Big discounts on Heil AMT's

e6zion

Never heard one--only familiar with their reputation.  I thought maybe someone here would be interested.
https://essspeakers.store/collections/heil-amt

Gowa

Holy smokes!

rjj45

Yeah, Javad's already posted a couple of FR graphs. Broad 5-7 dB bump at about 5khz. Other than that, very good. I got a pair. Super heavy. Totally impressive. Thinking about a 3 way.

jholtz

Where is he posting the graphs?

Jim

dcibel

It's all on Facebook now, real shame.

jholtz

Bummer! I don't have a facebook account. My wife does. Do you know what she should search for?

I'm just curious about the drivers. I'm also curious if they're going out of business. I always thought Heil's were really expensive.

Jim

Wolf

Loudspeaker Project Pad. I don't have FB account either, and don't plan to.

rjj45

jholtz said:

Bummer! I don't have a facebook account. My wife does. Do you know what she should search for?

I'm just curious about the drivers. I'm also curious if they're going out of business. I always thought Heil's were really expensive.

Jim

DIY Loudspeaker Pad - closed group - admins are Jeff Bagby and Javad Shadzi
Jeff has posted a couple of good tutorials in the last few months.

jholtz

Thanks guys! I'll check it out and see what is available for me to see.

Jim

jr@mac

I was a member of that page, but the same people problems happened there that plague other busy forums. Javad, Jeff, and Chuck do their best but sifting through the non-linear Facebook presentation fashion is just too much for me. 

Gotta be up to 10,000 people or more by now, I imagine. 

hifiside

Around 14.5k. Still a member. 

jholtz

Thanks guys. I also couldn't see much without making my wife a member. I'd really like to see the measurements but my wife would be very grumpy if I signed her up for a DIY group.

Does anyone have measurements of the Heil's that can post them? I'm particularly interested in the smaller version they offer. Of course frequency and distortion measurements are what I'm looking for.

Thanks for all the help!

Jim

hifiside

Jim.

Gowa

This is quite weird. I was going to carry them a few years ago but couldn't get the price I needed. I wonder if they are in trouble. I hope not.

jr@mac

https://essspeakers.store/collections/black-friday/products/6-amt-series-speaker-pair

Wonder what that woofer is, looks remarkably similar to the GRS model at PE, although I would hope they stick a better woofer under that tweeter. The GRS punches way above its weight, but...

I wonder how the cans sound? Those are on sale as well 

PWRRYD

I wonder if there are any cavity resonances with the AMT mounted like that. 

dcibel

ESS has never been known to make great woofers, unfortunately.

I have heard good things about the 422H headphones though, the sale price isn't such a great discount as the big AMT. IIRC the 422H is a 2-way headphone, since AMTs have trouble with the low frequencies.

e6zion

Looks like it could cross pretty low... Does a 2 way with the new Epique 8in or Satori WO24 make sense?  That or a higher end pro woofer?  I am interested to hear your thoughts.

rjj45

Nicholas_23 said:

Def need something thats efficient for the mid or woofer . Pro woofers or pro mids would be a neat build. I sent JR a txt, and tossed around the idea of two vifa woofers per side.

That's my decision point also. 
Do I go with 2 x 4-5 inch "regular" mid woofers in a MTM with the Heil, or do I use one 8-10 inch pro woofer?
As for high efficiency pro woofers, FaitalPro and Beyma are looking good to me.

A critical part of the design process is determining exactly what is the efficiency of the Heil?
Gonna crank up Arta and true RMS DMM this weekend.

dcibel

If it's like the other large AMT competition out there, it'll have amazingly low distortion and then hit a brick wall. I think you should be able to manage a crossover in 1.2-1.5kHz range with the big guy, which gives you a lot of options. It would be nice to verify the sensitivity. It's rated 96dB@1W, but with a non-linear (but workable) response I'd question at what frequency is it 96dB? Past experience would wager a guess of around 5kHz.

dcibel

I'd also note that Javad is showing an impedance >5 Ohms, where Nick is showing and impedance closer to the specs.

rjj45

Guys - I need to measure the sensitivity of the Heil AMT tweeters, and the only reference I have off hand is the ARTA manual. Is there an easier way to measure 2.83V and maybe use Omnimic?  Should I measure closer and scale to 1 meter? Just want to do this right.

Wolf

if you want to impulse, use a cap to protect it. 25-50uF should do. 1m and 2.83V at pink noise and use an RTA in OMic. This should give you a rough estimate with a best-fit plot being the best assumption.

dcibel

rjj45 said:

Guys - I need to measure the sensitivity of the Heil AMT tweeters, and the only reference I have off hand is the ARTA manual. Is there an easier way to measure 2.83V and maybe use Omnimic?  Should I measure closer and scale to 1 meter? Just want to do this right.

If you have an Omnimic, that's the way to do it. Look in the help file, there's an instruction there.

You can measure closer than 1m and calculate sensitivity at 1m, but be real accurate with your distance measurement, at 1/4 m a small error in distance is multiplied by 4.

dcibel

Maybe irrelevant information but at a similar price point (now), here's my full dipole measurement of the Dayton AMTPRO-4.

5dB/div.

rjj45

dcibel said:

rjj45 said:

Guys - I need to measure the sensitivity of the Heil AMT tweeters, and the only reference I have off hand is the ARTA manual. Is there an easier way to measure 2.83V and maybe use Omnimic?  Should I measure closer and scale to 1 meter? Just want to do this right.

If you have an Omnimic, that's the way to do it. Look in the help file, there's an instruction there.

You can measure closer than 1m and calculate sensitivity at 1m, but be real accurate with your distance measurement, at 1/4 m a small error in distance is multiplied by 4.

Dang it! I'm such a dumbo! I did a Google search and found your post on PE TT, which is perfect for me, since I have OM
Thanks twice, dude. Owe you a beer.

ani_101

Dang it! I'm such a dumbo! I did a Google search and found your post on PE TT, which is perfect for me, since I have OM
Thanks twice, dude. Owe you a beer.

Can you post the post?

dcibel

rjj45 said:

dcibel said:

rjj45 said:

Guys - I need to measure the sensitivity of the Heil AMT tweeters, and the only reference I have off hand is the ARTA manual. Is there an easier way to measure 2.83V and maybe use Omnimic?  Should I measure closer and scale to 1 meter? Just want to do this right.

If you have an Omnimic, that's the way to do it. Look in the help file, there's an instruction there.

You can measure closer than 1m and calculate sensitivity at 1m, but be real accurate with your distance measurement, at 1/4 m a small error in distance is multiplied by 4.

Dang it! I'm such a dumbo! I did a Google search and found your post on PE TT, which is perfect for me, since I have OM
Thanks twice, dude. Owe you a beer.

Glad I could help, I don't know the post, but RTFM is always a good answer

Gowa

Can't wait to see what you guys do with these. Inquiring minds need to know.  
The 12'' AMT Series with a good woofer would be nice.

dcibel

Just another thought as I'm sure these tweeters are quite sensitive. 95dB at 1m is very loud, so you could also measure at a lower voltage and do some math to determine sensitivity at 2.83V

dcibel

The blurb from the "how to" section of the Omnimic manual:

Loudspeaker sensitivity is normally expressed as the SPL level that is sensed at 1 meter from the loudspeaker when it is driven from a voltage of 2.83Vrms.  When you are using a CD as the signal source with OmniMic, the nominal level of the swept sine signals can be determined (or set) by use of the 50Hz reference tones that are at the end of the Version 3 OmniMic Test Signal CD or DVD.

To use these, you may want to disconnect the speaker of the channel being tested (the output voltage of quality amplifier should not be affected by whether a speaker is being driven).  Then attach a Digital Voltmeter (also known as a "DVM") to read AC Voltage across the amplifier terminals.  Be sure to configure the voltmeter for AC Volts and that the probes connect to the meter's Voltage (and not its Current!) reading terminals. 

Turn any equalizer or tone controls off.  You can then play the 50Hz reference tone tracks and measure or set the voltage level from the amplifier.  Next, reconnect the loudspeaker, set OmniMic at the 1 meter distance from the loudspeaker and play the desired sweep track of the test CD.  Use the OmniMic software in its Frequency Response measurement mode for Sine Sweep, and the plot should then be a reading of SPL sensitivity.

The reason 50Hz tone is used is because 50-60Hz is where a multimeter will be most accurate. One of the great benefits the Omnimic has over the competition is that it is calibrated for SPL so you can measure absolute SPL with it.