Hedd Type 07 A-Core Monitors

[Rick63]

I must admit that I'm confused.

Is there anything wrong/broken about the sound, or is your complaint just that you're having to turn a knob further in order to get the results you're looking for?

The output is way too low through through XLR inputs, and there is loud buzzing when trying the RCA inputs. Same results regarding the buzzing with two different interfaces so something is wrong with them.

 

[Rick63]

I don't know why I bothered, but for the heck of it up before packing them back up this morning I hooked one of them up again using the RCA input. This time the buzzing sound was lower and I heard some music out of the monitor, but like the XLR input the level was way, way lower than it should be.

I have zero tolerance for issues with new gear, and most of the time it prevents me from trying the same brand again. That will most likely be the case here.

Too bad because they sounded fantastic to my old ears...

 

[Rick63]

 

[2020]

If I had EQ I could easily get the upper midrange - lower treble boost I was looking for in a new monitor out of the Dyn's, due to taste and age related hearing. The problem is my options are very limited due to my system is simply based on physical media devices, so I have no PC EQ options available. My only option is something like a a Schiit Lokius EQ and if not for the bad review I'd have already ordered one.

Get an IK ARC Studio. https://www.ikmultimedia.com/products/arcstudio/

Yes, you will have to use a computer to get started (the calibration and initial setup), but the external box can be used separately after with NO software required beyond the initial setup, in fact it's designed for this. It won't be the most customizable in the world, since it's mainly a calibration type product, but it will have more than just equivalent priced hardware only options. It's less than $400 to get started this route for the software, mic, AND the DSP box. That seems like a good value to me. Any old laptop can be used for the setup too.

 

[Cbdb2]

Looks like the xlr inputs are at pro level ( about 10db hotter, its actualy 12db difference) and the rca ins are consumer level, which is the way it should be, these are pro monitors.

This is a problem few people seem to be aware of, even at ASR. It was one of the reasons consumer electronics never had xlrs.

You use a consumer source into pro in and your level is low, other way around, distortion and clipping.

What spec do these new consumer devices with xlrs conform to?

 

[dfuller]

Looks like the xlr inputs are at pro level ( about 10db hotter, its actualy 12db difference) and the rca ins are consumer level, which is the way it should be, these are pro monitors.

This is a problem few people seem to be aware of, even at ASR. It was one of the reasons consumer electronics never had xlrs.

You use a consumer source into pro in and your level is low, other way around, distortion and clipping.

What spec do these new consumer devices with xlrs conform to?

5.2V RMS input on every active speaker I've ever used is more than enough to drive them to full output levels.

I mean, Neumann's lowest sensitivity is 0dBu (0.775VRMS) = 94dB SPL. That's pretty normal.

 

[Rick63]

I've owned 6 pair of studio monitors and none of them had such a low output whether through RCA or XLR inputs.

I had to have the volume knobs on the monitors all the way up and the volume level on the SMSL RAW-MDA1 up about 25% higher than before with my Dynaudio's (set at 0) to get the same levels, leaving me with little headroom. The Dynaudio's even have more output with their switch at -10 than the Hedds do with their knobs all the way up. There's also the fact that the Hedds amps are twice as powerful. I also swapped out the RAW-MDA1 for my Topping DX3 Pro+ and got the same results using the RCA inputs.

Then there is the buzzing through the RCA input.

This ain't my first rodeo, something is wrong with them. I have started the return process and won't be trying another pair. At $1600 a pair I expect better QC and even if I received another pair and they didn't have any issues, I'd always worry about them failing. Peace of mind is a wonderful thing.

It is frustrating that I have typed fairly long posts describing the issues in detail and some folks still don't seem to understand. This will be my last post in this thread.

 

[JaapD]

I've owned 6 pair of studio monitors and none of them had such a low output whether through RCA or XLR inputs.

I had to have the volume knobs on the monitors all the way up and the volume level on the SMSL RAW-MDA1 up about 25% higher than before with my Dynaudio's (set at 0) to get the same levels, leaving me with little headroom. The Dynaudio's even have more output with their switch at -10 than the Hedds do with their knobs all the way up. There's also the fact that the Hedds amps are twice as powerful. I also swapped out the RAW-MDA1 for my Topping DX3 Pro+ and got the same results using the RCA inputs.

Then there is the buzzing through the RCA input.

This ain't my first rodeo, something is wrong with them. I have started the return process and won't be trying another pair. At $1600 a pair I expect better QC and even if I received another pair and they didn't have any issues, I'd always worry about them failing. Peace of mind is a wonderful thing.

It is frustrating that I have typed fairly long posts describing the issues in detail and some folks still don't seem to understand. This will be my last post in this thread.

Most likely the buzzing through the RCA port isn't caused by the monitor itself but by problematic grounding. Keep in mind that the return signal of the RCA input is directly connected to the mains ground wire. This can result in mains signals flowing through the RCA return cable. I've had a similar case myself with an Adam monitor, so speaking from experience

 

[AnalogSteph]

Yeah, having RCA inputs on IEC Class I equipment is just asking for trouble with ground loops, so running into them is pretty much normal and expected. In the combination of studio monitors + PC it has in fact been so common that I would classify it as a FAQ.

Honestly, the fact that both speakers appear to be behaving exactly the same would seem to rule out QC issues for me. This model may just have unusually low input gain, possibly as the flipside to the low noise levels observed. The goal may have been best performance in nearfield use with this 5" variant, and the designer may have overdone it a bit. So basically, exactly the opposite problem to the smaller Genelecs. The issue may have been more obvious if there actually were an official sensitivity spec, but like many smaller makers that tend to find it hard to measure, HEDD did not give any.

(If I had to do it, I would probably grab a speaker of known sensitivity, like some Genelec model, use band-limited pink noise of like 300 Hz - 3k and replace the known speaker but the speaker under test while the measurement microphone stays where it is. Few people would care if the number is off by a dB or even two, but knowing the ballpark tends to come in quite handy indeed, and the comparison speaker does not need to be ruinously expensive, maybe an 8030C or something. Heck, if you're in Berlin you could probably just rent a pair when needed.)

 

[Sokel]

I've owned 6 pair of studio monitors and none of them had such a low output whether through RCA or XLR inputs.

I had to have the volume knobs on the monitors all the way up and the volume level on the SMSL RAW-MDA1 up about 25% higher than before with my Dynaudio's (set at 0) to get the same levels, leaving me with little headroom. The Dynaudio's even have more output with their switch at -10 than the Hedds do with their knobs all the way up. There's also the fact that the Hedds amps are twice as powerful. I also swapped out the RAW-MDA1 for my Topping DX3 Pro+ and got the same results using the RCA inputs.

Then there is the buzzing through the RCA input.

This ain't my first rodeo, something is wrong with them. I have started the return process and won't be trying another pair. At $1600 a pair I expect better QC and even if I received another pair and they didn't have any issues, I'd always worry about them failing. Peace of mind is a wonderful thing.

It is frustrating that I have typed fairly long posts describing the issues in detail and some folks still don't seem to understand. This will be my last post in this thread.

It would be easy to find the actual cause if you used an isolator on the PC side or if your DAC had a ground-lift or so (later not so much, but sometimes... )

That's of course if the noise is not there when speakers are on their own, with nothing connected to them.

PC sounds has turned into an epidemic,no matter RCA or XLR connection, specially the ones with cheap/not nice PSU's or not properly grounded.
The fact that caused issues to these speakers is ominous for other ones as well.

It's a shame that USB isolation is not a standard feature in DACs.

 

[Rick63]

I said I wasn't posting in this thread anymore, but I'm going to post 1 more time to clear up any misconceptions.

There is no PC in this system so there can't be any USB related grounding problem. I don't even own a PC. I only use the optical input of my SMSL RAW-MDA1 for TV, and a coax each for my Audiolab 6000CDT & Sony UBP-X800M2.

The buzzing issue occurs with two different DACs.

Everything is hooked up to an APC H15 power conditioner.

I have tried plugging them directly into a wall outlet with the same results.

There is/was never an issue with excessive noise with any other monitors I have owned in the exact same setup, nor have any had such a low output.

Oh, and they are the 7" model not the 5".

 

[dfuller]

I said I wasn't posting in this thread anymore, but I'm going to post 1 more time to clear up any misconceptions.

There is no PC in this system so there can't be any USB related grounding problem. I don't even own a PC. I only use the optical input of my SMSL RAW-MDA1 for TV, and a coax each for my Audiolab 6000CDT & Sony UBP-X800M2.

The buzzing issue occurs with two different DACs.

Everything is hooked up to an APC H15 power conditioner.

I have tried plugging them directly into a wall outlet with the same results.

There is/was never an issue with excessive noise with any other monitors I have owned in the exact same setup, nor have any had such a low output.

Oh, and they are the 7" model not the 5".

No, something was definitely wrong if you had to dime the input gain with something that can put out +16dBu or so at full scale, and that level was fine with other actives. Whether you got two defective or the design itself was the problem is another matter entirely.

But, yes, buzzing when you have two class 1 devices and use unbalanced connections between them is not unheard of - it's pretty much how ground loops happen, after all.

 

[audio2920]

I'm not entirely surprised by a measured 85dB average @ -1.5dBu* / approx 2m distance for this size of monitor. Except for the volume pot saying it's giving 12dB of gain!

I.e. let's assume 10dB crest factor for music; 85dB avg becomes 95dB peak. At 20dBu you'd therefore be putting peaks at 116.5dB @ 2m. And that probably means you'd be up in the Hedd's limiters.

*meaning 0dBFS peaks sit at -1.5dBu, since the DAC is running 17.5dB down and full scale = +16dBu, per spec.

If the volume control was labelled -24 to 0, I'd say performance was *perhaps* about as expected. But it isn’t.

 

[Bwaslo]

Try with only the optical imput to the dac and no input coaxes or hdmi connected. If no buzz then, ---> ground loop. That said, there are single contact input circuit arrangements that provide considerable immunity to ground loops, not all gear uses them though.

If the gain knob has to be at +10 for reasonable operation, operate it with it set to +10, that's why it's there. If you can't get to full output (where the speaker starts to distort, then there is a problem.

 

[Muelli]

I don`t think the monitors are defective.

This is a quote from the manual:

Note: When you first plug in the speaker, you might notice the volume] seems low. This is because the speaker is set for a nominal input of +4 dBu at 0dB volume setting—a professional standard that prioritizes clean signal reproduction over high gain. To correctly gain stage your system, adjust the output level on your audio interface until you reach a robust signal that fills out the dynamic range. Increase the gain gradually until you achieve your desired SPL without the interface or speaker clipping, ensuring the sound remains clear and distortion-free. This process maintains the integrity of the audio signal while optimizing overall performance

Regarding the buzzing noise, chances are high that it is in fact a ground loop. I`ve had this issue several times with different brands.

It would have been a nice feature, if the manufacturers equipped their monitors with a ground-lift switch.

 

[AwesomeSauce2015]

Looks like the xlr inputs are at pro level ( about 10db hotter, its actualy 12db difference) and the rca ins are consumer level, which is the way it should be, these are pro monitors.

This is a problem few people seem to be aware of, even at ASR. It was one of the reasons consumer electronics never had xlrs.

You use a consumer source into pro in and your level is low, other way around, distortion and clipping.

What spec do these new consumer devices with xlrs conform to?

I agree here.
Pro spec calls for the DAC to be able to output +24dBu iirc.
My DSP (Biamp tesiraForte) outputs +24dBu, which equates to around 12 volts RMS or ~30V peak.
I've driven several amps with widely varying sensitivities to their peak levels using tesira gear.

Personally if I had active speakers, I would want them to give me max output with ~+20dBu dBu input on the XLR ports... Like what Meyer requires for their Ultra X40 (Scroll down): "Audio source must be capable of producing of +20 dBV (10 V rms) into 600 Ω to produce the maximum peak SPL over the operating bandwidth of the loudspeaker."

Typically when I am doing pro audio work, I try to adjust the speaker gain such that it gives me peak output at full +24dBu input, or 0dBu if the source I'm driving it with gets unhappy above 0dBu. (Or... If I don't need anywhere near peak output I adjust it such that 0dBu input gives me the desired level)

Now to answer the question you posed...
I have no clue what "spec" these things hit lol. If the DAC can only swing +5V output then that isn't hitting pro spec. Maybe it's designed to interface with other consumer equipment that has XLR connections but doesn't expect +24dBu signals? I don't know of any device like that but I also generally focus on the pro audio side of things.

And lastly to sort of respond to OP:
There was definitely something wrong with the setup you had, and if the speakers didn't work for you I agree that sending them back is the right move. If you want to use pro audio monitors going forward, then I'd recommend verifying that your DAC can output 24dBu on the balanced outputs. If it can't output that signal level you will have issues with other monitors, and either way you'd be giving up performance since gain in a DAC is often cleaner than gain in an amplifier.

 

[KSTR]

Traditionally, nomimal pro level is +4dBu with 20dB headroom, thus +24dBu.
Monitors ideally should be able to reach maximum output with +4dBu as well as reaching usable low levels with +24dBu input, without clipping before the volume control.
If a monitor can do 115dBSPL peak then they should be able to reach 95dBSPL with +4dBu input, but also like 80dBSPL or less with +24dBu input.
This requires the volume control (sensitivity setting) to span a range of at least 30dB.

Neumann is one of the few companies who got that right, with a 35dB span. Also all their monitors have the same range of settings with absolute scale, same settings gives same output level.

 

[2020]

There is no PC in this system so there can't be any USB related grounding problem. I don't even own a PC. I only use the optical input of my SMSL RAW-MDA1 for TV, and a coax each for my Audiolab 6000CDT & Sony UBP-X800M2.

That's a shame. Have you ever considered getting a cheap laptop? It will let you experiment with deep EQing, to see what is possible outside of your computerless scenario, as a way to investigate leads or understand what you would need going forward to get the response you like.

You are really limiting your enjoyment level by having this arbitrary limitation in place. I think ARC is a good idea.

 

[spiritualgroundbeef]

instead of sending them back i would shoot msg to HEDD support first. I've owned a lot of HEDD products and support been pretty great when things went wrong. Type 07 however (MK1 and MK2) are my least favorite of their products owned both mk1 and mk2 for very short periods of time and somehow they just dont sit right with me.
Type 05 + sub with crossover (doesnt have to be HEDD) would work better for room your size from my experience. Or Type 20 (mk1 used or mk2) if you want to level up. Since you're Dynaudio guy also take a look at Dyn LYD 48s those are seriously nice speakers.