As well, I have all intentions of sitting as close as possible to this thing. Call it an experiment if you will. The xo is low enough that directivity is omni from the lower source. I want to raise the horn up to get it suitable for ear level, and I will sit probably about arms length away. I was wondering if I should raise the woofer up, along with the horn. Even though, the floor position seems to give a better FR, I believe when I sit close enough, the FR will be very good, regardless. This should give me the best bass I have experienced. From their its the other things like multi sub or possibly cardioid that will help me get to somewhere, not so bad. I think one person advise to the use rear subs to cancel out the rear wave.
Can´t say much about IF "your" calculations is even "right" (or wrong), i don´t have the skills for that.
But i DO KNOW my stereo setup in my basement.
Do you have the knowledge/skills to calculate all variables inclueded?
Roomgain, real usable xmax, real usable max power in peaks etc etc?
I had help from my friend ho is a electrical engineer who builds sonar amplifiers for US military submarines.
Don´t even know if using the Peerlees 830847 dubble coils in serie/paralell in any other way make any difference, or box-size. or placement.
And I haven't made a final measurement just at 20 hz tone, but I measured the speaker many times and it´s almost flat to 20 hz.
The SPL measurement my post was about, was from the speakers while listening to real loud music.
My speakers are diy MTM with 2 x Audax HM210Z10 and Mundorf AMT29CM1.1, and 3 X ported peerlees 830847 tuned to 22 hz each side.
On that measurement it peak at 124 dB, and I didn't experience my speakers as "stressed" then, but they had no problems with audible distortion.
So maby your right that my speakers "just" reach 22 hz or "something" ( in my peak 124 dB measurement)
But maby you are wrong also, for me it dosen´t matter.
But for sure your calculations are in any case not completely correct, for MY setup AND MY room.
Yea,, Maybe I shouldn't have phrased it exactly like that.
But after so many measurement earlier showing almost a flat curve down to 20 hz, and knowing the "last" SPL measurement peak at around 124 dB, so I summed up my impression that way.
Maby not 100% "in the church" correct, but damn near
Best regards John
Boys comparing the length of their ... subwoofers ...
A good reflex design gains up to 8-10dB at the resonance frequency! And membrane movement is very low, so you can go to the thermal limit. So in THEORY it would be possible to achieve the level with a 20Hz optimised cabinet. But you would not be able to achieve the level at 30Hz ... it's (a little) complicated.
When measureing MUSIC at 124dB PEAK ... there was no 20Hz in the signal at all. Sorry but this "measurement" is completely useless for what you claim. Very low frequencies in music are usually 35-40Hz (except only some instruments) and these are 10-20dB lower as for e.g. the kick drum at 60-70Hz. These very low frequencies are also lower as the first 1-2 harmonics of the instrument! (that's special for natural, very low frequencies. Therefore cheap tuners are often missleaded).
And now let's listen to music in peace together again 🍻
A good reflex design gains up to 8-10dB at the resonance frequency! And membrane movement is very low, so you can go to the thermal limit. So in THEORY it would be possible to achieve the level with a 20Hz optimised cabinet. But you would not be able to achieve the level at 30Hz ... it's (a little) complicated.
When measureing MUSIC at 124dB PEAK ... there was no 20Hz in the signal at all. Sorry but this "measurement" is completely useless for what you claim. Very low frequencies in music are usually 35-40Hz (except only some instruments) and these are 10-20dB lower as for e.g. the kick drum at 60-70Hz. These very low frequencies are also lower as the first 1-2 harmonics of the instrument! (that's special for natural, very low frequencies. Therefore cheap tuners are often missleaded).
And now let's listen to music in peace together again
🍻
I'd say that bass runs further down to 30hz, commonly enough in certain genres like EDM, and they usually run near or at true peak in particular, 808 or similar type instruments.
10-20db lower than a kick at 60-70? Sounds like you are describing the sound event of an acoustic bass drum type instrument tuned a certain way but definitely not an average of all music available in particular electronic music
10-20db lower than a kick at 60-70? Sounds like you are describing the sound event of an acoustic bass drum type instrument tuned a certain way but definitely not an average of all music available in particular electronic music
Boys comparing the length of their ... subwoofers ...
No offense, but First of al it isen´t about subwoofers, its about driver working up tp 340 hz
I don´t know what music you listen to, but many of my listening song reach 20 hz.
The Beatles and Pink Floyd both have songs that hit 20Hz so I'm sure plenty of raggae, hip hop, R&B, pop, classical/baroque, country, and other types of music have songs that do as well
Jazz/new age usually range as low as 35 Hz and have seldom drops to well in the 20's.
Contemporary music/pop/techno,rap etc... usually range as low as 30 Hz and have seldom drops in the 20's as well.
Classical usually range as low as 40 Hz, but drop in the 20's quite often.
Pop/contemporary/rap/techno, etc... - bass guitar, keyboards, computer generated burps, and or equipment that is capable of producing 20 hz frequency.
Classical with the accoustic bass, tuba/souzaphone, tympany drums, pipe organ.
And now let's listen to music in peace together again
Im always in peace and just respect other´s opinions, music through sound is always our big love
I was talking about "natural" instruments (double bass, bass guitar, piano, organ ...). Their low fundamentals are weaker as their higher frequencies. Just do a FFT and have a look.
Of course there is a particular electronic music which tries to put in very low frequencies for the cause of it - but that's pretty special.
Pop/contemporary/rap/techno, etc ... usually DON'T have 20Hz in it! And when some songs have it it's not as loud as other signals (and somtimes simply just per accident like food tapping on a resonant floor). Have a look, do your FFTs, do some research.
There is a pretty good analysis tool in my DAW and I had a look into many songs ...
"Classical usually range as low as 40 Hz, but drop in the 20's quite often"
Show me. Which instrument?
Here is a link where they did an analysis of a broad variety of music - just use a translator or have a look at the graphs: https://hifi-selbstbau.de/grundlage...6/81-musik-qvergleichenq-mit-dem-waveanalyzer
These are 260 tracks of test CDs - reverence listening material, also with good low frequency content.
In average there is VERY low content at 20Hz but also the PEAK VALUE shows way lower level at 20Hz. So there are songs with information at very low frequencies but it's 10-20dB lower as the main frequencies in songs.
And now you can search for songs and do FFTs to prove me wrong - there are for sure some songs out there which will not stay in this "borders" and I would love to hear them on my system
There are 16 tracks of test cd's lol! But I've seen plenty of signal under an RTA, its old news by now, it is rare that you get a fundamental lower than 30hz but there definitely can be signal lower than 30hz in electronic material, even its less often than seldom. I haven't studied much classical/jazz under the RTA so I can't comment but why are we talking about this anyway>? Because of the relationship to efficiency, I sometimes like at LF extension capability as representative of Sound Quality level....Once again we are talking about headroom, just in a particular part of the spectrum.
For music, a system can be cutoff at 30hz and for cinema ,the cutoff is more like 25-20hz.....whats to discuss? True peak will represent a general flat average across a 1/3octave rta and RMS will fall 15db or lower under true peak, while rms for sub bass can be found matching true peak at times of high level low bass content, but you wont see RMS match true peak in midbass and treble because our ears would die. In music, sub bass or possibly the kick drum may represent the hottest instrument in the song, but the variance is less, like maybe 3.5db over the other highest playing instruments. Of course I am generalizing in a vary vast amount of material with unique character, so I could be referring to electronic music that I have studied or worked on ie heavy bassed, EDM/Rap. In rock the kick maybe much weaker, in whatever genre things might change else wise but there is a musicality to it and thus, a Norm of ranges for specific sounds/genres that come with an expectation of presentation.
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Mostly, it simplifies the issues regarding modal behavior within the room. Oh, the peaks and nulls will still happen in the room elsewhere, but if you set your butt down as close to the source as you can or within the phantom source if between two subwoofers that are close enough to mostly couple together then you're going to get the response nearfield measurements give you with less of the room involved. This is easy enough to check if you're set up to take your own measurements (mic and REW for the most basic). The response within a meter will be close to what you model while at the listening position the room gain, modal behavior and other artifacts will give a very different curve unless you've done what you could to treat your room, have worked hard at getting positioning right and added some DSP in there to fine tune things.
I have tried this myself, but ultimately opted for positioning, treatments and DSP for matters of practicality. My first 24" sub had the driver mounted fairly high in the cabinet, which I noticed one day put it right at head level when I was sitting in my listening chair. So, getting a bit of a wild hair and wanting to try it for fun, I moved it to immediately right behind the seat. If I leaned back a bit, my head actually went in the cone a bit. It was certainly a more tactile experience doing that. Despite it being sealed, it moved enough air that sitting that close really got my shaggy locks moving and shirt shaking at lower playback levels than usual. You have to remember that subwoofer drivers are pistons pumping air. That whole displacement thing. They don't just magically make the air shake where in situ, they move it. The more the displacement, the more it moves and it takes a little bit of distance to settle out. Not much, less than the diameter of the driver, but within that zone there's more...turbulence for want of a better word. (There's also an element related to particle velocity before its convolved to sound pressure with distance, but that's a bit too esoteric here.) You can visualize this with your own subwoofer if you wish. Take a couple of plastic shopping bags and fluff them up. Set one right in front of the driver, but not touching and another set on the floor a couple of meters out. Even with a sealed sub, the one in front of the driver will visibly shake at much lower playback levels than the one farther away. (Ported is another thing especially below tune. Those blow air, if you're not careful, when the driver unloads even if it's not producing anything other than port noise at that point.)
Besides the response reasons, having the driver so close that that turbulence can be felt is much of why this near nearfield placement has its proponents. The audible threshold for sound even at low frequencies is significantly lower than the tactile threshold. We hear bass long before actually we feel it (despite that tired old myth that gets thrown around). (Though we sometimes "feel" what we hear even if it's not felt. Listen to bass heavy music on headphones and a bit of synaesthesia will make a little vibration with the beat seem to be felt. The brain's funky like that.) So, our brain knows to interpret felt bass as being much louder than just that being heard. Kinda obvious, that. (It's related to sound intensity and its components of particle velocity and sound pressure, but, again, too esoteric to bring up here.) So, having the subwoofer right up at the listening seat like that means that "turbulence" is more likely to get your chair and clothes vibrating even just a little bit than even the same playback level from the sub sitting farther away. The body feels that and the brain goes "oh, that must be much louder" and thus it's subjectively perceived as such.
Convenience, though, is another matter. I moved my sub back where it belonged after a few days. The rest of the sound suffered too much for it. Having a large, reflective conical surface right behind the ears does not benefit anything else. Soundstaging became garbage and that much air moving in my ears muffled the midrange. Plus, it felt like a combination of being tickled across the back of the neck constantly with a little kid kicking the back of the seat. Wasn't a fan of that. Even with levels adjusted, it still felt like the bass was imbalanced to the hot side for it.
Rick,
I tried my subs in several positions of the room and behind the chair gave, by far, the best bass quality. It is incorrect to block the back of your head with subs, furniture or even the back of your chair, in doing so, you compromise soundstage, even more when the room is treated and has diffusers installed in the back wall (as I did).
You do not needed for the near field bass to stay within a foot, one driver diameter will give good results. And IMO you still need to treat your room with bass traps. I have installed a total of 30m3 of those plus several Mondo Traps plus 7m2 of diaphragmatic bass traps.
Since you will listen to the monopole radiation of the subs you do not need to enclose the back wave of your drivers, leaving them dipole. I very much prefer the sound of open back subs and by a big margin, this is only a personal preference.
As I already shown in other thread, these are 4 x 24" SH24 subs, H-Frame, flat to 20Hz. Delayed 5.3mS to the mains w/DSP. This is a room for music only, zero interest in HT.
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Look at the Elsinore thread in these forums. I have a lowly 8 watts driving mine, and base is something i have in gobs.. oh, from a tube amp no less.. i lurked that thread for many many years, along with a few other options until i was ready. Pulled the trigger 2 or so years ago on the Elsinores and i honestly have never heard a better speaker. In the years I have had them, literally hundreds of people have commented on them (wifes family is huge and everyone has been friends since elementary school.. a few people over to her is 50+!!)
A huge 16 ft stopped pipe organ goes down to around 16 Hz
And Okay, I'm not a "regular listener", I'm usually looking for heavy bass music., and then digital instruments often enter the music for sure.
Will come back to you some othertime about good songs, late here in Sweden now.
This Norwegian girl "Kari Bremnes" sings beautifully by the way, here is a 3 song concert with quite good bass
