Greetings

I have a pair of KH O300D monitors and I?m considered to add a sub in order to achieve better low and higher SPL.

In my search I was found the KH O870 sub in a price little higher than KH O810 (+300$).

Which are your thoughts, with the O870 I will have the same results in SPL as 2 x O810?

It is a better option the O870 than one O810 or 2 x O810?

Any opinion?

I'm looking into the exact same sub scenario...

From a quick look at specs I thought the more expensive unit was built for bass management a la 5.1.

Looking forward to any other opinions...

As far as which sub option between the two, I'd go with two 810s so that I could place each with their respective main. It does make a difference over a single sub because you can hear where the bass is coming from in many instances. However,

A sub is only a good idea IF:

-The room can handle it acoustically, which would mean that it's either purpose built for critical listening or extensively treated properly to control reflections and excessive bass buildup (or if it's a room that is crazy large, so that reflections at the listening position aren't a problem).

-You actually have a need to hear what is going on in the ultra low frequency range. There isn't much music going on down there, so if you're getting the results you need then adding the complication of a sub isn't necessarily worth it. You have to know for certain you need it.

-You are going to properly integrate it with the mains. This means calibrating the entire system properly and placing the sub properly, as well as fine tuning the setup as needed. A sub when working properly in a critical listening environment when soloed sounds like it's not doing much at all. But when playback comes from all speakers the entire playback is greatly improved in realism, headroom and detail. But that ONLY happens when you properly integrate the sub in a room that doesn't suck.

The 0300 reaches quite deep. It's not really a necessity in most cases that one would need an additional sub with that set, as they come with properly integrated subs in each speaker cabinet. They reach down to 35Hz with a gentle roll off from there and that's very good. They're also exceptionally good in the time domain and I'd not want to mess that up. A poorly integrated sub (or subs, even more hassle) could make things much worse. Spending the kind of money you're talking about is only worth it if you're doing everything right with the room and integration of components.

I agree with your thoughts. My main need is to have a higher SPL from O300 and as a second one the improved low. The solutions which I found are:

1) KH O810 (10" woofer /200w) for 3500$ New
2) KH O870 (2 x 10" woofer /2 * 200w) 3800$ slightly used
3) 2 * KH O810 (10" woofer /200w) for 7000$ New

#3 seems as the more efficient & flexible solution but with the higher cost. I?m wondering if the #3 worth the additional money or it is close with #2.

Between #1 & #2 the prices are more or less the same..
My room is about 30SQM and not acoustically treated...

Hi Ketster,

Have you found any further information on this scenario?

You live near a good hifi shop? I'd consider finding something else, try it with your system and when you find something that works... buy it. I bet you 3500 bucks you'll spend less than 3500 bucks and be just as happy.
Heck, you might even discover a match made in heaven and have to tell all of us about it....

I'm curious: how much increase in SPL do you expect from adding one or more subs? I give credit to Neumann for embedding a lot of frank and useful info on their website about how they design their monitor systems and details on how they measure them. Also a good discussion of options for incorporation of subs, but I didn't see any figures on the difference a sub makes to max SPL. I suppose it depends on the distribution of energy vs. frequency in the program material of interest.

Cheers,

Otto

I would not be that sure. The K&H subs are one of the best and I never heard any sub, that costs much less, that is closely as good as the K&H. What me still astonishes the most (after 7 years of owning a O800) is how dry and accurate the lows sound. That's one of the things most of my clients say when they hear my K&H system the first time.

Most hifi subs can't handle strong lows tightly and cleanly. Mostly they just wobble around.


To the OP: I'd suggest you start with one O810 and if you later still feel you need more, get a second one. In general K&H are NOT made for high SPL. For high SPL, to check the club feeling, we have a PA system with 1500W that cost us 3k. Maybe that would be the better solution for you.

I don't know. I've heard the sub. Nice yes, but something as good or better can be had on the second hand hifi market.
No replacement for displacement. Size matters and that sub barely has it.
Just a suggestion though. Very fine sub.

As I see at KH product selection guide (http://www.neumann-kh-line.com/klein-hummel/globals.nsf/resources/neumann_product_selection_guide_v08_en20110906.pdf/$File/neumann_product_selection_guide_v08_en20110906.pdf)

the o300D may give with the o870 (high performance sub +6db) 112,8 + 6 =118,8 db @18Hz..

I don?t want exactly the club feeling but many times @95db the protection alarms are come flashing...
I?m just looking to see if I can improve the superb sound of this speakers to a higher level

My main speculation is if it is worth to go to o870 sub for +300$ instead of o810...

I'd have a good long chat with a knowledgeable dealer to verify this. Either sub extends rated output down to an 18 Hz cutoff. The overspec'd sub does give you more headroom and lower distortion down in that bottom octave from 18-35 Hz, but it won't raise overall max SPL, which will still be 112dB at 3% distortion.

Cheers,

Otto

Sorry for late response.

I got sidetracked buying a tape machine and outboard. Now I need to get my sub so I'm interested in the info the other posts here offer.

So in summary, the higher spec'd and priced units offer lower distortion, higher headroom? I s'pose this is what I should have expected. I guess if mastering is main bread and butter, then 870 the way to go. I think I could get away with saving some cash and getting the 810 or even 0800.