I posted at least some of these on DIY audio but don't remember in what thread, but here are some measurements of SPL and distortion. JR had a build on MAC too and I know he posted both SPL and distortion, but he didn't use the full driver model so it doesn't come up under a normal search.
https://diy.midwestaudio.club/discussion/comment/53913/#Comment_53913
https://diy.midwestaudio.club/discussion/comment/54364/#Comment_54364
https://diy.midwestaudio.club/discussion/comment/53913/#Comment_53913
https://diy.midwestaudio.club/discussion/comment/54364/#Comment_54364
All of this brainstorming is why I created this thread. The exchange of philosophy and ideas is what prompts others to come up with out of the box concepts not usually considered with your everyday cookie cutter 6 + 1" 2 way speaker.
Everyone's priorities are different for various reasons and there are no wrong reasons, just wrong solutions or bandaids. Those who prefer the resolution, dynamic range and accuracy of a well designed multi way speaker won't be in the market for a veiled, overly smooth and vague sounding fullrange or 2 way speaker. In a studio setting, we'd usually verify the way something sounds both on range restricted speakers (Auratones), headphones, portable players, etc.
The main reason I prefer the sound of large dome midranges is the lack of a deep cone, tiny VC, resonant spider, floppy surround. They all add their own disfunction to the pot. As already said, there are some excellent examples of cone mids close to the resolution, dynamics and THD of well engineered dome mids.
The place where most cone mids don't equal a good dome is the upper midrange resolution, linearity and a not so bumpy top end rolloff. What makes mid domes more challenging is finding a reasonably low enough crossover point. Most cone mids have an easier time here, maintaining a lower average THD, but the FR is usually not as smooth or extended, especially off axis.
In the modem world, the people who are most obsessed with perfect power response and off axis linearity are the studio and live sound guys. Engineers will want an analytical tool to hear temporal, phasing and EQ errors, demanding a linear FR, phase, low THD and immediacy. Most consumer hifi doesn't need or even want this.
Its rather surprising and disturbing how much deviation and disfunction some high priced boutique speakers allow while still demanding an outrageously high price for what we sound guys would deem unacceptable for professional use. The amount of "character" added to the audio coming out of quite a few of these speakers is usually too colored and contorted for anything but consumer grade use ie. passive listening for background music, entertaining guests, etc. Some people still attempt to utilize this type of speaker as a monitoring tool for mixing, but unless you're extremely experienced and can adapt to the added noise and mess, there's no way a competitive mix can be achieved.
From the my perspective, when designing a suitable speaker, I want the best of both worlds whenever possible. I really enjoy the sound of a large monitor style multi way speaker, unlimited in dynamics, resolution and low distortion where it counts - the midrange. Having heard just about every type of driver technology out there (dome, cone, ribbon, AMT, ESS) along with enclosure types and designs, i always come back to using larger domes for the midrange or at a bare minimum, the best cone mid with the least compromises I can get my hands on.
There are obviously some very good cone mids out there, however most of them force an earlier mid cutoff point and steeper rolloff due to their physical limitations in design ie. sharp cone breakup, edge resonance, spider resonance, dust cap cavity resonance, etc. There are many things which need to be wrangled in, which are often less problematic with a good dome mid.
Yes, sometimes its the lesser evil to push the LP filter cutoff on a cone mid higher up despite beaming and breakup setting in. This is IMO less problematic than having a crossover point in the ultra critical 1 to 4k area, which is one of THE fundamental reasons I prefer a large dome mid over any other type of mid driver. None of the other driver topologies (with exception of a large planar or AMT) support that wide of a practical bandwidth and aren't held back by a tiny VC, flimsy cone and other limiting design attributes. They won't support a decent dynamic range or the desired SPLs I expect from a 3 way system.
This also leads me to the second big issue (pet peeve) I have with most 2 way speaker designs using larger woofers. Most guys push the tweeter down in crossover as far as HD measurments allow to get the off axis FR they want. This will in most cases produce a speaker with limited SPL capability in the mids, creating that tell tall strained tweeter sound I despise. I understand this is the easy way to achieve better off axis linearity and enabling the use of cheaper, less ideal woofers.
I get alot of friction from the "pros" on here because I'm stating a smaller dome tweeter driver which measures low in HD sounds strained, harsh and rough crossed around 2k while being pushed hard. From my POV, if I can hear the tweeter draw attention to itself, that's a good indication its doing something its not good at and shouldn't be used that way. The specs can say what they want all day long, but when it sounds bad, it is bad. My ear is the final judge on this and it tells me there's an issue.
Most 2 way systems are a huge compromise anyways. The component which is skimped on the most is usually the woofer, being the most expensive part. Tweeters are cheaper and can be designed to cope with alot of abuse, but in most cases durability is favored over the best possible SQ. Most people won't play an average 2 way speaker loudly, so the necessary SPLs aren't a big factor. As long as the tweeter survives, that's the most important aspect from a warranty claims POV. Most powered speakers have limiting built in anyways, so thats a non issue.
Someone who designs a higher end, reference grade 2 way speaker will instead use a better LF driver, integrating it carefully with the crossover (ie Harbeth), getting as much out of those as they can. There will always be some coloration and distortion, but its more important where and what type those are.
And to be very clear, even though THD measurments support the use of a tweeter as far down low as possible, you'll always be able to tell when that small tweeter starts breaking its poor little back trying to play a decent rock guitar track at "fun" levels. 1" domes don't have an easy time supporting a 105 + dB track crossed = < 2k (regardless of slope) without very noticeably complaining about it sonically. I've heard the argument a million times that the tweeter supposedly has the supporting low THD on paper to comfortably do those levels, but my ears tell me differently.
I'd always rather push the cone driver further up than the tweeter down, especially when the crossover wants to land in the 1 to 4k area. Yes, the power response suffers etc, but it will still sound more pleasant to listen to. I'd even go through the hassle of notching the woofer in one or two places if it will allow the tweeter to come in later. This way the vocals mostly come from the larger driver, sounding more cohesive and less strained, like the way most fullrange drivers do.
Thats where ALOT of the guys who listen with a professional vs consumer ear split their fundamental philosophy. The pros will want to hear all the mistakes to make the recording as good as it can be. The consumers want to hear the existing lousy recordings without the bad stuff being a huge distraction.
Everyone's priorities are different for various reasons and there are no wrong reasons, just wrong solutions or bandaids. Those who prefer the resolution, dynamic range and accuracy of a well designed multi way speaker won't be in the market for a veiled, overly smooth and vague sounding fullrange or 2 way speaker. In a studio setting, we'd usually verify the way something sounds both on range restricted speakers (Auratones), headphones, portable players, etc.
The main reason I prefer the sound of large dome midranges is the lack of a deep cone, tiny VC, resonant spider, floppy surround. They all add their own disfunction to the pot. As already said, there are some excellent examples of cone mids close to the resolution, dynamics and THD of well engineered dome mids.
The place where most cone mids don't equal a good dome is the upper midrange resolution, linearity and a not so bumpy top end rolloff. What makes mid domes more challenging is finding a reasonably low enough crossover point. Most cone mids have an easier time here, maintaining a lower average THD, but the FR is usually not as smooth or extended, especially off axis.
In the modem world, the people who are most obsessed with perfect power response and off axis linearity are the studio and live sound guys. Engineers will want an analytical tool to hear temporal, phasing and EQ errors, demanding a linear FR, phase, low THD and immediacy. Most consumer hifi doesn't need or even want this.
Its rather surprising and disturbing how much deviation and disfunction some high priced boutique speakers allow while still demanding an outrageously high price for what we sound guys would deem unacceptable for professional use. The amount of "character" added to the audio coming out of quite a few of these speakers is usually too colored and contorted for anything but consumer grade use ie. passive listening for background music, entertaining guests, etc. Some people still attempt to utilize this type of speaker as a monitoring tool for mixing, but unless you're extremely experienced and can adapt to the added noise and mess, there's no way a competitive mix can be achieved.
From the my perspective, when designing a suitable speaker, I want the best of both worlds whenever possible. I really enjoy the sound of a large monitor style multi way speaker, unlimited in dynamics, resolution and low distortion where it counts - the midrange. Having heard just about every type of driver technology out there (dome, cone, ribbon, AMT, ESS) along with enclosure types and designs, i always come back to using larger domes for the midrange or at a bare minimum, the best cone mid with the least compromises I can get my hands on.
There are obviously some very good cone mids out there, however most of them force an earlier mid cutoff point and steeper rolloff due to their physical limitations in design ie. sharp cone breakup, edge resonance, spider resonance, dust cap cavity resonance, etc. There are many things which need to be wrangled in, which are often less problematic with a good dome mid.
Yes, sometimes its the lesser evil to push the LP filter cutoff on a cone mid higher up despite beaming and breakup setting in. This is IMO less problematic than having a crossover point in the ultra critical 1 to 4k area, which is one of THE fundamental reasons I prefer a large dome mid over any other type of mid driver. None of the other driver topologies (with exception of a large planar or AMT) support that wide of a practical bandwidth and aren't held back by a tiny VC, flimsy cone and other limiting design attributes. They won't support a decent dynamic range or the desired SPLs I expect from a 3 way system.
This also leads me to the second big issue (pet peeve) I have with most 2 way speaker designs using larger woofers. Most guys push the tweeter down in crossover as far as HD measurments allow to get the off axis FR they want. This will in most cases produce a speaker with limited SPL capability in the mids, creating that tell tall strained tweeter sound I despise. I understand this is the easy way to achieve better off axis linearity and enabling the use of cheaper, less ideal woofers.
I get alot of friction from the "pros" on here because I'm stating a smaller dome tweeter driver which measures low in HD sounds strained, harsh and rough crossed around 2k while being pushed hard. From my POV, if I can hear the tweeter draw attention to itself, that's a good indication its doing something its not good at and shouldn't be used that way. The specs can say what they want all day long, but when it sounds bad, it is bad. My ear is the final judge on this and it tells me there's an issue.
Most 2 way systems are a huge compromise anyways. The component which is skimped on the most is usually the woofer, being the most expensive part. Tweeters are cheaper and can be designed to cope with alot of abuse, but in most cases durability is favored over the best possible SQ. Most people won't play an average 2 way speaker loudly, so the necessary SPLs aren't a big factor. As long as the tweeter survives, that's the most important aspect from a warranty claims POV. Most powered speakers have limiting built in anyways, so thats a non issue.
Someone who designs a higher end, reference grade 2 way speaker will instead use a better LF driver, integrating it carefully with the crossover (ie Harbeth), getting as much out of those as they can. There will always be some coloration and distortion, but its more important where and what type those are.
And to be very clear, even though THD measurments support the use of a tweeter as far down low as possible, you'll always be able to tell when that small tweeter starts breaking its poor little back trying to play a decent rock guitar track at "fun" levels. 1" domes don't have an easy time supporting a 105 + dB track crossed = < 2k (regardless of slope) without very noticeably complaining about it sonically. I've heard the argument a million times that the tweeter supposedly has the supporting low THD on paper to comfortably do those levels, but my ears tell me differently.
I'd always rather push the cone driver further up than the tweeter down, especially when the crossover wants to land in the 1 to 4k area. Yes, the power response suffers etc, but it will still sound more pleasant to listen to. I'd even go through the hassle of notching the woofer in one or two places if it will allow the tweeter to come in later. This way the vocals mostly come from the larger driver, sounding more cohesive and less strained, like the way most fullrange drivers do.
@Rokytheman That ITT dome is also a Philips driver made by Peerless. Its a legendary driver used by many companies.
Its been a while. There were 2 production runs of it and neither one stood out. I'll have to check my PC.
I thought that ITT, Phillips and Peerless were all separate companies with no overlap 😕
This 'old' catalog contains many interesting drivers, including dome midranges.
Does anyone have knowledge or experience with the German company > ETON ?
Does anyone have knowledge or experience with the German company > ETON ?
@Mister Audio They did share some drivers. Specifically some mid and HF domes along with cone mids. Valvo was another company sharing technology.
Eton always was a small company. I believe they were recently acquired by someone else. Their Hexacone technology was around for a few decades. I remember the older drivers having VC centering issues. They used tight VC gaps, making alignment critical. Their 12" woofer was a high end performer. It played very low, accurate and loud in a big vented cab. Their soft dome tweeters were also good, on par with the higher end Audax neo tweeters.
Eton always was a small company. I believe they were recently acquired by someone else. Their Hexacone technology was around for a few decades. I remember the older drivers having VC centering issues. They used tight VC gaps, making alignment critical. Their 12" woofer was a high end performer. It played very low, accurate and loud in a big vented cab. Their soft dome tweeters were also good, on par with the higher end Audax neo tweeters.
While the 8PE21 is an excellent cone midbass (more of a mid), it doesn't have the micro details of a decent larger mid dome, not even close. I've used 8PE21s horn loaded, vented, sealed, etc. THD is very low in the upper mids for a relatively larger cone. Very low xmax too. I use them 300 hz to 1k in BLH. This is their strength IMO. Do you have any measurements?
I'm going to try what you suggested but I'm skeptical due to previous experiences with the 8PE21.
Philips owned Valvo since 1927. You will find a lot of drivers with the same name as Philips too.
No measures to share….sorry. I would agree with you that they don’t have the timbre of a silk or metal dome……and this where preferences become a matter of personal taste IMO. To me, the very subtle response of the paper cone sounds warm, natural and vocals are more authentic. Could be the larger surface area as well……purely subjective of course.
Never tried it in a BLH. I’ve front horn loaded em and that was my first introduction to the 8pe21 in a pro use application. My favorite is aperiodic…..the rear of the enclosure as the entire vent surface but highly resistive. I only run it down to 400 is this application though……as you mentioned there’s no travel to speak of. I like to let ‘em beam a little too……a little narrowing of the DI around 2k works well for a lot of recordings……
@mayhem13 What you describe are exactly the preference for a specific type of driver based on fundamental design ie. diaphragm material composition, breakup behavior and HD spectral distribution. I've always been a big fan of paper composition cone drivers and how a good example of these behaves in the mids. I agree, a 6 to 8" paper cone driver sounds very good with vocals and larger acoustic instruments. Lower density paper and most other cellulose fiber cones have a softer, wider band breakup behavior above their max pistonic range, often making them useful (at reduced dispersion angles) for operation past this point. I usually roll off a driver like this just above fmax, so the crossover region is within the breakup range (phase permitting). There aren't too many drivers you can do this with.
I have a different philosophy than most designers. I use more shallow filter slopes with more overlap, which requires wider pistonic operational bandwidth. I want to choose the crossover point instead of the driver dictating it. That way most of the midrange is kept clean from crossover points (at least 700 hz to 3.5k). I also try to use the largest radiating surface area for a given frequency range.
I have a different philosophy than most designers. I use more shallow filter slopes with more overlap, which requires wider pistonic operational bandwidth. I want to choose the crossover point instead of the driver dictating it. That way most of the midrange is kept clean from crossover points (at least 700 hz to 3.5k). I also try to use the largest radiating surface area for a given frequency range.
I didn't do all the measuring but i combined a 8 inch bass / low mid range woofer (Vifa 21WP250) with a Dynaudio D54 dome with a 6 dB filter: 1.2 mH and 15 uF and it gives a integrated sound. I think i get maximum dispersion from both drivers but i can be wrong. My idea was to create a two way with a super tweeter (RHT12S) so the midrange between 1.2 KHz untill 5 KHz comes from one (fast) source. The units have time alignment and mid and high are place back slightly curved to focus the highs. This dome mid was the starting point of my design because i want (almost) transparant sound like a ESL but with a more point source focus like instruments have. I alway's felt that small cone mid's just not give this wide and open sound a good dome mid range can give.
No ITT produced its drivers at Neu Ulm in Germany: it later became LPG. It is not at all affiliated with Philips nor Peerless.
Those who own Martin Colloms H.P. Loudspeakers will find a crossectional drawing of the ITT 50mm Mid-dome. Its construction is unique and very different from the Phlips or Peerless Mid-domes.
Guess which British company copied the design, changed the Alnico magnet to an optimized Ferrite circuit one and upsized to 75mm??
The only company I remember selling ITT specific drivers was Eton, which mainly pertained to dome tweeters and mids. I believe ADS (Braun) used ITT domes as well.
In my teenage years working for an electronics store in Munich, we sold 50mm chambered dome mids made by ITT (said so on the box). Inside the box was a driver actually branded Peerless, specifically part number 821214. Thats the 50mm dome mid I referred to.
While I dont know specifically who made who in every case, the drivers were often labeled differently than the box. Philips sold both cone and dome mids made by Peerless. They had kits which also contained Isophon and various others. There was also a famous, excellent 130mm cone mid (dont remember the part number) which had the small (made in W Germany) production date label printed in blue ink which LPG used on practically all of their drivers. Heco also re-boxed cone and dome drivers from LPG and Philips.
The specific 821214 50mm dome I mentioned was definitely a Peerless driver. I dont know why who put who's drivers in different boxes. I just know what we had in our hands at the time. I also have catalogs with these parts sold in the same way and labeled differently. Most of my experience bases on the Peerless 821214 but they used different numbering systems as well just to make things even more complicated.
MB quart also sold LPG dome mids and tweeters. Their metal domes were very popular in the car audio scene. IMO, LPG makes the best compact titanium dome tweeter available on the market. Its really small for its dome size and fits nicely inside some 2" VC openings, making an excellent coax retrofit tweeter.
In my teenage years working for an electronics store in Munich, we sold 50mm chambered dome mids made by ITT (said so on the box). Inside the box was a driver actually branded Peerless, specifically part number 821214. Thats the 50mm dome mid I referred to.
While I dont know specifically who made who in every case, the drivers were often labeled differently than the box. Philips sold both cone and dome mids made by Peerless. They had kits which also contained Isophon and various others. There was also a famous, excellent 130mm cone mid (dont remember the part number) which had the small (made in W Germany) production date label printed in blue ink which LPG used on practically all of their drivers. Heco also re-boxed cone and dome drivers from LPG and Philips.
The specific 821214 50mm dome I mentioned was definitely a Peerless driver. I dont know why who put who's drivers in different boxes. I just know what we had in our hands at the time. I also have catalogs with these parts sold in the same way and labeled differently. Most of my experience bases on the Peerless 821214 but they used different numbering systems as well just to make things even more complicated.
MB quart also sold LPG dome mids and tweeters. Their metal domes were very popular in the car audio scene. IMO, LPG makes the best compact titanium dome tweeter available on the market. Its really small for its dome size and fits nicely inside some 2" VC openings, making an excellent coax retrofit tweeter.
Last edited:
This popped up on my youtube feed and sounds nice on the video. I see the D7608 + HDS, but anyone recognize the woofer?
https://www.elfton.cz/?p=65
https://www.elfton.cz/?p=65
Looks like a Seas L26RO4Y
https://seas.no/index.php?option=co...4-l26ro4y&catid=97:extreme-woofers&Itemid=600