Post by andrewp on Oct 27, 2021 16:20:08 GMT 12
Greetings gents...
Just a general question and maybe not one that I'd act on ...but I might...
I was reading a review on the Tube a day of three back from a bloke who reckoned a decent sub was an absolute must in ANY system..No matter the size of your main drivers for a variety of reasons. Sounded plausible but maybe not. So...with that in mind. I have a pair of TAD R1s
I'll just go and get a new bag of pop corn..
Thanks guys
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Post by foveaux on Oct 27, 2021 16:51:17 GMT 12
you have these? I'd be flabbergasted if you'd require a sub/s but...depends on your room dimensions. You have access to Room Correction system/analyzer? - test first i.m.h.o. and I've read for best results you need two subs for bass stereo reproduction?
"I see music as a lifetime affair." [Rory Gallagher]
"Free - I miss that band, but when I look back, we were very young" [Paul Rodgers]
850 posts
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Post by michaelw on Oct 27, 2021 17:00:59 GMT 12
Subs are the Devil's work
Those big TADs go down into the low 20s ?
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Pundit
Post by raveydave on Oct 27, 2021 18:38:10 GMT 12
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Post by RdM on Oct 27, 2021 19:23:37 GMT 12
You have access to Room Correction system/analyzer? - test first i.m.h.o. and I've read for best results you need two subs for bass stereo reproduction? You mean like for instance, a link example
Yes, some for bass stereo - despite (I've heard) some LPs will have bass mixed down to mono (?) there are certainly CDs of dual bassists, one mentioned recently elsewhere, and I even have a Rob Wasserman CD with a triple bass guitar (only) track. And naturally with a bass duo in L&R, or a threesome in LCR, one would want separate stereo subwoofers to reproduce them, the center being phantom mixed to mono, especially with satellites, but two floor standing mains might not need the extra.
But also for cancelling out bothersome room nodes with subtle placement, I gather.
See if you can find a copy of Floyd Toole -Sound Reproduction - Loudspeakers and Rooms (Elsevier, Focal Press 2009) or, it may have superseded, Floyd Toole - Sound Reproduction - The Acoustics and Psychoacoustics of Loudspeakers and Rooms (2008) I might scan a page or so about stereo subwoofers and room nodes from it.
And the mighty TAD would hardly seem to need extra?
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Post by RdM on Oct 27, 2021 19:52:17 GMT 12
Greetings gents... Just a general question and maybe not one that I'd act on ...but I might... I was reading a review on the Tube a day of three back from a bloke who reckoned a decent sub was an absolute must in ANY system..No matter the size of your main drivers for a variety of reasons. Sounded plausible but maybe not. So...with that in mind. I have a pair of until you post the links I'll just go and get a new bag of pop corn.. Thanks guys
Perhaps the reviewer on The Tube (I like it!;-) was talking nonsense or crazy talk or just expressing an opinion, er espousing one, or giving an authoritative lecture, or even just a calm reasonable essay. Ha! Or something else?
We will never know, until you post the link, day or three back, somewhere in browser history? ;=})
But the TAD R1s look magnificent!
Cheers !!
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Post by andrewp on Oct 27, 2021 21:15:36 GMT 12
Thanks guys for the banta... They certainly do the job make no mistake. At 150kgs a corner they are quite the mission to move!!
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Pundit
Post by harvey on Oct 27, 2021 21:43:05 GMT 12
If they are that essential you'd think they'd be a lot more popular yet by far the majority don't bother.
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Pundit
Post by peter0c on Oct 28, 2021 10:59:44 GMT 12
Time for a rant and it is drizzling. Subwoofers are an acceptable compromise if you have high quality bookshelf speakers, a small room and / or only use Netflix. Here's why. It is an accepted principle that the ideal total system Q for speaker systems (we're talking about bass only here) is .7. Any lower and the bass (particularly the decay) will be dry and restrained, any more and it will be boomy and under-controlled, particularly with valve amps. (This can be used to advantage with open baffle speakers which work best with high Q drive units and valve amps.) The system Q is derived from the Qt of the drive unit (typically between .2 and .4 for modern neodymium speakers) AND the box size, design and port tuning. The Thiele - Small alignments and equations made the designing of the best box (infinite baffle and ported) for a given drive unit easy and predictable. All drive units have a pass band, that is the range of frequencies (typically 25 hz to 1000hz for 15 inch speakers, 25 to 1500hz for 12 inch speakers and 25 to 2000hz for 10 inch speakers, all in free air) that a given drive unit will propagate. If you put these drive units in too small a box, say a 60 to 100 litre box, the lowest frequency that they will propagate before falling off a cliff is about 150, 120 and 100hz respectively. This is not subwoofer territory! To achieve a lower threshold of say 20 to 25 hz the bass needs to be progressively boosted by up to 30 to 40db at the lowest frequencies. This is why subwoofers have Class D plate amps of between 300 and 1000 watts but this is not the only bad thing. Because the drive units are over-damped in such a small enclosure, the normal bass decay doesn't happen. The resulting sound is a dry thump and not particularly musical. This however is recognised by subwoofer designers and often countered by a servo-feedback system. One of the earliest of these (and in full range speakers not modern subwoofers) is the 1980 Infinity IRS system which used dual voice-coil Watkins drivers. One of the coils was fed by a series LCR circuit tuned to the resonant frequency of the speaker / enclosure combination, thus flattening the impedance curve and it was argued providing corrective feedback. Other's argued that it resulted in a delay and a smearing of the signal. I suspect that modern subwoofers use digital technology to provide feedback which can be compared to the input signal, and a correction signal then applied to the voice coil. You will see that the professional literature frequently refers to the difficulty in integrating subwoofers with satellite speakers (and yes you ideally do need two subwoofers), and this might be because of the delay in the correcting servo doing it's trickery. And another thing, the floor space taken up by subwoofers is more or less the same as the floor space taken up by a decent full range speaker! The TM add above for a PMC XB3 is an example of a subwoofer done correctly. An additional bonus is that it is transmission line, which in my opinion provides the most musical bass of all. However transmission lines (unlike say ported cabinets using Thiele-Small equations) are very difficult to design and get right. I have a pair of Chris Roger's designed TL subwoofers (currently dismantled and so a work in progress) which uses 10 inch SEAS drivers and are flat to 23hz with no equalisation and no need for kilowatt amplifiers. They are driven through a First Watt analogue active crossover. Much nicer that all this digital stuff with room correction and so on! Not drizzling so time to walk the dogs.
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Post by RdM on Oct 28, 2021 21:07:43 GMT 12
I somewhat regret posting the tracks above, and thought I could delete and move to What I'm Listening To, but before I do, beside that - I've been troubled over the last few weeks with some erstwhile purported "studio" which has opened up, with a rear door facing my apartment block. Immensely powerful subwoofer which I suspect is overlapping with the mains, so a DOOF DOOF sound lacing the neighbourhood. For hours a day and to late at night. I've made a few visits, hard to determine who is in charge, offered to bring a signal generator, microphone & laptop with spectrum analyser software, but to no avail so far. Indeed, the dominant guy is perhaps PI, heavily built and tattooed, seems to couldn't care less about the effect on the residential environs. But I doubt he's the real boss. I finally found their website, starting this new tiny studio, with equipment and floor plan details. (I don't think they should even be operating in "Level 3" but they hang out ...) Their sub (or two?) seems to be this: www.adam-audio.com/en/subwoofers/sub10-mk2/www.rockshop.co.nz/adam-audio-sub10-mk2-10-inch-200w-rms-active-studio-subwoofer-2-year-warrantyVery intrusive. Palpable, physically from 30m away. Now I've also found the contact details of the perhaps parent company, maybe I can get some sense, else finally noise control. It doesn't help that at 45 degrees away from a door that opens at the end of a walkway makes a concrete block corner horn.
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Post by Citroen on Oct 28, 2021 21:18:22 GMT 12
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Post by michaelw on Oct 28, 2021 21:54:53 GMT 12
Subs behind the listener ?
Or are they surround speakers
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