JTR Speakers. They can't be this good!!!

[rmk]

the soundbroker website mentioned a quintuple 8 speaker ...

i couldn't get the triple 8 because RMK had triple 12's - im pretty sure i'd get the buyer's remorse thing afterwards.

i couldn't get the triple 12 as that was too wide...

hmm, quintuple 8.

I think the new Triple 8's would have been a very nice solution for you and I seriously doubt you would have needed more speaker ... ever. To bad you missed that intro price as that would have covered the shipping cost.

 

[Robof83]

the soundbroker website mentioned a quintuple 8 speaker ...

i couldn't get the triple 8 because RMK had triple 12's - im pretty sure i'd get the buyer's remorse thing afterwards.

i couldn't get the triple 12 as that was too wide...

hmm, quintuple 8.

I doubt you would get buyer's remorse. In the email I received he said that there really was no difference in sound quality between the 8 and the 12. The 12 was just meant to do what the 8 could do, but louder.

 

[MidnightSensi]

I've heard the JTR 12s, /great/ speakers. I posted some impressions a bit back I'll take a look for.

Jeff at JTR is also a really nice guy.

Honestly, I think you will be fine with the XPA-5 unless you want to listen to AC/DC Live at Donington BR at reference levels. More power is always better but you can give a try and sell the XPA-5 if it doesn't get it done for you.

I have and like a Sunfire TGA 400/7 and it is rated @ 800WPC for the 4 Ohm 12LF's. The pro audio amps are a great value but the fan noise can be an issue if they will be kept in the room. There are some fan mods that make then run cooler and quieter. I use a QSC (recommended by Midnightsensi) for my subs and it has been a great amp but it is has some fan noise too. My equipment is in a separate closet so that is not an issue for me.

I also like the new Ice powered amps (D-Sonic and Wyred) but they are very pricey as compared to the EP2500.

Cheers. QSC makes a great amp, I've spent many-a-quality-time with them. QSC makes a great, reliable, amplifier at a good price.

I more recently realized that the Crest CC series amplifiers are almost silent, quieter than my PlayStation 3. They also make a great amplifier, I've used them a long time just never noticed how quiet they were until I connected one in my home theater. Needless to say, now my home theater rack is all Crest. Their protection is partially solenoid based, so when you turn it on it makes a big mechanical "clank" after it stabalizes but then after that they are extremely quiet.

Also, both QSC and Crest are American companies, which is a bit of a "thing" with me lately considering the economy.

 

[bandphan]

I think the new Triple 8's would have been a very nice solution for you and I seriously doubt you would have needed more speaker ... ever. To bad you missed that intro price as that would have covered the shipping cost.

you know he has "cone size" envy and no matter what Dr.Katz says, he still wants more

 

[jostenmeat]

mike does not like the cone of shame

 

[rmk]

I've heard the JTR 12s, /great/ speakers. I posted some impressions a bit back I'll take a look for.

Jeff at JTR is also a really nice guy.




Cheers. QSC makes a great amp, I've spent many-a-quality-time with them. QSC makes a great, reliable, amplifier at a good price.

I more recently realized that the Crest CC series amplifiers are almost silent, quieter than my PlayStation 3. They also make a great amplifier, I've used them a long time just never noticed how quiet they were until I connected one in my home theater. Needless to say, now my home theater rack is all Crest. Their protection is partially solenoid based, so when you turn it on it makes a big mechanical "clank" after it stabalizes but then after that they are extremely quiet.

Also, both QSC and Crest are American companies, which is a bit of a "thing" with me lately considering the economy.

Sure, NOW you mention Crest

 

[MidnightSensi]

Sure, NOW you mention Crest

Hahaha. Well, at the time I didn't know they were quiet, I always used them in noisey places. They don't advertise it (well, they advertise variable speed fans), and if I wouldn't have hooked one up one day in my theater I probably still wouldn't have noticed.

 

[rmk]

Hahaha. Well, at the time I didn't know they were quiet, I always used them in noisey places. They don't advertise it (well, they advertise variable speed fans), and if I wouldn't have hooked one up one day in my theater I probably still wouldn't have noticed.

Actually, the QSC is perfect for my use so no regrets there. If my Sunfire ever dies, I will look into Crest to drive the JTR's.

 

[WmAx]

After reading this review

http://www.jtrspeakers.com/12lf_review.html

I am a little in dis-belief. The reviewer claims that these $1500 speakers out-performed the $135,000 Alexandria X2s. Every review I have ever read about the X2s has glorified them beyond belief saying they makes speakers such as the B&W 800d sound like tin cans.

In another review, the reviewer claims that these speakers have also bested the likes of the Revel Salon speakers and the $20,000 Aerial 20T's.

Could these speakers truly be a diamond in the rough?

Artificial excitement.... even the 802D is engineered far better than then Alexandria (and costs but a tiny fraction)... difference is the 802D is probably far more linear in response. Want a nice roller coaster response? Add a nice DSP eq and you can get just about any sound you want out of an 802D, assuming good room acoustics (a must for any speaker). Only thing the Wilson has going for it is the impressive looking size/presence. None of Wilson's highest end speakers ever measured very well in the past - if the Alexandria 2 does, it would be a big surprise - they perform merely 'good' historically and use a hard wired EQ curve to get a specific coloration and response from certain people it seems. If you want the best overall measuring monopole commercial loudspeaker in the world, look towards the high end offerings from YG Acoustics.

-Chris

 

[WmAx]

Yamaha pro amps are superb for home use. They have ZERO fan noise. Superbly designed/built. Available in a large variety of power ranges to meet your needs. Reasonably priced (about the same as QSC RMX line).

-Chris

 

[Seth=L]

Yamaha pro amps are superb for home use. They have ZERO fan noise. Superbly designed/built. Available in a large variety of power ranges to meet your needs. Reasonably priced (about the same as QSC RMX line).

-Chris

Chris, I am curious what your thoughts are about these JTR speakers.

 

[WmAx]

A speaker like the JRT is not going to provide the absolute resolution and realism of a live unamplified performance, but they will perform superbly for HT/surround use and amplified live concert recordings/DVDs, etc.. You only need 100 watts/channel to have real concert level SPLs in your room. Just keep in mind, this is in the 115-120 constant slow weighted range and will start to cause permanent hearing damage inside of 30 minutes. Personally, 95dB is very loud to me - and even this will damage your hearing eventually. Classical music concerts vary, and very roughly, you can expect from about 77-85dB averaged slow weighting, with 20-35 dB peaks. Some large scale concerts with very specific music, will play on average louder, even in the lower to mid 90's on average - but this is not all that common. These dB ranges are based on typical seating positions by audience members. Obviously, the very front row... to the conductor to the musician perspective gradually increases in constant SPL level. Typical high end speakers like 802D as example, have more than ample dynamic range to reproduce these kinds of performance. However, when one wants to actually reproduce the SPL ranges of live amplified concerts..... you obviously need something with greater output. You do in most cases, give up absolute SQ for this SPL ability. It is possible to get this SPL level without any compromise, or very little compromise, but this would require extremely expensive solutions such as a special line array speaker with low resonance construction (this would result in huge expense and very high mass). It may also be possible to come close for less money, using a very specific combination of pro drivers. The primary problem here is that it would have to be at least a 5 way system, most probably, to avoid the problems of the very narrow ideal bandwidths of the very high sensitivity pro drivers. I may look into this area of design later on, if demand for such sensitivity ranges is more popularized. I'm not one to not have practical engineering experience in designing a 'state of the art performance' version of anything related to consumer sound reproduction loudspeakers, if it can be helped.... and there seems to be some potential here.

-Chris

 

[WmAx]

Chris, I am curious what your thoughts are about these JTR speakers.

Indeed. I just posted them.

-Chris

 

[rmk]

A speaker like the JRT is not going to provide the absolute resolution and realism of a live unamplified performance, but they will perform superbly for HT/surround use and amplified live concert recordings/DVDs, etc.. You only need 100 watts/channel to have real concert level SPLs in your room. Just keep in mind, this is in the 115-120 constant slow weighted range and will start to cause permanent hearing damage inside of 30 minutes. Personally, 95dB is very loud to me - and even this will damage your hearing eventually. Classical music concerts vary, and very roughly, you can expect from about 77-85dB averaged slow weighting, with 20-35 dB peaks. Some large scale concerts with very specific music, will play on average louder, even in the lower to mid 90's on average - but this is not all that common. These dB ranges are based on typical seating positions by audience members. Obviously, the very front row... to the conductor to the musician perspective gradually increases in constant SPL level. Typical high end speakers like 802D as example, have more than ample dynamic range to reproduce these kinds of performance. However, when one wants to actually reproduce the SPL ranges of live amplified concerts..... you obviously need something with greater output. You do in most cases, give up absolute SQ for this SPL ability. It is possible to get this SPL level without any compromise, or very little compromise, but this would require extremely expensive solutions such as a special line array speaker with low resonance construction (this would result in huge expense and very high mass). It may also be possible to come close for less money, using a very specific combination of pro drivers. The primary problem here is that it would have to be at least a 5 way system, most probably, to avoid the problems of the very narrow ideal bandwidths of the very high sensitivity pro drivers. I may look into this area of design later on, if demand for such sensitivity ranges is more popularized. I'm not one to not have practical engineering experience in designing a 'state of the art performance' version of anything related to consumer sound reproduction loudspeakers, if it can be helped.... and there seems to be some potential here.

-Chris

Actually, the JTR’s (note letter sequence) are excellent for orchestral and un-amplified acoustic music. Of course that opinion is based upon actually listening to the speakers in question playing said music.

They do however rock hard when asked to do so.

Sorry to interrupt … you were saying?

 

[WmAx]

Actually, the JTR’s (note letter sequence) are excellent for orchestral and un-amplified acoustic music. Of course that opinion is based upon actually listening to the speakers in question playing said music.

They do however rock hard when asked to do so.

Sorry to interrupt … you were saying?

Unfortunately, the design premise of the JRTs would prohibit real sounding unamplified music reproduction. Such reproduction requires extreme low resonance, of both the cabinets and drivers, as well as a very wide off axis response. While I have not measured the JRTs, I am extensively familiar with the driver types used, their measured characteristics and as well, I can not see anything special about the cabinet used that would make it have extreme low resonance. This gives me a very good idea of the potential and limitations possible, measurably, from the speaker. If you have data showing this is immune to such typical limitations, that is, this speaker line uses some extremely innovative technologies to overcome these limits, that would make for an interesting read.

But you do realize my requirements for a 'hi-fi' speaker are not sane, right?

-Chris

 

[browninggold]

who makes the JRTs?

 

[rmk]

Unfortunately, the design premise of the JRTs would prohibit real sounding unamplified music reproduction. Such reproduction requires extreme low resonance, of both the cabinets and drivers, as well as a very wide off axis response. While I have not measured the JRTs, I am extensively familiar with the driver types used, their measured characteristics and as well, I can not see anything special about the cabinet used that would make it have extreme low resonance. This gives me a very good idea of the potential and limitations possible, measurably, from the speaker. If you have data showing this is immune to such typical limitations, that is, this speaker line uses some extremely innovative technologies to overcome these limits, that would make for an interesting read.

But you do realize my requirements for a 'hi-fi' speaker are not sane, right?

-Chris

Now I understand the problem ... you are describing JRT speakers which obviously you have heard, though as you say, never measured. Never heard of those myself, but I'm sure they are just as you describe them.

This thread is about JTR speakers.

Oh, and for the record, I do realize the "not sane" part.

 

[MidnightSensi]

Classical music concerts vary, and very roughly, you can expect from about 77-85dB averaged slow weighting, with 20-35 dB peaks.

30-35dB peaks?

So, um, lets take 80dB with 35dB peaks...

To handle those peaks without any clipping, with a 100watt sensitivity JTR you'd need 285watts at 9 feet. Which, it would handle no problem.

With a (generous) 90watt sensitivity of the B&Ws you'd need 2846watts at 9feet. ...which, I'm pretty sure the B&W would end up on your lap if you fed it that.

Now I understand the problem ... you are describing JRT speakers which obviously you have heard, though as you say, never measured. Never heard of those myself, but I'm sure they are just as you describe them.

This thread is about JTR speakers.

Oh, and for the record, I do realize the "not sane" part.

I've never heard the JRTs either.

The JTRs I did hear, one of the most striking things about them was the off axis response and wide coverage. It's probably one of the most obvious things someone would note on the speaker, and one of the funnier moments of our experts input on the "JRT" speakers.

 

[WmAx]

30-35dB peaks?

So, um, lets take 80dB with 35dB peaks...

To handle those peaks without any clipping, with a 100watt sensitivity JTR you'd need 285watts at 9 feet. Which, it would handle no problem.

With a (generous) 90watt sensitivity of the B&Ws you'd need 2846watts at 9feet. ...which, I'm pretty sure the B&W would end up on your lap if you fed it that.

I did quote those figures as the most extreme I have ever come across on any recording. 35dB is huge - but I have an opera recording from Mapleshade with that peak value over the RMS average value of the recording. I found that the recording sounded most realistic played at about 78dB average slow weighted. This required a peak value of just over 110dB for the maximum peak in the opera. 22-25db is the most common peak value for classical music. These peaks are instantaneous, lasing a few milliseconds at best. A speaker can easily handle 10x or more it's normal maximum power rating for a few milliseconds. The large speakers with high power handling and regular sensitivity levels can generally reach 110dB peaks when used in a pair, in a normal size room, without significant distortion. Also, the peak power is band weighted; almost always residing primarily in the LF to mid-bass band; with mid-range and treble progressively decreasing in actual power ratio. So, while if 110dB peak is true, this will be in the bass or mid-bass band, and as you cross the 400-500Hz threshold, 4-6dB average reduction in SPL average is true, and as you cross to treble, the SPL average ratio reduces further. The 802D as an example, places the mid-range xover point close to this first transition, so that the twin 8" woofers handle the majority of power. They should be fine for 110 or slightly higher peak ranges from 70-80Hz on up; but I would recommend high power subwoofer for under 70-80Hz so that full dynamic range can be realized.

General pop/rock/jazz has peak values of 15-16 dB if it's a modern audiophile high quality version, or a popular release from the early to mid 90's. 8-12 dB if it's a modern popular release on the top 50. If it's an 80's to early 90's super high quality recording of pop/jazz, it may have peaks of 18 - 22 dB.

I have gathered a great deal of statistical data on recordings from different genres and eras in order to be able to know appropriate power requirements and speaker requirements for a wide variety of scenarios.

I did make it clear that some people will require a very high sensitivity speaker to meet their particular preference(s) as the most practical solution.

I've never heard the JRTs either.

The JTRs I did hear, one of the most striking things about them was the off axis response and wide coverage. It's probably one of the most obvious things someone would note on the speaker, and one of the funnier moments of our experts input on the "JRT" speakers.

What you may consider 'wide coverage' is average to me. The JRT, based on inspection of the driver used for treble and the loading caused by the co-axial design, will at best equal the coverage afforded by a standard monopolar hi fi speaker design using a direct radiator 1" - 3/4" diameter tweeter; I do note this as potential - it's probably slightly worse, but it's hard to determine the specific cone profile used as the waveguide in the pictures. You really need even much wider dispersion to produce the effect of a more spacious/wider stage and more natural timbre for treble in the home environment; effects all well known in regards to perceptual research and correlation to the relevant dispersion. Ideally, to meet the potential, the speaker needs to have constant directionality as far as 70-75 degrees +/- (150 degree window) horizontally, and this needs to include the primary audible range (up to 14-15kHz minimum).

Do note this is only about dispersion/polar response. There are of course other issues that need to be addressed besides just dispersion.

-Chris

 

[fredk]

30-35dB peaks?

So, um, lets take 80dB with 35dB peaks...

To handle those peaks without any clipping, with a 100watt sensitivity JTR you'd need 285watts at 9 feet. Which, it would handle no problem.

With a (generous) 90watt sensitivity of the B&Ws you'd need 2846watts at 9feet. ...which, I'm pretty sure the B&W would end up on your lap if you fed it that.

Geez sensi, I had to run the numbers through the calculator to be sure. I'm sitting at 8' with 91db sensitivity and tend to listen at 80-85db max and know that gets me to between 60 and 70w with 20db of headroom.

I keep forgetting how quickly you run out of power once you pass the threshold.

FWIW I have measured as much as 25 db of dynamics from average on my limited classical collection (and my lowly ratshack meter).