Hartke HD112 speaker sensitivity

[Joe6Bass]

That’s not at all how it works. The power delivered to the speakers depend on many things, knob position being one of them. The bass, the setup, pickups and positions, playing style, pedals, all have a major impact on the power delivered.

Linear action of the gain/master control refers to how smoothly the gain and master volume act on the signal throughout its rotation. It has nothing to do with the power delivered. This is exactly why I am cautioning you.

This is incredibly insightful. Even though I've forgotten just about everything I learned 30 years ago as an EE, exactly NONE of this practical reality was imparted upon me.

I am aware that I am beyond the rated limits of the HD112s. As a pair with a combined impedance of 4-ohms, I should have 600 watts of speaker being driven by 800 watts of amp... about 133% overrun for the speakers. That being said, I don't play in an exceptionally loud band and my 500watt LX5500 drove the same pair of speakers to about the same SPL.

I shall proceed with caution.

I can't thank you enough, @agedhorse!

 

[JACKSON JS1XM]

Would you please stop posting incorrect information?

I am trying to help the OP understand WHY he is having the difficulties he is having, your information is not correct.

I am posting Hartke or any other speaker manufacturers information for as much as they're going to reveal. The HD series drivers do have Neodymium in them, and I quote Hartke.

"Packing two 10" Hartke patented HyDrive speakers with rare earth neodymium magnets..."

It makes zero sense for Hartke to make only a HD 10 inch speaker with Neodymium and anything from 6.5-8 or 12-15 inch speakers without Neodymium for a patented series of speakers that is used across their entire cabinet & combo product lines. The composition of a Neodymium is NdFeB. Fe is Iron for that element's portion of a composition. Ferrite is alpha Iron. There is nothing incorrect about anything I've posted. Let's pump the brakes on that, if anything I am very thorough in my research and links I provide. For amp cabinet speakers, they've been making Alnico, Ceramic & Neodymium magnets since well on the other side of the last century. And the electrical aspect of mismatched output ratings has always been more speaker vs amp output at any Ohm design/rating.

Ferrite - SN Cast Iron

As for comparisons, one certainly would compare speakers made from similar materials & design with one another. If you don't want to compare Hartke speakers with Eminence, maybe you would prefer Celestion for like comparisons.

PA Speakers & Guitar Loudspeakers | Products | Celestion

I offered advice so the OP can get a ballpark idea of what is going on. The TT-800 amp is doing what it's going to do to that 1x12 cab based upon it being a 300W RMS rating. If the warning limiter light comes on, the amp is going to do that, Mesa states in their owners manual that the light may be indicated 25% of the time. Nothing not factual or incorrect about that. Those are direct quotes, cut & paste, not either of our opinions. I did that intentionally, the EE's at Hartke & Mesa stated that in the product documentation, not me. If anyone has exception to that, they need to address that with those manufacturer's experts. I think a larger speaker for the Mesa's monster output is the solution, regardless of the 94-99 dB sensitivity that any bass speaker seems to be manufactured to. ore speakers and the TT-800's wattage is distributed evenly to each speaker.

Direct Quote, source: Hartke Owners Manual.
"HD112
Description 1 x 12” Bass Speaker Cabinet
Cabinet Type Vented bass enclosure
Cabinet Impedance 4 or 8 Ohms selectable
LF Drivers 300 watt, 12”, paper and aluminum hybrid cone HF
Driver 1” High Frequency Driver
HF level control 3-position switch (0,-6dB, Off)
Power Handling 300 Watts RMS
Frequency Response 35Hz - 17kHz -3dB
-10dB LF Response 25Hz
Dimensions 19” x 15” x 16”
487mm x 381mm 404mm
Weight 30.9lb
14kg
At Hartke, we are continually improving our products, therefore specifications and
images are subject to change without notice.

Direct Quote, source: Mesa Owner Manual.
"PROTECT LED: This red LED indicates that the amplifier has entered protect mode and is either protecting itself from an external fault (such as blocked ventilation, shorted speaker cable or defective speaker), or that there is an internal fault within the
amp itself. Verify that it’s not a fault external to the amplifier by disconnecting all cables (except the power cable) from the amplifier. If the protect LED is no longer lit, the problem is most likely a bad speaker cable or defective speaker. Testing with a set of headphones can help to narrow down the problem, as the headphone signal is derived post-power amp using a frequency compensated, cabinet emulation network.

LIMIT LED: This amber LED indicates that the power amp is nearing maximum power and is entering the soft clip/limit output tube emulation mode. Soft clip/limit output tube emulation mode mimics many of the desirable characteristics of tube amp output stage
overdrive (like soft clip character, damping, symmetry, recovery) while eliminating the common solid state clipping artifacts. There is approximately 6dB of range on this circuit, driving beyond this, of course, will cause gradual output stage clipping. It’s acceptable for this amplifier to operate in output stage overdrive mode (if that’s the tone you are after) with the LED flashing roughly 25% of the time on."

 

[JACKSON JS1XM]

Per Samson/Hartke, yet another direct quote & link & the HD/HL Series cabinets have been this way form their introduction in 2021. Again, not opinion, not incorrect, factual press release documentation from Samson/Hartke website. I doubt they've been hacked with incorrect information.

"Hartke is excited to introduce the new lightweight HL Series Bass Cabinets to their innovative line of HyDrive professional bass cabinets. All speaker configurations will be available Q2, 2021 at major music instrument retailers. The announcement was made for the NAMM 2021 Believe In Music Week virtual summit.
Lightweight Design

HL Series combine high-performance speakers with rugged construction using lightweight 16mm kiln-dried plywood which dramatically reduces the overall weight of the cabinets. A black textured paint finish, powder coated steel grille and chrome plated corners round out the robust build.

The HyDrive HL Series is available in four speaker configurations:

• HL112: 1 x 12" HyDrive speaker + 1" HF / Lightweight Cabinet / 24.8 lb / 300 watts / 8 ohms
• HL210: 2 x 10" HyDrive speakers + 1" HF/ Lightweight Cabinet / 29.5 lb / 500 watts / 8 ohms
• HL115: 1 x 15" HyDrive speaker + 1" HF / Lightweight Cabinet / 39.8 lb / 500 watts / 8 ohms
• HL410: 4 x 10" HyDrive speakers + 1" HF/ Lightweight Cabinet / 47.6 lb / 1000 watts / 8 ohms


Classic Hartke Sound, Smoother Frequency Response
HL Series speakers feature Hartke’s patented HyDrive speaker with neodymium magnets which further reduce the weight. The outside curved, Kevlar®-loaded paper cone delivers a smooth, even response with a deep tone, while the inner straight, anodized aluminum cone produces highly accurate, distortion-free output. The speakers include a 1” horn loaded tweeter, with a 3-position level switch, that adds the high frequencies. The result is a clean, full tone with the clear fundamental of each note and natural overtones.

Hartke Introduces New Lightweight HyDrive HL Series Bass Cabinets

The HD112 uses the Hydrive speakers, Aluminum & kevlar loaded paper cones, same as the HL cabinets & HD combos.

"HyDrive Evolved The HyDrive HD speaker design features a 2-piece composite cone that merges a straight anodized aluminum inner cone with a curved, Kevlar®-loaded paper outer cone that delivers clean, clear output with an extremely smooth response."

Samson Technologies

 

[dbase]

I ran the Mesa WD800 with two Hartke Hydrive 12's and the limit light would flicker once in awhile. I push to the limit because I'm in a loud band and like to be heard. Since I've switched to just one Mesa Subway 15, the light doesnt come on anymore and I'm still very loud. I'm assuming that the Mesa is more efficient then the Hartke's and also much more expensive as I could buy two Hartke cabs for the price of one Mesa cab and it was worth it. Behold my amp settings.

 

[agedhorse]

To clarify, it’s acceptable to the amp for the limit LED to be in 25% of the time. This is fine provided that the speaker has sufficient power handling. IME, and this is based on several (TalkBass) users that I have helped after they damaged their HD speakers, is that the amp is powerful enough to damage the speaker even when the speaker is operated in 8 ohm mode. One player had mistakenly placed the speaker in 4 ohm mode because it was louder, not understanding the power ratings and his speaker did not last very long. These were were preventable failures.

Part of the cause is the lower sensitivity of the HD cabinets, which make it much easier to misjudge how hard they are actually being overdriven. Amps larger than the speaker’s rated power makes this more likely, so while it’s fine for the amp when the limit LED is on 25% of the time but not for this particular speaker. I designed the limiting algorithm, I wrote the owner’s manual (with input and assistance from two TB members), and I stand by this as good, accurate information.

As far as comparing a Hartke HD driver to an Eminence driver to a Celestion driver, they are nothing alike. Sure that all might be round and a nominal 12” diameter, but the performance parameters are generally very different, and in the case of the HD driver, the dual impedance voice coil means that many of the parameters change completely in 8 ohm versus 4 ohm mode. There are very few drivers in the MI world that do this (I am not aware of any current production drivers except Hartke) and only a small number in the pro audio field (JBL’s differential drive being one, but used differently and for different reasons).

 

[agedhorse]

I ran the Mesa WD800 with two Hartke Hydrive 12's and the limit light would flicker once in awhile. I push to the limit because I'm in a loud band and like to be heard. Since I've switched to just one Mesa Subway 15, the light doesnt come on anymore and I'm still very loud. I'm assuming that the Mesa is more efficient then the Hartke's and also much more expensive as I could buy two Hartke cabs for the price of one Mesa cab and it was worth it. Behold my amp settings.
View attachment 4771358

Yes, this is exactly the case. High sensitivity, high power handling and greater low frequency extension in a lightweight, compact enclosure is expensive. There is no way around it unfortunately.

The problem arises when a player doesn’t realize that their speaker is lower sensitivity and tries to get performance out of the speaker with an amp larger than the speaker can safely handle. Invariably, the end result is a damaged speaker, and what I am trying to help the OP avoid.

 

[Old Garage-Bander]

Slick company sales brochures and used car salesmen.
They both have the same goal. To do whatever it takes to separate you from your money.
Why do people inherently trust one, but not the other?

 

[JACKSON JS1XM]

If the Mesa Subway 1x15 400W 8 Ohm speaker can handle the WD800, I would expect that the Hartke HD115 rated at 500W RMS would perform similarly ? Coincidentally, both are Neodymium magnet drivers too. Mesa indicates Average Sensitivity & SPL in their specs, as does Ampeg, can't imagine why Hartke would fail to provide those numbers for their cabs & combos.

Mesa/Boogie | 1x15 Subway Bass
Mesa Subway 1x15 Ultra-Lite Bass Cabinet | MESA/Boogie®
Samson Technologies

This Ampeg Pro-Neo 1x15 Neodymium is a monster though. Did they fudge the numbers or testing method just a little to get the higher rated specs win ?

Ampeg: Pro Neo Series - PN-115HLF

 

[agedhorse]

If the Mesa Subway 1x15 400W 8 Ohm speaker can handle the WD800, I would expect that the Hartke HD115 rated at 500W RMS would perform similarly ? Coincidentally, both are Neodymium magnet drivers too. Mesa indicates Average Sensitivity & SPL in their specs, as does Ampeg, can't imagine why Hartke would fail to provide those numbers for their cabs & combos.

Mesa/Boogie | 1x15 Subway Bass
Mesa Subway 1x15 Ultra-Lite Bass Cabinet | MESA/Boogie®
Samson Technologies

This Ampeg Pro-Neo 1x15 Neodymium is a monster though. Did they fudge the numbers or testing method just a little to get the higher rated specs win ?

Ampeg: Pro Neo Series - PN-115HLF

The OP's challenge is with the HD-112 not the HD-115. The HD-112 features the impedance switch, complicating the issue.

Different manufacturers rate their products differently. Sure, we could have rated the Subway cabinets higher, but that's not what we felt comfortable doing because we are in a more pro touring application market, with a 5 year warranty. It might appear to be a competitive disadvantage with lower published power handling numbers, but these include mechanical power handling and the speakers are intended to provide a very long, trouble-free life. This is the fundamental basis for all of our products.

 

[JACKSON JS1XM]

The OP's challenge is with the HD-112 not the HD-115. The HD-112 features the impedance switch, complicating the issue.

Different manufacturers rate their products differently. Sure, we could have rated the Subway cabinets higher, but that's not what we felt comfortable doing because we are in a more pro touring application market, with a 5 year warranty. It might appear to be a competitive disadvantage with lower published power handling numbers, but these include mechanical power handling and the speakers are intended to provide a very long, trouble-free life. This is the fundamental basis for all of our products.

That's always a win, not having to replace what you already paid for out of warranty, Reliability > a relatively negligible spec win. The HD112 could be sold and fund a HD115, if OP is not in love with 2x HD112's.

I wonder how that 4/8 Ohm switch works ? Do you think they're putting a dummy load on a 4 Ohm speaker to fool it into believing it's a 8 Ohm speaker with one of these in some type of switchable bypass like a passive attenuator ?

 

[JACKSON JS1XM]

OP could use an attenuator to tame the TT-800 output to more closely match the speaker(s) capability ? Is there even a product that would attenuate 800W of bass amp head ? Most of what I see are for 150-ish W amps. Probably just easier to go get more speaker.

 

[agedhorse]

That's always a win, not having to replace what you already paid for out of warranty, Reliability > a relatively negligible spec win. The HD112 could be sold and fund a HD115, if OP is not in love with 2x HD112's.

I wonder how that 4/8 Ohm switch works ? Do you think they're putting a dummy load on a 4 Ohm speaker to fool it into believing it's a 8 Ohm speaker with one of these in some type of switchable bypass like a passive attenuator ?

No, it's done via 2 windings on the voice coil. More efficient than using a resistor (without going into the other issues), but less efficient than a purpose designed 4 ohm or 8 ohm driver (without going into the other issues).

Reliability is important to the level of user that represents our primary player, they don't want to have problems in the first place, but in the event that there is a problem, it's covered at our cost.

The HD-115 might be a good option, it does not have the dual impedance voice coil which may improve sensitivity. I do not know the average sensitivity as it's not disclosed in their documentation.

Also, everything I have seen published for the HD series, as well as a driver that I have seen is a stamped steel basket with a conventional ferrite-ceramic (C5 or C8 Strontium-Ferrite) magnet and not Neo. Even the picture in their brochures is ferrite-ceramic.

 

[agedhorse]

OP could use an attenuator to tame the TT-800 output to more closely match the speaker(s) capability ? Is there even a product that would attenuate 800W of bass amp head ? Most of what I see are for 150-ish W amps. Probably just easier to go get more speaker.

No, there are no external power attenuators available that can safely be used with an amp of this size.

There is a function built into the amp that will limit the power into 8 and 4 ohms (by ~25%), by operating the amp in 2 ohm mode, but that's not going to solve the OP's problem because there is not enough volume into a single cabinet as it sits with the full 400 watts. It would likely be more of a false sense of security. Also, on this amp (not the other Subway models), the impedance switch also controls a power amp damping circuit, so the damping factor would change and not sound/feel as intended.

The general issue is not enough of the right type of speaker for the job. Throwing this much power at the speaker isn't going to help and will likely damage the speaker.

 

[Joe6Bass]

@agedhorse and @JACKSON JS1XM:

You've both been super helpful.

At this juncture, I'm considering selling the 2 Hartke HD112s for many of the reasons that have permeated through the discussion. There are a variety of considerations to think through, such as price, weight, and tone. There are probably 3 opinions per TalkBass user on the best approach.

I can't knock the Hartkes. They've served me very well. Carrying two to a gig is not terribly difficult. Their tone is tight, focused, punchy, and they pair nicely with the TT800, as long as I operate at <75% output.

In the end, I blame Larry. I met him at Sam Ash in Manhattan and his passion and enthusiasm for his namesake speakers is more contagious than Covid.

Now what!?

 

[agedhorse]

@agedhorse and @JACKSON JS1XM:

You've both been super helpful.

At this juncture, I'm considering selling the 2 Hartke HD112s for many of the reasons that have permeated through the discussion. There are a variety of considerations to think through, such as price, weight, and tone. There are probably 3 opinions per TalkBass user on the best approach.

I can't knock the Hartkes. They've served me very well. Carrying two to a gig is not terribly difficult. Their tone is tight, focused, punchy, and they pair nicely with the TT800, as long as I operate at <75% output.

In the end, I blame Larry. I met him at Sam Ash in Manhattan and his passion and enthusiasm for his namesake speakers is more contagious than Covid.

Now what!?

There's nothing wrong with enthusiasm. In your case, what you ended up with just didn't match up with your needs in part because you didn't understand what you really needed and in part because the information was not presented clearly and completely which makes it hard to calculate maximum SPL values (which is part of how we would know if you have enough rig for the gig.

In the pro audio world, pros don't guess how much PA will be required for a show. They will calculate (much easier now than in the good 'ol day) based on a combination of low frequency SPL needed and any active pattern control elements to arrive at the number of subs and power required. Then they will do the same with the mid-high frequency elements, factoring in throw length, surface boundary contributions, number of zones, etc. I used to do these calculations all the time, the better your calculations the more likely to have a higher success rate.

 

[JACKSON JS1XM]

No, it's done via 2 windings on the voice coil. More efficient than using a resistor (without going into the other issues), but less efficient than a purpose designed 4 ohm or 8 ohm driver (without going into the other issues).

Reliability is important to the level of user that represents our primary player, they don't want to have problems in the first place, but in the event that there is a problem, it's covered at our cost.

The HD-115 might be a good option, it does not have the dual impedance voice coil which may improve sensitivity. I do not know the average sensitivity as it's not disclosed in their documentation.

Also, everything I have seen published for the HD series, as well as a driver that I have seen is a stamped steel basket with a conventional ferrite-ceramic (C5 or C8 Strontium-Ferrite) magnet and not Neo. Even the picture in their brochures is ferrite-ceramic.

View attachment 4771985

I saw that exploded representation of the speaker, but everything I'm reading about the HyDrive series speakers is that in the HL cabs they are Neo magnets as HyDrive speakers with the same aluminum & Kevlar infused paper cones. Anyway, I found their webpage for the prior "discontinued model" it is a 4 Ohm speaker in those specs (features tab) the non-b designated name of a newer model that has the switch for the 4/8 Ohm function.

Samson Technologies
Samson Technologies

And going back to the 2015 (HD) HyDrive112 model, their manual is a Neodymium magnet.

http://www.samsontech.com/site_media/support/manuals/HYDRIVE-112-CUTSHEET_liY1aRa.pdf

 

[dbase]

I saw that exploded representation of the speaker, but everything I'm reading about the HyDrive series speakers is that in the HL cabs they are Neo magnets as HyDrive speakers with the same aluminum & Kevlar infused paper cones. Anyway, I found their webpage for the prior "discontinued model" it is a 4 Ohm speaker in those specs (features tab) the non-b designated name of a newer model that has the switch for the 4/8 Ohm function.

Samson Technologies
Samson Technologies

And going back to the 2015 (HD) HyDrive112 model, their manual is a Neodymium magnet.

http://www.samsontech.com/site_media/support/manuals/HYDRIVE-112-CUTSHEET_liY1aRa.pdf

View attachment 4772405

The one thing I didnt like about those cabs is it only had one handle. Very awkward to pick up and carry.

 

[JACKSON JS1XM]

The one thing I didnt like about those cabs is it only had one handle. Very awkward to pick up and carry.

I think with a 1x12 though, they come in at a certain weight and bulk for dimensions, the 1 handle might be more of helping to get the grunt of a lift started. At a certain size & weight, the cab better have casters/wheels to move, becoming a team lift at some point in the process of a relocation.

 

[Joe6Bass]

The one thing I didnt like about those cabs is it only had one handle. Very awkward to pick up and carry.

That's why you need two - one for each hand.

 

[dbase]

That's why you need two - one for each hand.