So a driver like
B&C Speakers
or maybe Celestion Axi2050 - AxiPeriodic Compression Driver
Thats about lowest you are going to get from a compression driver?
B&C Speakers
or maybe Celestion Axi2050 - AxiPeriodic Compression Driver
Thats about lowest you are going to get from a compression driver?
Asymmetric nonlinearities (even orders) will cancel when two identical drivers are wired out of phase, but the symmetric ones will add. To me this means that the nonlinear distortion is not really reduced, it stays about the same or increases. Since 2nd order tends to dominates the THD number in most loudspeakers, the % THD will likely go down, BUT, and this is a very big "but", the perception is likely to get worse or, at best, stay the same, because 2nd order nonlinearities are the least audible of all. Seems kind of like a waste of time to me.
The following is more or less a mute point considering the Tempests are NLA (and the universally positive reviews were removed when the Tempests were taken off the DIYSG site) but I’m not really in agreement with the above assertion.
Sometimes people don’t understand or outright disregard the stated purpose of certain loudspeaker designs and then publicly vent their frustrations when they are displeased with the results. In the case of the Tempests, subwoofers are required in any circumstance where anything less than copious amounts of LF would be insufficient. However, this is true of most of the offerings from DIYSG, regardless of whether they use the SEOS waveguide or not. This is because the SEOS project that snowballed into DIYSG was started at the AVS forum where the vast majority of its members are already using active subwoofers.
Jeff Bagby designed four loudspeakers for DIYSG using the SEOS (Tempest, Zephyr, 88 Special and the Maximus 12) and one using the EOS (Alchemy). In one instance, a member owned a pair of both the Tempests and one of Bagby’s most raved-about designs, the Continuums. He rated the Tempests as highly as the Continuums and retained both sets of speakers for that reason.
In an effort to find some mixed reviews of the Tempests, I found a reference to a negative review on Audiokarma. I read the whole thread and it’s pretty clear the individual in question would have struggled with any constant-directivity waveguide loudspeaker, let alone the Tempest. Attached are photos off his initial setup and then the properly toed-in setup where everything clicked for him.
The biggest drawback of the SEOS waveguide is that it is not always available separately due to the supply chain not being very steady. A drawback of DIYSG is that after sales spike and then subsequently fall off for a specific kit, Erich will just take it off the site (making it NLA) so he can make inventory room for a upcoming design that is more or less similar in form and/or function. One more mild critique is that the product write-ups don’t always specify the intended listening axis the model was designed for; some people need to be reminded that listening to a constant-directivity waveguide on-axis can foster the impression of it being excessively bright.
I have assembled and auditioned (in the same room) the Alchemys, the Tempests and the 88-Specials. The Tempests were very impressive with music, they do the disappearing act so well that a dinner guest refused to believe they were playing music and thought I was tricking him with some discretely hidden loudspeaker in the middle of the room. My personal preference was the 88-Specials which isn’t surprising because it uses the SEOS-15 waveguide, around which several well-received DIY projects have been made, including a unity horn. These experiences led me to purchase an Autotech SEOS-18 and Denovo BA-750, around which a project will eventually coalesce. It also led me to literally give away a pair of Klipsch Fortes as there was honestly no desire to go back.
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Good to hear from an actual user.
Compared to other horns, it would be a tossup i bet.
But hey, open discussion !!!
Any push pull folks, i suggest the ppsl thread, graphs are there, along with stuff from wayne parnham, links to the KEN KREISEL DXD-12012 Dual 12" Push-Pull Subwoofer - HomeTheaterHifi.com , difficult to locate, i believe they are better.
I'm glad a tempest owner has chimed in.
I want to do something with those pro12a drivers.
My buddy djk (rip) liked them, especially for the money.
He liked the horn (think he bought 2), but he also liked horns i found unusable for home reproduction.
12" 2-way is a rare thing in home audio nowadays.
Compared to other horns, it would be a tossup i bet.
But hey, open discussion !!!
Any push pull folks, i suggest the ppsl thread, graphs are there, along with stuff from wayne parnham, links to the KEN KREISEL DXD-12012 Dual 12" Push-Pull Subwoofer - HomeTheaterHifi.com , difficult to locate, i believe they are better.
I'm glad a tempest owner has chimed in.
I want to do something with those pro12a drivers.
My buddy djk (rip) liked them, especially for the money.
He liked the horn (think he bought 2), but he also liked horns i found unusable for home reproduction.
12" 2-way is a rare thing in home audio nowadays.
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@ Brinkman, thank you for posting this resume of DIYSG, very informative!
@ Norman Bates, djk was your buddy?
Judging by his posts, he was not only highly intelligent, but also a wise man.
The 12" 2-way concept is a rare thing, but still appreciated by some.
@ Norman Bates, djk was your buddy?
Judging by his posts, he was not only highly intelligent, but also a wise man.
The 12" 2-way concept is a rare thing, but still appreciated by some.
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@ ro808 ,yea, I worked with him, close friend, talked 30 minutes every day for years and years.
xt1464 horns ? he wanted to play with those too.
I remember a tempest review (when there were many, well over 50) saying 9.5 movies but 5.5 music.
I wanted them, saved up some coin, then they were no longer available (wanted 3 for movies) unless you build your own boxes.
I was (still) focused on the pro 12a driver (12").
Then I landed at my current jbl's.
I'm getting lazy, I like that I don't have to futz with 2 or 3 amps, just plunk another set of speakers down.
Actually I could live with what I have now (even without a sub).
And with radio, I listen to more music every day than I ever did when I could only listen to cd's.
Before current setup, many times I pick a cd to hear an artist or song (or 2), just not the next 45 minutes of (him,her,them).
I see how the streaming services have caught on.
Maybe throw every cd I have onto some hard drive thing, highlight favorites for random.
They sell stand alone things with coax output ?
You load the cd to its drive, toss all the junky tracks, then have hundreds of random favorites playing?
xt1464 horns ? he wanted to play with those too.
I remember a tempest review (when there were many, well over 50) saying 9.5 movies but 5.5 music.
I wanted them, saved up some coin, then they were no longer available (wanted 3 for movies) unless you build your own boxes.
I was (still) focused on the pro 12a driver (12").
Then I landed at my current jbl's.
I'm getting lazy, I like that I don't have to futz with 2 or 3 amps, just plunk another set of speakers down.
Actually I could live with what I have now (even without a sub).
And with radio, I listen to more music every day than I ever did when I could only listen to cd's.
Before current setup, many times I pick a cd to hear an artist or song (or 2), just not the next 45 minutes of (him,her,them).
I see how the streaming services have caught on.
Maybe throw every cd I have onto some hard drive thing, highlight favorites for random.
They sell stand alone things with coax output ?
You load the cd to its drive, toss all the junky tracks, then have hundreds of random favorites playing?
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I was hesitating to post as I cannot really add anything meaningful to the topic, only subjective impressions but here it is.
But first - thanks to Dr.Geddes to staying, if you give up we all loose and go back to the dark ages. Those who are here to create their own very convenient Universe will never listen, "my theory" is what is killing science everywhere.
Thanks also to those who challenge everything, even Dr.Geddes started with the challenge and we will never move on if we just assume it has been all discovered.
I have lots of DIY speaker building experience( 30 years?) and I honestly wasn't expecting the shock of encountering the JBL 4367. Man, was that a different experience! Most natural sounding and made my favourite Dynaudio C1 sound like a ham radio(still love Dynaudio, no offence). But there is a very slight muffling of the sound around the crossover frequency. I could live with that as the rest is simply marvellous and I will never go back to anything less than a 12 inch+CD. Guys, please help do it right.
And later I heard a Geithain 901K - how come there are several types of drums on music I know like nothing else??? How come nobody told us earlier about it?
But first - thanks to Dr.Geddes to staying, if you give up we all loose and go back to the dark ages. Those who are here to create their own very convenient Universe will never listen, "my theory" is what is killing science everywhere.
Thanks also to those who challenge everything, even Dr.Geddes started with the challenge and we will never move on if we just assume it has been all discovered.
I have lots of DIY speaker building experience( 30 years?) and I honestly wasn't expecting the shock of encountering the JBL 4367. Man, was that a different experience! Most natural sounding and made my favourite Dynaudio C1 sound like a ham radio(still love Dynaudio, no offence). But there is a very slight muffling of the sound around the crossover frequency. I could live with that as the rest is simply marvellous and I will never go back to anything less than a 12 inch+CD. Guys, please help do it right.
And later I heard a Geithain 901K - how come there are several types of drums on music I know like nothing else??? How come nobody told us earlier about it?
ALL Dynaudios sound very cloudy, curtained, lame, tired, noisy...
The complex crossover is the problem. A lot of parts that modulate their noise.
ALL Dynaudios love horrible 3-tone-amplifieres.
The C1: Use the 17W75 (?) only - without any crossover. Clamped and other, thin wires. And connect with a clean amp;-) A dream!!!
You could use a switcher: C1 original OR 17W75 only;-)))))))))))
Dynaudio build good drivers but horrible speakers;-!
Hello Mitchba
Well it depends on the driver. I know I was surprised when I measured one with a large 4" format compression driver. With the smaller 3" I can see why 1k would be the limit but you can get them a bit lower with the bigger driver. Here are a couple of measurements so you can see what I mean. I have the older PTH1010 with the throat pinches.
Rob
Thanks Rob and Norman, going to have closer look at that pth1010hf-1 waveguide.
@camplo - what is your intended listening distance from the speakers?
That's a pretty big jump to the problem. I don't see how the number of components in a crossover even matters as long as they deliver the correct solution. But "parts modulating the noise"!? That's not a real thing. Passive parts do have noise, but it is insignificant and "no", it is not "modulated".
Well,
I can relate to that, I used to be a tubes/fullrange type of guy. Until I heard Doug Sax's(RIP) Mastering lab in Ojai. There was a full set of the dreaded ATCs that somehow made the Dark Side Of the Moon come alive... Then I realised it is much more than what cap/coil/FUSE you are using.
All of a sudden the room became important??
Yes, I hear a change in a fuse but I am not going back there. There are much more important things and I love this thread for that exactly - if you open your mind a bit and just go a listen to something similar to what you guys are discussing here it might change your life.
JBL 2451, 4" aquaplas, 23" jmlc
~500hz-630hz
AE TD15m
~95hz-130hz
AE td18h+
The xover points are just theoretical at this point. All in sealed enclosures. I haven't been able to get a hold of Acoustic elegance, nor have I seen any updates on their facebook page. Its kinda bothering as its been over about 2 weeks since I messaged them about changing my order.
~500hz-630hz
AE TD15m
~95hz-130hz
AE td18h+
The xover points are just theoretical at this point. All in sealed enclosures. I haven't been able to get a hold of Acoustic elegance, nor have I seen any updates on their facebook page. Its kinda bothering as its been over about 2 weeks since I messaged them about changing my order.
The advantage of a compression driver in the horn is the smaller exit versus using a dynamic driver in a horn? I guess I don't fully understand how "compression" plays a role.
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Yes, the compression of the wavefront means a higher acoustic impedance seen by the driver and a resulting increase in efficiency. Horns are a somewhat efficient over a limited operating range, but compression is more efficient and works over a wider frequency range.