OK...🙂
That's a PA speaker then. Bit like the cloth surround reflex 15" Tannoys, which I built for disco use.
An externally hosted image should be here but it was not working when we last tested it.
I liked them. It's a high Qms in Thiel-Small parameters, isn't it? Joachim Gerhard approves of that. Low stored energy, lots of slam. 🙂
All a bit of a ramble tonight, but hey, it's Friday. Thanks for the Fuzzbuster info, Greebster, I think I know what you are talking about. I seriously aren't going to spend a lot of time looking for audio Nirvana from FM, but accept that a good aeriel might help. 😀
Partial quotes are commonplace and do not remove context.
I specifically mentioned that the size of the hole meant that it wasn't an issue to the acoustic suspension performance. I'm trying to talk about the topic. Your first post on this topic:
"Then it would not be acoustic suspension if that was the intended design. All designs would be adversely affected if this is a simple 'leak' unless designed in."
In the context of a small leak, this is simply not true. Pinholes and tiny leaks have too high resistivity to play an influence on the enclosure's behavior.
Now, they CAN be a source of additional noise, so that is a different issue. Your claim that it wouldn't be acoustic suspension anymore is simply wrong.
Moving on from that, where and when have you found leaks to be an issue? I've only noticed them as a meaningful problem in high pressure cabs- like small box eq'd subs really cranking.
I don't think much of UK FM broadcasts either but I don't think the limit is FM technology, more likely the UK implementation.
Can't compare german FM with cd because when I was there there were no cds. That said every saturday one station would broadcast one album without interruptions so you could record them and I could never tell the difference between a (cassette)recording from vinyl or FM.
I do remember a german review of a NAD tuner in the '80s. It sounded good but could only receive 8 out of 28 FM stations cleanly. Revox and Kenwood used to make the best overall. The Revox was the only quartz PLL tuner which could keep up with Kenwoods fully analogue offerings. The Revox was standard equipment for FM relay stations (may have been the otherwise identical Studer version with XLR outs though).
PS: Aerial-wise I only ever used that T-shaped wire thing you nail to an indoor wall.
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badman, in my experience a tiny hole or leak in the cabinet will make no difference to the sound with any speaker I have ever built. You must have golden ears to hear any difference at all. And I DO understand how acoustic suspension works. 🙂
Back to the FM issue, it is well known that commercial engineers design to satisfy the 90% majority of listeners. It so happens that we at diyaudio are the 10% who can hear the faults. 🙁
I can hear the difference between a good Denon or Decca London moving coil cartridge and the decentish low inductance moving-magnet Stanton 500A that was a common broadcasting standard on vinyl replay.
But seriously, since we are the multiway loudspeaker forum, give the cone tweeters a go and try and keep the top end impedance high if you use transistor amps. I'm really not responsible for all the other horrors in the audio chain. 😀
Back to the FM issue, it is well known that commercial engineers design to satisfy the 90% majority of listeners. It so happens that we at diyaudio are the 10% who can hear the faults. 🙁
I can hear the difference between a good Denon or Decca London moving coil cartridge and the decentish low inductance moving-magnet Stanton 500A that was a common broadcasting standard on vinyl replay.
But seriously, since we are the multiway loudspeaker forum, give the cone tweeters a go and try and keep the top end impedance high if you use transistor amps. I'm really not responsible for all the other horrors in the audio chain. 😀
We looked into that at one of the companies I worked for. We were bitching at production about cabinet leaks and they said "prove that it matters". We started drilling holes in a cabinet until we could see a significant frequency response loss.
Amazing how many 1/4" holes it takes to mess up the response. We never showed them the results.
Air noises are another matter, though.
David
System7,
So true about FM. Shame Dolby FM didn't catch on, bet that was due to the extreme retail price one had to pay to get it, then add in the few and far in between stations that broadcast in Dolby. I was lucky having the opportunity to have such a station close enough for good reception and discovered a tuner in a garage sale my mum drug me to, really hated going. Tho not the case that day. Didn't want to shop further, get me home! 😉
Didn't those Stanton's have a tracking force of like 3-4grams? Slinky makers and back tracking were it's credo
Pioneer had the best commercial tuner sensitivity I can remember. That NAD was nice, but was worthless if it couldn't pull the stations in. Revox, well it's a Revox 🙂
So true about FM. Shame Dolby FM didn't catch on, bet that was due to the extreme retail price one had to pay to get it, then add in the few and far in between stations that broadcast in Dolby. I was lucky having the opportunity to have such a station close enough for good reception and discovered a tuner in a garage sale my mum drug me to, really hated going. Tho not the case that day. Didn't want to shop further, get me home! 😉
Didn't those Stanton's have a tracking force of like 3-4grams? Slinky makers and back tracking were it's credo
Pioneer had the best commercial tuner sensitivity I can remember. That NAD was nice, but was worthless if it couldn't pull the stations in. Revox, well it's a Revox 🙂
Never heard a phono cartridge sound like another so it shouldn't be too hard to tell a Decca from a Denon.
But then in Germany at the time pretty much every station used EMT turntables, arms and their 'Ton Dose'. The BBC was quite fond of EMTs too.
As our systems got better over the years they now more faithfully reproduce all that's good along with all that's bad in the source material. It doesn't help that we lose the bass at lower volume settings which leaves the mid range unnaturally loud. I find this tiring to listen to at night, this effect is exaggerated by our ears being unable to hear low frequency sound at the same level as we hear higher frequency sound. Who remembers the old notion of bass boost at low volume, I had a Kenwood amp in the early 90s which had this function, I remember using it a fair bit at night.
To my mind hifi is similar to a computer, garbage in = garbage out.
When you find a very nice recording it really shows up the music industry for what it is and what it could/should be.
To my mind hifi is similar to a computer, garbage in = garbage out.
When you find a very nice recording it really shows up the music industry for what it is and what it could/should be.
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Yup lots about that online eh, I was reading something to get the recording engineers take on this, quite interesting. Fletcher-Munson Curve = Ideal way to EQ?
Well, I do have some pretty darned good ears 😀
They sit right where they're supposed to on either side of my head.
It was Greebster who was claiming that a small leak would ruin the alignment, not me.
Air noise, however, can be an issue, but I've only heard of it, never encountered a whistling cab, certainly not any of the ones I've built or worked with.
I remember reading something about the trials that were conducted in the late '50's to determine what stereo FM standard to use, and that a standard with much worse S/N ratio was chosen than the optimal one demonstrated because of corporate push. Anybody have any info on that?
From wiki:
Stereo FM[edit source | editbeta]
In the late 1950s, several systems to add stereo to FM radio were considered by the FCC. Included were systems from 14 proponents including Crosley, Halstead, Electrical and Musical Industries, Ltd (EMI), Zenith, and General Electric. The individual systems were evaluated for their strengths and weaknesses during field tests in Uniontown, Pennsylvania using KDKA-FM in Pittsburgh as the originating station. The Crosley system was rejected by the FCC because it degraded the signal-to-noise ratio of the main channel and did not perform well under multipath conditions. In addition, it did not allow for SCA services because of its wide FM subcarrier bandwidth. The Halstead system was rejected due to lack of high frequency stereo separation and reduction in the main channel signal-to-noise ratio. The GE and Zenith systems, so similar that they were considered theoretically identical, were formally approved by the FCC in April 1961 as the standard stereo FM broadcasting method in the USA and later adopted by most other countries.
I believe it was a compromise. Allowing increased dynamic range causes infinite sidebands, larger this difference, greater the bandwidth. Effectively requiring so much bandwidth that would put great pressure on the limited spectrum available. This would result in difficult to design and very costly tuner front end / IF stages. The capability of such bandwidth would result in poor sensitivity / selectivity. This is only looking at the problem from the reception end of things. To built such a transmitter would be vastly more difficult to design and overall power output would be significantly reduced due to the increased bandwidth requirement, let alone the TX antenna design complexity. Yes we could have done it "better" but at a very high cost on both sides of the fence and extremely limited usable range.
I like 2" cone tweeters, but their limited polar response turned me off (not completely). I believe this is the biggest reason the rise of the soft domes took over the market. They didn't have the low end clarity of cones, but had them beat in spades off axis. Pick your poison, beamy clear or wide and thin sounding. Personally think most domes are driven far to low, they simply don't have the acoustic output and or without adding significant distortion to the picture.
cone tweeters leave domes for dead in the range that counts. who gives a toss about 10k and over when you can't get the rest right.
What really makes this academic: I wonder why people assume think that drivers are airtight? (-: