audio-talk

Just wanted to post up my heartfelt thanks to Scott and Chris (aka chris661) without their help and expertise this project would never have got off the ground and I am convinced would not have turned out as well as it has. THANKS GUYS.

gninnam wrote: ↑Sun Nov 20, 2022 12:24 am Sounds like a great result and glad you managed to reign them in - would love to hear (and see) these speakers sometime if Colin would be up for it

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Toppsy wrote: ↑Mon Nov 21, 2022 2:23 pm

gninnam wrote: ↑Sun Nov 20, 2022 12:24 am Sounds like a great result and glad you managed to reign them in - would love to hear (and see) these speakers sometime if Colin would be up for it

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Thanks Colin, replied

Toppsy wrote: ↑Mon Nov 21, 2022 2:22 pm Just wanted to post up my heartfelt thanks to Scott and Chris (aka chris661) without their help and expertise this project would never have got off the ground and I am convinced would not have turned out as well as it has. THANKS GUYS.

Pleasure. They really are very good indeed; enough that I've had some inspiration for a new design at this end. I've also taken the liberty of suggesting to MA (in my capacity as a consultant) that they consider making a version of the CHN with a black cone, as they do look rather good in that shade.

How's it going now you've lived with the speakers for a while Colin?

Ray P wrote: ↑Fri Dec 02, 2022 8:10 pm How's it going now you've lived with the speakers for a while Colin?

Ray, apologies for not replying to you earlier, but as I noted in your SLOB speaker build thread I have been rather preoccupied lately and not really spent much (if any) time on the forum.

Anyway to answer your query in a single word, SPLENDIDLY.

I simply love these speakers. They do all I had hoped for and a fitting last build swansong. Once we have sorted the small bass issue niggle I can just sit back with a glass of wine and immerse myself in the music. Even given their large size, if I close my eyes whilst seated and listening to a record (or CD) the speakers just simply disappear into a presented wall of sound.

The caps and resistors to the prototyped crossover, have now been upgraded to better quality components and the boards installed in the designed space at the bottom of the speakers. I have also placed some of these https://www.amazon.co.uk/VIBIRIT-Vibrat ... GPGME3DXWF to the feet of the speakers to isolate the speakers from the wooden floor. These were recommended to me by Chris (Stratmangler) and I have to say work a treat. Nice find those Chris.

AndrewL came down from Scotland the other weekend to visit his mum and as usual stays over my place. The Saturday NickG joined us with the intent we try to bottom out the 100Hz perceived room suck-out and come up with a more acceptable fix then the DSP notch filter Chris (aka chris661) had dialled in to the Hypex amp units. It was hoped Chris could join us to take some fresh in room measurements but he was otherwise engaged and not able to come over. However, Nick had some thoughts that perhaps the large fireplace opening and chimney breast, central in the room dividing wall, may be acting as a large vented port to the room causing the room suck-out? Since Andrew had a couple room acoustic treatment panels, he and Nick use for shows, he brought these down with him. To all our surprise when these were placed over the fireplace opening the effect was quite dramatic to the base response, giving credence to his thought.

If you've been following these thread you'll have read that Chris had dialled in 3 presets for the base DSP response. Going back to the preset 1 which was just the 2nd order Bessel filter at 200Hz with a 3dB lift (corrected from 4dB incorrect original posting by me) the bass was better defined but still not quite right. With the acoustic panels in place however, this was a better bass integration then with preset 3 with the 100Hz 'fix'. So we used this preset to play around with the DSP programming and found that it was set at 265Hz crossover, not the 200Hz as Scott recommended to integrate with the passive midrange filter. Knocking this back to 200Hz both Nick and Andrew thought an improvement so we saved this as a new preset 1 and all sat down for further listening evaluation. We did use the manual volume control on the Hypex unit to increase bass a little and that is now how they are set. It would be good if Chris is able to come over sometime in the new year or after Christmas and we can take some fresh in room measurements and perhaps fine tune the bass response. But for now they are sounding really, really good.

Apologies for the lengthy waffle but I thought it worth explaining what we have been doing to fine tune the bass response to my room. I believe from experience that it is the bass response from speakers that is the hardest to get right and in that respect DSP is an invaluable tool into achieving a on-the-fly truly integrated bass sound.

I forgot to mention that during the above mini gathering I commented that I thought that folk whose goal was to reproduce a live performance in their home was a bit of a folly and unachievable in an ordinary domestic environment. Nick replied that to a large extent he agreed but it depended what type of live performance one was trying to replicate. At the time we were listening to Miles Davis 'Kind of Blue' and Nick commented that when he and Kay ran a pub they would hold live jazz concerts in the pub every Thursday night(i believe as I recall) and that if the volume we were listening at was a little louder he thought it sounded just like the real thing only missing the noise from a 'live' audience in the background. To me, coming from Nick, this is high praise indeed and was the icing on the cake for my and Scott's achievement. Though, achieved with a little help from my friends, as The Beetles would say.

Just to add to that. When we went to the original mk1 filter with -3db at 265Hz, when increasing the bass level to the point it sounded right, it was stamping on the clarity of the mid range. So that's when we noticed it was 265Hz not 200Hz, dialing it back to 200Hz allowed the bass level to be increased without messing with the midrange. Its possible that there is a better point between 200 and 265, but we never looked at that. I think that sort of stuff would be better done with measurement kit on hand. Also I don't know if the absolute phase of the bass system is correct or not, again looking at the response in the crossover point with measurement would help with that.

every Thursday night(i believe as I recall)

Not that it matters, but it was Jazz on Tuesday, Rock on Thursday.

Ah! One reason I need a new winter build project to keep my mind active and help not slipping into dementia.

Excellent Colin, it sounds like you have achieved your objective. It would be good to have a listen if I find myself up your way sometime.

Time to...

They sound great colin and like Ray I would love to hear them, getting them to the next owston would be an achievement

Yes, a fork-lift trolley and a sack barrow needs procuring for the next meet.

Nick wrote: ↑Fri Dec 09, 2022 1:53 pm Just to add to that. When we went to the original mk1 filter with -3db at 265Hz, when increasing the bass level to the point it sounded right, it was stamping on the clarity of the mid range. So that's when we noticed it was 265Hz not 200Hz, dialing it back to 200Hz allowed the bass level to be increased without messing with the midrange. Its possible that there is a better point between 200 and 265, but we never looked at that. I think that sort of stuff would be better done with measurement kit on hand. Also I don't know if the absolute phase of the bass system is correct or not, again looking at the response in the crossover point with measurement would help with that.

Nick,

The 265Hz filter point, with a lower Q-factor, formed a 2nd order Bessel rolloff with a -3dB point of 200Hz. There's a note on correction factors in the Hypex manuals.

Chris

I didn't think you had done it by accident. It was all a bit of guesswork on my part without measuring. The 18db or whatever it was peak for the room suckout (or whatever it was) was clearly audible when I heard it and the hole at 40hz or wherever was making me want to turn the gain up too far with the second profile without the peak. I suspect the room has changed from when you did your thing. I do also wonder if the phase of the lf would be better inverted, by the effect it has on the midrange.