can only be built with a Qts=0.312, so technically the design is a C6 (as are many from EV). ------------- djk |
Posted By: _djk_
Date Posted: 28 August 2013 at 3:24am
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Take a driver with a Qts=0.312 and put it in a sealed box sized to make it a D2 alignment. Now vent it to Fs and it becomes an SBB4, with the best transient response of all the vented alignments. Now add a Q=2 high-pass filter at Fs, and you now have a B6. It still has the transient response of the SBB4 because the box volume and tuning have not changed, you have just applied some EQ, mechanically it is the same. Fb=Fs=Faux. The Qts=0.312 is the intercept of two equations determining box size and low-frequency cut-off. The box size equation says that the size is proportional to the square of the Qts, so a Qts=0.3 can run in a box about half the size of a Qts=.4 driver. The problem is the bass response rolls off at a higher frequency the lower the Qts is. The two equations have an intercept at Qts=0.312, yielding the best bass extension and minimum box size, and allowing you to build a B6 alignment. If the Qts is a little off, don't worry about it. The response is no longer maximally flat, a B6, but now has a small amount of ripple, and so becomes a C6. I generally use drivers with a Qts a little below 0.312 and pretend the Qts is 0.312, you can get away with this as the lower Qts implies a stronger motor than you actually need on the driver. The interesting thing here is that as you pound the thing near x-max the Qts goes up and the box becomes perfectly tuned, and it sounds even better. Don't pretend on the Qts more than about 20% (optimum = 0.312, 20% stronger = 0.25), or it will sound very lean at lower levels. A quick estimate of where to start for box size is (Qts^2)*Vas*4.1 for a Qts=0.312, tune to Fs. As the Qts gets higher change the 4.1 to 4.5, and the box is tuned to (Fs/Qts)*0.312, or a lower frequency than Fs. I use BassBox Pro v6.0, it is very easy to model B6/C6 designs in it. The above are just starting suggestions, poke around modeling and see what happens. In BB v6.0, turn off the filter when modeling excursion vs power, then check how much power it will take to hit x-max at the worst case excursion frequency. ------------- djk |
Posted By: SonicXtasy
Date Posted: 28 August 2013 at 10:54am
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Thanks, That clears some things up. Does BB Pro v.6 have a calculate B6/C6 option or do you still have to manually tune it like in WinISD? ------------- The member formally known as vwbidder. |
Posted By: SonicXtasy
Date Posted: 28 August 2013 at 11:52am
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When entering data of a driver that has a Qts lower than .312 (.27 for example) into WinISD that I want to model as a B6, do I enter the correct Qts or do I enter it as .312? Meaning I would have 2 database's for one driver, one for standard alignments and one just for B6. ------------- The member formally known as vwbidder. |
Posted By: SonicXtasy
Date Posted: 28 August 2013 at 11:56am
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Also, I assume the D2 alignment is a Q of.707? ------------- The member formally known as vwbidder. |
Posted By: SonicXtasy
Date Posted: 28 August 2013 at 10:32pm
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Can I use the Q=2 high pass trick on a normal SBB4 alignment? I have modeled the Faital Pro 10HP1060 4 ohm and it's SBB4 alignment is 2.9 cu ft tuned to 34.75hz. When I add the peaking HP I get a beautifully flat response. ------------- The member formally known as vwbidder. |
Posted By: _djk_
Date Posted: 29 August 2013 at 1:40pm
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D2 is a Qtc of 0.5 (IIRC). Faital Pro 10HP1060, no data found, even at Faital Pro. "Can I use the Q=2 high pass trick on a normal SBB4 alignment?" Only when the Qts is 0.312, for other values of Qts the Faux frequency and Q will need to be adjusted, and the result will be a C6 (with a small amount of ripple). "When entering data of a driver that has a Qts lower than .312 (.27 for example) into WinISD that I want to model as a B6, do I enter the correct Qts or do I enter it as .312? Meaning I would have 2 database's for one driver, one for standard alignments and one just for B6." The assumed higher Qts 'trick' may be done with any alignment, not just a B6 (C6). Speaker sims are based on small signal behavior, not with any real power applied. ------------- djk |
Posted By: _djk_
Date Posted: 29 August 2013 at 4:36pm
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An interesting inexpensive design: Driver Properties Name: Sigma Pro 18A-2 Type: Standard one-way driver Company: Eminence Speaker LLC No. of Drivers = 1 Fs = 28 Hz Qms = 8.28 Vas = 441.2 liters Cms = 0.239 mm/N Mms = 135.2 g Rms = 2.872 kg/s Xmax = 6.1 mm Xmech = 18 mm P-Dia = 381 mm Sd = 1140 sq.cm P-Vd = 0.695 liters Qes = 0.3 Re = 6.29 ohms Le = 1.9 mH Z = 8 ohms BL = 22.1 Tm Pe = 650 watts Qts = 0.29 no = 3.113 % 1-W SPL = 97.08 dB 2.83-V SPL = 98.12 dB ----------------------------------------- Box Properties Name: Type: Vented Box w/ Active HP Filter Shape: Prism, square (optimum) Vb = 3.5 cu.ft Fb = 38 Hz QL = 6.099 F3 = 38.08 Hz Fill = minimal No. of Vents = 2 Vent shape = rectangle Vent ends = one flush Hv = 10.87 in Wv = 2.5 in Lv = 25.3 in ----------------------------------------- Active 12 dB/oct. HP Filter Fx = 38 Hz Qx = 1.93 ************************* The port could be made smaller, the x-max isn't that huge. Minimum recommended No. of Vents = 1 Vent shape = other Vent ends = one flush Av = 32.77 sq.in Lv = 11.71 in ------------- djk |
Posted By: SonicXtasy
Date Posted: 30 August 2013 at 2:57am
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http://faitalpro.com/products/LF_Loudspeakers/product_details/index.php?id=201070126" rel="nofollow - Here is the link to the Faital Pro 18HP1016 4 ohm. Please sim it and see what you think. I like Eminence but have had bad luck with the Sigma and Kilomax 18's and therefore avoid them.
------------- The member formally known as vwbidder. |
Posted By: _djk_
Date Posted: 30 August 2013 at 12:21pm
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Driver Properties Name: 18HP1060 Type: Standard one-way driver Company: Faital Pro No. of Drivers = 1 Fs = 35 Hz Qms = 11.1 Vas = 175 liters Cms = 0.0975 mm/N Mms = 212 g Rms = 4.2 kg/s Xmax = 11.45 mm Xmech = 21 mm P-Dia = 378.3 mm Sd = 1124 sq.cm P-Vd = 1.287 liters Qes = 0.38 Re = 5 ohms Le = 1.26 mH Z = 8 ohms BL = 24.77 Tm Pe = 1200 watts Qts = 0.367 no = 1.904 % 1-W SPL = 94.94 dB 2.83-V SPL = 96.98 dB ----------------------------------------- Box Properties Name: Type: Vented Box w/ Active HP Filter Shape: Prism, square Vb = 3.5 cu.ft Fb = 35 Hz QL = 6.505 F3 = 35.13 Hz Fill = minimal No. of Vents = 1 Vent shape = other Vent ends = one flush Av = 50 sq.in Lv = 24.71 in ------------------------------------ Active 12 dB/oct. HP Filter Fx = 35 Hz Qx = 1.5 ***************************** Takes about 2KW to hit x-max, Q=1.5 is only a max boost of 3.5dB ------------- djk |
Posted By: SonicXtasy
Date Posted: 01 September 2013 at 1:35pm
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Thanks djk, the 18HP1060 8 ohm (whats above) is probably what I am going to go with. When I simmed it in WinISD I got a volume of 3.717l but I may have input the data wrong, I will double check. Either way they fit my goal. I was planning on using triangle ports at the 4 corners of the cab. I have been simming them as two 4" square ports but in reality they will be cut in half. Same total area, just spread across more ports, is there a problem with simming it like that? ------------- The member formally known as vwbidder. |
Posted By: snowflake
Date Posted: 21 December 2014 at 2:32pm
| just trying to get my head around what drivers to use for B6 alignment. I need an Fs equal to the target f3, Qts up to 20% below 0.312 so it becomes tuned at high power. apart from that is it better to go for a high Vas for higher efficiency and so that I get a larger box volume (0.4*Vas per driver) and the vent length doesn't become impractically long? |
Posted By: snowflake
Date Posted: 24 November 2020 at 12:20pm
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this paper seems to discuss B6 as a specific application of a more general approach: https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwjX-ej1i5vtAhVfThUIHZEaAbAQFjAKegQIAxAC&url=http%3A%2F%2Fforum.vegalab.ru%2Fattachment.php%3Fattachmentid%3D28510%26d%3D1205526981&usg=AOvVaw176KcC3xlyS5vhERQgez_E" rel="nofollow - https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwjX-ej1i5vtAhVfThUIHZEaAbAQFjAKegQIAxAC&url=http%3A%2F%2Fforum.vegalab.ru%2Fattachment.php%3Fattachmentid%3D28510%26d%3D1205526981&usg=AOvVaw176KcC3xlyS5vhERQgez_E |