• Welcome to The Audio Annex! If you have any trouble logging in or signing up, please contact 'admin - at - theaudioannex.com'. Enjoy!
  • HTTPS (secure web browser connection) has been enabled - just add "https://" to the start of the URL in your address bar, e.g. "https://theaudioannex.com/forum/"
  • Congratulations! If you're seeing this notice, it means you're connected to the new server. Go ahead and post as usual, enjoy!
  • I've just upgraded the forum software to Xenforo 2.0. Please let me know if you have any problems with it. I'm still working on installing styles... coming soon.

I have decided I don't need surround sound, ever

Everything is wired up and basic crossover settings have been made. They sound great, and the extreme minimalist simplicity of the setup is a dream for me!!!

That said, I have a hum issue I need to troubleshoot before I get into the more advanced crossover tunings.

Just for a kick I got a smart plug/switch which can be controlled by Alexa. I plugged a 12V power supply into it and soldered a 2.5mm plug to the output wire and connected it to the 12V trigger controls for all my amps. Now I can turn my rig on from anywhere in my house, garage, or patio by saying, "Alexa, turn on the stereo." HA! Take that fuckers!!!
 
Flint said:
Everything is wired up and basic crossover settings have been made. They sound great, and the extreme minimalist simplicity of the setup is a dream for me!!!

That said, I have a hum issue I need to troubleshoot before I get into the more advanced crossover tunings.

Just for a kick I got a smart plug/switch which can be controlled by Alexa. I plugged a 12V power supply into it and soldered a 2.5mm plug to the output wire and connected it to the 12V trigger controls for all my amps. Now I can turn my rig on from anywhere in my house, garage, or patio by saying, "Alexa, turn on the stereo." HA! Take that fuckers!!!
Click to expand...
And there's your hum.
 
Towen7 said:
Care to enlighten us on the source of said hum?
Click to expand...

Well, I wasn't able to perfectly pinpoint any single source. When I plugged everything into the same AC circuit it got better, but was still audible at the listening position. The 12V trigger power didn't seem to make any difference, so I kept that in use. I then started unplugging line level cables, and the amps didn't buzz when not plugged in, but they would buzz if a single cable was plugged in. So, the source was somewhere between before the amps. However, if I put a audio line level isolation transformer on the signal wire, it would stop on that amp. So, I found a nice 8 channel studio grade isolation transformer component and inserted between the crossover and the amps, everything was fine then.

Once I got that cleared up I started the fine tuning of the crossover. I measured, calculated, and made adjustments and compared them back and forth (the crossover allows for four presets, so I could finish one set of changes and switch between the prior and the new to compare in near real-time.

While I think I can do more, I am very happy with the sound now. I am hearing things I've never heard before - such as in the Spock's Beard song "At the End of the Day" there is a mellow section where I clearly hear the sound of a household security system making that beeping sound they make when someone opens a door or window. It is way back in the mix, but I definitely heard it because I thought it was MY security system. Funny, eh? I've been listening to that track since the it was released on headphones and other systems and this was the first time I heard it. So, I am happy with that. These are very good speakers.
 
Here's what sucks...

I've been marveling at the improvements my new speakers make over my previous speakers. Better dynamics in the midrange, better clarity & detail, depth, soundstage, imaging, etc. But damnit!!! after spending a few days in Heeman's killer HT with the incredible bass acoustics and performance, no amount of speaker design or amplifiers or crossover tuning can match his bass performance. Heeman has the best bass I've ever heard, and even though I spent more money on more bass drivers and cabinets, Keith will always be ahead.
 
Flint said:
Here's what sucks...

I've been marveling at the improvements my new speakers make over my previous speakers. Better dynamics in the midrange, better clarity & detail, depth, soundstage, imaging, etc. But damnit!!! after spending a few days in Heeman's killer HT with the incredible bass acoustics and performance, no amount of speaker design or amplifiers or crossover tuning can match his bass performance. Heeman has the best bass I've ever heard, and even though I spent more money on more bass drivers and cabinets, Keith will always be ahead.
Click to expand...

Once Again, Many, Many Thanks Flint!!!

:toast:
 
And here's the averaged response from both channels with the microphone at the listening position.

Ellipticor_FR_4Way_StereoAverage_2018-09-30.png

The dip at 42Hz is a room acoustics issue and isn't nearly as deep in the right channel as in the left. I am working on how I can remedy that. The dip at 2,700Hz is intentional and is for my tastes and hearing. I am very sensitive at that frequency and at louder levels it grates on me. The ripple in the upper bass is all room acoustics.

Ignoring the 42Hz dip, the response is rather linear at a tilted +/- 2.0dB from 10Hz to 20,000Hz (+/- 1.2dB from 60Hz to 20,000Hz). This is only one way to measure or appreciate performance, but it is one of the easiest to understand.
 
Last edited:
Today I took some time to tune a little, but then I did a dynamic response measurement run on the right speaker. Below is the resulting chart. I was going to put notes and arrows on the chart, but it is very self-explanatory.

Ellipticor_DynamicResp_4Way_StereoAverage_2018-10-01.png

As you can see, the lower portion of the chart shows the response measured at 70dB SPL, 80dB SPL, 90dB SPL, and 100dB SPL. This was with the microphone at the listening position. Clearly the response is almost identical at each volume setting.

The top lines are the normalized responses where the 70dB SPL curve was the normalized reference point. As the volume is increased by 10dB increments, the difference between 70dB SPL and the higher volume is shown in these curves. There is a tiny amount of power compression at 100dB SPL in the lowest octave of about 1dB SPL. Other than that, the curves are virtually identical.

This suggests the speaker is capable of reaching 100dB SPL without experiencing any audible dynamic compression. It also suggests the speaker can deliver these levels without any overload or experiencing significant distortion.

Since this is for one speaker, in this case the right speaker, that means that with 2 speakers I can get a solid extra 6dB SPL of output in the room without dynamic compression with typical stereo music where the bass is typically shared across the left and right channels, or for any soundtracks where the mono LFE channel is sent to the Left and Right channels equally.

I am very pleased with this. I may take the time to measure 110dB SPL, but my ears felt it when I did the 100dB SPL test, so I stopped raising the volume at that point. Most of us would find 100dB SPL RMS to be far too loud at which to spend any amount of time listening.

SUPLEMENTAL EDIT:
I did the math. Based on the measured sensitivity of the tweeter (95dB SPL at 2.83V into 4 ohms, or 2 watts, at 1 meter), the power needed to produce the measured 100dB SPL output from 8 feet away is about 21 watts. So, I could probably get away with a 25 watt tube amp if I got really crazy with this setup. Currently I am using the Parasound Z-Amp v3 which is capable of 65 watts into 4 ohms, which would get me about 106dB SPL at the listening position without clipping. The midrange units are 3dB less sensitive, but there are two which allows for 6dB of gain over one, so the two are 3dB more sensitive than the tweeter, or about 109dB SPL before clipping at the listening position. They can all handle way more power than that, but I'd need bigger amps. Maybe the Monolith 5 channel beasty?
 
Last edited:
Flint said:
Here's what sucks...

I've been marveling at the improvements my new speakers make over my previous speakers. Better dynamics in the midrange, better clarity & detail, depth, soundstage, imaging, etc. But damnit!!! after spending a few days in Heeman's killer HT with the incredible bass acoustics and performance, no amount of speaker design or amplifiers or crossover tuning can match his bass performance. Heeman has the best bass I've ever heard, and even though I spent more money on more bass drivers and cabinets, Keith will always be ahead.
Click to expand...

Dayummm, that's quite a compliment. Well done both of you.
 
I am almost done playing with the crossover to perfect the sound. I am stunned at what I am hearing. Great stuff.

All this time there's been a hum/buzz issue which has been just barely above audible in the room when the AC was silent (but masked by the sound of AC when it is blowing).

After gobs of unsuccessful troubleshooting, I decided to try out the Ebtech Hum-X ac ground loop remedy device on the crossover/preamp.

Today I installed the Hum-X device on the crossover's external power supply. Immediately the main speakers had a drop in the mouse of about 6dB, enough to make it essentially silent from the listening position. However, I quickly noted a buzzing in the distance which I deduced was likely coming from my IB subwoofers since the buzzing wasn't coming from the main speakers.

I tried to listen to the IB subs, but they are 9ft high and I cannot easily put my ear near them, but the buzzing seemed to get louder at the rear of the room and that seemed like evidence of the buzz being in the subs.

I crawled into the attic where the amp for the subs is located and I could clearly hear the buzzing, and so I thought I had it figured out.

I turned off the amp to experiment with settings and cabling to see if i could cure the buzz problem. But, to my surprise the buzzing continued after I turned off the amp. So I unplugged the amp. Still heard the buzzing. I unplugged the speaker cables. Tge buzz persisted.

What?

How does a speak buzz when it isn't plugged into an amp??

I assumed I may have been mistaken when I thought I didn't hear it from the main speakers, so I climbed out of the attic and made my way back into the listening room to check out the main speakers. But, they weren't the source of the buzz.... but I could still hear it. Hmmmm.....

I decided to take a break and eat, so i made my way downstairs to the kitchen when I noticed my across the street neighbor working on his driveway... he was using a power washer... a loud buzzing power washer.

Damn!!!

I had completely disconnected my IB sub amp and I had to climb back up there to reconnect everything over my neighbor's power washer!!!


I think I need a break.
 
So, I decided to downgrade my amps to lower power models which have lower self-noise, in other words the self-noise for a 65 watt amp is less than half the self-noise for a 150 watt amp. Basically, since my rig is incredibly efficient - the bare drivers have a sensitivity of over 93dB SPL at 1 watt and 2.83V and there are no gain reducing passive crossovers used - I needed to reduce the general hiss coming from the system. So, instead of the Halo A23 amps and Parasound HCA-1000 amps, I am now using my trusty Parasound 250W mono amps on the bass woofers and several Parasound Zamp v3 amps for the midrange and treble drivers. Works well, and it takes up much less shelf space. I actually have empty selves in my amp racks where I had to use to the tops of the amp racks before. Crazy.
 
That said, I am still intrigued by the idea of using a good tube amp for the tweeters. Maybe even for the midrange drivers, if I can find a model which can handle a 4 ohm load extremely well.
 
So how would the self noise of a tube amp compare with the Solid State ?
Also how fast is the rise time on tube in comparison with solid state?
If the rise time is faster would that help the impact?
 
malsackj said:
So how would the self noise of a tube amp compare with the Solid State ?
Also how fast is the rise time on tube in comparison with solid state?
If the rise time is faster would that help the impact?
Click to expand...

In my case, the concern about noise is less one of S/N (ratio) and more about the noise level at the speaker outputs when there is no signal. If a tube amp can have an inherent noise as low as a transistor amp, then all is good. In my experience that is the case. However, I've discovered over the decades that higher output power amps tend to have high inherent noise (noise when the input is silent) greater than the noise of amps with lower power limits. If I can get enough output (about 50 watts minimum for a transistor amp or about 15 - 25 watts for a tube amp) and still get a very low inherent noise, I will be happy.

Rise time, or slew rate (I assume), don't matter all that much to me. At one time the feedback circuits used to force amplifier components to measure more linearly with lower THD can add ringing to the amp, both pre-ringing and post ringing. Slew rate, or rise time, was one way of judging a transistor amp's ringing qualities, as well as measure the high frequency response. Today I feel the slew rate spec is a bit of a outdated tool as the issues it reveals are well known and usually dealt with really well (though there can be exceptions with cheap-ass amps or less than ideal DIY designs). Most tube amps I've looked at have very smooth frequency response characteristics to well above 25kHz, so they'd work well for my tweeters. The midrange drivers are fine with nearly any audio range amp.

That said, my new elliptical Voicecoil midrange and tweeter drivers have exceptionally low odd order distortion characteristics, but they have a slightly higher than normal second order distortion characteristics than other, similar, drivers. As such, they sound cleaning due to an absence of odd harmonics, especially the 3rd harmonic, yet have a smoothness and harmonic shimmer from the more pleasing 2nd harmonic. If that discussion sounds familiar, it is along the same lines as why many say Tube amps sound better than Transistor amps - the higher THD from tube amps is almost entirely even order harmonics while the THD from a transistor amp is equal across all harmonics, making the odd order harmonics louder, potentially higher than the same odd order harmonics as the tube amp equivalent.
 
TO share more data on my drivers, the midrange driver I am using produces less than 0.1% 3rd harmonic distortion in the operating range when generating 94dB SPL at 1M. I have two drivers per signal channel and thus for the same SPL in my room the 3rd harmonic level is more likely below 0.05%. The 2rd harmonic at the same levels is higher, mostly below 0.5%, but peaking at 0.8% in the 800Hz to 2,000Hz range while producing 94dB SPL at 1M. That can cut in half for the same SPLs in my dual driver design.

Compare that to another top end midrange driver, such as the Eton 4-512 model, the same 94dB SPL results in an average of about 3.5% 2rd harmonic distortion and 1.3% for the 3rd harmonic in the same range. Or, we can compare to the amazing Scan-Speak Revelator 6.5" Midrange (used in some the highest end speaker systems in the world) which at the same SPL produces about 0.8% 2rd Harmonic distortion and 0.2% 3rd harmonic distortion.

Basically, the odd order THD of these amazing ellipticor midrange drivers is 4x lower than one of the best drivers on the market previously, and the 2rd order harmonic THD is almost half that of the best previous model on the market.
 
You must log in or register to reply here.
Back
Top