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Post by speedysteve on May 3, 2016 21:40:39 GMT
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Post by MartinT on May 4, 2016 5:24:57 GMT
I also spot a My Morning Jacket LP there. I love that band. So do I! |
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Post by speedysteve on Jun 9, 2016 18:30:09 GMT
I've bitten the mid bass bullet and ordered a Crown xls 1500.
I also have a Cerwin Vega CV 1800 on loan / can buy if I like.
The Crown hasn't arrived yet.
I'll play them off against each other and the Behringer Inuke I currently have on the tapped horn subs.
So far the Cerwin Vega has been a revelation on speed and clarity. It really grips the mid bass cones.
It is a beast weighing some 18kgs.
The Inuke and Crown are lightweights in comparison.
I'd have to strangle the fan noise though, it is horrendous!
Pics to follow:)
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Post by John on Jun 9, 2016 18:34:55 GMT
Great result Steve
I remember how well the horns sounded with Martin Chord doing the mid bass duties so think this is a wise move
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Post by speedysteve on Jun 9, 2016 22:27:34 GMT
Yes, we'll see what's what. The Cerwin Vega has dual fans each reportedly running off a separate 24V power supply. Wiring them in series to one power supply so they get 12V each solves the noise! There's quite a lot under the hood  |
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Post by speedysteve on Jun 10, 2016 21:01:00 GMT
Doing some more listening.
Behringer inuke still on tapped subs 20-100 Hz. Has a damping factor of 150.
The Cerwin Vega is quoted at 280! @ 400Hz. I am using it for 100Hz to 350Hz at the moment.
The Crown is quoted as 200 10Hz to 400Hz.
I love the new found drive and attack on the mid bass. It's really tightened things up! Very clear too with bags of get up and go, stop/start pump when needed. Drums are excellent. Can almost be too clear at times, complex stuff can get a little tiring, perhaps I am not used to all this extra info?
It will be interesting to try the Cerwin on the tapped horns and the Crown on the mid bass (when it arrives).
Just turned the Cerwin down a notch and it is better balanced now. The joys of having 5 vol levels to get right:). Need to get the measuring mic out to check things out. Well do both once the Crown arrives.
I usually tweak the levels a bit to sit my ear anyway.
Making me realise how inadequate the Topping TP-60's were at managing bass cones.
Come on delivery man.
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Post by John on Jun 10, 2016 21:07:47 GMT
Sounds like the mid bass was just a bit to strong Always takes me awhile to get the balance right
It sounds like the Crown will probably have better control of the low bass than the Inuke
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Post by MartinT on Jun 11, 2016 7:49:12 GMT
Great stuff, Steve. Yes, the Toppings were inadequate but then T-Amps are not great at control generally.
I didn't know Cerwin Vega made power amps. I remember their thunderous speakers of old and the 'Bass Excavator'. I've never heard bass like it this side of a Roger Waters concert.
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Post by speedysteve on Jun 11, 2016 11:50:41 GMT
Sounds like the mid bass was just a bit to strong Always takes me awhile to get the balance right It sounds like the Crown will probably have better control of the low bass than the Inuke It may, if damping factors are the biggest factor then depending on how they measure the Cerwin Vega could be mega. It certainly is a beast! Might handle the Eminence Kappa Pro LFII 650w bass cones ok:) I'll wait until Crown gets here, then try both in both slots. The in-series mod on the fans worked perfectly. I made up a cable with the right connectors so it's totally non invasive:) just plugs in. Still drawing good air but can't hear them from the listening chair. In fact the slow running mod on the Inuke is a bit louder. Wonder what the Crown will be like? I don't trust it when they say variable speed cooling fans, that seems to be very loud when tickling the amp and deafening I expect when pushing it:), but if you have 2 amps running bridged mode and 1800wpc into PA speakers, you are not going to worry about some fans are you:) Also the blue power lights on the CV are killers. Drill holes into you eyes, even in broad daylight. Two blutak blobs to the rescue. Listening now and with some subtle X/O changes its a very nice sound indeed coming out of the CV. Can't fault it. Yes, Martin. Rather sloppy in comparison. The bottom end keeps up with the upper horns now. |
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Post by speedysteve on Jun 11, 2016 13:58:51 GMT
Just solved the over bright LED problem. I have a set of leather hole punches.
These leave perfect round discs as a bi-product of the hole they make.
Took a 4mm dia one and punched some of the Scotch magic tape to get sticky discs. Took 4 layers to get a nice soft but visible blue light.
Did my Icon Audio SET amps too;)
Guess I'll be doing the Crown as well <rollseyes>
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Post by Firebottle on Jun 13, 2016 12:41:37 GMT
Yes it always strikes me that the manufacturers don't take into account the efficiency of modern blue LEDs.
So they stick the normal current through them and wonder why they are so bright.
I usually end up with 0.1mA or less and they are still bright....
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Post by speedysteve on Jun 13, 2016 13:31:30 GMT
Too true!
The Crown has arrived and the Fan is apparently silent until the unit is driven hard.
That's something that I will never do as my mid bass horns are 110dB/W efficient and in not being used at PA volumes... Hehe
I put the Crown on mid bass and has a listen and level check.
Sounds good. Same as the Cerwin Vega as far as I can hear.
Then I put the big Cerwin on the tapped horns. They are 'only' 105dB/W.
After a bit more levelling in Najda, all sounds good.
Can't tell yet if the Cerwin is doing better on tapped horn duty than the trusty Inuke yet... More louder epic bass listening needed.
One question for John and other knowledgeables-
I've got -48dB to +48dB line level adjustment range per channel.
Overall line output is set at 2.0V rms. That can go as high as 9V I believe.
I currently have the PA amps volume controls set to around 3/4 of max or more.
Is it better to have the amp vols on max and line level throttled back or up the individual dB outputs and lower the amp vols settings?
I don't want to up the overall output setting to more than 2.0V, as I have three Hifi SET amps in the mix as well that would not handle high PA line ins.
Guidance much appreciated.
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Post by MartinT on Jun 13, 2016 16:17:50 GMT
Amp vols on max and line level set appropriately, as long as noise is not a problem. That way, you're taking the pots out of the signal path.
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Post by speedysteve on Jun 13, 2016 16:18:44 GMT
Just driven the Crown adequately. Hehe, get the signal light on constantly (but not higher) on good mid bass action - like Cream at the Albert Hall 2005, Toad drum solo.
At 0dB (max) on Nadja overall volume (V. Loud), the cooling fan just starts to spin up a bit a very little.
You'd have to get it past the -20 and into the -10 or clipping light area to get the fan on full I suppose - best variable speed fan implementation so far.
The CV gets hold of the Kappa Pros nicely too.
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Post by speedysteve on Jun 13, 2016 17:29:27 GMT
Amp vols on max and line level set appropriately, as long as noise is not a problem. That way, you're taking the pots out of the signal path. Yes, that was my usual (or as near as), but others have said its better not to use digital attenuation. But we are using digital processing for everything else, so I can't see that mattering. I cannot have zero attenuation in Najda anyway as loud settings set the tapped horn amp into clipping so need to use higher vol settings and -dB in Najda. The joys of gain structures. TBH I can't hear a difference on bass channels either way. |
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Post by John on Jun 13, 2016 21:00:43 GMT
Yes on the bass channel think not be as critical
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Post by speedysteve on Jun 17, 2016 19:44:45 GMT
I've been living with the Cerwin Vega CV1800 on the tapped horn subs and the Crown on the mid bass. The 400wpc of the Cerwin and high damping factor really gets hold of the 650w Eminence Kappa Pro LFII drivers. It's not that they are any louder per say, it's the control and grip. Quite subtle. Similar with the Crown XLS1500. It's musical enough for mid bass no problem and has the JBL2220H drivers working a treat. Here they are  I had to work a bit at getting the gain structures in Najda right esp on the Cerwin Vega channels. The analogue volume chip that Nick designed in is a real boon here. Not so much the amp, but wanting to be able to have enough gain for quieter ripped CDs like the Drottningholm Baroque Four Seasons, and then being able to play stuff like Joan as Police woman and invisible Beauty of My Flower track (John or Martin's bass test track top tip), without getting clipping due to some of the room correction I've had to do in this difficult room. All in all I've got a sound I can be proud of and really enjoy again, to rival the old room actually. It's taken a while fiddling and tuning, and some beefier bass amps to do it:) But to me that is all part of the hobby. Without Najda I'd be absolutely nowhere, due to huge suckout at 41Hz and big peaks at 28 and 58Hz. Yes, rollercoaster that close together. Perversely the mid bass is a smoother ride than previously. I could play the 'Flower' track at full whack now with no technical problems but it would probably cause my ear drums to cave in so I don't:) It's def good enough to entertain a MartinT and John visit sometime;) if and when you guys have the time? Martin I know you are in the process of moving so will be very busy for the next half of forever:) at least that's how long moving felt like for us. It's actually a year now since we first viewed this cottage! |
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Post by MartinT on Jun 17, 2016 21:04:51 GMT
Without Najda I'd be absolutely nowhere, due to huge suckout at 41Hz and big peaks at 28 and 58Hz. Yes, rollercoaster that close together. I can believe it. Real rooms are horrible! Thanks for the invite, Steve. I will deffo come over later in the year. |
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Post by John on Jun 18, 2016 6:31:46 GMT
Yes eager to visit Steve
The Invisible Flower of Beauty is a great test track to test what the bass is doing to mid and treble.
Agree you not be able to tackle the room modes you have without the Najda
I come round when Martin is ready as always nice to meet up as a group
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Post by speedysteve on Jun 19, 2016 15:42:18 GMT
Thought I'd share how I solved my gain issues and got a better overall SQ.
Nick of Najda puts it better than me 
I'll include the link next time I'm on a laptop as Tappatalk doesn't seem to do it right.
My issues were gain structures of mixing PA and Hifi amps, varying driver efficiencies and worse still, EQ'ing the bass.
I was searching through things and came across a post by Nick of Najda. He was discussing the inclusion of the analogue chip in the Najda architecture (quite an addition to BOM cost). He explained how using the analogue settings in Najda could overcome just such gain variations as you see with various drivers and EQ'ing without lowering quality as you would in the digital domain by being able to best use the dynamic range of the digi processor side of things.
With the analogue control in use I can set all the digi gains at 0dB and using some negative and some positive settings in the analogue output config section and the amp vols set at optimum for SQ per amp, I've get a nicer cleaner sound.
The PA bass amps sound best flat out and are totally silent. The SET amps have various degrees of buzz into the compression driver horns and so work best throttled back a tad.
Link (hope it works now)
techtalk.parts-express.com/forum/tech-talk-forum/56144-najda-a-new-dsp-board-for-loudspeaker-applications?p=976958#post976958 |
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