One problem with high volume to get bass is that you invariably get a fat gloop of it where the room modes are - typically 35Hz and probably around 90 - 120 somewhere.
With active DSP correction these can be dialled out, or in, for any volume. It does annoy Marie when I do room shaking test sweeps from 20Hz and upwards, over and over though

i have found I need to dial some room action back in though to make it sound impressive - that goes for all volumes. Flat and accurate is a bit boring - I did play bass in a band once upon a time...

My thoughts changed a lot when I made the tapped horns - first time I'd heard bass like it. Back then it was uncontrolled and was like having the potential power of thunder in your room. I remember humming along to stuff and not being able to hum that deep and the feeling of it in your chest.
Like driving fast cars and braking impossibly late (for any passengers) you kind of get used to it.

I could literally have the ornaments dancing off the mantle piece if wanted! The DIY Audio guys were taking 1000W drivers putting them into tapped horns and driving them to destruction to see / hear / feel = driver coil piston punched through the cone - and those were tough PA drivers too. Must have been bonkers!  - I've never done that. Not my thing.

Refining it into a deep Hifi quality bass was always my goal. I don't like fat or sluggish bass, or PA bass, and as Martin says the sort of one note boom that some speakers do is really not where it's at.
Fun and games.

 I had that kind of experience at Nottinghill Carnival once. Extreme sound can kill

Well, after the flirtation with 4 way using the Raal ribbon tweets to their full, and then going back to 5 way with S2's etc but on various test X/O points - I am back on the S2's coming it at 1200Hz on 3uF 1st order cap X/O.
It is just so full of life, energy and vocal impact/realism (yet easy on the ear), that I love.

I did try the S2's at 1500Hz and even 2000Hz. But giving them more to do (within reason), and the JBL2482's less to do, just works.

So the upper end of the system is the same as Martin and John heard it, but I've revised the bass since and like it too.

To some extent it is 'a change is as good as a rest', and I sometimes seem to need to stray a bit, and then go back to realise how good it was before - still X/O shaping itchy feet costs nothing but a bit of time to do

What did you change, Steve?

The last time Martin, John and I met, Martin I think it was, suggested I try some more beefy amps on my bass channels.
John and Martin kindly offered to bring their amps round.
John uses a Behringer Inuke 1000 DSP on his open baffle bass and Martin uses a Chord power amp circa £9000mrp!


The day arrived and we got down to business.

First we had a listen to my setup - the two cheap Topping TP-60 amps on mid bass and sub (tapped horn) bass.
John and Martin commented on how things sound better bass wise - I had gone back to my earlier (slightly cruder) room correction setup in Najda) than the one they had heard... I was also using the JBL2482 compression drivers on the mid horns down to 300Hz instead of 350 or 400Hz. The latter measured better, the former sounds more natural and interesting!

First we plumbed in the Chord on the mid bass channel. This is crossing in at 90Hz and out at 300Hz. Hardly using the Chords beautifully engineered capabilities of 20-20000Hz!
Vol equalisation was done in Najda so we got an appropriate integrated sound.

Here's a pic of the Chord.



Firstly it is quite difficult to hear a change to just one of five channels straight away. It takes several reference tracks too get a handle on what's going on.
However we perceived better attack and edge on the double bass from the Armstrong / Ellington together track we used.
Zero 7 was also improved, more texture in that freq range.

We then tried comparing just the mid bass Chord vs Topping and to me the topping sounded rather flat and dull!
Listening to just one channel is hard work...

We persisted and then tried the Chord on mid bass and the Berhringer on the sub / tapped horns.
Again listening to just these two channels was hard - things don't sound like they should! Too much of the harmonics etc missing.

We gave up with that and went over to listening to full 5 way.

Now the speed and control of the bass was evident!

We swapped the Chord and Behringer over (John was convinced the Behringer would be best on lower freqs only - and so it proved).
The sound was a bit mushy in comparison!

Back with the Chord on mid bass and Behringer on subs, really rocked. The rhythmic underpinnings of the music were rock solid.

I'd never heard the Tapped horns sound so dynamic, with speed and control!

Here's a pic of the Behringer (John has painted it black)




I am never going to afford a Chord so we then tried the Topping on mid bass and Behringer on sub bass. 

This was not a bad sounding solution at all - All of the deep bass punch and control and yes, less clear and dynamic mid bass but the improvement in the deep bass was so clear - I loved it!

A Behringer Inuke 1000 will set me back all of £145 delivered off the bay! A very worth while investment indeed I think!

I will investigate other beefy silicon amps for the mid bass upgrade, but there is definitely more low hanging fruit with the Behringer and sub / tapped horn channel to be had - huge, huge payback!

I would never have thought an amp that you can lift with one hand would sound so good on my 15" Eminence Kappa Pro LFII drivers!
They are of course PA drivers rated at 650w RMS each and the Behringer is a PA amp!
John has disconnected the fan - it is so noisy he says. We are just tickling the thing in our hifi systems - it didn't eve get luke warm!

I'll leave it there for John and Martin to chime in.

an apology to Mike (musicmike), who also came round a little bit later on, but we where so engrossed playing loud music that we did not hear the doorbell, knocker or see him waving at the window!

You are welcome round Mike to hear the new atomic bass once I get me a PA amp!

Should I go for an even bigger one the 2000, 3000, 6000 or 12000 ?  er the 1000 sounded just fine though.

It was a really enjoyable afternoon and I learned a lot more about what the different frequency bands do, as well as enjoyed some great music. Listening to only tapped bass with and without the upper bass teaches you a lot about which instruments feature where in the frequency spectrum. Oboe and trumpet sounded odd without their harmonics, but we could still tell the difference between the amps. The Behringer sounded excellent in tapped bass duty, just where an efficient class D amp should perform at its best (I would go for a bigger model as headroom is always a good thing, especially on bass duty). The Chord showed that more can be achieved in the upper bass area, which I guess is now Steve's homework.

Not worth getting a broken one they cost a lot to fix

I had a little play running the two bass TP-60's with the vol pot wound right round to max.
I can't remember if I ever did that before in all my trials?
Hard to tell if it really is any different compared to having them as I did at about 70% of full.
The TP-60's are quiet, I'll say that for them.
There's plenty of oomph but not the same delineation, impact and even tone of John's Behringer...

Finger itch duly scratched. I got me a INuke NU1000.
Arrives tomorrow. I love pro gear delivery speeds - the show must go on!
So that's the deep stuff sorted to my satisfaction.
For the mid bass, I am looking into
a Crown XLS 1500, but will see if the price is right, as might need to move it on if it disappoints.
The INuke is a keeper as I know it's good thanks to John.

I have room for one or perhaps two of these in my main rack, or can put the 3 icon audio SETs in the rack, but then the slightly less visually pleasing PA gear would be on full display:)

Perhaps that is good to crystallise the minds of hi-fi enthusiasts who turn their noses up at PA gear (4 of my 5 driver sets come from the PA world, although 3 have that classy / respected vintage kudos amongst horn aficionados).