Thats incorrect, in particular if you are referring to my build, its working out beautifully 😊 Im crossing the horn at 200hz without any issues, and it plays louder than I care to expose my ears to, without issue, and thats with just one channel... The dual 18"s cover 200hz and below at high spl and no issues of IMD. I am very happy. Still a few quirks to work out but everything is looking up ☺️
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Sorry, I didn't follow the complete thread, which driver do you use from 200hz up?
Thx
The thing is, measurements can be confusing. Measurements done indoors are not the best interpretation. Headroom is more of a challenge than 90db/1meter so thats where most of my research was focused. Measuring THD for a horn is not as cut and dry as you think. It becomes a two part ordeal. There is a matter of thd levels at the listening position vs true thd levels from the source. I am concerned about THD at the source, first, and then THD at the listening position second. Mainly because I am more worried about damaging the driver, after that, we can talk sound quality.
So first I checked the raw response outside at 1meter ~2.83v IIRC. This gives the nature of the horn
Eventually I had a rough draft of a crossover. Here it is playing at 116db/1m, outside, which is ~4db higher than necessary. The main take away is that THD remains somewhat level, that is, it does not increase in level as the crossover filters out the LF. This is important, to me, because in combination with the low woofer, the fundamental note will be equal level with the rest of the response and THD will remain where it is or lower due to the low THD of the woofers in that area.
So what really matters is if the Compression driver is over extending or not, reflected by THD at driver. With the same Voicing as above.... 3.54volts@1000hz@2.5inches with no horn, we see that below, THD is doing fine, as far as what could be expected for headroom. Just under 10% is the peak of THD, at 3.54volts, which is much louder than 110db/1meter I'd need to monitor at 95db average at 1 meter.
The important thing is that I am trying to discern headroom, and true peak is actually much higher than these measurements elude to. The True Peak of a Sine is about 5db higher over average as shown in the below measurement taken at the same input and distance as above. With that information, you go back and look at the measurement taken at 116db and its like, wow, that measurement is likely 3db in regards of true peak, looking at the trends between SPL meter, and measurement results.
In the end, there is a lot of headroom. The measurements at 2.5" proves that LF isn't over extending the driver, and that is what is most concerning to me. When you factor in how high the actual true peak levels are, in the THD measurements, I think it becomes obvious, there is enough headroom. The idea that I can achieve the above levels without over extending the driver while using just one channel really should be convincing to a doubter. Now what becomes the topic is THD at the listening position. When I finish the horn stand, I will take an outside measurement of both horn and woofers in concert, but I mean, really, I have no worries. THD has already been spoken on, and if in the eyes of an expert, this is the general affliction;
Then at this point, given the above evidence... I am only left to Judge what I hear, and not what focus on what the numbers say.... I am only concerned with over extending the driver, and the above is proof that I am not... From the time spent auditioning the 2way in past. I can tell you that there is no Flaw that I can hear and this Headroom issue, for me, has been put to rest.
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What in particular are you looking at? the 116db measurement, would have a true peak of 119db btw. 115db/1m was my goal post and if true peak is 3db over measurement average, in stereo, a measurement at 109db per channel would be the adequate measurement. True peak would be 112db per channel and in stereo it would hit 115db true peak... the data below at 3.53v would slightly more than enough to hit those numbers... with THD this low, transients are still still fine, I would think... and the transient accuracy is really the thing to care about.
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No response, How can he be so opinionated about it but have no comments to your inquiry. At this point the change from immediacy to delay is telling.Hello
At 116db ??? And how audible is 5% THD? At 85db yeah OK because it is going to get worse but not at those SPL levels. That's at short duration peak levels not at the average.
Rob
Who listens at 116 dB? maybe peaks... but on short peaks I doubt that distortion figures are so important.Hello
At 116db ??? And how audible is 5% THD? At 85db yeah OK because it is going to get worse but not at those SPL levels. That's at short duration peak levels not at the average.
Rob
So why not show 85 dB data.... or 95...?
Sorry for the "late" feedback - different time zones...
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Gentlemen. Keep it clean, keep it civil.
Reciprocity? Are you serious? You realize that I was a customer... this wasn't a mutual transaction... I mean unless you are suggesting I paid with fake money or didn't pay the full amount I agreed to. Whats funny is shortly after payment, I was meet with story about how I talked them into a price that they couldn't fulfill my order.. In real life I said, if you can't do it at such n such price, I can't afford you.... so we made an agreement, and I paid....they had so much of my money that out of fear of being robbed I went against our original agreement, of having already paid for shipping. Then the estimated 1-2 months turned into something close to a year.... I bought a larger horn than any other customer, from them. Meaning I provided them with more business than any other customer purchasing a horn, has ever done.... till this date.... During my wait I was not provided any details of the horn... how it was designed, what the exact dimensions would be, etc etc.... and they had me by round things because I agreed to pay them not using the business transaction method of paypal... which removed all protections a buyer would normally have on that platform... its my fault, but also something I did at there suggestion to help reduce extra fees. "Reciprocity" - do you think that I was rude to person who had thousands of my dollars, on the other side of the world... with no real vindication to deliver? I was extremely nice, trust me, I work hard for my money. There was always a very dismissive, don't worry everything is fine, attitude towards any inquiries of details, during my wait... I'm talking about details about the horns dimensions and projected performance.... Obviously I should have been more educated before purchasing said product. The real smack in the face was this Butterfly patch on the face plane of a wood horn that cost several thousand dollars.... Do you know what this will look like with stain? I'm going to have to add a step into the finishing process to ensure that this can't be seen. I bet the money I gave them is doing everything it was supposed to do... Reciprocity... pfft.
Celestion cold called (messaged) me and wants to put my design on their website... what a great opportunity it would have been to draw attention to their business.... instead it will be a great opportunity to repeat how I ended up with the final horn used in the design, instead of the pictured
I would of loved to use a horn designed by you but non of the models you provided had the cutoff I desired along with the desired shape
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