3"-75mm-apex diameter wave guide for SS 10FF

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Hi,
Need your advice please for a LLCP aka Locdown Low Cost Project

I would like to putt the little ScanSpeak 10FF/8424G00 8 ohms neo I have in a not too deep wavguide looking like a Visaton WR148R WG. I plan this last Visaton WG for a tweeter. Loaded in a sealed 0.8 l tube enclosure that coulld be damped to reach artificially one liter load

Targets :

- Give the 10FF 5 to 8 dB gain, i.e. a little more spl max to stay -30 dB H2 at 112/115 dB no to reach the x-max - 112 to 115 dB dynamic peak more than enough. 105-8 db is the max spl at H2 -30 dB iirc. Not sure of the data for the 8 ohms unit though :(

- matching a 8" or ?? (15") from circa 750/800 Hz -F3 to a tweeter at circa 4 Kz minium + F3 - almost constant directivity in mind as well - passive LR2 max or why not first order allowed by the wave guide gnd (one can dream who knows :D) - A 8" subwoof driver seems logical to me (targett price 100-150 USD max), but a bang bang 15" PA for slam chest in the 80/200 area may be fun (Faital 15PR400 ?)

- deep of the wave guide is ideally for a close time/phase weeding with the lower mid-woof driver

- On shelves wave guide :eek: (no diy 3D print or CNC hability)

What's your thought about that please ? living in Europe, I'm not sure I can pick up some cool Seos. Should stay cheap, it's a kill bore me to death project.

Cons :

-the bump given by a WG between 700 to ... maybe difficult to manage in passive XO : good for the bafle step but difficult above till the tweeter for a clean mid to treble XO ?
- center to center distance between the mid wave guide & the tweeter wave guide for a 4 K hz XO !



Does such on shelf wave guide exists or may suit ?

With the plain entire suround the SS10F in mvt is 73.5 mm, so I assume a 75 mm/3" apex is all what it needs. :rolleyes:

Less apex diameter may be possible with a little front chamber to allow the surround not to touch the apex face plate with some wood diy adaptor perhaps : the inside cone surround beginns at 31 mm from center so 62 mm diameter is the cone diameter with the internal surround edge - 60 cm is the cone diameter without the ruber edge- 62 mm is 2.45".

Many thanks for your inputs

attachment docs : 4 ohms neo MarK 10F measurements + 8 ohms ferrite by Klang measurements not the same but near
 

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  • 10F8424HH.pdf
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  • SS 10F 4424 by MarkK.pdf
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Mark K measurment part II - splitted cause the weight.


Is there really no horn on shelves that could fit these little sized drivers or is the idea so bad ? Or give up the round horn for a tractrix with a smooth flare beginning at the apex then a steep one at the mouth like Iwata's ? (but acoustic center may be ruined due to the deepness of such a horn.



... though I' not against cubes on cubes for each way as the waited speaker from Humblehomemade hifi... it's a low cost project in mind... price of such good horn is often too expensive but some polyer PRV 2.5" ?


Both because the good price and acoustic center distance I think more about wave guides a la Visaton/Monacor... their tweeter WG seems to be made for a weeding with 8" to 10" mid-woof units ? ... Now, how t suit the 3" ScanSpeak 10F 8 ohms to be a 8" or 10" patern driver with a wave guide without having a huge JLMC horn or an Avantguard huge mid horn please ???


Very wrong idea I have or just such horn doesn't exist with a 3" apex eye ??
 
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Thanks guys to be here, I was thinking to be the last man of Earth wanting to coock hifi with a wok.


Tmuimku, Joseph Crow skills is just incredible, if I have monney for such good work I will jump in it to purchase some stuning devices from this sympathetic guy... halas it's more about to kill cheap the boredom fro thiose days... I'm more looking for a knife than a missile... I should say I'm more looking for a little spoon, should I?


Xrk971 made also an incredible work with the 10F with cheap handmade horn from Yoga foam: just brillant, halas...some people are more gifted than others with hand skill.


AllenB, not sure I understand what you meant.


Maybe because myself I'm not so clear in the description or I mistaked in the phrase? I meant : is the 2.5" ScanSpeak 10F which is good between 750/800 hz to 4 k hz raw on a bafle, could be good as well in wave guide to match easilier any bass unit from 8" (it can already raw but easier if in a WG ?) or /greater bass driver (10" to 15") that could climb till to 750/800 hz to the wave guide (if such exists) ? In order first to give it (the SS 10F) a little extra gain first.

I'm not understanding if you refer to the mid + treble or the mid + bass and which should be raw (not horned)...


Edit : I was thinking to a wave guide not to break the good linear behavior of the 10F as I plan a simple passive, deep horns make the thing more difficult without active EQ but some rare combos developed by brands like JBL 18thSound and so on.



Bamboo plate from Ikea ?????
 

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  • SS 10F 4424 by MarkK- part 2.pdf
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  • SS 10F 4424 by MarkK - part3.pdf
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diyAudio Moderator
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OK, to make it clearer I'll suggest some numbers. An 8" driver in a baffle or large box will radiate 90 degrees half angle at 750Hz. A 1" dome tweeter will also radiate at 90 degrees half angle at 4kHz. This means your full-range should be mounted on a baffle as well and have the same directivity over its band.

On the other hand, if you want to change this, maybe specify your own directivity then waveguides may play a part.
 
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thank you AllenB,


baffle step plays no role here ?


I understand from tha answer than whatever the directivity of the mid, it's ok if the polar plot of the lower and upper drivers match the mid around the XO till 90°... in a baffle.


But a wave guide if keeping the 90° rule for a good XO matching will change the pass band XO of the mid because it will not radiate 90° degree at 750 hz and 4k hz.


For illustration : if a wave guide make radiate the mid 75° at 750 hz and 75° at 4000 Hz then I should find the bass 8" or more that radiate 75° at 750 hz (so basicly a greater 10" or 12") and same for the tweeter choice (more difficult to find I assume) ?


So if I sumarize : first putt the 2.5" in a wave guide then measure the spl gain vs raw on a bafle. If the extra efficienty gives the needed Xmax spl wished, then measure how it radiate at the XO you want and take the 2 units that polar plot match at those angles around the XO (1 octave around the XO for a LR2 for instance ?) ?


Had I understand you AllenB ? Sorry if I"m a little slow, my english skill doesn't help as well.
 
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I only have the 10F Scan Speak 8 ohm units. Hence the idea (bad?) to putt it in a WG both for a little spl gain (3 db per WG ?) and start from here. Now I'm not aware if such WG with a 3" apex aperture exists and if the concept is doable. The idea comes from Gedles speaker when looking at them with the mid-bass unit slightly "horned" to match the directivity of the upper waveguide horn...
 
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diyAudio Moderator
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How far with budget ... hummm, bad idea so, cause wanted it stays cheap... so a 3 way classic à la Troel G. is more what I should look at... :( not funny !
Thanks for clearing this up. I always build my own horns and waveguides. It is difficult to find finished products that I could buy that will satisfy my needs.

If you want to buy, I suggest you collect links to all the larger horns you find in your research. We can speculate about how well they guide, load, and blend as well as their directivity.
 
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Hi,

@ AllenB, designing a horn indeed is asking knowledges few have + the extra knowledge and experience about crossovers...

I'm not aware about wave guide with a 3" aperture, but maybe a german site I discover yesterday but wood focussed more than acoustic science : Waveguide 28 | Galerien the guy behind seems to ask irrealistic prices for all his work. I know some cone horn from Beyma for 8" drivers for PA uses.

Then I saw some affordable products that could ask a little diy, i.e. a diy front chamber on the apex to adapt a 2.5" radiating cone on a 2" apex : Timpano Audio TPT-HL14-50 Slim 2" Aluminum Shallow Mount Horn 4-Bolt Only 3" deep WG :cool:

45° : PRV Audio WG 14-50CR 45 x 45 Aluminum Waveguide 2" 4 Bolt

@ wolf_teeth : thanks for thi input, I don't want an impossible challenge indeed. And when I look for instance here Wave guides & horns I can imagine it's not for a beginer as I am. And I have no idea about wave guide in mid and bafle step atenuation till a circa 750/800 XO (or less fhz XO as did XRK971 member but in a deep foam tratick).

Humm I beginn to say myself I had a bad idea with your input and AllenB's... If some brand like YG speakers that like to make expensive speakers with cnc wave-guide for tweeter and that can sell even more expensive stuffs with mid wave guide didn't make it, it's indeed it should be not feasible but complex work. Everyone is not Gedles or JBL with M2 horn design. Avanguard use a horn for the mid but the mid is more looking like a Morel dome than a cone driver...

And frankly I had in mind not something bigger than a 8" to 10" diameter WG for the little ScanSpeak mid unit... not a PA loudspeaker look.

The too much simple idea I had behind the mid WG was to give an extra gain to winn + 6 dB with a stereo pair and the overall diameter to marry it wirth a 15" PA driver for instance for the punch of it. Naive I am....:eek:

The simpliest is to double the SS 10F unit for a D'Apolitto, but cost will raise and other problems show their nose with this pattern...as a steefer Lr4 if my understanding is correct. Not my targett, wished somthing fun and cheap to break this boredomeness.

I really, really, really make a step forward active filtering with cheap class D thingy... but hey, all these bad sound cards & mini DSP sound for active filtering ! Good active filtering is expensive...

But when I see the centered bump given by such WG with each side deep curve it makes me dreaming of a filler mid unit between a bass and a treble unit.
 
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diyAudio Moderator
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that could ask a little diy, i.e. a diy front chamber on the apex
This is how I started in waveguides. One thing you will want to consider is extending the higher frequencies. If your driver has a cone larger than 2" then this might be helpful with a 2" throat.

The latter two waveguides you show are 6". I am inclined to guess they will radiate wide at 700Hz. This might be similar to the 8" at that frequency. It would be interesting to see a beamwidth plot.

The last one in particular seems to start narrow but end small. If you want a waveguide to hold its directivity lower for a given size it shouldn't try too hard at the start.
 
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I droped a mail on the Timpatino WG from PRV to know if they have a datasheet. but I surmise with an extra 0.5 cone distance to the throat with a diy adaptator I could not get better than a 1400 hz minimum usefull range with this WG... but I don't know really, I made a fast input on an on line calculator.


Diameter of this WG for car is around 3" deep and around 8" diameter... which ruins the idea of a tweeter because the CNC too much increased perhaps ? And it's deep enough to call it a horn :zombie: !



Emissive Sd of the SS 10F is 2.5". Are you please aware about a front chamber volume/diameter calculator ? Hornresp maybe ?


Scan-Speak 10F/8424G00 Discovery 4" Midrange in 8 ohm
The Discovery series is designed for the discerning audiophile customer. To meet the needs of this audience, several new technologies were developed with the goal of lowering distortion and damping in the speaker. The coated fiberglass cone reduces vibration and standing waves, and the vented motor system minimizes power compression. The combined result is a very open and dynamic sound. With this curve you could even consider this as a full range.

  • Very wide Frequency Range
  • Coated NRSC Fibre Glass Cone (patent)
  • Compact Size
  • Neodymium magnet
  • Aluminum Chassis
  • High Sensitivity 87dB / 2,83V
  • SBR Rubber Surround
  • Copper Cap on Pole Piece
Madisound recommends:

  • In a 1.2 liter sealed box your F3 is 208Hz
  • In 1.5 liters vented box with a 1" diameter vent by 3" long your F3 is 105Hz
An externally hosted image should be here but it was not working when we last tested it.

10F_8424G00-specs.jpg

10F_8424G00-mech.jpg

10F_8424G-side.jpg
 
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with an extra 0.5 cone distance to the throat with a diy adaptator I could not get better than a 1400 hz minimum usefull range with this WG.
How did you do this, do you have a link to the calculator?
front chamber volume/diameter calculator ? Hornresp maybe ?
Do you think it is a good idea to have a front volume with this waveguide?
 
I can fully vouch for the 10F/8424 in a front horn. It sounds extremely good and drastically alters every sound quality aspect for this particular driver...it sounds like a completely different driver. I would suggest adding only a 3mm spacer ring in front of the driver for the front volume. I would also suggest making the throat a vertical slot that's 43mm wide. The vertical slot height can be up to 76mm high. By limiting the horizontal width of the throat you can achieve much wider horizontal off axis coverage than with it just direct radiating. Off axis becomes similar to a 25mm dome tweeter. You can use this driver up to 20kHz in a good horn but you need to apply some EQ either with a passive contour network or DSP. The rear chamber should be ported with a tuning frequency just below the Fc (cuttoff) of the horn. This will control diaphragm movement near the system FS which reduces distortion by 50% and improves power handling by a factor of 2. I would suggest a rectangular horn mouth but make sure the top/bottom throat walls are no closer to 14 degrees from being parallel, otherwise reflections occur in the throat. I hope this helps!
 
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Thank you so much JosephCrow for visiting this thread... your Urusshi/TAD horns make me dream :cool: !

Have to say I have the "worse" of the two 10F cause it's the 8 ohms that is a little less flat because its step break up towars 1500/2000 (but relativly flat said an american fellow here when bafled). thanks for sharing your horn experience with this driver. A lot of tips here :) ... I have to read it twice not to miss something.

@ AllenB, I just played with the mh-audio.nl : back loaded expoential horn calculator to have an wide idea... The Timpatino looks like more a simple conical thingy..

About your second question : I absolutly don't know, the only experience I have with horn was to listen to some at enthusiasts' houses.

But here as the rubber surround is taller than the ScanSpeak front plate, if no 3" throat then it ask a gasket for a 2" throat horn that you talked about for a treble curve frequency increase. I called the space between the bigger cone and the littlier 2" throat a "front chamber", "front load chamber", maybe it's not the good word for it? I surmise it plays like an aperiodic load sort of but dunno! But did you mean instead that the Timpatino is not a good idea at all both for the SS 10F & a "front chamber"?


I have maybe an unenderstanding about the max spl the SS 10F 8 ohms version could play at Xmax ? I believe it's 105 dB Xmax so 108 with two - 6db if the speaker is 2 meters from the listening position... 102 dB may be short for some transcients... hence the naive idea to winn few dB with a wave guide for a cheap project.



Didn't find on shelves a 3" throat obloid sphrerical wave guide nore a cheap 3" throat horn for this... But Joseph Crowe and Xrk971, I'm not aware of anybody doing it... even though those 2.5 to 3" Sd cones with full range behavior looks like on the paper a hifi candidat swap of the professional compresion driver for hifists.:confused:.... I mean something smaller than the huge mid horn from Avantguarde. But wolf_teeth alert and Joseph Crowe testimonial like your's look it's too touchy for a beginner and cheap project. Thanks to alarm me if you think such purchase on shelf is a waste of monney btw :).
 
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