Top Cabs

jimsvox

Hi - I'm trying to upgrade my HF cabs to accommodate a loud rock band playing in small to medium venues. Here's my current set up:

2) JBL MP418S subs (600w/2400w) - 4ohms

2) QSC RMX 2450 (bridged - 2400w@4ohms) for subs

2) Carvin LM15 top boxes (475w/950w) - 8 ohms (these are what I'm considering replacing)

2) QSC RMX 850 (bridged - 600w@8ohms, 830w@4ohms) for HF (Carvin LM15s)


I was also using two Carvin 832s (15/horn) to bring my HF to 4ohms, but I read that this was a bad practice in terms of phasing, so I'm thinking I need to discontinue that practice??

Some parameters are: must load into minivan, so can't be gigantic, and must me under 100 lbs, since I often set up alone.

I'm looking first at JBL top cabs, like the MRX525, but haven't seen any reviews, so I'm a bit leery. I'd like to get 4ohms, to get the most from my RMX 850s. I've been told that for doing a rock band (lots of 80s pop metal, etc), I should go with a dual 15 cab. I'd love to find a good used cab to get more bang for my buck.

Additionally, I don't know how to tell my driverack that my top cabs are powered by 2 RMX 850s running in bridged mono. The wizard only gives bridged option for the subs.

I'm also open to the possibility that my allocation of power is not ideal, but I thought the subs would have the greatest transients, so I opted for more headroom there. Maybe I'm wrong?

Any help would be greatly appreciated. Thanks!

Jim

Gadget

Well.. I don't like JBL at all...let me get that out of the way right off the bat...Even their supposed \"good stuff\" is sub par in my opinion... their older stuff was ~ok~ I guess but the new stuff... not good...

That said, we have already been through this with a couple others and the cheapest true \"pro audio grade speakers are Peavey SP-2's even used ones would be better than what you have, but you are also very short on power. Your correct that you should have the bigger amp on the subs....

You are also correct that the dissimilar speakers do interact badly...I would consider getting more power as well...

Gadget

Dra

Gadget, since we are talking power... The guys on PSW have power recs all over the board. Some say one , some say another. then they start shouting obscenities at each other. I know you like to say that there is no such thing as too much power. But, put a number on it. Let's say a good minimum number and a preferred typical number.
For example:
Passive top cabs that run 100-125hz and up: 1.25x / 1.75x program rating
General duty subs (say, nothing under 40hz): 2.5x / 3.5x program rating

Throw in bi-amped tops if you wish. Then perhaps put that in the \"Read me first section\".

DRA

Gadget

Well.. as a rule that is the toughest thing to get anyone to agree on...The Crown website says 2-4 times the rated power... thats the RMS value and its for headroom purposes... I don't remember seeing Bennett Prescott or anyone else that used the \"Digam 10K\" complaining that it had too much power.. only that it seemed to have limitless headroom.. and walloped the hell out of the subs they were hooked to and sounded better than any amp they had tested...

The ONLY problem with too much power is exceeding the speakers Xmax (linear excursion) and slamming the voice coil into the magnet structure's back plate, or tearing the cone at the apex or the spiders.... The fact is the more power you have the less sag and the more excursion control (the ability of the speaker to stop and restart in another direction) you have and so a tighter sound and cleaner sound is derived... I have NEVER seen a cone fried by TOO MUCH POWER... I have heard those guys SAY it will but I see too little power damage ALL THE TIME! and I re-cone speakers so I know...

I stand by my statement... too much power is never enough...But in the light of your question I would say 2x for mid on up and 4x for sub duty... IF you want to be safe... your calculations are close enough to be in the ballpark, but I would like a higher number.. but at this level it's usually academic, you get what you can afford...I suppose we could put something together and post it.. usually just falls on 'def' ears though...

Gadget

jimsvox

Thanks so much for the insights. It seems like I'd do well to find a bi-ampable top cab, use one or both RMX 850s just for highs and get a couple more RMX 2450s for the mids.

Any other notions on top cabs besides the SP2s? I've read elsewhere that their sound is harsh. I don't think my budget will take me into the EAW range yet. I'm looking to spend around $1000 per cab. Would there be a significant benefit to be basing my choice on the models that are already in the Driverack's tunings? Thanks again.

Jim

Dra

If you are ready to spend up to $2000 for the pair, then you should consider the Yorkville Unity U15 (80 lbs). Full range or bi-ampable. Looking at the optional processor curve, I believe there are enough PEQ's in the DRPA to duplicate the processor. Everyone at PSW slobbers all over them. Shop around for the best deals. The popular internet stores have them for like $995, but they can be had for much less at the places that you have to call to get the best price.

Settings in the wizard...Nice, but don't buy based on that. I almost bought JBL M-Pros because of the wizard, but didn't. What a relieve! A lot of companies have tunings on their sites.

DRA

Dra

May be your lucky day. Here is the powered U15P (2nd available). You might get them for a steal.

http://cgi.ebay.com/Yorkville-U15P-Unit ... dZViewItem

DRA

Gadget

I concur...the U15's they are really nice sounding!

jimsvox

Wow, great info. Thanks. The U15 looks great. Now because I have to be able to set these up myself, I've come into a dilemma. It stems from the weight of better cabinets like U15 and others, which all seem to be heavy Baltic Birch cabinets. A single 15 and horn is around 75pounds. Since I won't be able to get a cab like that on a pole myself (and I must be able to manage what I get alone), and the dual 15s are both cost and weight prohibitive, I'm left with the following two options:

1) a better cab (like U15), sitting flat on the sub and thus probably about chest level. My subs are 24\" H, + U15 (34\") = stack height of 58\"

2) a lesser cab (JBL MRX 525) dual 15, sitting on sub, but horn would be about head height or slightly over. This stack would be 72\" high.

Thoughts? Thanks again for all the help!

Jim

Dra

The fact that you can lift the dual 15 JBLs should tell you something.

DRA

jimsvox

Well, I can lift the JBLs (84lbs), or the other cabs, enough to set them atop the 24\" high subs, but not enough to get them up onto a pole. I'm not really clear on what you're saying it should be telling me. Would you please clarify? Thanks.

Jim

Dra

:oops:
My bad.

DRA

Dra

Actually, just though of something. Lay the cab on it side. Stick the stand in. Pick up the cab and walk it up. I don't try this with a really tall cab, but good for the shear weight, just keep the cab supported as you lift.

DRA

Gadget

He's telling you the JBL's are CRAP! A quality speaker made of wood is a heavier cabinet by default... The newer cabs with Neo magnets are lightter though, usually by 10-20lbs.

How about a 53 lb speaker... thats 30\"tall...12\" woofer 3 way with horn loaded mid
http://www.northernsound.net/Sales/spea ... frame.html
Community is a well respected name and there are only about $370

This one has a 15\" woofer and weighs in at 58 lbs and about 32\" tall
http://www.northernsound.net/Sales/spea ... frame.html

130 db peak 123 continuous... great price... excellent company...

Or these...
http://www.northernsound.net/Sales/spea ... frame.html
Rf12.85.. at 48 lbs... they have a 15\" version thats 58 lbs... but twice the price of the Communities...

At 80 lbs I can see where you'd have trouble.. but 40-50... doable?

Gadget

jimsvox

Wow, thanks very much for your patience and insights. This puts me miles ahead of where I was before! 40-50 lbs is definitely doable. Thanks again.

Jim

Gadget

Jim,
Those people are great to deal with and have the best prices by FAR on what they sell...I would ask their opinion, or get some references of customers that have bought those cabs and see what they say...(if possible) I like the 12\" lo mids in a 2 way cab, not as important in a three way system with a cone midrange.. like the Community's...there a 15\" is acceptable if the power is available, and the subs can't go high enough to cross to a 12\" which isn't a normal problem since most can go to 200 hz and above...

K?
Gadget

jimsvox

Great! Thanks again, Gadget. All this has really helped me to zoom in on how to address my needs.

Jim

Gadget

your welcome

jimsvox

I've checked out the Community cabs and found that though the weight is managable, the power handling is about what I have now. I know it would still be a huge upgrade over my Carvins, but I'd also like to up my power handling at the same time.

So, I'm steering back toward the U15s which are, by every account I can find, phenomenal cabs, and they handle 800w. I may use shorter poles to make them more managable, and/or enlist bandmates to help with them.

Just one last fly in the ointment: my JBL (I know, I know) subs which only weigh 64 lbs each. In many situations, I won't have space to use extra stands, so is it asking for trouble to mount 80lb cabs on 64 lb subs? My lust for the U15s may be prompting a dumb question, but does anyone have experience on this?

If a problem, I may have to look at dual 15 cabs again, like Community MVP215HO (MDF construction???). Presumably, it's better than the JBL MRX525 even though it's cheaper. Either way, my first priority is safety, so though I'd much rather do the U15, I need something that's stable on the 64lb sub.

Thanks for any help!

Dra

The weight of the sub cab is not important (unless it is the result of a flimsy design) but the footprint is. It really is a matter of leverage. Put a pole in the sub socket and see how much force it takes to tilt it in any direction. Another option - if you have storage cases that would be \"presentable\" and sturdy that could stack on the subs for tops risers.

DRA

Gadget

Not that I'm trying to talk you out of the U15's I have been recommending them for years...But the power handling factor isn't always the whole story... What you should be looking at id the efficiency factor and the Continuous output/max output spl capability...Now if you look at the two side by side the Community below has an average SPL capability of 123, (which is LOUD) and a max SPL of 130....here is the MFG spec's... for the community...Note the 130 max spl...
Maximum SPL @1m/1 watt 123 dB continuous / 130 dB peak

and here are the specs for the U15... which does NOT publish a continuous spl but only a MAX...

Max SPL (dB) 127

Interestingly, they both have a comparable power handling capacity.. if you know which spec to look for...Community, actually gives you some info here...

Max Power Handling:
(passive)
200W RMS
500W Program / 990W Peak

Note the 990 watt peak power handling...

The U15, again only states one spec..

Power handling 800 watts...(actually I found this spec as well...Program Power (Watts) 800 / 200)

The interesting thing here is that the U15 uses the Eminence Deltalite 15 \"woofer that has a 2.5\" voice coil and has a 300 watt power handling capability...That would then be the \"RMS\" spec which is similar to the Community speaker's RMS value... The problem here is that without a \"published and mandated measurement criteria\" we have little real usable specs to go on...so it's really a crapshoot...

So, what have I been getting at? well one for sure is manufacturers specs are ... suspect at best... they can twist the numbers to mean almost anything...I mean community could have published the 990 watt figure like Yorkville did... but thats misleading...Really, those speakers could take even more CLEAN power... but I digress...

Also, I'm not maligning either in any way, but pointing out they both have attractive pluses... in this case the U 15 has the unity horn aperture which make for a smooth midrange... the community's however also have a horn loaded mid/hi configuration, that has proven very effective and pleasant sounding...The Communities are light, and attractively priced and the \"spec\" performance is equal to the U15's in every critical respect...

So don't judge a speaker by the specs... dig a little deeper and compare apples and apples and I think you'll see that it isn't all in the numbers...

And.. as Dra pointed out.. the base dimensions and the actual height of the structure will determine the ability of the structure to avoid tipping...

GAdget

jimsvox

Again an education! Thanks very much.

Jim

jimsvox

Hope I'm not taxing anyone's patience, but any thoughts on how the EAW FR159z compares to the Community Sonus 3594? Some differences I see (with my non-technical eye) is that the EAW isn't biampable, and the EAW has peak spl of 133db vs the 3594's 130db. I've never heard either cab.

Community 3594 specs: http://www.loudspeakers.net/files/specs ... S-3594.pdf

FR159z specs: http://www.eaw.com/info/EAW/Loudspeaker ... S_rev1.pdf

Thanks for any input!

Jim

Gadget

The EAW's are well thought of also... I am actually an \"acoustic partner\" with them, but those are in a whole different price bracket...If your looking for strictly SPL get something like the D.A.S. RF - 1264 with a 2\" throat horn and 4\" voice coil woofer... and STILL only 55 lbs and around $800... not $1100 like the EAW's...Remember you specified under or around $600 dollars.. if you want do the the FRZ price range that opens up a whole different can of worms :shock:
Gadget

jimsvox

Thanks. I may have miscommunicated at some point, but I'm looking at up to $1000 per cab. Way back at the beginning I was considering the JBL MRX525 at $950 per cab. I'd like to get the highest quality and power I can (obviously) for up to that price range.

I was surprised to see EAWs within that range, and I have to admit I may be suspect to some lust to own EAWs just because all my musician friends think EAW are great.

Dra

Gadget, look the other way. 8)

The EAW's and 418's are in the updated wixard. Complete with x-over points and also PEQ's for the sub. You won't even have to have to turn a knob to make them sound good. :roll: People like EAW, because they heard someone say they are good. I bet that if you told your musician friends that you were going try some Eastern Acoustic Works speakers, they would say, \"No, get the EAW's!\".

DRA

Gadget

Ok Dra... what did you say that would have me LOOK the other way :roll: was it that the settings are in the wizard? I have nothing against that.. in fact if they are in the wizard by all means.. go for it.. I just happen to be a tweeker..and sound is subjective.. I like to make speakers sound the way I think they should sound...It's pretty tough to beat what the manufacturer comes up with though...BUT if the Bi-amp setup isn't needed then the settings for \"tops +subs\" are dubious...as they don't take power amp selection or anything else into consideration...

As for the FRz's and EAW in general.. I'm a little pissed at them right now since they went offshore.. and now the quality is suspect... but the price has not taken a corresponding cut either...and thats a LOT of money to pay for a name...Now, that said...EAW is a fine company with a vaunted reputation... are they the do all end all of speakerdom...no...If thats all your looking to do is impress people then ya.. go for it.. otherwise I suggest you go for bang for the buck...I also am a proponent of \"listen before you buy\" when possible.. although I can make most anything sound good...

Note though that the FR series only uses 1\" exit horns..and lower wattage woofers...(and weighs in a around 80 lbs) remember what I said about numbers... 133 db isn't the number you should be looking at...besides what frequency was that reached at? Ok...So remember when we talked about speaker components? I would think that something with a 1.5\" or 2\" exit horn, something with either a midrange speaker, or a 12 inch woofer for midrange quality would be best...A horn/15 inch is ok, but the vocals aren't as good in a 15 inch...and as long as you have subs then that is what I suggest.. If you are strictly looking for volume, and projection then a horn loaded system will get LOUDER and project FARTHER,(and have better efficiency... louder with less watts) a three way system will have a more pleasant midrange sound, but you'll sacrifice power handling and projection.

When you start talking about higher power handling speakers you need higher power.. do you have the kind of power to drive an 8 om speaker to 2400 watts? are you going to biamp, and is that the plan? It would give you the most output for the power you have available...Also Yorkvilles Elite series (I have them) are nice.. I also like OAP.. I have some of the 1222's and although VERY heavy for the size sound great! (they have the B&C 750 2\" driver, and use a really heavy duty 12 \"woofer...

all for now..
G

jimsvox

As always, very enlightening. Thanks.

Jim