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[Jack Hawkins]

I agree with the others in that I don't see the Q99 as an upgrade. The RMX4050HD is a really beefy design with dual power supplies including a pair of toroidal transformers and you are using it in the optimal configuration at 4ohms/ch, to best the power this generates you would need 4 Q99s... one per 218 in bridge mode and even then I doubt it would sound better. I'd also say that I think you are already fully powering those subs for DJ applications, they won't take the program or peak ratings for more than miliseconds at a time which requires a more dynamic program material than what a DJ typically plays.

I also don't buy the notion that "switch mode powered amps can't do bass" that seems to be popular on the UK forums again. I say again because it was a common claim back in early 2000's until a few Speakerplans members did the amp and subwoofer shootouts and a couple switch mode amps rated very highly in the listening tests, the Yamaha T5n among them. The only claim that tends to hold true with amplifier designs is that cheap amps sound cheap... or perform poorly relative to more expensive models if you like, this should not really be a surprise though.

Yeah I thought the Q99 is a torroidal amp as pictures of it clearly show a transformer, I know the old switch mode amps can't do bass thing is all over the place but I think like you mentioned it's a problem that plagues the cheaper switch mode amps. I think it's widely known by the Speakerplans guys that the more expensive ones from companies like Powersoft, MC2 etc..are great at powering subs generally because they have the power supplies big enough. I think a lot of cheaper amps are rated in burst ratings but don't state burst so the specs confuse people into thinking they can output their rated power continuously over hours.

Anyway here's the EV Q99 which shows a transformer.

I was thinking about bridging one per sub but if there's not going to be much or any difference in sub sound then I suppose it's not worth it. The actual reason I decided on Wharefalde Delta was because of you guys, from this thread below.

https://forums.prosoundweb.com/index.php?topic=148585.0

It was said that old LX218 subs were the best budget subwoofer and a club beat the hell out of a member of this forum's pair and wanted to buy them. So I took a chance and bought a pair and then tested them out at home on one of my RMX4050HD amps and wow for a budget sub they sounded lovely. I could feel that deep bass in my stomach so I have no doubt they're around -3db at about 37hz. My old JBL MP418S subs were louder but they could only really get down to about 50hz (despite JBL's specs) as most of the bass was in the top of your chest. So anyway I bought another two Delta 218B subs and another RMX4050HD and started doing small dance music parties in a bar and a hall in town.

[Paul G. OBrien]

I was thinking about bridging one per sub but if there's not going to be much or any difference in sub sound then I suppose it's not worth it.

Well here is the thing.. it will sound different and should get louder.. for a while at least until driver power compression sets in, but I don't think it will sound better.  Bridged 4ohm operation is equivalent to 2 ohms per channel which is something an amp more survives than excels at. This also puts your system into a range where you could melt the sub drivers without ever seeing a clipping light. It is quite possible you could end up after some experimentation running the subs at roughly the same power level as they are now because they just start to sound ragged and uncontrolled at higher drive levels, which means you spent a bunch of money for additional power you're not going to use. Or you might like it.. louder is simply better for some people.

[Jack Hawkins]

Louder is good I like music very loud but not at the expense of sound quality.

[Mark Wilkinson]

Louder is good I like music very loud but not at the expense of sound quality.

I figure if you're considering putting a bridged amp on each sub, that you have already tried that with your two 4050HD's, on either 1 or 2 subs....
Did it sound better? 

If so, and the EV's are really cheap, and you're really on top of the applied power...heck, go for it !
The subs do look pretty decent imo...without knowing the drivers. The cabinets look good and stout with a well braced design.

All that said, personally, I'd keep using what you have. Risk/reward you know....

[Jack Hawkins]

I figure if you're considering putting a bridged amp on each sub, that you have already tried that with your two 4050HD's, on either 1 or 2 subs....
Did it sound better? 

If so, and the EV's are really cheap, and you're really on top of the applied power...heck, go for it !
The subs do look pretty decent imo...without knowing the drivers. The cabinets look good and stout with a well braced design.

All that said, personally, I'd keep using what you have. Risk/reward you know....

I've only used my two RMX4050HD amps with one sub per channel, obviously dual mono as the RMX4050HD is a dual mono amp with dual power supplies. I'd never bridge one on one sub it's far too much power, 4,000 watts continuous average power into a 1,600 watts continuous average power sub would be silly. I'm not a professional sound engineer but I know doing that would be silly. I also know power compression raises the impedance and means less power is extracted from the amplifier so i'd lose probably 4-6db anyway with power compression. But I kind of thought maybe the 2,800 watts of the Q99 would be the most i'd dare use. Although that's a 1khz rating so i'm thinking full bandwidth power output thinking about the possible limits of capability of the amplifier the full bandwidth power output maybe be around 2,400 watts average power. My original thoughts weren't "lets put masses of power through the subs to make them louder", it was more of a "if I bridge an amp capable of about 2,400 average power into 4 ohms I have SOME headroom".

The RMX4050HD outputs about 1,400 average power into 4 ohms so I was thinking about 2.2db of headroom is better than no headoom.

[Scott Holtzman]

I've only used my two RMX4050HD amps with one sub per channel, obviously dual mono as the RMX4050HD is a dual mono amp with dual power supplies. I'd never bridge one on one sub it's far too much power, 4,000 watts continuous average power into a 1,600 watts continuous average power sub would be silly. I'm not a professional sound engineer but I know doing that would be silly. I also know power compression raises the impedance and means less power is extracted from the amplifier so i'd lose probably 4-6db anyway with power compression. But I kind of thought maybe the 2,800 watts of the Q99 would be the most i'd dare use. Although that's a 1khz rating so i'm thinking full bandwidth power output thinking about the possible limits of capability of the amplifier the full bandwidth power output maybe be around 2,400 watts average power. My original thoughts weren't "lets put masses of power through the subs to make them louder", it was more of a "if I bridge an amp capable of about 2,400 average power into 4 ohms I have SOME headroom".

The RMX4050HD outputs about 1,400 average power into 4 ohms so I was thinking about 2.2db of headroom is better than no headoom.

I am not sure the power would be silly but I would want a voltage limiter on it.  Having reserve means the amp doesn't have to work as hard.  It's like driving a 600hp car. Transients are effortless.  It's somewhat ephemeral but noticeable.


Subs and amps is somewhat voodoo too.  We have some Lab.gruppen Pl6400's that on paper should not keep up with a PL380 yet they do.  We also were using some Peavey IPS7500's and the Lab's just decimate them even though the numbers say they should be within a db or so.


But anyway back to the voltage limiters.  Our Meyer 650R2's are rated at about 400 watts per driver.  We are running Yamaha P7000 amplifiers which deliver 3 times that output.  The Meyer processors have voltage sense leads.  We can still tickle the limit lights on the P7j's without tripping the limiter in the processor on rock and roll type music.  EDM will trigger the processor limiter.  We have yet to nuke a driver.  I will say that myself or my partner or always around when the Meyer's are out as a ham fisted engineering could probably toast them as the processor limiter is not fast acting.  The higher powered amp really opened those subs up, made them "musical" for lack of a better word.  They never sound strained.  We run them either 8 or 12 boxes at a time so lots of acoustic coupling too. 


I would give it a try and see if you like the results.

[Jack Hawkins]

Try out a voltage limiter you mean?

[Paul G. OBrien]

Try out a voltage limiter you mean?

Yes... this becomes mandatory when you have more than a speakers continuous power rating available. With your current config it appears the amp will reach it's limits before the drivers reach any of their limits.. be that long term thermal or short term peak power, so the system can be safely used with only basic processing and program material doesn't matter.
But with more power on tap more protection is necessary because the amp can now deliver more than the drivers can handle continuously, which means the system would be OK with relatively dynamic material like R&R but it would be all too easy to cook drivers with heavily compressed recorded material that has long sustained bass lines or worse yet continuous synth tones. Either of those apply to your situation?

[Jack Hawkins]

Yes... this becomes mandatory when you have more than a speakers continuous power rating available. With your current config it appears the amp will reach it's limits before the drivers reach any of their limits.. be that long term thermal or short term peak power, so the system can be safely used with only basic processing and program material doesn't matter.
But with more power on tap more protection is necessary because the amp can now deliver more than the drivers can handle continuously, which means the system would be OK with relatively dynamic material like R&R but it would be all too easy to cook drivers with heavily compressed recorded material that has long sustained bass lines or worse yet continuous synth tones. Either of those apply to your situation?

I play techno and drum & bass.

[Scott Holtzman]

Try out a voltage limiter you mean?

No try the EV amp and see if it makes a difference.

[ProSoundWeb Community]