Post by speedysteve on Oct 19, 2014 14:53:32 GMT
Right bass stuff. Summer 2013 I'd been researching drivers that are good for horn bass.
Unfortunately many of today's drivers are not great in that they have too high a Q factor - mech and electrical resistance.
The Eminence Kappa 15A is a great mid bass driver - it was designed after all for 4 string bass sort of freq range and reproduces that and other bass instruments really well. I am using these drivers from around 350Hz down to 90Hz - so not asking them to play high notes at all as you would in a two or 3 way speaker. This keeps it simple for the cone and IMHO can create a more tuneful / timbreful bass than when you stretch things.
A pal of mine (who incidentally took over my conical system from the Bass mid horns to the upper mid horns), had a pair of Vitavox 15" AK-157 drivers and they sounded pretty darn good in the conicals.
He (being a bit of hifi cleppo), also had a pair of JBL2225 15" drivers. They are the ones with the ribbed cones and they look the business - not that you see much of the cones down a horn with a 20cm throat...
He kindly lent his very nice nick 2225's.
However, I'd found an even more lovely slightly older 15" driver with Alinco magnets and super low Q... The JBL2220!
The relative Q's of the drivers
Kappa 15A - 0.32
JBL2225 - 0.28
JBL2220 - 0.17 (See what I mean!)
Here are the 2220's model in Hornresp to prove them:-
Nice flat line anyway, just where I want it! Play nicely down to 90Hz too.
Anyway I plumbed in the borrowed JBL2225's and they sounded really nice - a bit more tuneful in the exponential.
I had them in for a good 3 weeks, so really gave them a go...
Before I'd borrowed the 2225's I had bought a pair of 2220's on ebay. The 2220's are like hens teeth this side of the pond, but pretty much 2 a penny in the States / North America. There was a nice working pair in Canada for $100 each. Would they ship to the UK - they said yes and pretty cheaply I though for 2 x 15" drivers - $100 CANADIAN. OK I went ahead. Then they came back to me and said that they had got the shipping wrong and it would be much more!
We left it that they would refund and I would carry on the search. Then after a delay, the lady in charge of their 2nd hand sales (it was a pro audio / driver business, you see) came back to me and said she had talked to her local postmaster and he would do it for $100 CAN!
Only downside was it would take 2 months by slowboat! No worries - I had drivers and the 2225's borrowed for some of that.
They duly arrived and looked / worked fine - 70's drivers but nice nick.
One plumbed in (yet to put the foam in)
Here's how she (they) measured
This was with no X/O - Note the nice flat extension to 500Hz - this meant I could experiment with crossing from anywhere as low as 300Hz or so (lowest my JBL2482's will go on mid) upto 500Hz - interesting!
I did play around a bit and chose X/O points that measured best. I absolutely love the bass coming out of these.
Put something on like AC/DC - The Jack, Or The Beatles - Come Together, or Cream - Toad (the long drum solo from the 2006 Albert Hall gig), or White Stripes - 7 Nation army, or for classical Viole de gambe (Bach) - Suite V Prelude, the Viole de gambe solo (playing now), etc, etc, and just lap up the timbre and smooth fast bass, that is horn bass - Awesome
Pete - I_should_coco had always said to me back in the days when I had not heard anything much of horn systems, "you ain't heard bass, until you've heard horn bass" - he was right - I had to build a system of ever larger horns = deeper notes & more tuneful drivers, to find out though!
So that's it for driver and horn line up changes for the moment (well over a year in fact!)
I have toyed the idea of trying a 4 way, just to prove the Vitavox S2's are indispensible - when I've caught up with this blog I will do it...
It will be
Tapped horn subs (Eminence Kappa Pro 15" LFII drivers) 20 - 90Hz
Mid bass horns (JBL2220 15" drivers) 90 - 350Hz
Mid horns (JBL 2482 2" throat compression drivers) 350 - 3000 or upto 5000Hz - depending on what sounds best
Tweeters (Raal Lazy Ribbons) 3000 or upto 5000Hz - depending on what sounds best
I don't for a moment think that the above will actually cut it - but I can give it a try in a few minutes with DSP X/O's - ok a bit longer to fully sort it, but i can see the potential... All I have to do is turn off the amp that does to the S2 and re-order the X/O using Najda as a full 4 way X/O, then play with the crossover points until best is achieved...
Other things in the pipeline are those bigger amps for the bass... One day.
Next up streaming and music serving - whole catalogue at your finger tips
Unfortunately many of today's drivers are not great in that they have too high a Q factor - mech and electrical resistance.
The Eminence Kappa 15A is a great mid bass driver - it was designed after all for 4 string bass sort of freq range and reproduces that and other bass instruments really well. I am using these drivers from around 350Hz down to 90Hz - so not asking them to play high notes at all as you would in a two or 3 way speaker. This keeps it simple for the cone and IMHO can create a more tuneful / timbreful bass than when you stretch things.
A pal of mine (who incidentally took over my conical system from the Bass mid horns to the upper mid horns), had a pair of Vitavox 15" AK-157 drivers and they sounded pretty darn good in the conicals.
He (being a bit of hifi cleppo), also had a pair of JBL2225 15" drivers. They are the ones with the ribbed cones and they look the business - not that you see much of the cones down a horn with a 20cm throat...
He kindly lent his very nice nick 2225's.
However, I'd found an even more lovely slightly older 15" driver with Alinco magnets and super low Q... The JBL2220!
The relative Q's of the drivers
Kappa 15A - 0.32
JBL2225 - 0.28
JBL2220 - 0.17 (See what I mean!)
Here are the 2220's model in Hornresp to prove them:-
Nice flat line anyway, just where I want it! Play nicely down to 90Hz too.
Anyway I plumbed in the borrowed JBL2225's and they sounded really nice - a bit more tuneful in the exponential.
I had them in for a good 3 weeks, so really gave them a go...
Before I'd borrowed the 2225's I had bought a pair of 2220's on ebay. The 2220's are like hens teeth this side of the pond, but pretty much 2 a penny in the States / North America. There was a nice working pair in Canada for $100 each. Would they ship to the UK - they said yes and pretty cheaply I though for 2 x 15" drivers - $100 CANADIAN. OK I went ahead. Then they came back to me and said that they had got the shipping wrong and it would be much more!
We left it that they would refund and I would carry on the search. Then after a delay, the lady in charge of their 2nd hand sales (it was a pro audio / driver business, you see) came back to me and said she had talked to her local postmaster and he would do it for $100 CAN!
Only downside was it would take 2 months by slowboat! No worries - I had drivers and the 2225's borrowed for some of that.
They duly arrived and looked / worked fine - 70's drivers but nice nick.
One plumbed in (yet to put the foam in)
Here's how she (they) measured
This was with no X/O - Note the nice flat extension to 500Hz - this meant I could experiment with crossing from anywhere as low as 300Hz or so (lowest my JBL2482's will go on mid) upto 500Hz - interesting!
I did play around a bit and chose X/O points that measured best. I absolutely love the bass coming out of these.
Put something on like AC/DC - The Jack, Or The Beatles - Come Together, or Cream - Toad (the long drum solo from the 2006 Albert Hall gig), or White Stripes - 7 Nation army, or for classical Viole de gambe (Bach) - Suite V Prelude, the Viole de gambe solo (playing now), etc, etc, and just lap up the timbre and smooth fast bass, that is horn bass - Awesome
Pete - I_should_coco had always said to me back in the days when I had not heard anything much of horn systems, "you ain't heard bass, until you've heard horn bass" - he was right - I had to build a system of ever larger horns = deeper notes & more tuneful drivers, to find out though!
So that's it for driver and horn line up changes for the moment (well over a year in fact!)
I have toyed the idea of trying a 4 way, just to prove the Vitavox S2's are indispensible - when I've caught up with this blog I will do it...
It will be
Tapped horn subs (Eminence Kappa Pro 15" LFII drivers) 20 - 90Hz
Mid bass horns (JBL2220 15" drivers) 90 - 350Hz
Mid horns (JBL 2482 2" throat compression drivers) 350 - 3000 or upto 5000Hz - depending on what sounds best
Tweeters (Raal Lazy Ribbons) 3000 or upto 5000Hz - depending on what sounds best
I don't for a moment think that the above will actually cut it - but I can give it a try in a few minutes with DSP X/O's - ok a bit longer to fully sort it, but i can see the potential... All I have to do is turn off the amp that does to the S2 and re-order the X/O using Najda as a full 4 way X/O, then play with the crossover points until best is achieved...
Other things in the pipeline are those bigger amps for the bass... One day.
Next up streaming and music serving - whole catalogue at your finger tips