HiFi Subjectivist ¦ Audio Forum ¦ NVA User Group

I'm here. Feeling a zonked out today and didn't have the ability to write anything cogent. I fell asleep in a chair after lunch. :/

I read on diyaudio the SB65W needs 100 to 200 hours break in. Reports of the sound calming down considerably when broken in. I will wait for that to happen before playing any more with it. I feel I should be breaking it in with a full range 8f frequencies rather than crossed at 7kHz like I am doing now.

I do sense it's performance is improving very slowly.

Other thoughts- when I tried high passed at 1.5kHz I forgot about baffle step from the small 15cm sphere. Might explain the sound I experienced.

Couple of quotes from diyaudio.com

"I consider the SB65 the Schwarzenegger of tweeters. It has the high end reach, and can be crossed between 300-500Hz. "

Crossing this at 300Hz with a first order might be asking a bit much of it. The above wax probably using second order and above. Distortion goes up below 300Hz but what do you expect from a 2" cone. If I end up using them in my B&W P4 then xover may have to be higher than I planed and into the telecom range.

"After listening to these drivers for a little while I'm really impressed with them. One thing about them is they sound very good at low volume, better than anything else I've heard."

I like the low volume comment as that is how they will be used.

"Yeah I'm blown away by the sb65's. The sound is solid and clean.

I'm scrapping another build to do a fast with these using this woofer.

Dayton Audio RS150P-4A 6" Reference Paper Woofer 4 Ohm It has a great midbass and transparent sound.

I think a 500hz 12 db/octave active crossover should be good. They will be close enough that they are within 1/4 wavelength till about 1000 hz. So it will be a true point source.

iirc when you are within 1/4 wavelength the drivers need to cross at the -6 db point to sum flat."

From diyaudio.com again

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Old 13th May 2020, 02:48 AM #2
5th element is offline 5th element United Kingdom
diyAudio Member

"If you don't know how to select good drivers then you certainly don't know how to design a crossover"

That's me fooked then

There is a lot to be said for a nice adjustable active crossover. I have a dcx2496 in the lounge. Had plans to replace it with something simpler one day. Hasn't happened yet.

None of that sort of thing upstairs of course.

Quote

"The 'sound' of bass also has lot to do with what is happening higher up. When an instrument makes a crisp snappy bass sound there are not just bass frequencies produced but also mids and treble because there are a lot of harmonic tones to go a long with the bass fundamental tone. Without the mids and highs all bass instruments just sound like a sloppy wet farts.
Since the OP plans to use another driver to handle the mid and treble, the perceived quality of the bass in the finished speaker will not only depend on how the woofer behaves but also how the mids/tweeter handle the high order harmonic content of the bass instruments"

I have to remember the above. Changing things high up affects everything else. The bass tightened up when I changed from 3 tweeters to one 2" mid tweeter. Doing things purely subjectively with no measurements to help track down issues is really like flailing about in the dark.

I just put my cubes back with upfiring doped 6.5" and the front firing 2" mid tweet in a sphere. Listened and have come to the conclusion that nothing is gonna beat this. It's just right for me in so many ways. My ears are very very easily annoyed it would seem. I can live with it's faults as the things it does well are worth more to me and my ears.

I have become completely used to the sound of no electrical filters or as few as possible. I am yet to hear a xover that suits me. I am not sure I can live with a single full range driver either. The only decent one I have is thd little 2" but expecting that to do any bass in a sealed box is a fantasy. It will always need woofer support and even then I wouldn't high pass is too low with 1st order because it will distort from having to do bass and there will be inter modulation distortion and treble will suffer. There are quite a few reports of harsh sounding single driver solutions. It's all personal opinion of course.

I think I have the best use of it now unless I go line array but that is way beyond my ability. I need to remember the limited extent of my knowledge and ability and just stick to a simple 2 way with up firing doped mid bass and forward firing 2" mid tweeter. All in sphere's of course I get these ideas way above my station that will only end in frustration. It's a pity the bipole up and down firing mid bass was just a bit too much for a back to the wall position with bass heavy music I like. Otherwise it kicks arse and if I had a large room and them well away from the walls i would do the final build bipole no questions asked.

Striving for the unattainable is pointless and a waste of time and resources.

Good to hear u are back on track- but I thought the cubes were eventually going to be spheres?

As a side line I’ve had a complement from a fellow diyer who could tell the semi omni worked in my room compared to traditional PnS. Just to get it better for me I’ve removed the mid bass units and am listening to the tweeters only- enlightening as they sound shocking- so meddling with various unit, resistors and caps …..ahhhhhh