And here it is, the 340SE2!!!

[James]

Another educational post from the GOAT himself!

This is why I hesitate to take REW measurements. I see some weird response stuff and then think there are flaws to fix, but I am probably not even hearing any effects from it. Measurements are a great way to see what is happening in your room though. I will go back into my MiniDSP at some point and try to improve my dual subwoofer response, but it sounds pretty great now and I worry that I'll make it worse!

It's an interesting process, for sure.

I've been playing with using the psychoacoustic smoothing for eq instead of the variable smoothing - if it really better represents what we hear, it seems like it would be better for eq correction.

The main difference seems to be that the eq corrections with the psychoacoustic smoothing are broader and shallower than with the variable. The frequencies and amount of filters are essentially the same.

[davef]

This is how we deal with floor bounce in order to get more accurate production line measurements. A bit messy, but effective... Warning, only try this if you are single (trust me on that)

IMG_6209.jpg

[davef]

Will an upgrade kit be made available?

I am sorry but due to critical cabinet changes, it is not possible to upgrade a 340SE to 340SE2.

[Jamy]

I am sorry but due to critical cabinet changes, it is not possible to upgrade a 340SE to 340SE2.

Yeah I knew there were cabinet changes, so wasn't expecting cabinets as part of any upgrades. Was hoping the new drivers, tweeters, etc would be sold as an upgrade.

[curtis]

Yeah I knew there were cabinet changes, so wasn't expecting cabinets as part of any upgrades. Was hoping the new drivers, tweeters, etc would be sold as an upgrade.

The SE2 has a different cabinet, it isn't just the drivers and crossovers.

So you can't take an SE and just put in the new drivers and crossover to make it an SE2.

[TimW]

Yes, this is floor bounce and this reflection should be left alone. It is not advisable to attempt to correct for this by boosting a frequency range. This reflection is determined by the distance of the driver to the floor, the distance from your ear to the floor, and the distance from your ear to the driver. Even a slight change in listener positioning will have dramatic effects on this reflection, such that if you attempt to correct for it by boosting this frequency, you will cause more damage than good by ruining the overall in-room response. Best method to reduce this dip is to throw a bunch of thick pillows on the floor, located halfway between you and the speaker.

Thanks for the insight Dave. I have wondered whether floor bounce dip is really an audible issue or just a measurable one. I imagine simply boosting the frequency response of the speaker in that region could cause more problems than it solves, although this is probably what an automated room correction system would do. The measurements of my room which show the dip are taken using the MMM technique which uses a moving microphone with an RTA and averaging. It is not a single point measurement and it covers the whole area around my listening position. Even with all of that averaging, the dip is still there so it seems like it would be audible.

I also do not recommend this. You can't simply add drivers to an empty cabinet and assume it will turn out well. Those midbass drivers would have to have a very steep low pass filter at a decently low frequency with the proper Q to even hope to get them to blend and properly sum with the bass response of the 340SE2 (or any speaker). This isn't a simple task, and you could not do it passively - it would have to be an active crossover with proper phase compensation and its own amplifier, and if that is even accomplished, you would then have to high pass the woofers in the 340.

Well I used WinISD to compare multiple woofers in the volume I estimated for that stand (0.78 cu ft). Assuming an imperfectly sealed enclosure with moderate stuffing, QTC would be roughly 0.65 using two of those Peerless woofers. I would use my MiniDSP SHD for crossovers using LR4 slopes. I would have to play with the crossover and delay settings to get a good response and then let Dirac do the final smoothing. I'm just not sure how much of a benefit these woofers could bring vs a 8" subwoofer placed behind the mains. The woofers in stand would lack as much rear wall reinforcement and wouldn't be as close to the floor as an 8" sub. However, if the two woofers are spaced vertically there will be different floor bounce frequencies and the average between those should be smoother. Interestingly the CMT-340 should exhibit this behavior already since it is an MTM.
Two woofer averaging.jpg

[davef]

Yeah I knew there were cabinet changes, so wasn't expecting cabinets as part of any upgrades. Was hoping the new drivers, tweeters, etc would be sold as an upgrade.

There is different port tuning (a different port tube) and the new crossover will not properly fit into the older cabinet without significant work. The 340SE has the crossover attached to the bi-wire terminal cup, the 340SE2 uses a different terminal cup and the crossover is mounted internally. Upgrading the old 340SE would be extremely difficult and frankly, you would need (2) new woofers, the new tweeter, the new port tube, the new crossover and when we must factor in the testing and labor on our end, any possible 340SE2 upgrade kit would actually cost more than simply buying new.

I am sorry, but from a difficulty standpoint and cost standpoint, it simply does not make logical sense to offer this.

[davef]

Thanks for the insight Dave. I have wondered whether floor bounce dip is really an audible issue or just a measurable one. I imagine simply boosting the frequency response of the speaker in that region could cause more problems than it solves, although this is probably what an automated room correction system would do. The measurements of my room which show the dip are taken using the MMM technique which uses a moving microphone with an RTA and averaging. It is not a single point measurement and it covers the whole area around my listening position. Even with all of that averaging, the dip is still there so it seems like it would be audible.


Well I used WinISD to compare multiple woofers in the volume I estimated for that stand (0.78 cu ft). Assuming an imperfectly sealed enclosure with moderate stuffing, QTC would be roughly 0.65 using two of those Peerless woofers. I would use my MiniDSP SHD for crossovers using LR4 slopes. I would have to play with the crossover and delay settings to get a good response and then let Dirac do the final smoothing. I'm just not sure how much of a benefit these woofers could bring vs a 8" subwoofer placed behind the mains. The woofers in stand would lack as much rear wall reinforcement and wouldn't be as close to the floor as an 8" sub. However, if the two woofers are spaced vertically there will be different floor bounce frequencies and the average between those should be smoother. Interestingly the CMT-340 should exhibit this behavior already since it is an MTM.
Two woofer averaging.jpg

Rather than trashing a TP-24 stand, I'd recommend simply getting some MDF and build a single cabinet to experiment with. Once completed, if you get the results you hope, then order a pair of stands.

[Nnice]

I'm curious if anyone has opinions/reviews on the sound of these, specifically how is the level of resolution compared to the Sierra 1's and luna's. Thanks.

[davef]

I'm curious if anyone has opinions/reviews on the sound of these, specifically how is the level of resolution compared to the Sierra 1's and luna's. Thanks.

I would say resolution is easily on par with Sierra-1's, with a slight disadvantage in resolution compared to the Luna (due to the RAAL ribbon tweeter). The 340SE2 offer effortless dynamics combined with high efficiency and a very smooth non-fatiguing yet detailed presentation.