What are some really good values in speakers?

[Steve81]

So I agree, you don’t necessarily need a waveguide or horn to get wide off axis dispersion, but it is certainly one way of achieving it, and really the only way to achieve it in two way designs.

As a KEF fan, I like waveguides as much as anyone. OTOH, Dennis produces some excellent sounding and measuring equipment, including two-ways like his Philharmonitor:


Personally, I'd call that pretty good dispersion performance, but YMMV.

 

[yepimonfire]

As a KEF fan, I like waveguides as much as anyone. OTOH, Dennis produces some excellent sounding and measuring equipment, including two-ways like his Philharmonitor:
View attachment 22624

Personally, I'd call that pretty good dispersion performance, but YMMV.

I’d call that perfect ha.


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[ATLAudio]

@yepimonfire

Is there anything you don’t know?

Serious question.

 

[Dennis Murphy]

I was mostly referring to two way designs. Your run of the mill speakers with 5.25” or 6.5” woofers and a 1” dome tweeter with a 2500hz xover.

If you follow the rule that a driver should have a ka=2 at the crossover frequency, an effective piston diameter of 5” sets this point at 1706hz, a 6” diameter 1312hz. Most soft dome tweeters would be destroyed by such a low crossover point, ignoring the massive distortion from them that low as well. With a two way design, the only way to manage such a low xover point is a waveguide or horn, which controls the excursion of the driver within it operating range. A titanium dome tweeter attached to a horn/waveguide in, for example, the RP-150m speakers I own, are crossed over at 1500hz, perfectly matching the directivity of the drivers. Klipsch uses the exact same tweeter for all of their reference speakers, but each one is crossed over differently depending on the woofer diameter and horn size. An rb 10 with a 4” woofer has an xover of 2200hz, while the 150m using a 5” driver has an xover of 1500hz, matching the directivity of both woofers.

You are correct that a horn by itself cannot reduce beaming, but horn/waveguide mounted tweeters are usually fit with a phase plug in order to direct the highest frequencies into the horn/waveguide for dispersion control.

I 100% agree with what you have said, that good crossover design and matching of drivers can provide perfect off axis response. As previously stated, I was only referring to typical direct radiating two way designs. 3 way or 4 way speakers can be better matched with good crossover design for excellent off axis dispersion. With a two way direct radiating design, a “proper crossover point” matching the drivers directivity doesn’t exist in designs utilizing 5”+ woofers. The woofer will start to beam as the wavelength of the frequency approaches the diameter of the woofer, and even if some magic tweeter could somehow survive a low xover point, a 1” tweeter will start beaming at about 8500hz. 9/10 polar plots I’ve seen of common two way designs display problems at the 2500 xover frequency vertically off axis, and a rapid drop off off axis beginning at around 8khz because of this.

The solution is (like you mentioned) a multi way design with good driver/crossover matching based on directivity or a tweeter mounted to a waveguide/horn that allows a lower crossover frequency, using a phase plug to direct the highest frequencies into the waveguide for controlled dispersion.

So I agree, you don’t necessarily need a waveguide or horn to get wide off axis dispersion, but it is certainly one way of achieving it, and really the only way to achieve it in two way designs.

While I don’t agree with everything he says (especially his aversion to line arrays in live sound) I think this guy makes a good case as to why he insists on 4 way designs (or 3 way with a sub) http://education.lenardaudio.com/en/05_speakers.html




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Thanks for the very informative reply. I think this comes down to a question of what's really necessary to achieve satisfactory sound from a 2-way. There's no arguing with physics. A typical 5" - 6" will start to narrow in dispersion before it reaches the crossover frequencies that are dictated by the tweeter's limited low-frequency extension. Eventually the off-axis response is going to get ragged due to differences in the tweeter and woofer dispersion, and that will show up to some extent in the delayed reflected sound. Assuming you can keep things fairly tidy up to around 40 degrees off axis, I just haven't found the dispersion mismatch to be a problem in my designs. At the same time, my 3-ways do throw a broader and deeper sound stage. I'm not at all sure that a wave guide would change that disparity, because I don't see how the guides can broaden dispersion. They just keep the response tidier when the off-angles start to get fairly large. I haven't heard any advantage to this in 2-ways with wave guides, and I have heard colorations and squished vertical sound stages from some.

I'm still confused by your discussion of beaming from a tweeter at higher frequencies. Again, wave guides don't increase dispersion. And I don't see how they can avoid dips at the crossover frequency vertically off axis. Those dips are caused by cancellation between the woofer and tweeter because their relative distances to the mic or ear change as you move up or down vertically, and that changes the phase relationships. I think that will occur with or without a wave guide. The cause is not related to dispersion. I think the only way to avoid that is with concentrically mounted drivers.

This is certainly an interesting issue, and one that I don't think has been definitively resolved. I probably should order a pair of JBL's (some cheap ones) and listen and measure carefully. Or maybe some Klipsch--what's the cheapest model I can get away with that has what you think is a successful wave guide implementation?

 

[KEW]

This is certainly an interesting issue, and one that I don't think has been definitively resolved. I probably should order a pair of JBL's (some cheap ones) and listen and measure carefully. Or maybe some Klipsch--what's the cheapest model I can get away with that has what you think is a successful wave guide implementation?

I don't know if an active monitor is a consideration, but the JBL lsr305 runs around $300/pr. AFAIK, it has the distinction of being the lowest priced speaker that claims to be based on the wave guide/horn technology used for the M2's. When TheWarrior and ATLAudio were sitting at the LP, I picked up one of the monitors and moved it all around by more than 30 degrees off-axis at the extremes and they did not hear a change in the sound. I think the new Klipsch horns are very nice compared to older designs, but if you are wanting to experience the best example for the lowest price, I'd give the nod to the JBL's!
You can likely do a quick and dirty evaluation at you local pro audio shop (these are popular speakers and most places like Guitar center would have them on display).
One of the members here found them for $258 recently (maybe at B&H)
Also, as Speakerman/Phil pointed out, they were discounted to $200 for Black Friday sale last year if you want to wait a few weeks.

 

[speakerman39]

Also, as Speakerman/Phil pointed out, they were discounted to $200 for Black Friday sale last year if you want to wait a few weeks.

Kurt, the 305's can be had for $258 shipped as we speak. But, between Black Friday and Christmas day I look to see them go back on sale for $200 shipped!

http://www.pssl.com/Studio-Monitors-Active/JBL-LSR305-5-Inch-Powered-Studio-Monitor-Each


And Here:


https://www.crutchfield.com/p_855305/JBL-LSR305.html?tp=63655



Cheers,

Phil

 

[Dennis Murphy]

I don't know if an active monitor is a consideration, but the JBL lsr305 runs around $300/pr. AFAIK, it has the distinction of being the lowest priced speaker that claims to be based on the wave guide/horn technology used for the M2's. When TheWarrior and ATLAudio were sitting at the LP, I picked up one of the monitors and moved it all around by more than 30 degrees off-axis at the extremes and they did not hear a change in the sound. I think the new Klipsch horns are very nice compared to older designs, but if you are wanting to experience the best example for the lowest price, I'd give the nod to the JBL's!
You can likely do a quick and dirty evaluation at you local pro audio shop (these are popular speakers and most places like Guitar center would have them on display).
One of the members here found them for $258 recently (maybe at B&H)
Also, as Speakerman/Phil pointed out, they were discounted to $200 for Black Friday sale last year if you want to wait a few weeks.

Thanks, but I'm really looking for a passive design. I'm not equipped to run active monitors in my main listening room, and actives wouldn't work well with my measurement setup.

 

[lovinthehd]

Thanks, but I'm really looking for a passive design. I'm not equipped to run active monitors in my main listening room, and actives wouldn't work well with my measurement setup.

I'd be interested in your take on the JBL 530 but they're kinda pricey at the moment ($1660/pr at Amazon for some reason, altho the retail was much less). Maybe the JBL 230, it seems to get a fair amount of praise and they're $300/pr at Amazon at the moment.

 

[Dennis Murphy]

I'd be interested in your take on the JBL 530 but they're kinda pricey at the moment ($1660/pr at Amazon for some reason, altho the retail was much less). Maybe the JBL 230, it seems to get a fair amount of praise and they're $300/pr at Amazon at the moment.

$1,660--nope. $300--maybe. It's passive, right?

 

[lovinthehd]

$1,660--nope. $300--maybe. It's passive, right?

Yes, both are passive.

 

[yepimonfire]

Thanks for the very informative reply. I think this comes down to a question of what's really necessary to achieve satisfactory sound from a 2-way. There's no arguing with physics. A typical 5" - 6" will start to narrow in dispersion before it reaches the crossover frequencies that are dictated by the tweeter's limited low-frequency extension. Eventually the off-axis response is going to get ragged due to differences in the tweeter and woofer dispersion, and that will show up to some extent in the delayed reflected sound. Assuming you can keep things fairly tidy up to around 40 degrees off axis, I just haven't found the dispersion mismatch to be a problem in my designs. At the same time, my 3-ways do throw a broader and deeper sound stage. I'm not at all sure that a wave guide would change that disparity, because I don't see how the guides can broaden dispersion. They just keep the response tidier when the off-angles start to get fairly large. I haven't heard any advantage to this in 2-ways with wave guides, and I have heard colorations and squished vertical sound stages from some.

I'm still confused by your discussion of beaming from a tweeter at higher frequencies. Again, wave guides don't increase dispersion. And I don't see how they can avoid dips at the crossover frequency vertically off axis. Those dips are caused by cancellation between the woofer and tweeter because their relative distances to the mic or ear change as you move up or down vertically, and that changes the phase relationships. I think that will occur with or without a wave guide. The cause is not related to dispersion. I think the only way to avoid that is with concentrically mounted drivers.

This is certainly an interesting issue, and one that I don't think has been definitively resolved. I probably should order a pair of JBL's (some cheap ones) and listen and measure carefully. Or maybe some Klipsch--what's the cheapest model I can get away with that has what you think is a successful wave guide implementation?

A waveguide or horn doesn’t reduce dips at the xover by itself, it’s the ability to use a lower xover than one could normally get away with due to acoustic loading. A tweeter loaded in a horn or waveguide can be crossed over at 1500hz, or lower, vs 2500hz.

A waveguide also by itself doesn’t stop beaming, but a phase plug does, by directing very high frequencies away from the center and into the horn, some horn/waveguide geometries also incorporate modifications to improve directivity control of high frequencies, for example, the old Klipsch tractrix horn from the Reference II series started rolling off quite sharply at about 10khz, the newly designed modified tractrix horn incorporated a circular throat to improve the control over high frequencies. While the exact engineering behind it is a mystery due to it being a trade secret, the measurements show a clear difference in off axis response.

I have no doubt your designs do not need a waveguide, obviously there is more than one way to achieve consistent off axis response.

If you want to analyze and measure some speakers with waveguides, a pair of open box Klipsch rp-150ms will run you about $280 on eBay. I haven’t actually had a chance to measure any jbl designs, but I suppose you could look to their cheaper studio monitors.

It would be very interesting to hear your thoughts on them.

This has been an interesting discussion, and I do realize you are far more knowledgeable than me in speaker design, and appreciate you humoring me


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[ATLAudio]

@yepimonfire

Your inane conclusions about the RP vs Ref II are as wrong today as they were wrong when you first did your “measurements.”

 

[KEW]

If you want to analyze and measure some speakers with waveguides, a pair of open box Klipsch rp-150ms will run you about $280 on eBay.

Do you mean RP-150M?
Google gave me 150M instead of 150MS when I searched for these.

If it is the 150M, NewEgg has them for $300/pr. (refurbished)

 

[yepimonfire]

Do you mean RP-150M?
Google gave me 150M instead of 150MS when I searched for these.

If it is the 150M, NewEgg has them for $300/pr. (refurbished)

Yup. Ebay has them cheaper for open box. I got mine for $279 and free shipping.


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[bboro30]

I enjoy the speaker theory conversation, because I don't know much on the topic. The few speakers o have heard with wave guides (including new klipsch's) always sound bright and at least a tad harsh in the long run. I have a pretty simple speaker theory: If I need new speakers, I look to Dennis Murphy.

 

[shkumar4963]

As a KEF fan, I like waveguides as much as anyone. OTOH, Dennis produces some excellent sounding and measuring equipment, including two-ways like his Philharmonitor:
View attachment 22624

Personally, I'd call that pretty good dispersion performance, but YMMV.

What is the resolution on these FR curves?

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[Dennis Murphy]

What is the resolution on these FR curves?

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I'm not quite sure what your'e asking, exactly. It's a standard one-meter quasi-anechoic plot with no smoothing. The measurement program (Praxis) transitions to a wider sampling window below about 250 Hz in order to capture some of the bass information. But that also introduces room effects into the measurement, and I've cut off the response at that point in order to avoid confusion. In any event, You don't need super high resolution in order to show differences between on and off-axis response. A very similar speaker from a certain California firm also exhibits excellent off-axis response.

 

[Matt34]

The Elac's that someone mentioned earlier or the Wave Crest HVL-1. https://www.wavecrestaudio.com/products/hvl-1-two-way-loudspeaker-pair

 

[shkumar4963]

I'm not quite sure what your'e asking, exactly. It's a standard one-meter quasi-anechoic plot with no smoothing. The measurement program (Praxis) transitions to a wider sampling window below about 250 Hz in order to capture some of the bass information. But that also introduces room effects into the measurement, and I've cut off the response at that point in order to avoid confusion. In any event, You don't need super high resolution in order to show differences between on and off-axis response. A very similar speaker from a certain California firm also exhibits excellent off-axis response.

I apologize for not being clear earlier. What i meant was the sweep scanning resolution like 1/24 octave.

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[Dennis Murphy]

I apologize for not being clear earlier. What i meant was the sweep scanning resolution like 1/24 octave.

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All I can say is that there is no smoothing. What you see is every little wiggle, dip, or peak that was recorded during the 6 ms sampling window. There is less resolution at the bottom of the frequency response measurement due to the longer bass waves, and the less information that can be gleaned in such a short sample. But off-axis effects occur at higher frequencies, and there is adequate resolution in my measurements to show those.