SWR Triad; very interesting...

[silverfoxnik]

Hi Folks,

Just when I thought I'd got my sound settled a couple of months ago, I started to thing it might be better to have a full-range cab so I bought this SWR Triad from Lee-Man recently and used it for the first time at a gig last night. Overall, it sounded great, though I think it's going to take a bit of getting used to as it 'seems to throw' out the low-end in a completely different way to my Peavey 410TVX.

During the gig, I was standing near to the cab (as usual) and the sound was crystal clear which was nice as I wanted to get a little more definition in the mids for gigs, hence going for this 3-way cab. Having said that, during the soundcheck it felt like it lacked a bit of bottom, so I added some bass from my GK 700RB to compensate and it seemed fine. But at the end of the gig, the drummer and guitarist both said that my sound had too much bass and not enough in the mids?? Seems from what they're saying is that with the 15" driver, this cab projects the bass into the room in a totally different way to my 410, so I'm going to have to adapt the way I use the cab and the way I set up my sound at gigs..

And it might have been because I had too much bass in my settings but apparently, the silver grill was rattling quite a bit so I'm going to have a look at that today to see how to stop it happening.. but if anyone's had any experience of that particular problem and has a few hints, I'd be grateful?

It never stops does it, this search for the perfect sound!!!

Cheers

Nik

[Kiwi]

Was the venue you played long and narrow? There might have been issues with standing waves.

Is the cab front or rear ported? (I can't remember on the one I used to own)

[SMART]

[quote name='silverfoxnik' post='195851' date='May 10 2008, 09:36 AM']And it might have been because I had too much bass in my settings but apparently, the silver grill was rattling quite a bit so I'm going to have a look at that today to see how to stop it happening.. but if anyone's had any experience of that particular problem and has a few hints, I'd be grateful?

It never stops does it, this search for the perfect sound!!!

Cheers

Nik[/quote]

Neoprene strip along the edge behind the grill??

Ciao

Ian

[Dubs]

I had a similar grill problem with an old 4x10 Trace cab that I owned for about 6 months. The only thing I could do to stop the grill rattling was to just take it off. It didn’t rattle all the time so occasionally it was alright. It was quite easy to take out though because the tuned port covers actually held the grill on so I didn’t actually have to use the screws so it only took about 20 seconds to put it on/take it off. Don’t know if I would have settled for that solution if it took longer and screws were involved.
The same thing happened on my 7210H Trace combo that I've just sold so I used to do the same thing on that...just take the grill off.

Don’t know if that helps [i]at all [/i]but I’m sure there are ways of reducing the vibration across the grill and I’m sure it’s a very common issue with cabs that have a metal grill. Lucky my SVT is cloth

[silverfoxnik]

Cheers guys!

CK, the cab is front-ported and the venue was wide and not very deep, so not sure what that means in terms of 'standing waves'? All that speaker science stuff tends to go over my head to be honest but thankfully here on BC, Alex & Bill etc put it into simple, bite-sized chunks that I can just about get my head around.

Ben.. seems like it's quite a common problem then? But Ian's neopryne strip behind the grill is a brilliant idea that could be the quick and simple solution I'm looking for!

Cheers

Nik

[charic]

Standing waves are a form of resonance. It is usually found in longer rooms and effects bass frequencies waveforms are much "longer" and more powerful than high frequencies (told you bass was better than guitar). Basically your waveform could of been reflected off of the far wall and if to peaks of a wave hit each other they add together and at that point the bass frequencies will sound louder.

Its not really amp science but acoustics. I find it hard to explain without pictures and im not at my home comp, may try again later

[Dubs]

[quote name='charic' post='195886' date='May 10 2008, 10:53 AM']Standing waves are a form of resonance. It is usually found in longer rooms and effects bass frequencies waveforms are much "longer" and more powerful than high frequencies (told you bass was better than guitar). Basically your waveform could of been reflected off of the far wall and if to peaks of a wave hit each other they add together and at that point the bass frequencies will sound louder.

Its not really amp science but acoustics. I find it hard to explain without pictures and im not at my home comp, may try again later[/quote]

it happens in every room though to a certain extent? my limited understanding of it would be that standing waves can only occur in rooms with parallel walls and typically only affect frequencies between about 70Hz and 300Hz? so boxy rooms and bass guitar are terrible for it and occasionally recording studios are built at an odd shape to avoid this although any room with a flat ceiling will naturally have 2 parallel sides (floor and ceiling) although it would have to be a pretty high ceiling to cause problems.

The formula for determining the fundamental frequency of a standing wave for a particular room dimension is:

fo = V / 2d

Where:
fo = Fundamental frequency of the standing wave
V = Velocity of sound (1130 feet per second)
d = Room dimension being considered in feet (length, width, or height)


^^that's just something from some lecture notes to help you work out what frequencies are likely to cause you problems in a particular space. Don't know if what I've said is 100% accurate or relevant.

[silverfoxnik]

Thanks Charic / Ben for the more detailed explanation, though I must admit to my eyes glazing over at the sight of some maths and a formula! Does help explain things a bit more though....

[Gwilym]

hi Nik
on the off chance that it isn't the grille, you might want to check the side handles too. My old SWR Bigfoot used to rattle occasionally, it turned out to be the side handles, (the ones that are spring mounted and lift up/out to the horizontal).
cheers
G

[silverfoxnik]

[quote name='Gwilym' post='196254' date='May 10 2008, 10:29 PM']hi Nik
on the off chance that it isn't the grille, you might want to check the side handles too. My old SWR Bigfoot used to rattle occasionally, it turned out to be the side handles, (the ones that are spring mounted and lift up/out to the horizontal).
cheers
G[/quote]
Hi Gwil,

Good to hear from you - hope all's well?

That's a good point because I checked the grill and it's very securely screwed on, so maybe it is something else like the side handles.. which are the same as the ones you described.. I still think I might use some neopryne as well, but what did you do to rectify it in the end?

Cheers

Nik

[XB26354]

[quote name='charic' post='195886' date='May 10 2008, 10:53 AM']Standing waves are a form of resonance. It is usually found in longer rooms and effects bass frequencies waveforms are much "longer" and more powerful than high frequencies (told you bass was better than guitar). Basically your waveform could of been reflected off of the far wall and if to peaks of a wave hit each other they add together and at that point the bass frequencies will sound louder.

Its not really amp science but acoustics. I find it hard to explain without pictures and im not at my home comp, may try again later[/quote]
Standing waves usually occur in rooms with parallel walls, regardless of the whether the room is long and thin or square. Standing waves occur when a peak amplitude wave hits a trough amplitude - add them together and you get (near enough) zero, so they cancel frequencies out instead of enhancing them (like 2 mics that are out of phase). This is unlikely to be the cause. Bass frequencies need a fairly big space to start reflecting. It may be that the room was big enough to start reflecting the bass end off the walls, meaning front of house (and the audience) were hearing loads of bass. How big was the room? I have found that I need my amp to be louder in a small rehearsal room than a medium venue because of this.

[silverfoxnik]

[quote name='XB26354' post='196294' date='May 11 2008, 01:08 AM']Standing waves usually occur in rooms with parallel walls, regardless of the whether the room is long and thin or square. Standing waves occur when a peak amplitude wave hits a trough amplitude - add them together and you get (near enough) zero, so they cancel frequencies out instead of enhancing them (like 2 mics that are out of phase). This is unlikely to be the cause. Bass frequencies need a fairly big space to start reflecting. It may be that the room was big enough to start reflecting the bass end off the walls, meaning front of house (and the audience) were hearing loads of bass. How big was the room? I have found that I need my amp to be louder in a small rehearsal room than a medium venue because of this.[/quote]
This stuff just gets more and more fascinating!!

The room is the front of a fairly large pub, maybe 40ft x 25ft, something like that and the band is set up at an angle facing into the 25ft deep part of the room from a corner (if that makes any sense?).

The guitarist described my sound as being shaped like a reverse funnel, i.e getting bigger and bassier the further away it was from my rig.. Not a very flattering description I know, but quite illustrative I suppose...

[clauster]

I think your guitarist was experiencing the effect of bass frequencies spreading and highs going straight out.

I was thirty to forty foot from your amp, but prettty much straight on to it, and there was no way it was too bassy. If anything the mids were more pronounced than previously.

Just checked with MrsC and she said, "it sounded nicer."

[Gwilym]

[quote name='silverfoxnik' post='196285' date='May 11 2008, 12:49 AM']Hi Gwil,

Good to hear from you - hope all's well?

That's a good point because I checked the grill and it's very securely screwed on, so maybe it is something else like the side handles.. which are the same as the ones you described.. I still think I might use some neopryne as well, but what did you do to rectify it in the end?

Cheers

Nik[/quote]

hi Nik, I'm good thanks, even better with the sunny weather I trust you are also ok?

Sorry, I should have said what I did to fix it! Well, before I realised what it was, the Bass Centre had already replaced a driver! When I did figure out that it was the handle(s), (they were just hanging a bit loose when they were at the hanging vertical position) I was able to adjust the foam around the handles by pushing them as much as possible to the "side", (towards the right-angle of the metal), this seemed to brace the handle in postition a bit better but pushing it out by a very slight amount, which was enough to stop the vibration.

cheers
Gwil

[silverfoxnik]

[quote name='Gwilym' post='196551' date='May 11 2008, 03:07 PM']hi Nik, I'm good thanks, even better with the sunny weather I trust you are also ok?

Sorry, I should have said what I did to fix it! Well, before I realised what it was, the Bass Centre had already replaced a driver! When I did figure out that it was the handle(s), (they were just hanging a bit loose when they were at the hanging vertical position) I was able to adjust the foam around the handles by pushing them as much as possible to the "side", (towards the right-angle of the metal), this seemed to brace the handle in postition a bit better but pushing it out by a very slight amount, which was enough to stop the vibration.

cheers
Gwil[/quote]
Thanks Gwil,

I'm good thanks.. Like you, enjoying the sunshine which is a nice antidote to dark, sweaty pub gigs! I've got two gigs coming up at the weekend so I'll try that suggestion of yours and get some neopryne too..

Cheers

Nik

[silverfoxnik]

[quote name='clauster' post='196484' date='May 11 2008, 12:44 PM']I think your guitarist was experiencing the effect of bass frequencies spreading and highs going straight out.

I was thirty to forty foot from your amp, but prettty much straight on to it, and there was no way it was too bassy. If anything the mids were more pronounced than previously.

Just checked with MrsC and she said, "it sounded nicer."[/quote]
Just seen this post Nick - thank Mrs C for me!!

Finally getting there with the sound now.. You're spot on about the mids being more pronounced with the Triad and it was really troubling me after my gig on Friday. Everything seemed too 'growly' for me and some of the lows felt like they were missing.. So, I had a play with it at home yesterday afternoon and at last night's gig I think I finally got the sound right for me and for the band.

All I did was to keep things pretty much flat on my amp as per normal but change the settings on the RBV so that both p/ups were in single-coil mode. End result; plenty of nice fat low end and clear highs, without it being too middy.. Think of a classic jazz bass sound and you've got it!

Also used a bit of gaffa tape to stop the grill from rattling so after a bit of investigating and tweaking, I'm much happier now!