fun generation HP5
Published: Dec-19-2022
NO SMOOTHING is applied to the shown plots. Most measurement sites have some smoothing applied which ‘irons flat’ sharp peaks and ‘wiggles’. I do not use smoothing because some info about sound quality is lost when plots are smoothed.
Aside from a small correction of the microphone itself also some correction in the lowest frequencies is applied to the plots to compensate for the perceived loss of bass when using headphones. This is described HERE in more detail.
A ‘horizontal‘ frequency response curve on the shown frequency response plots on this website thus indicates a perceived ‘flat’ tonal signature.
ALL measurements are made with a good SEAL on a flatbed measurement rig.
The shape of your head, bone structure, pad size, pad ‘softness, (compliance), hair or no hair and or wearing glasses may (drastically) change the frequency response of some headphones, so… your personal experience may differ substantially from these plots.
Frequency response (tonal balance) is the most sound-determining aspect of headphones. A horizontal line shows audible neutral response in the plots on this website. Deviations in different severity at different frequency bands have an effect on the sound character.
The bigger the deviation the stronger the effect.
Below an aid to help determining the sound character of headphones with relation to the frequency response.
fun generation HP5
The fun generation HP5 is a closed over-ear headphone. The fun generation’ and ‘the t.bone’ are brands that are exclusively distributed by Thomann.
The same headphone is also sold as the Rane RH-1 and M-Audio HDH40 by other distributors.
It was launched in 2017 and is still being sold (end 2022) for €18.- which is a bit cheaper than what the Rane and M-Audio sell for.
The build quality is quite good, certainly given its price.
The cups can be rotated 180 degrees and have enough swivel to create a good fit. The headphone comes with 2.9 meter long fixed (not replaceable) cable terminated in a goldplated 3.5mm TRS jack with screw-on 6.3mm adapter. The cable is mildly microphonic. This means touching the cable and it rubbing against clothes is slightly audible in the left cup.
The headband can extend 30mm. The cups can tilt and swivel far enough for a comfortable fit on most heads. The headband is pleather covered and feels soft enough and is wide enough not to create hot-spots on the head. The headband can be adjusted over a decent range (35mm).
The clamping force is on the high side with its 5N.
The replaceable pads have firm regular foam inside and are covered with pleather (PVC covered cloth). Room for the ears is not plenty though The 50mm height and 36mm width is only enough for small ears. The 18mm depth also is a bit less ideal. Chances are the ears touch the pads. A bit bigger pads would have been preferable.
The sensitivity is decent (115dB/V @ 1kHz) and with a 35Ω impedance it can play decently loud even from portable sources like phones etc. Even with EU phones with output power restrictions it can play loud enough.
Not suited for music enjoyment. To be fair to the product, that’s not the intended market. It is meant to be a cheap closed monitor headphone with decent build quality and that’s what it does quite well.
Isolation is not very good though but it is better than (semi)open headphones.
This headphone is low in weight (220 gr without the cable).
specifications:
Type: Over-ear, closed
Usage: Home, Portable
Isolation: medium
Driver type: dynamic
Pads: replaceable, pleather
Inner pad dimensions: Height: 50mm, width: 36 mm, depth: 18mm, oval shaped
Collapsible: no
Headphone connector: fixed cable
Cable: 2.9m straight with gold plated 3.5mm TRS plug + 6.3 mm screw-on adapter
Driver size: ø 38mm
Max. power rating: 0.2W
Max. voltage: 2.6V
Max. current: 75mA
Max. S.P.L.: 130dB
Impedance: 35Ω (measured)
Sensitivity: 115dB @ 1V @ 1kHz, (122dB @ 1V below 200Hz)
Efficiency: 100dB @ 1mW @ 1kHz
Weight: 220g. (without cable) 270g. with cable.
Color: black
Clamping force: high (5N)
Accessories: 6.3mm adapter.
Sound description:
The sound is bassy powerful but lacking in clarity and brilliance. Overall a bit muddy/muted sounding. Treble is coarse and ‘muted’. No sibilance nor sharpness simply because of the treble being muted and not of high quality.
Can play loud with loud bass due to recessed upper mids/treble. Lows ‘pull’ a bit to the left on occasion but could be this particular one only though.
measurements:
Below the frequency response of the HP5 (left, right)
Channel matching is not that good below 500Hz. Bass response goes quite deep, when a good seal is achieved.
Bass and lower mids are accentuated quite a bit. From 3kHz upward the response becomes ‘ragged’ with lots of peaks and dips. This often goes hand-in-hand with ‘coarse’ and ‘grainy’ treble which is certainly the case here.
Below the phase response of the HP5 (left, right)
Slow phase shifts are not very audible. Steep changes in a narrow frequency bands may well be audible. Above 4kHz there are many substantial variances in narrow frequency bands which also point to a low treble quality. Not much of a problem when using it as a monitor.
Seal
Seal is quite important for closed headphones and this headphone is no exception. Below the effect on the tonal balance is shown when the seal is not perfect. The bass suffers. Perfect seal, seal broken with thick armed glass resting against the skin, seal broken with thin armed glasses not resting against the skin, seal broken by thick armed glasses that are not flush against the skin.
Breaking the seal lowers the amount of bass. A small leakage is already quite audible and not necessarily a bad thing but lower bass is gone. Fine for monitoring all but bass instruments.
Comparison
Below the HP5 versus some other cheap models and some more expensive and bassier tuned headphones.
output resistance / damping-factor
As this is a closed dynamic headphone the frequency response can be amplifier output resistance dependent when certain higher output resistance amplifiers are used.
Instead of showing impedance plots, which are hard to ‘read’ when it comes to assessing the tonal balance change in the real world, the HP5 is measured via a few different resistance outputs (0.2Ω, 10Ω, 32Ω and 120Ω). On a higher output resistance amplifier the output level will be lower of course due to voltage division. To compensate for this the amplifier is turned up to the same level (12.2dB for 120Ω at 1kHz in this case at max. volume setting). This way the plots are overlaid and it is easier to see how the tonal balance changes. 
The headphone does not react much to higher output resistances. The resonance frequency is around 80Hz. The tonal balance is not changed much when using a higher output resistance. This means it can be used from various interfaces and music instruments as these often have output impedances that can range between 10Ω and 100Ω.
distortion
Below the distortion measurements of the HP5 (right channel) at 90dB SPL.
Below the same distortion plot but with the vertical scale in percentages instead of level differences.
Distortion at 100dB SPL (around 100 Hz) is a bit high (2%) and is both 2nd and 3rd harmonic.
The 2nd harmonic distortion above 400Hz is may be lower than shown as limits of the test rig are around 0.2%.
Around 5kHz there is a substantial peak (2%) which is potentially audible and also not helps with the treble quality.
Below the CSD of the HP5 (left and right are overlaid).
Above 5kHz some resonances are showing up. The ringing is not long lived though.
Below the spectrum plot of the HP5 (left channel). 
There is a resonance at around 1.3kHz. Possibly a cup resonance.
Below the group delay plot of the HP5 (left, right)
Around 90Hz there is some ‘pad bounce’ but this is very small. Up to 400Hz there are some issues in the time domain. Also above 4kHz there are some resonances showing up. Remember, this is a cheap monitoring headphone and not intended for music enjoyment.
The step response of the HP5 (left, right)
The initial rise comes up 12dB ‘short. The slow rise in the first ms shows the bassy and dark sound character of this headphone.
Pad change and modifications
To increase the comfort and sound quality some easy and reversible modifications can be done.
To lower the amount of bass the driver can easily and reversible be tuned with some tape.
For this the pads need to be removed. The baffle of the driver is now visible.
Remove the 4 screws and the baffle can be taken off.
The driver is connected with thin wires so be careful with those wires.
The rear of the driver is shown on the right.
The driver magnet has 4 small holes in it.
3 of those holes need to be fully covered with some tape. Here some paper self-adhesive packaging tape was used. It was cut in the same size shape as the magnet.
Before it was applied to the driver a small hole was made into the paper. In this case with a small jewelers screwdriver, 1.4mm wide. Do NOT make the holes while the tape is on the driver. Directly behind the holes is the voicecoil which can be damaged.
On the left the driver with the packaging tape and the small slit/hole in it.
The bass level can be tuned by making a slightly bigger hole.
Make sure the holes for the left and right driver are exactly the same size otherwise bass levels will differ between left and right side.
Making the hole a tiny bit bigger will already increase bass levels.
Removing the tape reverses this simple modifications.
Below the effect on the frequency response when sealing the holes.
Holes open (stock), 3 holes closed (1 open), all holes closed.
Playing with the size of the open hole can get the tonal balance between the brown and teal trace.
When tuning it and checking for the desired effect (amount of bass) the headphone needs to be assembled and both drivers must be modified with the exact same hole size. An iterative process.
Do not tighten the baffle screws too much when experimenting.
When using the original pads the front side also needs some modifications otherwise the sound will be too bright.
This can be achieved using the same packaging tape. All that needs to be done is to cover most of the square ports in the baffle so only 2 of them are not covered.
When using Shure SRH940 velour pads the baffle does not need to have this tape applied.
The picture on the right shows where to stick the pieces of tape. This can also be done with other tape. Removing the tape could damage the damping paper so if needed remove slowly and carefully.
Below the effect of the tape on the sound. The effect is small but essential.
All ports covered, only 2 ports not covered (as shown above), half of the ports covered, no ports covered (original).
Covering the ports tunes the ‘warmth’ of the mids.
Above the difference between stock and when modified with the modifications described above.
So. driver rear covered with just a small slit open on one hole and the front ports all covered except 2 also as shown above. This is with the stock pads. These modifications cost nearly nothing and are reversible.
pads
The original pleather pads are a bit small in internal size and pleather can be a bit sweaty/sticky after a while. As can be seen in the seal measurements the frequency response is quite seal dependent so also quite pad dependent. The Shure pads are easy to fit, of good quality and not very expensive and can be ordered along with the headphone (Thomann).
The pads can simply be pulled off.
Below some experiments with some oval pads that were lying around and fitted on this headphone.
original pleather pad, Shure SRH-840 pleather pad, SRH-940 velour pad, a fake M50X pad I had.
The Shure pads are bigger so sit a bit ‘sloppy’ but stay on fine. They allow more room for the ears and are more comfortable.
The Shure HPAEC940 Ear Pads cost € 2.- more than the whole headphone but increase the comfort and substantially and positively change the sound (also needs the rear of the driver modification, so not just pads).
The pads basically double the price of this headphone but increase comfort and sound quality beyond a € 40.- price point.
HPAEC940 pads lower the sensitivity and the treble, while improving in quality, is elevated too much.
When this pad is used the ports on the baffle should not be taped-off and the rear of the driver must have only 1 hole partially open. 2 plies of toilet paper applied (see below) and 3.5 driver holes closed (the fourth hole half covered) modified versus stock HP5.
The elevated treble can be lowered with some toilet paper covering the front of the driver as shown below.
For this 3-ply toilet paper is used. A single sheet of toilet paper is cut to the size as shown below. The amount of treble reduction can be tuned by pulling one or two ‘plies’ off. For me a 2-ply piece of toilet paper offered the sweet spot. Less plies = more treble, more plies = less treble. Tune to taste.
When putting on the pads be careful not to tare the fragile toilet paper.
Below the response of the modified HP5 (3,5 holes on the rear of the driver taped shut, 2 plies of toilet paper and the Shure HPAEC940 pads. (left, right)
The channel imbalance has improved, bass levels are ‘normal’. Bass extension is well below 10Hz.
Treble quality improved, comfort improved. Distortion numbers are still the same and sensitivity has dropped a bit to 112dB/V.
This still isn’t an excellent headphone but is still cheap with good tonality, comfort and decent build quality.
Below the HP5 with SRH-940 velours pads fitted.
summary
The fun generation HP5 is a cheap closed headphone of decent build quality (a.k.a Rane RH-1, M-Audio HDH40). The fun generation is only available from Thomann and cheaper than the other branded versions.
It is sold as a monitoring headphone and does that job. Don’t expect this to be a cheap but excellent headphone. After all this is a very cheap headphone …. with some potential to become a decent closed headphone with a little more money and effort.
The clamping force is high.
This is not a headphone suited for music enjoyment as is… but… with some (reversible) simple mods and the purchase of a pair of earpads, that cost just a little more than the headphone itself, this headphone can be used as a decent closed headphone.
DIY-Audio-Heaven 