audio-talk

steve s wrote: ↑Mon Jul 17, 2017 9:04 am You must have exceptional auditory skills Mark

I never thought I was exceptional - and wasn't when I started - like a lot of people, all I could say was 'that sounds better' or 'there's something I don't like about that' !
Doing all the speaker builds has given me a better ability to concentrate on the different frequency bands when listening to a speaker or a system - or to check things like low-level detail or timing while ignoring other things eg. something bad or distracting in the treble for instance.
In terms of comparisons I couldn't make a fine judgement about very similar systems a week or a month apart, but if I have an overview of what's driving some speakers and it's similar enough to my own system, then I can listen to some familiar tracks & I can retain the pros/cons of that speaker for quite a while. With different speakers, the differences are often not subtle.
There's no way my own project would have started unless I'd retained the audio memory of the TAD 2001's on the wooden bi-radials at ETF , or some of the bass guitar tone on James's with the best combos at Eggborough or Owston.
Bear in mind James and Nick can spot stuff in the bass and timing quicker than I can - although I can get there in the end. Higher-up I think I'm quite good - maybe because I haven't been to a lot of loud gigs over the years.

Funny comment from James today on email -
"everyone has their audio prejudices - I like my audio prejudices best ! "

I finally have these speakers up and running. I went with the Eminence Betas in the end. I'm using a miniDSP active crossover so I can play with the crossover easily. I plan to use passive crossovers in the end, but I must say miniDSP is very easy to get up and running and active crossovers are a bit seductive.
The power amps I was planning to use didn't want to play, they've been in storage a while and I think they need a bit of TLC. I'm currently running with Cyrus II on the left and Technics on the right. The Cyrus amp is the first proper HiFi I ever bought, and the Technics amp is the first proper HiFi Mrs N ever bought. Both still sound great.
And I have to say the speakers sound surprisingly good considering I haven't played with the crossover settings at all yet.
Currently running at 500Hz with 48 dB/octave LR.
The only tweaking I've done is to roughly time-align the drivers by delaying the Alpair a bit, by ear, which was audibly better.

Very good effort - not to say, perhaps, even ... shoddy

You've ran out of fruit BTW.


Otherwise, shoddy +1!

Like.

Nice work Max. Try crossing at 200hz, that sounded best to me.

BTW, if you do decide to stick with active, the miniDSP 4x10hd is considerably better than the basic unit (assuming that's what you are using). Gives you remote volume control too.

They are really rather shoddy max

IslandPink wrote: ↑Thu Aug 17, 2017 8:46 pm Very good effort - not to say, perhaps, even ... shoddy

Cheers Mark. Very happy I went with the Betas now.
Interestingly, Basta allows you to include the output impedance of the amp, and the effect it has on the Qts of the speaker drive unit. When I enter a typical SET output impedance on a parallel pair of Betas, it raises Qts to around 0.7...

Max, what are the benefits of having the Alpair central rather than on top of the two Betas ?

Dave the bass wrote: ↑Thu Aug 17, 2017 10:09 pm You've ran out of fruit BTW.

Otherwise, shoddy +1!

Like.

Mrs N says she still finds me plenty fruity thank you very much

Actually the fruit basket has been appropriated by Cocoa the cat as a bed, which tended to make the fruit a bit hairy, so nowadays its just a cat bed......
There's a joke in their somewhere...
Pussy hair on my plums etc etc

Ali Tait wrote: ↑Thu Aug 17, 2017 10:14 pm Nice work Max. Try crossing at 200hz, that sounded best to me.

Thanks Ali. I'm working my way down, currently at 300Hz and sounding better than 500...

Ali Tait wrote: ↑Thu Aug 17, 2017 10:18 pm BTW, if you do decide to stick with active, the miniDSP 4x10hd is considerably better than the basic unit (assuming that's what you are using). Gives you remote volume control too.

Yep, I just went for the basic version, but am now considering sticking with active so may well upgrade. Was looking at the 2x4HD for the USB audio in...will take a look at the 4x10HD, thanks

Ant wrote: ↑Thu Aug 17, 2017 10:19 pm They are really rather shoddy max

Cheers Ant

pre65 wrote: ↑Sun Aug 20, 2017 10:11 am Max, what are the benefits of having the Alpair central rather than on top of the two Betas ?

I have a theory, but its just a theory because I haven't experimented (although it would be very easy to do so may well try it)
My theory is that the two Betas are acting like a D'Appolito or MTM. From an 'image' point of view, the apparent location of the sound coming from the Betas is coincident with the Alpair.

I am really liking these speakers.
As well as sounding great, they make it easy to hear the differences between different power amps.
On Friday I dug out some old Meridian power amps and gave them a listen.
Yesterday I got the 300B PSEs hooked up. I have to say I think this is the best sound I have had in this room.





The inner pair are pretty much stock WAD 300B PSEs, I think the only mod is the bigger cap on the 6au6 screen. These are doing bass duty with a set of JJ 300Bs.
The outer pair are modded. Choke input PSU with SS rectifiers, Mike's E-choke (FETreg), GZ37 just for slow start up. 6j5gt gain stage into 6sn7 cathode followers, all with active loads. 300Bs adjustable fixed bias running 65mA. These are driving the Alpairs with WE300Bs.



Crossovers are set to 300Hz. The 40Hz room mode is still there, although I think it is excited less by these than box speakers. I'm currently experimenting with a notch filter in the miniDSP EQ to take it out.
Really really enjoying this sound