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Forte II, why so bass shy?


vondy

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Guess I'm going to have to do some experimenting to figure it out. Thinking about moving them into a smaller room I can close off just to see the difference. I've checked all the wiring several times but have not switched the old crossovers back in. I think I still have them....?   Couple things to make clear... I'm not expecting sub bass from these. I'm expecting more of a live bass. My two channel listening, which is what I'm describing, is from my Emotiva, or HK 430 in the past, not my Onkyo AVR.   I'm hoping all I need to do is upgrade amps, otherwise I'll eventually have to find another speaker that will work in my room. My old JBLs I had since high school had plenty of punch in this room. The fortes should too I suspect.   Thanks for everyone's thoughts.
I'm sliding in here without reading everyone's posts up to now, but I don't think the amount of power available has much of anything to do with the issue.  Pardon me if others have raised this, but have you checked for your Fortes being in phase, and for whether your individual drivers are in phase within each speaker and between your speakers?  You can really hear out-of-phasenss by the tendency of the speakers, or of some drivers, to seem to (a.) want to pull your ears apart, or (b.) a tendency of the volume level to drop as you walk around the speakers.  If the character of the blending changes when you walk around the speaker or speakers, then something might be out of phase.

 

Speakers out of phase will lose a lot of bass!

 

You need to have an expert hi-fi listener come over to your place.  Don't you have quite a few of those around your parts?

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Strangely enough, I just turned on Pandora through my avr for some background music. Noticed how much better the bass seemed. The onkyo has more power than my 2 channel amps but I've never really enjoyed it for 2 channel listening. It does have deeper bass at lower levels though. Maybe the EQ kicking in?

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I'm always a bit confused over the ohms, fortes say 8 ohms on the back so where would all this 4 ohms talk come into play?

 

 

 

The 8 ohm rating on the back is considered the "nominal rating" and the actual impedance will typically change from the nominal rating with changes in frequency.   Basically, an impedance analyzer is used to measure the loudspeaker’s impedance as it will change across the frequency range.  The lowest impedance that is measured is typically at DC, which is also known as the DC resistance. The IEC method of specifying the nominal impedance of a speaker is set so that minimum impedance should not fall below 80% of nominal.  Therefore, in general, an 8 ohm nominal rating of a speaker should be 6.4 ohms minimum; and for a 4 ohm nominal rating it should be 3.2 ohms.  However, in certain situations the "nominal ratings" that we see for consumer speakers do not seem to follow this formula.

 

I posted the impedance curves of the Forte II and several other Klipsch speakers to demonstrate how it can vary among the different Klipsch speakers.  For example, with the Klipsch Forte II (re-posted below), has an overall impedance curve that is all over the place and varies widely. The chart demonstrates that the Forte II impedance curve drops to a low of almost 3.5 ohms at the range between 100 Hz to 200 Hz and rises to a peak of about 106 ohms at about 2,150 Hz. 

 

 

 

_ Forte II impedence curve.jpg

Edited by Fjd
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Fjd, I'd like to know what the folks at prestonelectronics are smoking.

Impedance matching is only applicable in telecommunications, radio engineering, and transmission lines. It isn't even a factor in constant voltage loudspeaker systems/ pro audio. The statement regarding impedance matching as being the best way to maximize power transfer in audio, isn't accurate. An exception might be when using a zero feedback tube amp.

Earlier, I pointed out that high sensitivity extends the headroom of amplifiers by default. The OP is using a watt or less. I used to run Heresys with a battery powered Tripath amp! Placed the way intended - the bass was just fine.

Vondy, buy bigger loudspeakers or add a powered subwoofer, "there's no replacement for displacement". This whole impedance thing is a non-issue. Paul Klipsch was not a moron.

Edited by Deang
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Just my opinion, but it seems like the Forte is a speaker that some people love while other people find all the imperfections unlistenable. I find myself in the group of people who find them unlistenable... either that, or there was major quality control issues going on at the time of their production.

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I had the same lack of bass and harsh treble from my Forte II's when I bought mine a few months back, they were replacing a pair of Dynaco a25's because I needed a bigger speaker to fill my room, the Fortes were a disappointment at this point to be truthful but as soon as I replaced the ribbon like DMN cable that worked so well with the Dynaco's with a heavy gauge cable (Supra) the speakers came to life and I'm very happy with them now, plenty of bass and the shrillness gone.  

 

I originally bought the Forte's to front a few low powered amp's I had gathered over the years, they work well with most of the amps particularly the 22 series of Marantz receivers and the early wood cased Sugden class-A A21 (IMO)

Edited by lionheart-uk
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I'm no physicist and my engineering degree is not electrical. However, my Forte IIs are in a 15x30 room being driven by a Cambridge CXA80 integrated amp with Zu Audio cables.

My experience is amazing, rich full bass that fills the space. Speakers are 10" off the wall, but not nestled into the corners. Probably 3 ft from the corners. I had planned for a sub, but see no need to do so. Best $750 I've ever spent.

Joe Bonamassa is sounding particularly nice with my cup of coffee this morning.

BTW....If you've never heard the live acoustic recording from the Vienna Opera House, you're missing out. This performance had no bass guitar or full drum kit, so the bass is infrequent and from more exotic and sometimes simplistic percussive elements. IMO, making it more pronounced and punchy at times.

Anyway, I offer no expertise on the root cause, but suggest you are not listening to proper Forte IIs. Something is wrong, and like some others, I don't believe it's the space.

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Room it is. I moved them into our bedroom and hooked them up to the HK. No problem rattling the windows on some more bass heavy songs.

In here I'm able to close off all the doors and pull the shades down. Room is also bigger and more square.

Guess the next step is to build my sliding barn door for the living room and see if that helps by closing it off. That or buy a new house just for the fortes ;-)

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I've been thinking it is a power issue or an acoustics issue, and it seems you have narrowed it to an acoustics problem. I'll bet you have a couple of things going on:

 

1) There is quarter wave cancellation due to the width between the centers of the Fortes and the woofer-to-ceiling height being close to the same. I didn't see a height listed for the room, I'm assuming 8 foot ceilings. Having these dimensions equal can create a serious bass suckout around 35 to 50 Hz depending on the exact distances. Solution - move speakers. 

 

2) If the floors in that room are hardwood with no carpeting, large area rugs, or drapes covering windows there may be excess treble energy in the room that makes the bass seem weak in comparison. Solution - apply carpeting or rugs in front of the speakers and consider acoustic treatments for the room.

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It would be simple to test if Don is right about the bass cancellation. 

 

Take the speakers into a different room and place them farther apart. If there is a difference, then the room modes are to blame for the lack of bass. It might not just be the triangulation causing it. By the dimensions alone, you have axial modes at 51Hz. That's right about where the chest thumb bass lives.

 

I noticed all your furniture is against the wall. My experience has taught me that bass is poor at the walls. This is subjective, but it seems like there is science behind that; I can't remember. Try moving out a even a little bit and the bass may improve. 

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Floors are hardwood, rug in from of the speakers, lots of furniture and shades over windows.

 

We are pretty much stuck with this layout. Like I said, next project will be a sliding barn door to close the room off. If that doesn't help, might have to think about getting some speakers that are easier with this room.

 

I don't know if that means I need something bigger like a cornscala, or do I need something more mainstream like from the reference series, or even another brand that is less sensitive to room placement.

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Your bedroom experiment (?lol)  was exactly what was needed here. My forte II live in a 14x14 mahogany paneled office 8' ceiling and I can tear the roof off with a 60 wpc Yamaha receiver. 

 

 

What is your square/cubic footage please??  It matters a LOT how much air you're trying to energize. It's not going to be concert levels within that entire space with only a pair of forte II, no. 

 

 

 That attached kitchen area is part of this room for acoustic purposes. Let's remember that THX specs ( as a starting point for our illustration) operate in a 3000ft3 space, and that requires a 1000 watt amp and two specially designed subwoofer cabinet.  

 

It's not the room placement, it's a matter of efficiency and wattage for the given space.  With Klipsch you're dealing with some of the most efficient speakers on the market so you're correct there.  For really ripping sound in that space you have, something like LS would make a lot of sense. Do you have some numerical expectation of decibel level you hope to achieve for peaks/ average listening in this rooom? 

Edited by colterphoto1
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Below is a side-by-side comparison of the two rooms. In the bedroom, all doors and blinds were closed. Ceilings are 8 ft. in both.

 

The kitchen area connected to the living area is larger than the bedroom FYI.

 

Would a cornscalla be a better fit to energize the area? I'll probably go with a sliding barn door to close the living room off when listening, that also helps keep the sound down at night when everyone else is asleep. 

post-20986-0-37720000-1465847783_thumb.p

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